This study utilized a retrospective cohort design with data extracted from electronic health records. Patients in the sample were admitted to a SNF located in Western New York over a nine-month period and were excluded from the sample for the following reasons: 1) discharged against medical advice (AMA); 2) hospitalized; 3) deceased; 4) not placed on program for PT/OT; 5) under 21 years old; 6) not placed on restorative programs with functional goals; 7) incomplete data.
Functional GG scores were used to measure the level of patients’ functional status. The functional GG scores were obtained from plans of care developed by PT and OT under the MDS 3.0 section GG reporting mobility and self-care measures [31]. Scoring was completed under instruction of the Long-Term Care Facility Resident Assessment Instrument 3.0 User’s Manual v 1.14 [31]. Therapists completing the functional scores were unaware of the FI at time of completion. Scoring for GG items was based on the MDS value of each functional status, from dependent to independent. The codes of “7”, for patient refusal, “88” for not attempted due to medical condition, or “9” for not applicable, were converted to a zero. These scores do not follow the same ordinal pattern related to functional level and thus would result in inaccuracy with observing functional status. To limit type 1 error for functional change, wheelchair mobility GG measures were excluded [32]. The GG Functional scores were totaled with a score of 60 being the highest score, indicating a more independent functional status. Table 1 lists the measures included. Table 2 correlates the billing code to the converted scores for the purpose of this study. The data collected allowed for the observation of GG admission score (GG A), GG discharge score (GG D/C) and the difference in GG score from admission to discharge (GG AvD/C). Under the PDPM, the required GG codes were anticipated to become a standard of measurement in function and this expectation was a considering factor for the design of this study to improve its feasibility of the findings.
This study depended on an electronic FI calculated by Patient Pattern software produced in Buffalo, New York [33]. The FI was generated from MDS data with a focus on function, cognitive/psychological status, nutrition, motivation, and mood. The proprietary algorithm used to calculate the Patient Pattern FI was modeled after the Rockwood Deficit Accumulation model of frailty and was completed for each patient within 2 weeks of admission date [28, 34]. If a patient’s change in a condition required additional frailty assessment within the date range, the FI closest to the evaluation date was recorded. Participants were classified into the frailty risk categories based on their FI as follows: under 29.9% considered Mildly Frail/Low Risk group (MildF/LRG), between 30-39.9% as Moderately Frail/Moderate Risk group (ModF/MRG), and over 40% deemed Severely Frail/High Risk group (SevF/HRG). The descriptive text “moderate, mild, and severe risk” for each frailty category was adapted to the subacute care setting from that of the Canadian Study of Health and Aging Clinical Frailty scale [35]. Due to the inconsistency of FI cut points for frailty categories within the literature, this study utilized previously studied FI risk stratification for mortality, hospitalization, institutionalization in addition to Patient Pattern internal risk validation data to establish the FI category cut points [36, 37]. The recommended level of therapy of services for patients during this retrospective analysis were not influenced by GG score or FI. Provider recommendations were allocated based on professional judgment alone.
Comorbidity was assessed using the CCI and derived from documentation of the Physician and Nurse Practitioner at time of admission [30]. Other data, including age, sex, and length of time on skilled PT and OT, was gathered manually extracting from therapy documentation notes.
Statistical Analyses
The GG AvD/C score was computed for each patient. The study utilized a multiple regression modeling approach to evaluate the variation of the GG AvD/C score across the different levels of frailty. Patients’ sex, age, CCI, and length of time on PT program were included in the regression modeling as covariates to reduce potential confounding effects. We also noticed that GG AvD/C scores increased as age went up to a certain point but then declined afterwards. The regression analysis also included an age-squared variable to address the non-linear relationship between the age and the GG AvD/C score. The value of the coefficient of determination (R2) was computed to estimate the amount of variance accounted for by the frailty level and covariates. Coefficient estimates and their 95% confidence intervals (CI) were calculated and a two-sided alpha of less than 0.05 was defined a priori for statistical significance with p-value < 0.05. All analyses were performed using SPSS Version 24 (SPSS Inc, Chicago, IL, USA).