SINCE THE PROSPECTIVE payment system (PPS), based

1514 Functional Gains and Therapy Intensity During Subacute Rehabilitation: A Study of 20 Facilities Christine C. Chen, ScD, OTR/L, Allen W. Heinemann, PhD, ABPP, Carl V. Granger, MD, Richard T. Linn, PhD ABSTRACT. Chen CC, Heinemann AW, Granger CV, Linn RT. Functional gains and therapy intensity during subacute rehabilitation: a study of 20 facilities. Arch Phys Med Rehabil 2002;83:1514-23. Objectives: To document patient, program characteristics, and therapy service provision in subacute rehabilitation across 3 types of facilities that provide subacute rehabilitation, to examine the determinants of therapy intensity, and to evaluate the contribution of rehabilitation services to functional gains. Design: A retrospective study linking administrative billing data and patients functional assessment records. Setting: Twenty facilities part of the Uniform Data System for Medical Rehabilitation (UDSMR) subacute database Participants: A total of 1976 billing records of patients with stroke, orthopedic, and debility impairments, discharged in 1996 and 1997, were retrieved and linked with the FIM instrument ratings from UDSMR subacute database. Interventions: Not applicable. Main Outcomes Measures: Total therapy intensity and Rasch-transformed FIM domain gains (ie, gains in self-care, mobility, cognition). Results: Therapy intensity was mostly determined by impairment and facility type, although variances explained by the predictors were small. Patients in all 3 impairment groups made functional gains; gains were related weakly, although significantly, to therapy intensity and rehabilitation duration after controlling for other variables. Conclusions: The provision of rehabilitation therapies varied across facilities. Skilled nursing facilities with subacute rehabilitation units tended to provide more therapies than subacute units in acute or rehabilitation hospitals. Key Words: Cerebrovascular disorders; Orthopedics; Rehabilitation; Subacute care; Treatment outcome. 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation From the Rehabilitation Institute of Chicago (Chen, Heinemann) and Department of PM&R, Northwestern University Medical School (Chen, Heinemann), Chicago, IL; and Department of Rehabilitation Medicine, Center for Functional Assessment Research, Uniform Data System for Medical Rehabilitation, State University of New York, Buffalo, NY (Granger, Linn). Supported by the American Occupational Therapy Association and the National Institute on Disability and Rehabilitation Research (grant no. H133G60135). Presented in part at the American Congress of Rehabilitation Medicine s annual assembly, Oct 2000, Hilton Head, SC, and the American Occupational Therapy Association s annual conference, 2000, Seattle, WA. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to Christine C. Chen, ScD, OTR/L, Rehabilitation Institute of Chicago, 345 E Superior St, Chicago, IL 60611, e-mail: c-chen1@northwestern.edu. 0003-9993/02/8311-6833$35.00/0 doi:10.1053/apmr.2002.35107 SINCE THE PROSPECTIVE payment system (PPS), based on diagnosis-related groups, was implemented in 1983, considerably more patients have been discharged from acute hospitals prematurely and admitted to postacute care settings to receive rehabilitation services. 1 Comprehensive and subacute are the 2 major types of rehabilitation services provided at inpatient postacute care settings. The former is typically provided in a specialized, free-standing, rehabilitation hospital in which 24-hour medical support is provided; the latter can be provided in units established in hospitals or skilled nursing facilities (SNFs). Patients admitted to subacute units, although medically more stable than those admitted to the comprehensive rehabilitation hospitals, tend to be older and have less endurance to tolerate the rigorous 3-hour therapy schedule as mandated in comprehensive rehabilitation settings. 2 Because facilities may receive Medicare reimbursement for rehabilitation services in addition to the allowed per diem rates, subacute rehabilitation has become a profitable venue. In the late 1980s and early 1990s, many subacute rehabilitation units were established in general hospitals, free-standing rehabilitation hospitals, and SNFs. 2-5 After passage of the Balanced Budget Act (BBA) of 1997 and the ensuing implementation of SNF-PPS, many subacute rehabilitation units closed,* which had a major impact on the therapy job market. 6 During this rapid but short-lived subacute rehabilitation expansion, few studies examined its service provision patterns and outcomes. In the present study, we collected functional and therapy services data in 3 major impairment groups (stroke, orthopedic conditions, debility) across 3 facility types from a national sample during 1996 and 1997, just before changes in payment policy occurred. These data provide an opportunity to better understand the subacute industry and may provide insights into discharge planning decisions on the eve of rehabilitation hospital PPS. Literature specifically examining relationships between therapy intensity and outcomes in subacute rehabilitation is sparse. However, general effects of medical rehabilitation have been shown. In a recent meta-analysis, 7 rehabilitation intervention was shown to have a moderate effect on stroke patients functional improvement. Studies also showed that patients who received specialized rehabilitation care fared better than those who received only routine care in terms of mortality, community discharge, and physical and social functioning. 8,9 The positive effects of rehabilitation intervention were evident at discharge and at follow-up. 10,11 Factors that are associated with rehabilitation outcomes (eg, mortality, community discharge, and functional status) include age, time since onset (interval between a stroke incident and rehabilitation admission), 4 severity of impairment (usually measured by anatomic, physiologic, or combined tests), 12 degree of disability at admission * The BBA of 1997 changed reimbursement for skilled nursing care from a cost-based method to a PPS of fixed, predetermined rates. Restrictions were imposed and Part B therapy costs were capped at $1500. Many large, for-profit chain facilities had filed for bankruptcy and closed facilities.

FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen 1515 (ie, ratings of motor and cognitive status, or activity limitations), and social support. 13-21 Gender was associated with functional improvement in only 1 study. 22 Most of the studies identified here describe the effectiveness rather than the efficiency of rehabilitation. Studies 23-25 examining orthopedic patients have shown that good premorbid physical functioning, fewer complications or comorbidities, intact cognition, community residence prior to rehabilitation admission, and higher levels of social support are associated with better recovery and rehabilitation outcomes: patients achieved greater functional gains and were more likely to be discharged to the community. A few recent studies 3,4,26,27 have examined the effects of rehabilitation and cost across postacute settings (ie, rehabilitation hospitals vs SNFs with or without a subacute rehabilitation component) after stroke and hip fracture. These studies showed that stroke patients receiving comprehensive rehabilitation at rehabilitation hospitals had greater functional improvement and community discharge than patients receiving subacute rehabilitation services at SNFs. 3,4 Outcomes for orthopedic patients were less clear. Kramer et al 3 did not find significant difference in functional recovery (ie, number of activities of daily living [ADLs] restored to premorbid level) or discharge disposition in patients who received comprehensive (in rehabilitation hospitals) or subacute rehabilitation (in SNFs). Kane et al, 26,27 in contrast, noted that patients with less ADL dependency at admission made greater gains when receiving subacute rehabilitation care in rehabilitation hospitals than patients receiving subacute rehabilitation care in SNFs. It is difficult to compare these studies because they used different research designs, data sources, patient samples, and analysis strategies. A recently published 3-year Uniform Data System subacute report 28 found that (1) average inpatient length of stay (LOS) for orthopedic patients was shorter than that of stroke patients, (2) functional status ratings (the FIM instrument) at admission were lower in patients with stroke than orthopedic impairments, and (3) similar functional gains were made during rehabilitation in both groups. However, details of rehabilitation therapies were not part of the database, and therefore rehabilitation service provision could not be compared between impairment groups. Decisions about rehabilitation duration (LOS) and therapy intensity are typically made by the rehabilitation team. 29 However, in recent years, team decisions on both (LOS, therapy intensity) may have been greatly affected by third-party payer policies. As Keith pointed out, 29 clinicians are faced with providing less treatment (because of shorter LOS) without knowing the consequences. There is limited research on the relationship between treatment intensity and patient outcomes. It is not clear how therapy dosages are determined, nor is it clear if and how therapy doses are related to the responses (eg, functional outcomes). In an earlier study, Heinemann et al 30 explored both questions in the context of comprehensive rehabilitation. They found that the dose-response relationships in patients with spinal cord injury (SCI) and traumatic brain injury (TBI) were complex. By using each individual therapy intensity (occupational therapy [OT], physical therapy [PT], speech-language therapy [SLT], psychologic services) as the dependent variable, and patient age, measures of motor and cognitive function at admission, onset days to rehabilitation admission, and interrupted stay as independent variables, they found that little variance in therapy intensity could be explained by the (set of) predictors, except for intensity of psychologic services (R 2.26 for TBI patients; R 2.20 for SCI patients) and speech therapy (R 2.17 for TBI patients). The researchers noted that lower functional status at admission and greater therapy intensity significantly predicted greater functional gains. Similar results were found in stroke patients in a subsequent study conducted by Heinemann and Hamilton. 31 Keith et al, 4 in a combined sample of acute and subacute rehabilitation patients with stroke, found that the FIM gain was associated with longer LOS and greater daily rehabilitation therapy. The evidence from these studies suggests that more intense rehabilitation (therapy dosages) may contribute to greater functional gains (responses). In summary, there is limited research that directly examines therapy intensity and rehabilitation outcomes. Some studies suggest that age, type and severity of impairment, admission functional status, and rehabilitation intensity may be related to functional improvement and discharge disposition in patients receiving comprehensive rehabilitation. Recently, a handful of studies have compared the outcomes and/or cost between types of rehabilitation (comprehensive vs subacute) or types of setting (rehabilitation hospitals vs SNFs). 3,4,26,27 However, these studies are based on limited samples. The current study focused on rehabilitation service provision across subacute settings and examined the dose-response relationships (intensity of therapy and functional gains) across impairments. We used intensity of therapy instead of total amount of therapy because the latter is confounded with the duration of stay (ie, LOS). The specific aims of the present study were (1) to document the characteristics of patients, facilities, and subacute rehabilitation service provision during 1996 and 1997 in 3 facility types (general hospitals, free-standing rehabilitation hospitals, SNFs) and (2) to examine the relationships between therapy type, intensity, and functional gains in 3 major impairment groups. We hypothesized that (1) therapy intensity depends on patients primary impairment (ie, diagnosis) and functional status at admission and (2) greater functional gains are related to lower functional status at admission, longer rehabilitation duration (LOS), and more intense therapies. METHODS The data used in this study came from 2 sources: the billing records submitted by facilities that provided subacute rehabilitation and the FIM data stored in the subacute database at Uniform Data System for Medical Rehabilitation (UDSMR). The inclusion criteria for patient records were patients discharged during 1996 and 1997 with primary diagnoses of stroke, orthopedic impairment, or debility. The procedures are briefly summarized later; detailed description of facility recruitment and data collection can be found elsewhere and is available on request. 32 Recruitment Recruitment took place in late 1998 and early 1999, after receiving full approval of human subjects review boards at the State University of New York at Buffalo, NY, the Northwestern University Medical School, Chicago, IL, and the participating hospitals that requested additional institutional review board reviews. Facilities that were UDSMR subacute database subscribers were invited to participate in the study by a letter addressed to the FIM coordinators (CVG). Those who were interested faxed the researchers (CCC, AWH) a signed consent form; the researchers then followed up with telephone calls to discuss the logistics for data collection and transmission. The researchers explained to the facility FIM coordinator the purpose of the study, specified the inclusion criteria for patient records, and requested the following information: dates of birth, admission and discharge, impairment code, LOS, type and units of rehabilitation services billed, and total charges for each type of therapy. The FIM coordinator or another staff

1516 FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen Table 1: Study Sample Demographic and Medical Characteristics Compared With National Samples Study Sample National 1996 National 1997 No. of patients 1976 28,362 49,844 Age (y) 76 74 75 LOS (d) 21 22 21 Onset (d) 10 14 12 Gender (%) Female 66 64 64 Race (%) White 92 87 87 African American 5 9 9 Program (%) Interrupted 2 4 4 Admit from (%) Home 5 4 3 Acute care 94 91 90 Discharge to (%) Community 77 73 74 Nursing home 13 14 15 Rehabilitation hospital 2 2 2 Acute unit 1 7 7 Admission FIM* 72 73 74 Discharge FIM* 96 93 93 FIM efficiency 1.51 1.43 1.49 NOTE. For the national sample, see Iwanenko et al. 28 Only selected categories are presented; percentages do not always add to 100%. * Raw FIM total scores used for ease of comparison. Efficiency is calculated as (discharge FIM admission FIM)/LOS. person identified by the FIM coordinator (eg, the director of rehabilitation, the director of patients accounts or billing, a staff member from the medical records) then collected the data. Because the data we requested were sensitive in nature, the data acquisition process was intense and laborious, requiring persistent follow-ups and coordination. In total, 20 facilities submitted data before the deadline, and 1976 records entered the final analyses, with a range of 7 to 271 cases per facility being included after data cleaning. Although 25 of 188 contacted facilities agreed to participate, only 20 submitted data. Each facility was offered an honorarium up to $200. Constraints of time and resources (some facilities specifically attributed these to the preparation and implementation of the PPS), administrative changes, corporate acquisitions, and termination of UDSMR subscription were the most cited reasons for not participating. Although it was impossible to obtain data from the nonparticipating facilities, descriptive statistics of the 20 participating facilities were compared with the national samples, 28 and we found close resemblance (table 1). Data Collection, Cleaning, and Linking A survey was developed to collect facility information including size and type of the facility, accreditation status, room rate, rehabilitation services provided, and number of rehabilitation personnel employed (full-time equivalents) during 1996 and 1997. Patient-related information (ie, date of birth, admission and discharge dates, units and type of therapy, total charge during the rehabilitation LOS) was either extracted from facility database(s), or retrieved from billing records by the identified personnel. The data were sent via mail or electronically to the researcher (CCC) and entered into a database by a research assistant. Most facilities had the data formatted in Excel or ASCII and sent as email attachment or on disks. Few submitted the data by using data forms that contain the requested information 1 form for each patient. Almost all facilities submitted only a sample of their patients discharged in 1996 and 1997.* The researchers performed substantial data cleaning before and after data were merged with the FIM database. Raw data were carefully inspected for accuracy, consistency, outliers, and duplication. For example, age, onset, and LOS were calculated by using the admission and discharge dates; if negative values were noted, the cases were then individually verified with the original and/or FIM records. Cases with incomplete FIM scores and inconsistent records (eg, admission, discharge, birth dates, billing periods) were excluded. To examine patterns of service provision for typical patients undergoing subacute rehabilitation, we excluded records for patients with second and subsequent admissions, who were younger than 20 years of age, had LOSs less than 5 or greater than 150 days, and whose total therapies exceeded 6 hours a day (the average daily therapy intensity). Therapy data were converted into 15-minute units and summed within specific therapy type, including OT, PT, and SLT. Psychology services were not included because few patients received them; therapeutic recreation services were not included because they were not billed separately. An average daily intensity of each therapy was computed by dividing total billed therapy units by LOS. An intensity of all (combined) therapies variable was computed by dividing the sum of OT, PT, and SLT by LOS. Data Analyses Rating scale analysis. The FIM instrument consists of 18 items and uses a 7-point rating scale that ranges from 1 (total dependence) to 7 (total independence). 33 Rating scale (Rasch) analysis 34 was conducted to transform raw FIM scores into interval measures using WINSTEPS a for Windows. 35 Rating scale analysis helps define constructs by (1) arraying items along an easier-to-harder-to-perform continuum, (2) describing the fit of items to an underlying construct, and (3) estimating reliability and the number of performance strata that can be distinguished in a sample. Discussions about the utility of rating scale analysis applied to rehabilitation and outcomes measurement can be found in recent publications. 36-41 By using rating scale analysis, 3 measures from the FIM item ratings were derived: (1) self-care (eating, grooming, dressing upper and lower body, bathing and toileting), (2) * The participating facilities were given the following options: (1) the researchers supplied a list of eligible patients (randomly selected from the entire eligible sample of a facility based on records stored at UDSMR, but not exceeding 300 patients per facility), the facility then provided the necessary information based on this list; or (2) the facility queried eligible patients from their data system and randomly selected a proportion from the list (eg, 10%, 30%, or the first 60 patients on the list). Most facilities preferred the second option; however, several facilities did use the list we supplied (ie, option 1). We adopted the UDS rules used for interrupted stay. We excluded patients with program interruption over 30 days because they would be counted as having a different admission when readmitted. In calculating therapy intensity, no adjustments were made for weekdays or weekends, because we did not specifically request such information (ie, if therapies were provided on weekends) from the facilities. The rating scale analysis procedures were described in details elsewhere; it is available from the authors on request. We conducted rating scale analyses in the following sequence: (1) with all items and all patients included (both admission and discharge ratings), (2) the motor items only, (3) motor items without bowel and bladder (due to large infits and outfits), (4) self-care items only, (5) mobility items only, and (6) cognition items only. In all analyses, we examined person and item distribution (ie, targeting), separation and reliability indexes, fit statistics, average category measures and step ordering, item hierarchy, and the principal component analyses.

FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen 1517 mobility (bed/wheelchair transfer, toilet transfer, tub/shower transfer; walking; stair locomotion), and (3) cognition (comprehension, expression, social interaction, problem solving, memory). All scales were transformed into 0 to 100 measures, with higher values indicating greater independence. Reliability estimates ranged from.87 to.91. A separate B & B measure was created using the bowel and bladder items (which were excluded early on in Rasch analyses because of high misfits); unfortunately, the reliability estimate for the measure was only.66. Consequently, we analyzed only self-care, mobility, and cognition measures, although we report average bowel and bladder measures at admission and discharge because they varied in patients across facility types and impairment groups. Data analysis strategies. Preliminary analyses revealed variations in average therapy intensity across facilities. However, the small facility sample limited our ability to detect facility-level effects. Consequently, we used multiple linear regression to test hypotheses and included dummy-coded variables to indicate facility type. We first calculated correlations to evaluate the extent to which colinearity among the predictor and independent variables might confound the unambiguous interpretation of results. For example, the correlation (with all 3 diagnoses included) was.67 between admission self-care and mobility,.52 between self-care and cognition, and.32 between mobility and cognition. We examined enhancer and suppressor effects by conducting a set of analyses for each dependent variable, first including all predictor variables then excluding 1 or more variables that were highly correlated. We omitted variables only when it was clear that they had an enhancer or suppressor effect. In analyses in which we had a reduced sample (eg, prediction of speech therapy intensity for patients who received SLT), we used a backward stepping procedure to eliminate nonsignificant variables to keep a minimum 10:1 ratio of cases to independent variables. Finally, we used natural logarithms to reduce skewness (therapy intensity, onset days, LOS), and dummy-coded categorical variables (impairment [by using orthopedic as reference group], facility type [by using nursing home as reference group], prior living arrangement [1 alone, 0 not alone], rehabilitation program interruption [1 yes, 0 no]). For the first hypothesis, natural logarithm of individual therapy intensity or intensity of all therapies combined was the dependent variable; individual domain gain was the dependent variable for the second hypothesis. All parametric analyses were conducted by using SPSS, b versions 8.0 or later. 42 RESULTS Facility and Patient Characteristics Patient records came from 3 subacute rehabilitation units located in general hospitals (n 284), 7 units in free-standing rehabilitation hospitals (n 492), and 10 units in free-standing SNFs (n 1200). Seven of the 20 participating facilities were from the Northeast, 5 from the Midwest, 2 from the South, 3 from the Rocky Mountain region, and 3 from the West. Fifteen facilities (75%) were accredited by the Joint Commission on the Accreditation of Healthcare Organizations, 9 (45%) by the Commission on Accreditation for Rehabilitation Facilities, 8 by both, and 5 by neither. The number of subacute beds ranged from 10 to 80 in 1997, with per diem rates ranging from $150 to $1064. The average OT, PT, and SLT full-time equivalents were 5.1 (range, 1.5 11), 5.4 (range, 2 12.5), and 1.3 (range, 0.5 6.9), respectively. Among patients with stroke (n 554), 44% had a right cerebrovascular accident (CVA; with left hemiplegia or hemiparesis), 35% had a left CVA, 3% had bilateral involvement, and 18% were not specified. Among patients with orthopedic impairments (n 1124), 29% were posthip fracture, 19% had hip replacement, 23% were postknee replacement, and 19% were coded other. Debility is a new impairment category without subcategories defined by the Guide for the Uniform Data Set for Medical Rehabilitation. It includes patients who had general weakness or who were debilitated for reasons other than cardiac or pulmonary conditions. 31(pA15) Tables 2 and 3 provide a summary of patients demographic and clinical characteristics by impairment and facility type. Patients admitted to free-standing SNFs (ie, nursing homes) had higher self-care, cognition, and bowel and bladder function than patients admitted to acute or rehabilitation hospitals. Tables 2 and 3 also showed that patients made more gains in physical than cognitive function during subacute rehabilitation. Hypothesis 1 Hypothesis 1 is that therapy intensity depends on patients primary impairment and is predicted by patients functional status at admission. First, we examined the prediction of intensity of all therapies. We use total intensity to denote the intensity of OT, PT, SLT combined. Total and combined are used interchangeably. With all patients included, 10% of the variance was explained by the predictors (age, gender, impairment type, functional measures at admission, onset days, prior living arrangement, program interruption, facility type) (F 12,1638 16.96, P.0001). Greater total intensity was predicted for patients with stroke impairment (orthopedic as reference group), lower self-care, higher cognition at admission, and who received care in facilities other than rehabilitation hospitals. Next, we conducted separate regression analyses by impairment to predict intensity of combined therapies as well as separate OT, PT, and SLT intensities (table 4). As mentioned earlier, multiple analyses were performed for each dependent variable to evaluate the enhancer and suppressor effect and to guide the final inclusion of independent variables for each analysis. Stroke patients who did not live alone and who received care in an SNF or general hospital (rather than a free-standing rehabilitation hospital) tended to receive more combined therapies (table 4, column A). Orthopedic patients tended to receive more rehabilitation therapies if they were admitted with lower self-care, higher mobility, and higher cognition, if they were admitted sooner after their disability, and if they received care in an SNF or a general hospital (table 4, column E). Patients with debility tended to receive more therapies if they were admitted with lower self-care and higher cognition, if their rehabilitation stay was not interrupted, and if they received subacute rehabilitation in a general hospital (table 4, column I). The prediction of individual therapy intensities differed depending on impairment. Variance explained by the models ranged from 6% to 27%. In general, free-standing SNFs offered greater therapy intensity and free-standing rehabilitation hospitals offered less therapy intensity. In stroke patients, lower cognition at admission (table 4, column D) predicted greater speech intensity; greater self-care and lower mobility predicted greater PT intensity (table 4, column C). In orthopedic patients, younger age, shorter onset to rehabilitation admission, and greater mobility and cognition at admission predicted greater PT intensity, whereas older age, lower self-care, and higher cognition at admission predicted greater OT intensity (table 4, column G). In summary, the first hypothesis was partially supported. The variances explained by the predictors were small. The predic-

1518 FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen Table 2: Patient Characteristics by Impairment and Total Sample Stroke (n 554) Orthopedic (n 1124) Debility (n 298) Total Sample (N 1976) Age at admission (y) 75 11 76 12 81 10 76 12 (29 101) (22 101) (26 101) (22 101) Onset (d) 15 19 8 13 12 12 10 15 (0 196) (0 279) (0 118) (0 279) LOS (d) 25 18 19 12 17 10 21 14 (5 150) (5 97) (5 69) (5 150) Self-care measures* Admission 38 19 50 14 49 19 46 17 (0 100) (0 100) (0 100) (0 100) Discharge 56 23 74 17 68 21 68 21 (0 100) (0 100) (0 100) (0 100) Gain 18 14 24 14 19 14 22 15 ( 35 to 63) ( 6 to 73) ( 13 to 62) ( 35 to 73) Mobility measures* Admission 18 13 20 9 22 10 20 11 (0 92) (0 63) (0 75) (0 92) Discharge 35 19 45 15 42 17 42 17 (90 100) (0 100) (2 100) (0 100) Gain 17 12 25 13 20 13 22 13 ( 16 to 67) ( 19 to 66) ( 23 to 68) ( 23 to 68) Cognition measures* Admission 55 23 82 21 74 20 73 25 (0 100) (0 100) (14 100) (0 100) Discharge 63 22 86 19 78 19 79 22 (90 100) (0 100) (2 100) (0 100) Gain 9 11 4 9 4 11 6 10 ( 31 to 66) ( 31 to 67) ( 98 to 38) ( 98 to 67) Bowel & bladder measures* Admission 36 33 54 29 53 34 48 32 (0 100) (0 100) (0 100) (0 100) Discharge 56 34 78 26 67 32 70 31 (0 100) (0 100) (0 100) (0 100) Gain 21 25 24 24 14 23 22 25 ( 5 to 100) ( 66 to 100) ( 72 to 100) ( 85 to 100) NOTE. Values are mean SD (range). * These are Rasch-transformed measures; range, 0 (total dependence) to 100 (total independence). tion of therapy intensity depended on impairment, facility type, and, to a lesser extent, functional status at admission. We summarized the means and standard deviations (SDs) of individual and combined therapy in table 5 to gain a better understanding in service provision across facility types. Figure 1 displays the distribution of average daily units (15min units) of total therapies, arranged within type, from low to high across facilities. As noted, great variations existed in the provision of rehabilitation therapies among facilities. SNFs tended to provide the highest amount of total rehabilitation therapies, whereas rehabilitation hospitals provided the lowest. Hypothesis 2 Hypothesis 2 is that greater functional gains are related to lower functional status at admission, longer rehabilitation duration, and more intense therapy and are not related to patient demographic or medical characteristics. First, we used a general linear model multivariate procedure to evaluate the equivalence of gains in self-care, mobility, and cognition across impairment groups, with LOS as a covariate and the Bonferroni test for post hoc comparisons. Significant differences were found (F 6,3936 43.47, P.0001). The main effects for impairment (F 6,3936 9.14) and LOS (F 3,1968 20.76) were significant; the interaction between LOS and impairment group was not (F 6,3936 1.90). Consequently, we examined the relationships between functional gains, intensity of therapy, and LOS within each impairment group by using multiple linear regression analyses, controlling for age, gender, admission functional status, onset to admission interval, program interruption, and facility type. We present only the results for total therapies in table 6 but highlight the contribution of individual therapies when they differed. Functional Gains in Patients With Stroke Variances explained by the predictors ranged from 20% to 24%. Patients made larger self-care gains (table 6, column A) if they had lower self-care, higher mobility and cognition function at admission, longer stays, did not have an interrupted stay, received more intense therapies, and did not receive care in a rehabilitation hospital. Patients made larger gains in mobility (table 6, column B) if they were younger, admitted sooner after their impairment, admitted with lower mobility but higher self-care and cognition measures, had longer stays with no interruptions, and did not receive care in a rehabilitation hospital.

FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen 1519 Table 3: Patient Characteristics by Subacute Rehabilitation Facility Type General Hospital (n 284) Free-Standing Rehabilitation Hospital (n 492) Nursing Home Based Free-Standing SNF (n 1200) Female gender (%) 62 65 67 Impairment (%)* Stroke 47 40 18 Orthopedic 47 45 64 Debility 6 15 17 Interrupted program (%) 0 3 2 Admit from (%)* Community 25 2 1 Acute unit 69 97 99 Pre-rehab living setting (%) Home 72 96 95 Other 28 4 5 Discharge setting (%) Community 75 73 82 Nursing home 13 15 13 Comprehensive rehab 4 4 1 Other 8 8 4 Primary payer (%) Medicare 48 77 84 Indemnity 41 9 6 HMO 3 1 6 Other/missing 8 13 4 Mean age SD (y) 73.2 13.2 74.6 13.7 77.9 9.9 Mean LOS SD (d) 17 12 19 12 22 15 Mean onset SD (d) 10 18 14 20 9 11 Self-care Median (IQR) Admission 44.2 (32.2 50.8) 47.4 (37.7 56.3) 50.8 (40.9 56.3) Discharge 60.6 (44.2 72.9) 65.2 (50.8 75.8) 75.8 (58.4 86.8) Gain 15.5 (8.0 24.3) 17.4 (9.6 26.2) 24.0 (12.2 34.8) Mobility Admission 21.4 (11.2 27.2) 21.4 (13.8 26.4) 19.5 (13.9 24.7) Discharge 36.5 (26.4 6.8) 38.3 (28.0 47.2) 44.3 (34.7 57.6) Gain 17.1 (9.1 24.0) 16.3 (10.1 24.7) 24.7 (15.7 34.6) Cognition Admission 63.7 (44.6 92.9) 66.6 (48.4 84.7) 84.7 (63.7 99.7) Discharge 69.6 (52.1 99.7) 75.9 (58.9 98.2) 91.1 (72.1 99.7) Gain 2.6 (0 8.5) 5.9 (0 15.4) 0 (0 7.1) Bowel & bladder Admission 33.5 (13.3 66.4) 33.5 (13.3 50.4) 66.4 (33.45 85.4) Discharge 66.4 (24.5 100) 66.4 (41.4 100) 85.4 (66.4 100) Gain 11.2 (0 33.62) 25.9 (0 49.62) 16.9 (0 33.62) Abbreviations: rehab, rehabilitation; HMO, health maintainence organization; IQR, interquartile range. * Percentages do not always add to 100% because of rounding. Medians reported here are based on Rasch-transformed measures (range, 0 100). For cognitive gains, we completed separate analyses for the entire stroke sample and for the subset that received speech language therapy. Patients made greater cognitive gains if they were younger, female, admitted with lower cognitive and higher selfcare function, and had longer stays. Intensity of all therapies (table 6, column C) was related to cognitive gains in the entire sample, though speech therapy intensity was not related to cognitive gains in the subset that received SLT (not shown).* Functional Gains in Patients With Orthopedic Impairments Variances explained by the predictors ranged from 22% to 33%. Similar to the results for the stroke sample, admission functional status was inversely related to gains (ie, lower self-care at admission predicted greater self-care gains). Younger age, longer LOS, shorter onset-to-admission intervals, and uninterrupted stays also predicted larger self-care and * Separate analyses were conducted to examine cognitive gains in patients who received speech therapy in each of the impairment groups. However, we decided not to include these analyses in table 6 because of space limitation. Moreover, cognitive gains were not significantly predicted by speech therapy intensity after controlling for other variables.

1520 FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen Table 4: Prediction of Therapy Intensity by Impairment* Stroke (n 554) Orthopedic (n 1124) Debility (n 298) Combined OT PT SLT Combined OT PT SLT Combined OT PT SLT A B C D E F G H I J K L Admission self-care.26.16.11.17.25.19 Admission mobility.34 Omit.10.13 Omit Omit Omit Admission cognition.11.23.25.36.11.15.19 Age.11.11 Omit Female Omit Live alone.10.09.11 Omit Onset days.11.14 Omit Interrupted stay.12.13.13 Omit Facility type General hospital.26.08.11.32.15.15.40 Rehabilitation hospital.36.24.29.42.18.22.50.22.19.39 Adjusted R 2.11.09.19.14.12.11.12.27.14.09.06.17 F 6.79 5.30 11.44 7.39 13.72 12.44 14.26 5.70 4.84 3.41 2.46 3.44 df 10,438 10,438 10,438 9,353 10,961 10,961 10,961 9,105 10,219 9,220 10,219 4,45 P.0001.0001.0001.0001.0001.0001.0001.0001.0001.001.008.015 * The standardized regression coefficient ( ) is reported, all significant at P.05. P.06. We report this value for ease of comparison. Only patients who received speech language therapy were included in the regression analyses (n cva 362, n ortho 114, n debility 50). Variable was omitted: (1) when it had an enhancer or suppressor effect or (2) when the sample was reduced (see column L). To maintain a 10:1 sample to variable ratio, we omitted variables not significantly related to the dependent variable. mobility gains. More intense therapies predicted greater gains in self-care (table 6, column D) but not in mobility (table 6, column E). Cognitive gains were predicted by lower cognition at admission, more intense therapies, longer LOS, and care delivered in a rehabilitation hospital. The intensity of all therapies (table 6, column F) was related to cognitive gains in the entire sample, although the intensity of speech therapy was not related to cognitive gains in the subset that received SLT (not shown). Functional Gains in Patients With Debility Variances explained by the predictors ranged from 12% to 19%. Similar to the analyses for stroke and orthopedic samples, gains were inversely related to admission functional status. Longer LOS was significantly related to larger gains in selfcare and mobility. Greater cognitive gains were predicted by lower admission cognition, more intense therapy, and receiving care in a rehabilitation hospital. In the subset of patients who received speech therapy, neither speech therapy alone nor combined therapies significantly predicted cognitive gains. In summary, we found partial support for the second hypothesis: functional gains were more consistently related to admission functional status and LOS and less consistently to therapy intensity. DISCUSSION The study was designed to document patterns and characteristics of subacute rehabilitation service provision. The research questions were (1) What variables predict therapy intensity? and (2) Do patients make functional gains during subacute rehabilitation? If so, are functional gains related to intensity of rehabilitation therapies and LOS? In response to the first question, we found that therapy intensity depends on patients impairment type and admission function. However, it is puzzling that variances in therapy Table 5: Rehabilitation Therapy Intensity by Facility Type Intensity (min/d) Facility Type OT PT SLT Combined General hospital 41 16 47 19 11 14 100 34 (n 3) Rehab hospital 36 13 41 15 8 13 85 28 (n 7) SNF (n 10) 40 27 58 30 5 16 104 52 NOTE. Values are mean SD. Fig 1. Distribution of daily therapy intensity (in 15-min units) for subacute units within general hospitals (A1 A3); within rehabilitation hospitals (R1 R7); and within SNF (S1 S10). The boxes indicate interquartile ranges; lines within the boxes indicate medians; and the whiskers indicate the minimums and maximums. Abbreviation: SP, speech therapy.

FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen 1521 Table 6: Prediction of Functional Gains by Impairment* Stroke Orthopedic Debility SC Mobility Cognitive SC Mobility Cognitive SC Mobility Cognitive A B C D E F G H I Admis self-care.47.31.13.46.11 NS.43.35 NS Admis mobility.38.14 NS.11.20 NS.25.23 NS Admis cognition.38.17.44.42.31.50.21.20.44 Therapy intensity.08 NS.19.12 NS.20 NS NS.16 Age NS.10.08.08.06 NS NS NS NS Female NS NS.10 NS NS NS.11 NS NS LOS.23.18.25.23.16.15.20.16 NS Onset days.10.10 NS.05.09 NS NS NS NS Interrupted stay.09.11 NS NS.06 NS.11 NS NS Facility type Acute hospital.15.16.10.14.12 NS NS NS NS Rehab hospital.12.20 NS.09.14.18 NS NS.16 Adjusted R 2.21.20.24.33.22.26.18.12.19 F 14.42 13.30 17.12 50.75 29.04 36.68 6.72 4.70 7.22 df 11,540 11,540 11,540 11,1109 11,1109 11,1109 11,286 11,286 11,286 P.0001.0001.0001.0001.0001.0001.0001.0001.0001 Mean gain 17.83 17.10 8.96 24.34 25.42 4.25 18.81 20.17 4.25 SD 14.17 12.22 10.53 14.29 13.00 8.82 14.44 13.35 10.66 Abbreviation: SC, self-care; Admis, admission; NS, not significant. * The standardized coefficient ( ) is reported at the P.05 level. intensity (ie, R 2 ) explained by the set of predictors were so small, consistent with previous research. 30 Like earlier research, the results suggest that what determines therapy intensity is largely unknown. Moreover, no consistent patterns exist in the prediction of therapy intensities. Although lower selfcare and higher cognitive function at admission predict greater total therapy intensity in the orthopedic and debility groups, it is not the case for the stroke sample. In the latter, none of the admission functions significantly predicted therapy intensities. Perhaps colinearity among variables or a lack of variability in the dependent variable (ie, amount of therapy received among stroke patients) caused the phenomenon lack of significance. Preadmission living arrangement was related to OT, PT, and combined therapy intensity in stroke patients. Perhaps social support prior to rehabilitation admission helps the rehabilitation team anticipate patients potential discharge environments and their likelihood of returning to the community. This, in turn, might have indirectly influenced the team s decision to provide more intense therapy in order to facilitate rehabilitation gains. Alternatively, those who live with the stroke patients might have been effective advocates for greater therapy intensity for their families, relatives, and friends. Answers to the second research question (ie, Do patients make functional gains during rehabilitation and, if so, are larger gains predicted by greater therapy intensity and longer LOS?) are neither simple nor straightforward. Some patients had long rehabilitation stays and received a great amount of therapy but did not improve, whereas others did. But overall, patients improved functions during rehabilitation. Gains were not equal across domains or impairment groups. Patients made smaller gains in cognition than self-care and mobility*; patients with * This is possibly because of a ceiling effect. Fifty-seven percent of our sample had orthopedic impairments. Many of them had mild or no cognitive deficits mean admission cognition for the orthopedic group was 82 out of 100 (vs 73, mean cognition measure of the total sample) (table 2). orthopedic impairments made larger gains in self-care and mobility than patients with stroke and debility impairments. The next question was: What predicts functional gains? Although admission function, LOS, and therapy intensity all contributed to gains, greater therapy intensity and longer LOS do not always predict larger gains. Our analyses showed that, within each impairment group, gains in self-care were greatest for those who had deficits in self-care on admission and among those who had resources in other 2 domains, that is, mobility and cognition. Having resources in other areas, such as having intact cognition at admission, promoted larger self-care and mobility gains across impairment groups. Our results are consistent with previous research 24 on the role cognition plays in functional improvement. Striking facility differences existed with regards to case-mix, provision of therapies, patient LOS, and patient functional gains. Free-standing SNFs provided considerably more PT and total therapy but less speech language therapy than did rehabilitation hospitals. Patients in SNFs stayed longer and made larger gains in self-care and mobility than did patients receiving care in other settings. SNFs admitted more orthopedic patients and had the largest proportion of patients with Medicare as primary payers. These unexpected findings deserve further investigation. Are the larger gains in SNF patients a result of greater therapy intensity and longer LOS or a result of less impairment and/or fewer complex rehabilitation needs (ie, higher cognitive, bowel, and bladder function at admission)? Are all units of therapy indicative of direct treatments, or do they include services that were not otherwise covered in the per diem rates, such as patient and family education or team meetings? Does the provision of more therapy and longer LOS reflect reimbursement incentives or lower operating costs (than hospitals)? It is important but challenging to disentangle the relationships between case mix, patient needs, reimbursement mechanisms, LOS, and functional gains. After passage of the BBA, SNFs received a flat rate for individuals admitted as Medicare Part A patients; Part B ther-

1522 FUNCTIONAL GAIN AND THERAPY INTENSITY, Chen apy costs were capped at $1500 per resident with the intention to curb unnecessary therapy services. Although the reimbursement restrictions might not be the only cause, several large, for-profit SNFs have filed for bankruptcy since 1998. In response to the outcry of the SNF industry and patient advocates, Congress made adjustments to the law (in 1999, Balanced Budget Refinement Act; in 2000, Benefits Improvement and Protection Act), and increased payment rates for SNFs in selected resource utilization group (RUG) categories, including 3 RUGs in the special rehabilitation category. Congress also lifted the restrictions on rehabilitation therapies, and instituted a moratorium on Part B therapy caps in 2000 and 2001, which was subsequently extended through 2002. Although there is no clear evidence in the government reports to show that spending controls caused residents to lose access to rehabilitation therapies, there is some evidence showing SNF patients received fewer Part B therapies. 43,44 More research is needed to examine the impact of reimbursement-rule changes on therapy provision in SNFs and other facilities. Study Limitations Our data were not fine-grained enough to provide details about the nature (eg, group vs individual) or quality of therapy services. Although intensity of therapy is an objective way to measure rehabilitation dose, intensity alone does not capture the essence of rehabilitation. This might explain why the variance in therapy intensity was so small. Future studies should measure these important but difficult to quantify characteristics of rehabilitation care. Several methodologic shortcomings may limit the generalizability of the results including a self-selected sample, varied sample sizes across impairments and facilities, and unequal representation of facility types and geographic regions. Although we took great pains to avoid colinearity, many variables in the analyses correlated. These issues should be taken into account when interpreting the results. CONCLUSION Case mix in terms of proportion of patients with specific impairments, functional status of patients at admission, and therapy service provision varied widely across types of subacute settings. Most patients made functional gains during rehabilitation. Therapy intensity was mostly related to impairment and facility type and somewhat related to functional status at admission. Lower admission functional status, longer LOS, and more intense therapy predicted greater functional gains. However, the relationships differed across domains and impairment groups. Decisions about venues of care and amount of services for rehabilitation patients ought to be based on patients needs, facilities ability to provide services, and costs associated with care in different venues. Our study suggests that although greater flexibility in terms of minimum therapy requirements (therapy type, intensity) allows clinicians to plan and provide needed therapy services, different payment policies might have provided different billing incentives. When those allowances became more stringent, facilities quickly abandoned subacute care, and patients needing such care may suffer as a result. The results of this study can help guide policy discussions regarding prospective payment, minimum therapy requirements, and venues for rehabilitation. Acknowledgments: We thank Dr. Yow-Wu Wu for his statistical consultation, Drs. David Nelson, Stephen Mennemeyer, and Rita Bode for their comments on an earlier version of the manuscript. 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