Role of Interprofessional Primary Care Teams in Preventing Avoidable Hospitalizations and Hospital Readmissions in Ontario, Canada: A Retrospective Cohort Study

DOI: https://doi.org/10.21203/rs.3.rs-28270/v1

Abstract

Background: Improving health system value and efficiency are considered major policy priorities internationally. Ontario has undergone a primary care reform that included introduction of interprofessional teams. The purpose of this study was to investigate the relationship between receiving care from interprofessional versus non-interprofessional primary care teams and ambulatory care sensitive condition (ACSC) hospitalizations and hospital readmissions.

Methods: Population-based administrative databases were linked to form data extractions of interest between the years of 2003–2005 and 2015–2017 in Ontario, Canada. The data sources were available through ICES. The Study Design was a Retrospective longitudinal cohort. We used a “difference-in-differences” approach for evaluating changes in ACSC hospitalizations and hospital readmissions before and after the introduction of interprofessional team-based primary care while adjusting for physician group, physician and patient characteristics.

Principle Findings: As of March 31st, 2017, there were a total of 778 physician groups, of which 465 were blended capitation Family Health Organization (FHOs); 177 FHOs (22.8%) were also interprofessional teams and 288 (37%) were more conventional group practices (“non-interprofessional teams”). In this period, there were a total of 13,480 primary care physicians in Ontario of whom 4,848 (36%) were affiliated with FHOs—2,311 (17.1%) practicing in interprofessional teams and 2,537 (18.8%) practicing in non-interprofessional teams. During that same period, there were 475,611 and 618,363 multi-morbid patients in interprofessional teams and non-interprofessional teams respectively out of a total of 2,920,990 multi-morbid adult patients in Ontario. There was no difference in change over time in ACSC admissions between interprofessional and non-interprofessional teams between the pre- and post intervention periods. There were no statistically significant changes in all cause hospital re-admissions between the post- and pre-intervention periods for interprofessional and non-interprofessional teams.

Conclusion: Our study findings indicate that the introduction of interprofessional team-based primary care was not associated with changes in ACSC hospitalization or hospital readmissions. The findings point for the need to couple interprofessional team-based care with other enablers of a strong primary care system to improve health services utilization efficiency.

Introduction

Improving health system value and efficiency are considered major policy priorities internationally., While health system costs continue to be a challenge across jurisdictions, hospitalizations for ambulatory care sensitive conditions (ACSCs) and hospital readmissions have been a focus for policymakers.,,, ACSC hospitalizations are potentially avoidable by preventing the inception of disease, controlling an acute episodic illness, or managing a chronic condition effectively. When care is delivered to patients when and where they need it, hospital readmissions can sometimes be prevented. Evidence has suggested a link between the burden of multi-morbidity and health services use, particularly hospitalizations.,,, Hence, multi-morbid patients continue to be a key focus from a clinical care and population health perspective.,,, Interprofessional team-based care may have an important role to play in caring for multi-morbid patients by offering a collaborative approach to prevent ACSC hospitalization and hospital readmissions.

During the 1990s, federal and provincial governments in Canada faced fiscal challenges that resulted in limited healthcare spending and investments in primary care innovation. In the 2000s, Ontario introduced primary care reform in response to the recommendations of various federal and provincial reports., Primary care reform movement in Ontario included three major policy initiatives: new physicians’ reimbursement and organizational models, patient enrolment with a primary care provider and support to interprofessional team-based care.24 During the last twenty years, more than one third of Ontario primary care physicians have voluntarily transitioned from traditional fee-for-service practice to blended capitation payment and in some cases received additional funding to support interprofessional team members to join their practice. These models are described in detail elsewhere. There are many similarities between Ontario interprofessional Family Health Teams, Quebec Family Medicine Groups, Alberta Primary Care Networks and the Patient-Centered Medical Home in the United States (US).,,,

In Ontario, reducing hospitalization for ACSC conditions and all-cause re-admission are strategic priorities., In this study, we examined the association between the introduction of primary care interprofessional teams and unplanned ACSC hospital admissions and all cause hospital re-admissions among multi-morbid patients. We compared changes in those outcomes over time among physicians remunerated through the same physician payment model, some of whom transitioned to interprofessional team-based practice. We hypothesised that multi-morbid patients who receive care from an interprofessional teams will have lower ACSC hospital admissions and all-cause readmissions over time when compared to patients receiving care from non-interprofessional teams.

Methods

Setting

The setting was Ontario, Canada, the country’s most populous province with a population of 14.4 million people in 2019. Permanent residents of Ontario are fully insured for primary care services through the Ontario Health Insurance Plan (OHIP) with no co-payment or deductible. Primary care organization and payment has shifted over the course of the last 18 years. In 2002, primary care physicians billed fee-for-service and worked independently. Today, most Ontario physicians are paid through some form of blended payment and are part of an organised model with formal patient enrolment. The three dominant practice models in Ontario are: enhanced fee-for-service (85% fee-for-service, 15% capitation and bonuses, no funding for non-physician health professionals); non-interprofessional team blended capitation (20% fee-for-service, 80% capitation and bonuses, no funding for non-physician health professionals), and interprofessional team blended capitation (20% fee-for-service, 80% capitation and bonuses, and funding for non-physician health professionals). Approximately one in six Ontarians is not formally enrolled to a physician practicing in a new model. The focus of this study was on the dominant blended capitation patient enrolment model—Family Health Organization (FHO)—within which groups of physicians can be practicing in either interprofessional or non-interprofessional teams. FHO have formal patient enrollment, electronic medical records, physician-led governance and a minimum of three physicians practicing together. They offer comprehensive care, including preventive health care services, chronic disease management and health promotion, through a combination of regular physician office hours and after-hours services. FHOs were eligible to apply for additional funding to become interprofessional teams and typically include primary care physicians and nurses or nurse practitioners and at least one allied health care professional such as pharmacist, social worker or dietitian. Interprofessional teams are also eligible for funding an administrator or executive director and electronic medical records.

Study design and population

We conducted a retrospective cohort study with longitudinal design given the importance of temporal effect on interprofessional teams formation and maturation and their relationship to the outcomes under investigation. We used the “difference in differences” approach, an econometric method for evaluating changes in outcomes after policy implementation. We compared outcomes of interest before and after the implementation of interprofessional teams.

Several population-based administrative databases were linked using unique encoded identifiers at ICES (formerly known as the Institute for Clinical Evaluative Sciences) to form data extractions of interest. We generated a cohort that included the same patients at two different points in time, pre- and post-teams’ formation. The study population included patients between 18 and 105 years old, who had two or more of a list of 17 chronic conditions as identified at the beginning of the pre-teams’ formation period, March 31st 2003 and who were part of a FHO blended capitation model as identified at the beginning of the post-teams formation period, March 31st, 2015. The chronic condition selection was based on clinical relevance and impact on the outcomes being investigated as described in previous literature.,,,,, These conditions have been adopted in previous studies , and are consistent with the parameters outlined by the Department of Health and Human Services for defining and measuring chronic conditions. The conditions include: cancer, diabetes, asthma, chronic obstructive pulmonary disease (COPD), hypertension, chronic coronary syndrome (CCS), cardiac arrhythmia, congestive heart failure (CHF), stroke, acute myocardial infarction (AMI), renal failure, arthritis (excluding rheumatoid arthritis), rheumatoid arthritis, osteoporosis, depression, dementia and mental health conditions (full list of diagnostic information for defining the 17 selected chronic conditions under investigation in this study are included in Appendix A).

The baseline study population included people identified on March 31st, 2003 who were still identifiable on March 31st, 2015 and were part of the FHO blended capitation model. People in the baseline population were followed-up to February 28th, 2005 for first unplanned ACSC admission and up to March 31st, 2005 for first all-cause readmission and in the follow up period up to February 28th, 2017 for the first ACSC admission and up to March 31st, 2017 for all-cause readmission. Given that teams did not exist during the baseline period, assignment of patients to interprofessional and non-interprofessional teams was based on their post-intervention assignment. We excluded individuals who died and individuals who were in long term care or complex continuing care.

Measures and data sources

ACSC Admission and Hospital Re-admission

The primary outcome was hospital admissions for ACSCs, defined as the first hospital non-elective admission with a most responsible diagnosis code of: grand mal status and other epileptic convulsions, chronic obstructive pulmonary disease (COPD), asthma, diabetes, heart failure and pulmonary edema, hypertension and angina.

The secondary outcome was hospital readmissions, defined as the first subsequent non-elective all-cause readmission to an acute care hospital within 30 days of discharge, among hospitalisation for selected Case Mix Group (CMG) groups: stroke, COPD, pneumonia, congestive heart failure, diabetes, cardiac conditions, gastrointestinal conditions (List of CMGs codes in Appendix B). The primary and secondary outcomes were derived from the OHIP database and the Discharge Abstract Database (DAD) and the Registered Patient Database (RPDB) available at ICES. Both outcomes excluded people without a valid date of admission/discharge; and people who died during their hospital stay (relevant to admission but not readmission).

Physician Group and Physicians Characteristics

Physician group characteristics included the number of physicians per group and number of years under the capitation model. Physicians’ characteristics included age, gender, Canadian graduate status and number of years in practice. Those variables were derived from a health care provider data registry available at ICES.

Patient Characteristics

Patients’ characteristics included age, gender and recent OHIP registration as a proxy for immigration which were identified from a population and demographics data registry available at ICES. By linking patients’ postal code to census data we were able to derive neighborhood income quintiles. Income levels, adjusted for household size and specific to each community, were used to order postal codes into quintiles, with quintile 1 having the lowest relative income and quintile 5 the highest. Rurality was identified using the Ontario Medical Association Rurality Index of Ontario (RIO). The RIO is based on community characteristics including travel time to different levels of care, community population, presence of providers, hospitals and ambulance services, social indicators and weather conditions. RIO scores range from zero to 100 (zero indicating the most urban and 100 the most rural). RIO scores are divided into three main categories, major urban centres, semi-urban centres and rural areas. We used the Johns Hopkins Adjusted Clinical Groups case-mix system software to assign patients into expected Resource Utilization Bands (RUBs) categories. The RUBs range from 0 indicating no utilization to 5 indicating very high expected utilization.

Six chronic diseases conditions (AMI, asthma, CHF, COPD, hypertension, diabetes) were defined based on previously validated population-derived ICES cohorts.,,,,, For the conditions where a derived ICES cohort was not available (cancer, cardiac arrhythmia, chronic coronary syndrome, dementia, depression, arthritis (excluding rheumatoid arthritis), osteoporosis, renal failure, rheumatoid arthritis, and stroke), a similar approach for the derivation was adopted—at least one diagnosis recorded in acute care, or two diagnoses recorded in physicians’ records within a two-year period. The conditions were derived using the DAD and OHIP databases available at ICES.

Statistical analysis

For the descriptive results, we generated frequencies, percentages, means and standard deviations to describe the characteristics of physician groups, physicians and patients who are either in interprofessional teams or non-teams and their respective admission and re-admission rates.

For the admission and readmission models, as a first step we tested for patient clustering within physicians using a random effects logistics regression. As a result, we ran ordinary logistic regression models with binary outcomes of ACSC admission and all-cause readmission. The independent variables added to the models were the respective physician group, physician and patient characteristics.

To estimate the difference in differences we used Generalized Estimating Equations method to account for repeated measures within patients. The independent variables added to the models were the respective physician group, physician and patient characteristics.

All study analyses were conducted using SAS v.9.3 and statistical significance was assessed at a p-value < 0.05.

Results

Baseline physician group, physician and patient characteristics comparing interprofessional teams to non-interprofessional teams

As of March 31st, 2017, there were a total of 778 physician groups in Ontario, of which 465 were FHOs; 177 FHOs (22.8%) were also interprofessional teams and 288 (37%) were non-interprofessional teams. Compared to non-interprofessional teams, interprofessional teams had: more physicians per group and more years under the capitation model.

In this period, there were a total of 13,480 primary care physicians in Ontario of whom 4,848 (36%) were affiliated with FHOs, 2,311 (17.1%) practicing in interprofessional teams and 2,537 (18.8%) practicing in non-interprofessional teams. Compared to non-interprofessional teams, interprofessional teams had: fewer patients per physician, more female physicians, more physicians in the younger age group, more physicians who were Canadian graduates and fewer years in practice (Table 1A).

 

Interprofessional Teams

Non-interprofessional teams

All Ontario physician groups (patient enrolment models) and physicians

Physicians’ Group characteristics

 

 

 

 

 

 

Groups No. (% of all PEMs)

177

22.8

288

37.0

778

100.0

Number of physicians per group, Mean (SD)

13.11

10.7

8.8

7.6

17

188.9

Years under the capitation model, Mean (SD) 

6.00

3.0

4.3

2.6

6

3.3

Physicians characteristics

           

Physicians No. (% of all physicians)

2,311

17.1

2,537

18.8

13,480

100.0

Number of patients per physician, Mean (SD)

1,303

638.9

1,517

675.9

1,020

944.6

 Sex No. (%)

           

   Male

1,212

52.4

1,391

54.8

7,270

53.9

  Female

1,099

47.6

1,146

45.2

5,864

43.5

Missing

0

0.0

0

0.0

346

2.6

Age group No. (%) in Yrs.

           

<40

546

23.6

364

14.4

2,518

18.7

40-64

1,499

64.9

1,773

69.9

7,930

58.8

> 64

232

10.0

373

14.7

2,031

15.1

Missing

34

1.5

27

1.1

1,001

7.4

Country of medical graduation Canada No. (%)  

           

Yes

1,874

81.1

1,871

73.8

8,974

66.6

No

403

17.4

639

25.2

3,505

26.0

Missing

34

1.5

27

1.1

1,001

7.4

Years in practice No. (%)

           

<5

60

2.6

48

1.9

667

5.0

5_15

701

30.3

465

18.3

3,145

23.3

16-25

531

23.0

645

25.4

3,047

22.6

>25

1,019

44.1

1,379

54.4

6,275

46.6

Missing

0

0.0

0

0.0

346

2.6

Table 1A

Physicians group and physicians characteristics by enrolment model of care – comparing interprofessional teams to non-interprofessional teams to all groups (patient enrolment models) in Ontario based on March 31st, 2015

During the same period, there were 475,611 and 618,363 multi-morbid patients in interprofessional and non-interprofessional teams respectively out of a total of 2,920,990 multi-morbid adult patients in Ontario. Overall interprofessional teams had fewer new immigrant patients and more patients who reside in rural areas. Other patient characteristics were relatively similar between interprofessional and non-interprofessional teams. When compared to all physician groups, both interprofessional and non-interprofessional teams had less patients with high number of co-morbidities (Table 1B).

 

Multi-morbid patients in interprofessional teams

Multi-morbid patients in Non- interprofessional teams

All multi-morbid patients in Ontario

All Ontarians

Patients total

475,611

 

618,363

 

2,920,990

 

9,397,586

 

Sex No. (%)

               

Males

186,729

39.3

246,882

39.9

1,240,516

42.5

4,576,936

48.7

Female

288,882

60.7

371,481

60.1

1,680,474

57.5

4,820,650

51.3

Missing

-

0.0

-

0.0

-

0.0

-

0.0

Age group, yr. No. (%)

               

18-44

138,965

29.2

184,059

29.8

654,813

22.4

4,863,276

51.8

45-64

227,930

47.9

296,914

48.0

1,127,265

38.6

2,981,705

31.7

65-84

107,821

22.7

136,227

22.0

999,353

34.2

1,389,782

14.8

84+

895

0.2

1,163

0.2

139,559

4.8

162,823

1.7

Missing

-

0.0

-

0.0

-

0.0

-

0.0

New OHIP registrants (within 10 years) No. (%)

13,742

2.9

29,981

4.9

157,488

5.4

1,200,951

12.8

Income quintile, No. (%)

               

1 (low)

84,198

17.7

101,739

16.5

583,685

20.0

1,799,279

19.2

2

96,387

20.3

115,903

18.7

605,293

20.7

1,884,459

20.1

3

95,925

20.2

125,618

20.3

588,141

20.1

1,892,274

20.1

4

96,214

20.2

132,243

21.4

570,140

19.5

1,903,560

20.3

5 (high)

101,596

21.4

141,926

23.0

565,536

19.4

1,888,811

20.1

Missing

1,291

0.3

934

0.2

8,195

0.3

29,203

0.3

Rurality Index of Ontario, No. (%) 

               

Major urban (0 to 9)

257,792

54.2

475,286

76.9

2,026,660

69.4

6,698,329

71.3

Semi-urban (10 to 39)

150,810

31.7

111,986

18.1

608,960

20.9

1,852,225

19.7

Rural (≥40)

63,866

13.4

28,970

4.7

260,936

8.9

761,861

8.1

Missing

3,143

0.7

2,121

0.3

24,434

0.8

85,171

0.9

Resource utilization band (RUB), No. (%) 

               

0 (non-user)

2,157

0.5

2,431

0.4

30,338

1.0

938,240

10.0

1

2,252

0.5

2,595

0.4

11,227

0.4

555,466

5.9

2

23,325

4.9

27,403

4.4

114,781

3.9

1,588,712

16.9

3

306,213

64.4

399,620

64.6

1,691,226

57.9

4,685,817

49.9

4

109,010

22.9

146,389

23.7

734,298

25.1

1,253,298

13.3

5 (very high user)

32,654

6.9

39,925

6.5

339,120

11.6

376,053

4.0

Missing

               

Patients with Chronic disease

               

2 + Co-morbidity No. (%)

475,611

100.0

618,363

100.0

2,920,990

100.0

2,920,990

31.1

3+ comorbidities No. (%)

194,828

41.0

257,141

41.6

1,481,098

50.7

1,481,098

15.8

4+ comorbidities No. (%)

71,285

15.0

95,323

15.4

723,296

24.8

723,296

7.7

5+ comorbidities No. (%)

23,824

5.0

323,368

5.2

344,685

11.8

344,685

3.7

Table 1B

Patients’ characteristics comparing patients in interprofessional teams, non-interprofessional teams, all multi-morbid patients and all Ontarians adults on March 31st, 2003

ACSC hospital admissions and all cause 30-day re-admissions in interprofessional teams and non-interprofessional teams by physician and patient characteristics

During the period of April 1st, 2015 to March 31st, 2017, interprofessional teams were found to have higher ACSC admission rates when compared to non-interprofessional teams (2.5% versus 2.1%, respectively). When we investigated ACSC admissions during the same period across interprofessional and non-interprofessional teams by physician characteristics identified on March 31st, 2015, we found that the following were associated with higher ACSC admission rates: being a male, being in the older age group, and being a non-Canadian graduate (Table 2A).

 

 

Interprofessional Teams

Non-interprofessional teams

Numerator

Denominator

Rate per 100

Numerator

Denominator

Rate per 100

ACSC admissions and patients totals

                                             11,963

                                           475,611

                                                    2.5

                                                      13,160

                                                   618,363

                                                             2.1

Physicians characteristics

 

 

 

 

 

 

 Sex

 

 

 

 

 

 

   Male

                                               8,183

                                           298,763

2.7

                                                        9,547

                                                   407,328

2.3

  Female

                                               3,780

                                           176,848

2.1

                                                        3,613

                                                   210,599

1.7

Missing

 

 

 

 

                                                            436

0.0

Age group

 

 

 

 

 

 

<40

                                               2,013

                                             80,487

2.5

                                                        1,098

                                                      54,012

2.0

40-64

                                               8,170

                                           332,177

2.5

                                                        9,242

                                                   445,990

2.1

> 64

                                               1,648

                                             58,240

2.8

                                                        2,730

                                                   114,424

2.4

Missing

                                                   132

                                               4,707

2.8

                                                              90

                                                        3,937

2.3

Country of medical graduation Canada   

 

 

 

 

 

 

Yes

                                               9,389

                                           379,843

2.5

                                                        9,459

                                                   456,855

2.1

No

                                               2,442

                                             91,061

2.7

                                                        3,611

                                                   157,571

2.3

Missing

                                                   132

                                               4,707

2.8

                                                              90

                                                        3,937

2.3

Years in practice

 

 

 

 

 

 

<5

                                                   246

                                               9,457

2.6

                                                            180

                                                        6,971

2.6

5_15

                                               2,650

                                           105,104

2.5

                                                        1,464

                                                      71,094

2.1

16-25

                                               2,571

                                           107,080

2.4

                                                        3,047

                                                   144,860

2.1

>25

                                               6,496

                                           253,970

2.6

                                                        8,460

                                                   395,002

2.1

Missing

 

                                                      -  

 

                                                                9

                                                            436

2.1

Table 2A

ACSC hospital admissions between April 1st, 2015 and February 28th, 2017 among multi-morbid adults by physician characteristics on identified on March 31st, 2015

During that same period, when we investigated ACSC admission across interprofessional and non- interprofessional teams in relation to the patient characteristics identified on March 31st, 2003, we found that the following patient characteristics were associated with higher ACSC admission rate: being a male, being in the older age category, being a non-immigrant, being in the lowest neighborhood income quintile, being a resident of a rural area, being in the highest expected resource utilization band, and having five and plus co-morbidities (Table 2B).

Patients characteristics

                                                    

 

 

 

 

 

ACSC admissions and patients totals

                                             11,963

                                           475,611

2.52

13,160

                                                   618,363

2.13

Sex

 

 

 

 

 

 

Males

                                               5,265

                                           186,729

2.8

5,869

                                                   246,882

2.4

Female

                                               6,698

                                           288,882

2.3

7,291

                                                   371,481

2.0

Missing

                                                      -  

                                                      -  

 

                                                               -  

                                                               -  

0.0

Age group, yr.

 

 

 

 

 

 

18-44

                                               1,229

                                           138,965

0.9

1,288

                                                   184,059

0.7

45-64

                                               5,213

                                           227,930

2.3

5,665

                                                   296,914

1.9

65+

                                               5,521

                                           108,716

5.1

6,207

                                                   137,390

4.5

Missing

 

                                                      -  

 

 

                                                               -  

0.0

New OHIP registrants (within 10 years)

 

 

 

 

 

 

Yes

                                                   294

                                             13,742

2.1

470

                                                      29,981

1.6

No

                                             11,669

                                           461,869

2.5

12,690

                                                   588,382

2.2

Income quintile

 

 

 

 

 

 

1 (low)

                                               2,742

                                             84,198

3.3

2,859

                                                   101,739

2.8

2

                                               2,710

                                             96,387

2.8

2,815

                                                   115,903

2.4

3

                                               2,338

                                             95,925

2.4

2,631

                                                   125,618

2.1

4

                                               2,161

                                             96,214

2.2

2,545

                                                   132,243

1.9

5 (high)

                                               1,972

                                           101,596

1.9

2,290

                                                   141,926

1.6

Missing

                                                     40

                                               1,291

3.1

20

                                                            934

2.1

Rurality Index of Ontario

 

 

 

 

 

 

Major urban (0 to 9)

                                               5,741

                                           257,792

2.2

                                                        9,396

                                                   475,286

2.0

Semi-urban (10 to 39)

                                               4,062

                                           150,810

2.7

                                                        2,809

                                                   111,986

2.5

Rural (≥40)

                                               2,060

                                             63,866

3.2

                                                            881

                                                      28,970

3.0

Missing

                                                   100

                                               3,143

3.2

                                                              74

                                                        2,121

3.5

Resource utilization band (RUB)

 

 

 

 

 

 

0 (non-user)

                                                     37

                                               2,157

1.7

                                                              56

                                                        2,431

2.3

1

                                                     40

                                               2,252

1.8

                                                              27

                                                        2,595

1.0

2

                                                   399

                                             23,325

1.7

                                                            382

                                                      27,403

1.4

3

                                               6,410

                                           306,213

2.1

                                                        7,081

                                                   399,620

1.8

4

                                               3,370

                                           109,010

3.1

                                                        3,773

                                                   146,389

2.6

5 (very high user)

                                               1,707

                                             32,654

5.2

                                                        1,841

                                                      39,925

4.6

Missing

 

 

 

 

 

 

Patients with Chronic disease

 

 

 

 

 

 

2 + Co-morbidity

 

 

 

 

 

 

Yes

                                             11,963

                                           475,611

2.5

                                                      13,160

                                                   618,363

2.1

No

                                                      -  

                                                      -  

 

                                                               -  

                                                               -  

 

3+ comorbidities

 

 

 

 

 

 

Yes

                                               7,635

                                           257,141

3.0

                                                        8,657

                                                   257,141

3.4

No

                                               4,328

                                           280,783

1.5

                                                        4,503

                                                   361,222

1.2

4+ comorbidities

 

 

 

 

 

 

Yes

                                               4,213

                                             71,285

5.9

                                                        4,841

                                                      95,323

5.1

No

                                               7,750

                                           404,326

1.9

                                                        8,319

                                                   523,040

1.6

5+ comorbidities

 

 

 

 

 

 

Yes

                                               1,949

                                             23,824

8.2

                                                        2,329

                                                      32,368

7.2

No

                                             10,014

                                           451,787

2.2

                                                      10,831

                                                   585,995

1.8

Table 2B

ACSC hospital admissions between April 1st, 2015 and March31st, 2017 among multi-morbid adults by patient characteristics from March 31st, 2003

During that same period, interprofessional teams were found to have slightly higher all cause hospital 30-day re-admission rate when compared to non-interprofessional teams (15.0% versus 14.6%, respectively).

When we investigated hospital re-admission during the same period across interprofessional and non-interprofessional teams by physician characteristics identified on March 31st, 2015, being a non-Canadian graduate physician was associated with higher re-admission rate (Table 3A).

 

Interprofessional Teams

Non-interprofessional teams

 

Numerator

Denominator

Rate per 100

Numerator

Denominator

Rate per 100

All-cause re-admissions and patient totals

1,796

11,963

15.0

1,917

13,160

14.6

 

 

 

 

 

 

 

Sex No. (%)

 

 

 

 

 

 

   Male

1,231

8,183

15.0

1,375

9,547.00

14.4

  Female

565

3,780

14.9

542

3,613.00

15.0

Missing

0

0

0.0

0

0.00

0.0

Age group No. (%) in Yrs.

 

 

 

 

 

 

<40

320

2,013

15.9

156

1,098.00

14.2

40-64

1,208

8,170

14.8

1,346

9,242.00

14.6

65+

255

1,648

15.5

404

2,730.00

14.8

Missing

13

132

9.8

11

90.00

12.2

Country of medical graduation Canada No. (%)  

 

 

 

 

 

 

Yes

1,405

9,389

15.0

1,369

9,459.00

14.5

No

378

2,442

15.5

537

3,611.00

14.9

Missing

13

132

9.8

11

90.00

12.2

Years in practice No. (%)

 

 

 

 

 

 

<5

36

246

14.6

24

189.00

12.7

5_15

406

2,650

15.3

204

1,464.00

13.9

16-25

385

2,571

15.0

437

3,047.00

14.3

>25

969

6,496

14.9

1,252

8,460.00

14.8

Missing

0

0

0.0

0

0.00

0.00

Table 3A

All cause hospital re-admissions among multi-morbid adults between April 1st, 2015 and March 31st, 2017 by physician characteristics based March 31st, 2017

During that same period, when we investigated hospital re-admission across interprofessional and non-interprofessional teams in relation to the patient characteristics identified on March 31st, 2003, we found that the following were associated with higher 30-day re-admission rate: being a male, being in the older age category, residing in major urban areas, being in the highest expected resource utilization band, and having five or more co-morbidities (Table 3B).

Patients characteristics

 

 

 

 

 

 

All cause re-admissions and patient totals

                                               1,796

                                             11,963

15.0

1,917

                                                      13,160

14.6

Sex No. (%)

 

 

 

 

 

 

Males

                                                   807

                                               5,265

15.3

893

                                                        5,869

15.2

Female

                                                   989

                                               6,698

14.8

1,024

                                                        7,291

14.0

Missing

 

                                                      -  

 

 

                                                               -  

 

Age group, yr. No. (%)

 

 

 

 

 

 

18-44

159

                                               1,229

12.9

156

                                                        1,288

12.1

45-64

774

                                               5,213

14.8

787

                                                        5,665

13.9

65+

863

                                               5,521

15.6

974

                                                        6,207

15.7

Missing

 

 

 

 

 

 

New OHIP registrants (within 10 years) No. (%)

 

 

 

 

 

 

Yes

                                                     36

                                                   294

12.2

78

                                                            470

16.6

No

                                               1,760

                                             11,669

15.1

1,839

                                                      12,690

14.5

Income quintile, No. (%)

 

 

 

 

 

 

1 (low)

404

                                               2,742

14.7

453

                                                        2,859

15.8

2

423

                                               2,710

15.6

396

                                                        2,815

14.1

3

323

                                               2,338

13.8

366

                                                        2,631

13.9

4

349

                                               2,161

16.1

360

                                                        2,545

14.1

5 (high)

294

                                               1,972

14.9

340

                                                        2,290

14.8

Missing

D/S

D/S

D/S

D/S

D/S

D/S

Rurality Index of Ontario, No. (%) 

 

 

 

 

 

 

Major urban (0 to 9)

886

                                               5,741

15.4

1403

                                                        9,396

14.9

Semi-urban (10 to 39)

587

                                               4,062

14.5

392

                                                        2,809

14.0

Rural (≥40)

310

                                               2,060

15.0

115

                                                            881

13.1

Missing

D/S

D/S

D/S

D/S

D/S

D/S

Resource utilization band (RUB), No. (%) 

 

 

 

 

 

 

0 (non-user)

D/S

D/S

D/S

D/S

D/S

D/S

1

6

                                                     40

15.0

7

                                                              27

25.9

2

56

                                                   399

14.0

54

                                                            382

14.1

3

916

                                               6,410

14.3

1010

                                                        7,081

14.3

4

524

                                               3,370

15.5

534

                                                        3,773

14.2

5 (very high user)

289

                                               1,707

16.9

302

                                                        1,841

16.4

Missing

 

 

 

 

 

 

Patients with Chronic disease

 

 

 

 

 

 

2 + Co-morbidity No. (%)

 

 

 

 

 

 

yes

                                               1,796

                                             11,963

                                                  15.0

1,917

                                                      13,160

14.6

No

0

0

 

0

                                                               -  

 

3+ comorbidities No. (%)

 

 

 

 

 

 

yes

                                               1,226

                                               7,635

                                                  16.1

1,335

                                                        8,657

15.4

No

                                                   570

                                               4,328

                                                  13.2

582

                                                        4,503

12.9

4+ comorbidities No. (%)

 

 

 

 

 

 

yes

                                                   697

                                               4,213

                                                  16.5

770

                                                        4,841

15.9

No

                                               1,099

                                               7,750

                                                  14.2

1,147

                                                        8,319

13.8

5+ comorbidities No. (%)

 

 

 

 

 

 

yes

344

1,949

                                                  17.7

378

2,329

16.2

No

1,452

10,014

                                                  14.5

1,539

10,831

                                                          14.2

D/S refers to data supressed for observations with a count between 1 and 5 and have been suppressed to comply with Personal Health Information Protection Act privacy legislation

Table 3B

All cause hospital re-admissions between April 1st, 2015 and March31st, 2017 among multi-morbid adults by patient characteristics from March 31st, 2003

When we stratified the results by males and females for both outcomes, we did not identify sex differences (results not presented but can be made available on request).

Association between enrolment in an interprofessional team model and ACSC hospital admission and all cause hospital re-admission

During the post-intervention period, when we adjusted for physician group, physician and patient characteristics, being in an interprofessional team increased the likelihood of having ACSC hospital admission by 7%. For the same period, we did not find significant difference between interprofessional and non-interprofessional teams for hospital all cause readmission (Table 4).

 

Interprofessional team ACSC Admissions

(Reference: Non-Interprofessional teams)

OR

95% CI

P-Value

Unadjusted (null model)

 

1.19

1.16

1.22

<.0001

Adjusted* for:

     

 

Physician group characteristics

 

1.15

1.12

1.18

<.0001

Group and physician characteristics

1.17

1.13

1.18

 

<.0001

Group, physician and patients

 

1.07

1.04

1.18

 

<.0001

 

 

Interprofessional team re-admissions (Reference: non-teams)

OR

95% CI

 P-value

Unadjusted (null model)

 

1.31

0.98

1.75

 

0.073

 

Adjusted* for:

       

Physician group characteristics

 

1.17

0.86

1.60

 

0.323

 

Group and physician characteristics

1.17

0.84

1.60

0.323

Group, physician and patients

 

1.20

0.84

1.65

 

0.260

 

*Adjustment used physician groups and physicians’ characteristics from March 31st, 2015 (post-intervention) and patients’ characteristics from March 31st, 2003 (pre-intervention)

Table 4

Association between enrolment in an interprofessional team-based model and ACSC admissions and all cause hospital readmissions post intervention April 1st, 2015 to March 31st, 2017

When we examined change over time between the post- and pre-intervention periods, there was a significant increase in the ACSC hospital admission rate: 1.34% for both interprofessional and non-interprofessional teams. There was no difference between interprofessional and non-interprofessional teams in the change in ACSC admissions across the pre- and post-intervention periods.

For the same period, when we compared for change over time between the post- and pre intervention there was a significant difference in hospital all cause re-admission rate with an increase of 4.90% for interprofessional teams and an non-significant increase for non-interprofessional teams of 1.47%. We found a non-significant difference between interprofessional and non-interprofessional teams in the change in hospital all cause re-admissions between the pre- and post-intervention periods, 3.43% (Table 5).

 

Interprofessional Teams

Non- Interprofessional teams

2015-17

 

2003-05

 

Difference

(2015 to 2017 – 2003 to 2005)

2015-17

 

2003-05

Difference (2015 to 2017 – 2003 to 2005)

Difference in differences

(diff. Teams – diff. non-teams)

Unplanned ACSC admission

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

 

Unadjusted model

2.52

<.0001

1.07

<.0001

1.44

<.0001

2.13

<.0001

0.84

<.0001

1.29

<.0001

0.15

0.0008

 

*Adjusted for physician group characteristics

2.48

<.0001

1.06

<.0001

1.42

<.0001

2.15

<.0001

0.85

<.0001

1.30

<.0001

0.12

0.0008

 

*Adjusted for physician group and physician characteristics

2.43

<.0001

1.04

<.0001

1.39

<.0001

2.07

<.0001

0.82

<.0001

1.25

<.0001

0.14

0.0011

 

*Adjusted for physician group and physician and patient characteristics

2.31

<.0001

0.97

<.0001

1.34

<.0001

2.20

<.0001

0.86

<.0001

1.34

<.0001

0.00

0.0016

 

Unplanned all cause hospital re-admission

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

Rate per 100

P-value

 

Unadjusted model

17.71

<.0001

10.90

<.0001

6.81

0.0002

14.26

<.0001

11.96

<.0001

2.30

0.2191

4.51

0.1066

 

*Adjusted for physician group characteristics

17.36

<.0001

10.66

<.0001

6.70

0.0002

14.55

<.0001

12.21

<.0001

2.34

0.219

4.36

0.1062

 

*Adjusted for physician group and physician characteristics

20.30

<.0001

12.73

<.0001

7.57

0.0003

16.76

<.0001

14.39

<.0001

2.37

0.2806

5.20

0.0972

 

*Adjusted for physician group and physician and patient characteristics

12.38

<.0001

7.48

<.0001

4.90

0.0003

9.67

<.0001

8.20

<.0001

1.47

0.2798

3.43

0.0975

 

*Adjustment used physician groups and physicians’ characteristics from March 31st, 2015 (post-intervention) and patients’ characteristics from March 31st, 2003 (pre-intervention)

 

Table 5

Difference in differences model: difference in change over time in ACSC admissions and all cause re-admissions between interprofessional teams and non-interprofessional teams from pre-intervention (April 1st, 2003 to March 31st, 2005) to post-intervention (April 1st, 2015 to March 31st, 2017) periods.

Discussion

We used administrative databases to assess the association between receiving care from interprofessional and non-interprofessional primary care teams and unplanned ACSC hospitalizations and all cause hospital readmissions among multi-morbid patients. We followed the same patients before and after teams were implemented which allowed an assessment of the effect of the intervention—introduction of interprofessional team-based care. When we investigated the outcomes during the most recent available period of April 1st, 2015 to March 31st, 2017 interprofessional teams were found to have higher ACSC admission and hospital re-admission rates as compared to non-interprofessional teams. However, when we compared the outcomes over time, interprofessional teams were not associated with either an increase or a reduction of ACSC hospital admission and hospital re-admission.

The results are consistent with previous evidence that looked at utilization in relation to interprofessional team-based care and found differences in quality but not in healthcare utilization and cost.,,, One US study that evaluated the effect of multiplayer patient-centred medical home on healthcare utilization did not find a significant reduction in inpatient admissions. In contrast, several studies from the US assessed multiple components of the medical home model on health services utilization and found significant lower rates of avoidable hospitalization when more medical homeness was incorporated in the health system.,, Implementation of Family Health Teams appeared to contribute to a reduction in ACSC hospitalizations in a Brazilian metropolis, Belo Horizonte.

There is a body of evidence that links chronic disease management programs to lower preventable hospitalizations.,,, In Ontario, patients being served by both interprofessional and non-interprofessional teams have access to certain chronic disease programs including diabetes education and heart failure clinics. This could be one of the reasons for the absence of difference in our study between receiving care from interprofessional and non-interprofessional teams in ACSC hospitalizations. Additionally, there is heterogeneity of interprofessional teams features across Ontario. For instance, some interprofessional teams are co-located others are not. Hence, some interprofessional teams might not be ideally set up for care coordination and continuity of care. Continuity of care might be reduced within interprofessional teams if they are not well coordinated and might present a potential for fragmented care. Available evidence from a systematic review suggests that having an accessible and a long-term relationship with a primary care provider appeared to be more important in reducing potentially avoidable hospitalizations than how the primary care delivery is organized. Long-term relationships between primary care physicians and patients reduces hospitalizations for chronic ACSCs and continuity of care has been associated with both reduced health services utilization and patient satisfaction. ,, Continuity of care is critical to ensuring that everyone with chronic medical needs receive effective, timely and safe health care.

Based on Startfield’s model a strong primary care system should be the first contact for care, as well as continuous, comprehensive and well-coordinated to reduce unwanted outcomes such as preventable hospitalizations. It is important for any jurisdiction that has embarked on or is planning to set up primary care interprofessional team-based care to nurture all these enablers for a strong primary care system.

Our study has several limitations that should be acknowledged. First, administrative databases have not been originally set up for research purposes, which presented a potential for measurement error. However, all the databases used in our study have been validated in Ontario’s context. Additionally, any potential measurement error will be non-deferential between interprofessional and non-interprofessional teams and should not bias the results in a meaningful way. Second, this is an observational study and is susceptible to unmeasured confounding. However, by comparing the outcomes over time, potential risk of bias from unmeasured confounders was limited. Third, due to the adopted study design, to be included in the study population, patients had to survive throughout the study period—April 1st, 2003 to March 31st, 2017. However, a potential survival bias would have affected both interprofessional and non-interprofessional teams’ patients equally and does not present a threat to internal validity. Fourth, ACSC medical admissions and all-cause readmissions are not all unnecessary and preventable.

Conclusion

Our study findings indicate that the introduction of interprofessional team-based primary care was not associated with reduction in avoidable hospitalizations and hospital readmissions. Those results were not in-line with our hypothesis as we expected that, over time, interprofessional teams would reduce the likelihood of ACSC admissions and re-admissions. For jurisdictions aiming to expand physician participation in teams, our study results point to the need to couple interprofessional team-based care with other enablers of a strong primary care system such as access, continuity, comprehensiveness and coordination. Policies and practices that enhance those features will help to implement interprofessional team-based care in a way that it is best able to deliver on intended outcomes such as improving health services utilization efficiency.

List Of Abbreviations

ACSCs

ambulatory care sensitive conditions

US

United States

FHO

Family Health Organization

COPD

chronic obstructive pulmonary disease

CMG

Case Mix Group

DAD

Discharge Abstract Database

Registered Patient Database

RPDB

RIO

Rurality Index of Ontario

RUBs

Resource Utilization Bands

OHIP

Ontario Health Insurance Plan

Declarations

Ethics approval and consent to participate:

ICES (formerly known as Institute for Clinical Evaluative Sciences) is a prescribed entity under section 45 of Ontario’s Personal Health Information Protection Act. Section 45 authorizes ICES to collect personal health information, without consent, for the purpose of analysis or compiling statistical information with respect to the management of, evaluation or monitoring of, the allocation of resources to or planning for all or part of the health system. Projects conducted under section 45, by definition, do not require review by a Research Ethics Board. This project was conducted under section 45, and approved by ICES’ Privacy and Legal Office.

Consent for publication:

Not applicable

Availability of data and materials:

The dataset from this study is held securely in coded form at ICES. While data sharing agreements prohibit ICES from making the dataset publicly available, access may be granted to those who meet pre-specified criteria for confidential access, available at www.ices.on.ca/DAS. The full dataset creation plan and underlying analytic code are available from the authors upon request, understanding that the computer programs may rely upon coding templates or macros that are unique to ICES and are therefore either inaccessible or may require modification.

Competing interests:

The authors declare that they have no competing interests

Funding:

This study was supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). ICES is an independent, non-profit research institute funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). As a prescribed entity under Ontario’s privacy legislation, ICES is authorized to collect and use health care data for the purposes of health system analysis, evaluation and decision support. Secure access to these data is governed by policies and procedures that are approved by the Information and Privacy Commissioner of Ontario. Parts of this material are based on data and information compiled and provided by the Canadian Institute for Health Information (CIHI). The analyses, conclusions, opinions and statements expressed herein are solely those of the authors and do not reflect those of the funding or data sources; no endorsement is intended or should be inferred. Richard H. Glazier is supported as a Clinician Scientist in the Department of Family and Community Medicine at St. Michael’s Hospital and at the University of Toronto.

Authors' contributions:

WHA: Conceptualization, Methodology, Formal Analysis, Writing—Original Draft. RM: Conceptualization, Methodology, Formal Analysis, Writing—Review & Editing.BH: Conceptualization, Methodology, Writing—Review & Editing, Supervision. WPW: Conceptualization, Methodology, Writing—Review & Editing, Supervision. RHG: Conceptualization, Methodology, Writing—Review & Editing, Supervision.

Acknowledgements:

Not applicable

Appendix

These conditions represent a subset of all possible chronic conditions that may be experienced by individuals over a lifetime but represent the most substantial conditions from a population perspective.

Condition [reference for validated algorithm]

ICD 9 / OHIP

ICD 10

ODB*

Acute Myocardial Infarction (AMI) [1]

410

I21, I22

 

Osteo- and other Arthritis:

 

 

 

(A) Osteoarthritis

715

M15-M19

 

(B) Other Arthritis (includes Synovitis, Fibrositis, Connective tissue disorders, Ankylosing spondylitis, Gout Traumatic arthritis, pyogenic arthritis, Joint derangement, Dupuytren’s contracture, Other MSK disorders)

727, 729, 710, 720, 274, 716, 711, 718, 728, 739

M00-M03, M07, M10, M11-M14, M20-M25, M30-M36, M65-M79

 

Arthritis - Rheumatoid arthritis [2]

714

M05-M06

 

Asthma [3]

493

J45

 

(all) Cancers

140-239

C00-C26, C30-C44, C45-C97

 

Cardiac Arrhythmia

427 (OHIP) / 427.3 (DAD)

I48.0, I48.1

 

Congestive Heart Failure [4]

428

I500, I501, I509

 

Chronic Obstructive Pulmonary Disease [5]

491, 492, 496

J41, J43, J44

 

Coronary syndrome (excluding AMI)

411-414

I20, I22-I25

 

Dementia [6]

290, 331 (OHIP) / 046.1, 290.0, 290.1, 290.2, 290.3, 290.4, 294, 331.0, 331.1, 331.5, F331.82 (DAD)

F00, F01, F02, F03, G30

Cholinesterase Inhibitors

Diabetes [7]

250

E08 - E13

 

Hypertension [8]

401, 402, 403, 404, 405

I10, I11, I12, I13, I15

 

Inflomatary Bowel Disease (IBD) [9]

555, 556

K50, k51

 

(Other) Mental Illnesses

291, 292, 295, 297, 298, 299, 301, 302, 303, 304, 305, 306, 307, 313, 314, 315, 319

F04, F050, F058, F059, F060, F061, F062, F063, F064, F07, F08, F10, F11, F12, F13, F14, F15, F16, F17, F18, F19, F20, F21, F22, F23, F24, F25, F26, F27, F28, F29, F340, F35, F36, F37, F430, F439, F453, F454, F458, F46, F47, F49, F50, F51, F52, F531, F538, F539, F54, F55, F56, F57, F58, F59, F60, F61, F62, F63, F64, F65, F66, F67, F681, F688, F69, F70, F71, F72, F73, F74, F75, F76, F77, F78, F79, F80, F81, F82, F83, F84, F85, F86, F87, F88, F89, F90, F91, F92, F931, F932, F933, F938, F939, F94, F95, F96, F97, F98

 

Mood, anxiety, depression and other nonpsychotic disorders

296, 300, 309, 311

F30, F31, F32, F33, F34 (excl. F34.0), F38, F39, F40, F41, F42, F43.1, F43.2, F43.8, F44, F45.0, F45.1, F45.2, F48, F53.0, F68.0, F93.0, F99

 

Osteoporosis

733

M81, M82

 

Renal failure

403, 404, 584, 585, 586, v451

N17, N18, N19, T82.4, Z49.2, Z99.2

 

Stroke (excluding transient ischemic attack)

430, 431, 432, 434, 436

I60-I64

 

NOTES:

Abbreviations: ICD = International Classification of Disease; ODB = Ontario Drug Benefit program database; OHIP = Ontario Health Insurance Plan, physician billings database;

All case definitions look back to 2001 to ascertain disease status, with the exception of AMI (1 year prior to index), Cancer (2 years), Mood Disorder (2 years) and Other Mental Illnesses (2 years)

AMI, Asthma, COPD, CHF, Dementia, Diabetes Hypertension and Rheumatoid Arthritis are based on validated case algorithms (see Sources 1-8 below, respectively). All other conditions required at least one diagnosis recorded in acute care (CIHI) or two diagnoses recorded in physician billings within a two-year period.

*ODB prescription drug records are not available for the majority of persons under the age of 65

Appendix A:

List of diagnostic information for defining the 17 selected chronic conditions under investigation in this study.


List of Eligible Conditions (CMGs)

CMG+

CMG+ description

Stroke (Age ≥ 45)

CMG 2008

25

Hemorrhagic Event of Central Nervous System

 

26

Ischemic Event of Central Nervous System

 

28

Unspecified Stroke

CMG 2009

25

Hemorrhagic Event of Central Nervous System

 

26

Ischemic Event of Central Nervous System

 

28

Unspecified Stroke

COPD (Age ≥ 45)

CMG 2008

139

Chronic Obstructive Pulmonary Disease

CMG 2009

139

Chronic Obstructive Pulmonary Disease

Pneumonia (All ages)

CMG 2008

136

Bacterial Pneumonia

 

138

Viral/Unspecified Pneumonia

 

143

Disease of Pleura

CMG 2009

136

Bacterial Pneumonia

 

138

Viral/Unspecified Pneumonia

 

143

Disease of Pleura

Congestive Heart Failure (Age  45)

CMG 2008

196

Heart Failure without Cardiac Catheter

CMG 2009

196

Heart Failure without Cardiac Catheter

Diabetes (All ages)

CMG 2008

437

Diabetes

CMG 2009

437

Diabetes

Cardiac CMGs (Age ≥ 40)

CMG 2008

202

Arrhythmia without Cardiac Catheter

 

204

Unstable Angina/Atherosclerotic Heart Disease without Cardiac Cath

 

208

Angina (except Unstable)/Chest Pain without Cardiac Catheter

CMG 2009

202

Arrhythmia without Cardiac Catheter

 

204

Unstable Angina/Atherosclerotic Heart Disease without Cardiac Cath

 

208

Angina (except Unstable)/Chest Pain without Cardiac Catheter

Gastrointestinal CMGs (All ages)

CMG 2008

231

Minor Upper Gastrointestinal Intervention

 

248

Severe Enteritis

 

251

Complicated Ulcer

 

253

Inflammatory Bowel Disease

 

254

Gastrointestinal Hemorrhage

 

255

C

 

256

Esophagitis/Gastritis/Miscellaneous Digestive Disease

 

257

Symptom/Sign of Digestive System

Appendix B:

List of Eligible CMGs for hospital re-admission

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