Roger C. Fiedler

The reliability of the functional independence measure: A quantitative review

OBJECTIVE The reliability of the Functional Independence Measure (FIMSM) for adults was examined using procedures of meta-analysis. DATA SOURCES Eleven published studies reporting estimates of reliability for the FIM were located using computer searches of Index Medicus, Psychological Abstracts, the Functional Assessment Information Service, and citation tracking. STUDY SELECTION Studies were identified and coded based on type of reliability (interrater, test-retest, or equivalence), method of data analysis, size of sample, and training or experience of raters. DATA EXTRACTION Information from the articles was coded by two independent raters. Interrater reliability for coding all elements included in the analysis ranged from .89 to 1.00. DATA SYNTHESIS The 11 investigations included a total of 1,568 patients and produced 221 reliability coefficients. The majority of the reliability values (81%) were from interrater reliability studies, and the intraclass correlation coefficient (ICC) was the most commonly used statistical procedure to compute reliability. The reported reliability values were converted to a common correlation metric and aggregated across the 11 studies. The results revealed a median interrater reliability for the total FIM of .95 and median test-retest and equivalence reliability values of .95 and .92, respectively. The median reliability values for the six FIM subscales ranged from .95 for Self-Care to .78 for Social Cognition. For the individual FIM items, median reliability values varied from .90 for Toilet Transfer to .61 for Comprehension. Median and mean reliability coefficients for FIM motor items were generally higher than for items in the cognitive or communication subscales. CONCLUSIONS Based on the 11 studies examined in this review the FIM demonstrated acceptable reliability across a wide variety of settings, raters, and patients.

The Functional Independence Measure: Tests of Scaling Assumptions, Structure, and Reliability Across 20 Diverse Impairment Categories

OBJECTIVE The analysis presented here evaluated the psychometric properties of the Functional Independence Measure (FIM) as a summated rating scale within context of the 20 impairment categories of the FIM-Function Related Group (FIM-FRG) system. DESIGN This study involved a cross-sectional analysis of patient records, utilizing factor analysis and techniques of multitrait scaling to verify the summative properties of the motor and cognitive dimensions of the FIM and to study the statistical properties of admission FIM scores. PATIENTS Included were a total of 93.829 patients discharged from 252 freestanding rehabilitation hospitals and units during calendar year 1992. Cases were excluded that had missing or out-of-range values or atypical lengths of stay. These criteria were developed previously in conjunction with an expert clinical panel and confirmed through statistical analyses. RESULTS Factor analyses supported the motor and cognitive dimensions across all 20 impairment categories. The resulting subscales exceeded minimum criteria for item internal consistency in 96.9% of tests and item discriminant validity in 100% of tests. Reliability coefficients for each impairment category for both subscales ranged from .86 to .97. There were no major ceiling effects, but patients in certain impairment categories were unable to climb stairs at admission. CONCLUSION The psychometric properties of the summated FIM compare favorably to most standardized health measures used in medical practice. Findings provide support for the motor and cognitive subscales as used in the FIM-FRGs. As a unidimensional scale, the FIM quantifies care burden. Split into the motor and cognitive (as used in the FIM-FRGs) it distinguishes physical disabilities from those arising from communication or cognitive difficulties.

A Prediction Model for Functional Recovery in Stroke

BACKGROUND AND PURPOSE Stroke-related physical disability can diminish quality of daily living, place care burden on families, and increase need for long-term institutionalization. We developed a prognostic index for use in research and with potential for adaptation to clinical practice that establishes the likelihood of an individual achieving a specific stage of functional recovery after stroke rehabilitation. METHODS We constructed the index using logistic regression based on 3760 patient records from 96 rehabilitation facilities in 31 states. The stage, as measured by the Functional Independence Measure, includes achievement of the following: independence in eating, grooming, and dressing the upper body; continence in bowel and bladder; and transfer between a bed and chair with supervision only. RESULTS This stage was achieved by 26.1% of patients functioning below it at rehabilitation admission. Disability onset of less than 60 days was associated with more than a 3-fold increase in the likelihood of achieving the stage (adjusted odds ratio, 3.5; 95% confidence interval, 2.0 to 6.0). Each eight-point increase in an eight-item activities of daily living score, measured at admission to rehabilitation, increased the odds 2.5-fold (95% confidence interval, 2.3 to 2.8). For those living alone or employed before the stroke, the odds of achieving the stage increased by factors of 1.3 and 2.2, respectively. The index showed minimal shrinkage on cross validation. The achievement of this profile of function is important because 95.3% of stroke patients who achieved or exceeded it were discharged home, as opposed to only 66.8% of those who did not achieve it. CONCLUSIONS The index can be used to establish prognoses for individual stroke patients at admission to rehabilitation with regard to achieving this stage. Achievement of the stage is associated with a high likelihood of discharge to home.

Impairment-specific dimensions within the functional independence measure☆☆☆

OBJECTIVE The analyses presented in this article were intended to seek more fine-grained impairment-specific dimensions beyond the motor and cognitive dimensions of the Functional Independence Measure (FIMSM). DESIGN The study used factor analysis within 20 categories of impairment to test the hypotheses that FIM items can be grouped according to functional areas of the body and that these item groupings differ depending on the patients impairment. PATIENTS Data from 93,829 patients discharged in 1992 from 252 free-standing rehabilitation hospitals and units were obtained from the Uniform Data System for Medical Rehabilitation. RESULTS In 18 of 20 impairment categories, factor analyses of patients admission FIM scores showed impairment-specific FIM dimensions. Four impairments had a 3-dimensional factor structure, and 14 had a 4-dimensional structure. The impairment-specific dimensions were always nested within the motor-FIM subscale. Reliability coefficients for subscales based on these dimensions ranged from .74 to .97. The subscales appear to cluster FIM items by the area of body involved, neurological level, or relative energy consumption. CONCLUSION The FIM can be viewed as a multilayered multidimensional measure of human function. The impairment-specific dimensions, at an intermediate layer, provide insight about the causal linkage between the impairment and resultant patterns of disability. Impairment-specific subscales are relevant to those clinical or research applications where the type of disability needs to be more closely related to impairment.

Poststroke Rehabilitation: Outcomes and Reimbursement of Inpatient Rehabilitation Facilities and Subacute Rehabilitation Programs

Background and Purpose— To assess whether poststroke rehabilitation outcomes and reimbursement for Medicare beneficiaries differ across inpatient rehabilitation facilities (IRFs) and skilled nursing facility (SNF) subacute rehabilitation programs. Methods— Clinical data were linked with Medicare claims for 58 724 Medicare beneficiaries with a recent stroke who completed treatment in 1996 or 1997 in IRFs and subacute rehabilitation SNFs that subscribed to the Uniform Data System for Medical Rehabilitation. Outcome measures were discharge destination, discharge FIM ratings and Medicare Part A reimbursement during the institutional stay. Results— IRF patients that were more likely to have a community-based discharge, compared with rehabilitation SNF patients, were patients with mild motor disabilities and FIM cognitive ratings of 23 or greater (adjusted odds ratio [AOR]=2.19; 95% CI: 1.52 to 3.14), patients with moderate motor disabilities (AOR=1.98; 95% CI: 1.49 to 2.61), patients with significant motor disabilities (AOR=1.26; 95% CI: 1.01 to 1.57) and patients younger than 82 with severe motor disabilities (AOR=1.43; 95% CI: 1.25 to 1.64). IRF patients with significant and severe motor disabilities achieved greater motor function of 2 or more FIM units compared with rehabilitation SNF patients. Medicare Part A payments for IRFs were higher than rehabilitation SNF payments across all subgroups. Conclusions— For most patients, poststroke rehabilitation in the more costly and intensive IRFs resulted in higher functional outcomes compared with care in a SNF-based rehabilitation program. IRF and SNF outcomes were similar for patients with minimal motor disabilities and patients with mild motor disabilities and significant cognitive disabilities. Cost-effectiveness analyses require considering the costs of the full episode of care.

Comparison of logistic regression and neural networks to predict rehospitalization in patients with stroke

CONTEXT Rehospitalization following inpatient medical rehabilitation has important health and economic implications for patients who have experienced a stroke. OBJECTIVE Compare logistic regression and neural networks in predicting rehospitalization at 3-6-month follow-up for patients with stroke discharged from medical rehabilitation. DESIGN The study was retrospective using information from a national database representative of medical rehabilitation patients across the US. SETTING Information submitted to the Uniform Data System for Medical Rehabilitation from 1997 and 1998 by 167 hospital and rehabilitation facilities from 40 states was examined. PARTICIPANTS 9584 patient records were included in the sample. The mean age was 70.74 years (SD = 12.87). The sample included 51.6% females and was 77.6% non-Hispanic White with an average length of stay of 21.47 days (SD = 15.47). MAIN OUTCOME MEASURES Hospital readmission from 80 to 180 days following discharge. RESULTS Statistically significant variables (P <.05) in the logistic model included sphincter control, self-care ability, age, marital status, ethnicity and length of stay. Area under the ROC curves were 0.68 and 0.74 for logistic regression and neural network analysis, respectively. The Hosmer-Lemeshow goodness-of-fit chi-square was 11.32 (df = 8, P = 0.22) for neural network analysis and 16.33 (df = 8, P = 0.11) for logistic regression. Calibration curves indicated a slightly better fit for the neural network model. CONCLUSION There was no statistically significant or practical advantage in predicting hospital readmission using neural network analysis in comparison to logistic regression for persons who experienced a stroke and received medical rehabilitation during the period of the study.

Functional gain and length of stay for major rehabilitation impairment categories. Patterns revealed by function related groups.

This study evaluates the relationship of functional severity to patterns of functional gain and length of stay (LOS) for patients discharged from medical rehabilitation. It further compares differences in patterns between summed and Rasch transformed subscales of the Functional Independence Measure (FIM). Two different schemes of the FIM-Function Related Groups (FIM-FRGs) are used to define groups of patients who present with similar degrees of functional severity. The first scheme was developed using summed admission motor and cognitive FIM subscores (FIM-FRGs). The second scheme was developed by transforming these same motor and cognitive FIM subscores into logits (Logit FIM-FRGs), thus making FIM scores more equal-interval. The study included 32,494 patients who were discharged from 123 facilities that submitted data to the Uniform Data System for Medical Rehabilitation (UDSMR) and involved the separate evaluation of 18 different rehabilitation impairment categories. Motor FIM gain was calculated for each FRG in both schemes as the patients discharge motor FIM score minus the admission motor FIM score. There were four patterns of motor FIM gain and two patterns of LOS across rehabilitation impairment. The most common pattern in both schemes was linear trend, for which median gains and LOS were highest for patients in the most disabled FRGs and lowest for patients in the least disabled FRGs. Gain patterns differed across impairment and across the two schemes. The motor FIM gain distributions provide clinicians with a range of typical functional outcomes for patients admitted to medical rehabilitation. This descriptive approach provides clinicians and administrators with a simple way to compare the motor FIM gain and LOS patterns of patients teated in local facilities with broad-based norms. This sample includes about one-quarter of rehabilitation facilities nationwide, thus representing population standards for facilities participating in the UDSMR. Suggestions are made on how to use these norms most appropriately for both facility and patient comparison.

The Uniform Data System for Medical Rehabilitation report of patients discharged from comprehensive medical rehabilitation programs in 1999.

Deutsch A, Fiedler RC, Granger CV, Russell CF: The Uniform Data System for Medical Rehabilitation report of patients discharged from comprehensive medical rehabilitation programs in 1999. Am J Phys Med Rehabil 2002;81:133–142.This is the 10th annual report describing patients discharged from comprehensive medical rehabilitation programs in the United States that subscribe to the Uniform Data System for Medical Rehabilitation. The analysis included 298,973 complete records of first admission cases discharged alive from 676 facilities in 1999. The data show that patients receiving care in comprehensive rehabilitation programs show measurable functional improvement and that a high percentage of patients are discharged to community-based settings.

Outcomes and reimbursement of inpatient rehabilitation facilities and subacute rehabilitation programs for Medicare beneficiaries with hip fracture.

Objective:We sought to assess whether outcomes and reimbursement differ for Medicare beneficiaries with hip fracture when treated in an inpatient rehabilitation facility (IRF) compared with a skilled nursing facility (SNF) subacute rehabilitation program. Participants:Clinical data were linked with Medicare claims for 29,793 Medicare fee-for-service beneficiaries with a recent hip fracture who completed treatment in 1996 or 1997 in rehabilitation facilities that subscribed to the Uniform Data System for Medical Rehabilitation. Outcome Measures:We measured discharge destination, change in motor FIM™ rating, and Medicare Part A reimbursement. Results:For patients with moderate-to-severe and severe disabilities, case mix groups (CMGs) 704 and 705, the percentage of patients discharged to the community from IRFs was lower than for patients treated in subacute rehabilitation SNFs, after controlling for covariates. Adjusted odds ratios were 0.71 (95% confidence interval 0.55–0.92) for CMG 704 and 0.72 (95% confidence interval 0.63–0.83) for CMG 705. For patients in the 3 other CMGs, no significant differences were detected. Improvement in motor functional status was roughly equivalent for patients treated in IRFs and those treated in the subacute rehabilitation programs across all 5 CMGs, after controlling for covariates. Medicare Part A payments for IRFs were significantly higher than SNF payments across all CMGs. Conclusion:SNF-based subacute rehabilitation was less costly and outcomes were in most, but not all, instances similar or better than IRF-based rehabilitation for Medicare fee-for-service beneficiaries who had a recent hip fracture.

Discharge motor fim-function related groups

OBJECTIVE To develop a patient classification system that groups patients achieving similar functional outcome scores by discharge from medical rehabilitation. DESIGN Patient groups were developed using a recursive partitioning algorithm and clinical input. Results were validated in a separate set of patient records. SETTING Two hundred fifty-two free-standing rehabilitation hospitals and distinct part units that participate in the Uniform Data System for Medical Rehabilitation. PATIENTS The 84,492 rehabilitation inpatients discharged in 1992 were grouped into 20 impairment categories. MAIN OUTCOME MEASURE Discharge score on the motor subscale of the Functional Independence Measure (FIM). RESULTS In the Discharge Motor FIM-Function Related Groups (DMF-FRGs) system, patients are first classified into one of 20 impairment categories and then into FRGs by their admission motor FIM scores. Some FRGs are also subdivided on the basis of admission cognitive FIM scores and age. The entire system consists of 139 patient groups that explain 63% of the variation in motor FIM discharge scores in the validation data set. Nontraumatic brain injury and joint replacement DMF-FRGs are provided as examples. CONCLUSION Clinicians can use the DMF-FRGs to identify groups of patients whose motor FIM scores at discharge are below, within, or above nationally established ranges of values for the purpose of outcomes management, guideline development, and quality improvement. The DMF-FRGs can also be considered in the design of an outcome-based payment system for medical rehabilitation.