The study is a collaboration between Red Cross Copenhagen and Amager and Hvidovre Hospital, a large university hospital in the Danish capital region in the suburbs of Copenhagen. The Red Cross provided the medical respite care facilities, and Amager and Hvidovre Hospital planned and conducted the scientific evaluation and outcome assessment in relation to the present study.
Study design
The study “Bridge Copenhagen – medical respite care for homeless people” is a pragmatic randomized controlled trial including a health economic evaluation.
Setting
In Denmark, access to health care services, such as hospitalization and general practitioners, is free of charge, as most of the health care sector is financed by taxes. Hospitals are responsible for treating diseases in the acute phase, as well as the outpatient follow-up. The municipalities are responsible for rehabilitation after hospitalization, as well as other primary health care services, including services aimed at homeless people after discharge from the hospital. In Copenhagen, the health care services for homeless people includes street clinics with doctors and nurses, shelters, rehabilitation centers, drop-in centers, and inpatient and outpatient therapy for use of drugs and alcohol. The services are operated by municipalities and non-governmental organizations (NGOs).
The hospitals in the Capital Region of Denmark have employed nurses with specific training and experience in working with socially marginalized people, including homeless people and people with problematic use of alcohol and drugs (19). These social nurses assist in optimizing hospital treatment and care for marginalized patients. Upon discharge, they can facilitate contact with shelters and municipalities for further help. At the time of this study, the social nurses were the ones referring patients for stays in medical respite care (19).
Participants
Acutely admitted patients age ≥ 18 years who were self-reported homeless or functionally homeless and were going to be discharged from one of the 10 hospitals in the Capital Region of Denmark were offered inclusion in the study. The term ‘functionally homeless’ refers to a person who formally has an address but cannot stay there due to, for example, violence, threats, or poor condition of the residence (20). If participants were not able to be alone during the night, use the stairs to the first floor, were not self-reliant in daily activities, or were illegal immigrants, they were excluded due to internal rules at the center. If the social nurses or the principal investigator was in doubt about whether the patient fulfilled the inclusion criteria, they would consult the head of the medical respite care center. Questionnaires, patient information, and the consent form were available in Danish, English, Polish, Russian, and French; patients who could not read these languages were not included. There were no restrictions regarding drug and alcohol use. Because the study was conducted as a pragmatic randomized study in a normal clinical setting, we were not able to produce a full flowchart of all the homeless patients attending the hospitals during the study period. However, we collected data one month in September 2015 about all patients who were in contact with the social nurses but did not comply with inclusion criteria.
Post-hospital medical respite care intervention
In April 2014, Red Cross Copenhagen opened a medical respite care center with four beds for homeless people discharged after hospitalization. After 6 months, the capacity expanded to eight beds. The place was led by a paid registered nurse (RN) and primarily staffed with volunteers. The medical respite care center offered a 2-week stay including three meals a day, free of charge. The patients were accommodated in double rooms with attached bathrooms. The RN assisted with uncomplicated nursing tasks, such as caring for wounds, helping with medicine, catheter care, and monitoring of blood glucose, and helped patients with social issues, such as housing and communicating with municipalities about the provision of further services. The Red Cross medical respite care center differed from the services in the municipality in two important ways: it was free of charge, and there were no restrictions regarding drug and alcohol use. The medical respite center was financed by the government during the study period.
The control group was discharged from the hospital with help from the social nurses, but independently had to seek help from the described standard municipal facilities, such as shelters, street nurses, and doctors.
Randomization and blinding
The randomization was conducted in blocks of four with a 2:2 ratio and stratified for each hospital to ensure that each hospital had a chance to refer the homeless patients and that there was broad representation of patients from all over the Capital Region. The randomization was performed when the patient was ready for discharge. Participants were included by one of the 10 social nurses. When a possible participant for the study was identified, the social nurse informed the patient about the medical respite center and the study design. The patient signed an informed consent form and answered the health-related quality of life (EQ-5D-5L) questionnaire (21). The social nurse called the medical respite center, where the employees drew a sealed opaque envelope that concealed the group to which the participant was assigned. Thus, the actual draw took place in the respite center, where group assignment was also revealed. Afterwards, the primary investigator double checked the randomization. The principal investigator was the only one who knew the randomization code and prepared the envelopes. The first six patients included in the study were all assigned to the intervention group without randomization to get the medical respite care program up and running. Blinding of the participants was not possible due to the nature of the study. However, data analysis was performed blinded by a single researcher (M.K.).
Study perspective
This study is one of a few randomized controlled studies performed in acutely admitted homeless patients, a socially stigmatized group (22). The perspective of the economic evaluation is societal. The preconception is that it is challenging to perform randomized controlled trials with follow-up in a population of homeless people (23). Therefore, we initially designed the period of economic evaluation to be 3 months in an attempt to prevent the study from suffering from a high drop-out rate (23). The societal perspective of the economic evaluation was based on costs from the health and social care sector; however, some costs (e.g., prison) were not included. We included all costs from the Danish health care system, municipalities, and the medical respite care center. The analysis will not include patients’ or families’ use of time because homeless people often have limited or no contact with family and peers and are primarily supported by transfer income (24,25). Any costs or savings related to participants finding stable housing as a positive consequence of the medical respite care stay could be relevant to the investigation but is beyond the scope of this study.
Outcomes and measures
The primary outcome was a difference in health care costs for a period of 3 months after hospital discharge. Data on the costs of the health care services provided in hospitals and at general practitioners were extracted from the National Patient Register and the National Health Insurance Service Register through Statistics Denmark. Costs in the municipalities were collected through databases in the municipalities in the Capital Region of Denmark. We received information about the type of health care service, date of accounting, and costs. The costs of the medical respite care center were retrieved through Red Cross Copenhagen. Costs in Danish kroner (DKK) were converted to Euro (€) using the exchange rate €1=7.5 DKK (26). Data about immigrants without a Danish social security number were retrieved manually by their provisory social security number in the medical journals.
Secondary outcomes were a change in health-related quality of life (HRQoL), health care costs after a period of 6 months, and health care costs grouped into elective health care costs, acute health care costs, and social costs after a period of 6 months. The HRQoL were measured by EQ-5D-5L at baseline, after 2 weeks, and after 3 months. The measurement at 3 months was decided after inclusion of the first 25 participants because the 2-week time horizon was deemed rather short and we found it was possible to perform a satisfying follow-up after 3 months. The EQ-5D-5L is a generic and validated questionnaire that measures HRQoL in five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression (27). Each question has five possible answers: no problems, slight problems, moderate problems, severe problems, or unable to/extremely. The answers can give a total of 3125 possible health states that can each be converted to an index value using the cross-walk value set (27). The index values are used to calculate quality-adjusted life years (QALYs), which is the outcome presented in this study. Compared to the EQ-5D-3L, the EQ-5D-5L is more sensitive and able to detect smaller differences in interventions and treatments (21). The QALY measurement had the same time horizon as the cost measurements: 3, 6, and 12 months.
Follow-up was conducted mainly by the primary investigator either as personal interviews face-to-face or by phone. Nurses and social workers in the municipalities assisted in collecting the follow-up questionnaires based on instructions from the primary investigator.
Participant characteristics and covariates were collected from Danish registries: age, gender, having a social security number, source of income, highest completed education, admissions 2 years prior to inclusion, psychiatric diagnoses, and the Charlson Comorbidity Index, indicating the burden of diseases (28). Use of drugs and alcohol and housing status were collected from a database registering services provided by the social nurses, and information about what kind of help the intervention group received at the medical respite center was retrieved from the database of the medical respite center.
Sample size was calculated to detect a 25% difference in cost between the two groups. With estimated health care costs of €13,402 in the control group, standard deviation of €5,259, a significance level of 5%, and a power of 80%, 96 patients were needed assuming 20% loss to follow-up.
Assessment of costs
To investigate whether a medical respite care stay influenced the participants’ use of social and health care services, we split the costs into three categories: elective health care costs, acute health care costs, and social costs. Elective health care costs relate to all planned health care services, such as visits to the general practitioner, outpatient visits, elective hospitalization, rehabilitation in the municipalities, and inpatient and outpatient therapy for use of drugs and alcohol. Primary health care tariffs were used for costing primary health care, and a standard outpatient and bed-day tariff was used for costing hospital services. Acute health care costs comprise acute admissions and emergency department visits, as well as in-hospital days after inclusion. The latter is important because some participants remained hospitalized after inclusion, either because their condition deteriorated, or because they waited for an alternative level of care. The social costs include the social and health care services delivered in the municipalities, inter alia, the estimated hours of contact with social workers, and lodging at shelters. Costs related to the medical respite care stay were also categorized as a social cost, but only calculated for the randomized intervention group.
Hospital services and health care use in primary care were evaluated using the National Patient Register and National Health Insurance Service Register through Statistics Denmark (29,30). Information on the purchase of prescription drugs filled at pharmacies is found in the Danish National Prescription Register (31). It is customary for the hospitals to dispense medicine to homeless people at discharge without registering this in the electronic health record. Furthermore, pharmaceuticals are handed out in street clinics, where patients are sometimes treated anonymously. Therefore, we will conduct the analysis with and without data from the Danish National Prescription Register. Information about health care services in the municipalities are retrieved from both financial management systems and manually collected information about delivered services in street clinics. We received information about the type of health care service, date of accounting, and cost of the municipal service.
The municipal costs were valued using the unit costs given in Table 1. Health care professionals’ time was valued based on the 2016 and 2017 mean wages for registered nurses and staff physicians (€33 and €62 per hour, respectively) (32,33). Costs from the medical respite care stay were obtained from the financial management system at Red Cross Copenhagen. Costs consisted of salaries for the daily leader and other staff, including a consultant working in the head office at Red Cross Copenhagen, food, washing of clothes and linen, and cleaning and nursing requisites. Time spent by the volunteers was valued by the number of volunteer hours spent at the medical respite care center multiplied by an estimated unit cost of €25, including perks. This estimate is based on the mean salary for an unskilled worker in the welfare sector (34). Actual days in the medical respite care stay was registered and reported as median (IQR).
Costs in the primary analyses included all costs incurred at hospitals, general practitioners, and medical specialists, as well as the costs of prescription drugs and costs related to services delivered in the municipalities and the medical respite care center. Income transfers were excluded. Data from municipalities were double-checked in an audit by the principal investigator and M.K. Data from municipalities contained information on the date of accounting, but not the date of delivery of service; therefore, the analysis of municipal data was only performed for the 6-month period.
Statistical analysis and cost-utility analysis
Demographic information and information on transfer incomes and health history are presented as means, standard deviations, and percentages. The cost-utility analysis was performed as an intention-to-treat stochastic cost-effectiveness analysis because both costs and effects were determined using data from the participants in the study (35). The primary analysis compared costs during the 3 months following inclusion in the study for both groups and was adjusted for costs for the 3 months preceding inclusion.
For the secondary analysis with a 6-month follow-up, we adjusted for cost 6 months prior to inclusion. Post-hoc, we decided to also conduct the analyses for a 12-month period. The baseline covered a period of 12 months, equivalent to the period following inclusion in the study. Therefore, the cost regression was conducted as a difference in difference analysis as shown in model 1: (see Equation 1 in the Supplementary Files)
Where I is the group assignment and C indicates costs in the period after (t1) or before (t0) randomization.
For sensitivity analyses, we expanded the regression analysis with other covariates, such as level of education, Charlson Comorbidity Index, and type of homelessness as shown in model 2: (see Equation 2 in the Supplementary Files)
Where X is a vector of covariates.
In addition, health care costs were divided into the three categories (acute, elective, and social) and compared in a linear regression model. HRQoL values were used for computation of QALYs using Danish preference weights (36,37). Incremental cost-effectiveness ratios (ICERs) were computed by subtracting the QALY gain in controls from the QALY gain in cases, obtaining the incremental effectiveness; the incremental costs were achieved in a similar manner. Finally, the incremental QALY gain was divided by the incremental costs (35).
The ICER is a fraction; therefore, it is not straightforward to obtain confidence limits for the estimate. Therefore, the costs, effects, and ICERs were bootstrapped, drawing 10,000 samples with replacement, and the resulting ICERs plotted in a cost-effectiveness plane. In this exercise, whether the intervention is cost-effective is displayed visually, and the bootstrapping results in confidence interval values for the costs, effects, and ICERs (38). Bootstrapping was conducted on both the complete case data set (N=40) and a data set with imputed QALY values in case of missing values (N=89).
For statistical analyses, we used SAS® Enterprise Guide version 7.1 and SAS® 9.4. The bootstrapping of ICERs was conducted in STATA® MP 15.