A case-mix classification system for medical rehabilitation

Dissatisfaction with Medicare's current system of paying for rehabilitation care has led to proposals for a rehabilitation prospective payment system, but first a classification system for rehabilitation patients must be created. Data for 36,980 patients admitted to and discharged from 125 rehabilitation facilities between January 1, 1990, and April 19, 1991, were provided by the Uniform Data System for Medical Rehabilitation. Classification rules were formed using clinical judgment and a recursive partitioning algorithm. The Functional Independence Measure version of the Function Related Groups (FIM-FRGs) uses four predictor variables: diagnosis leading to disability, admission scores for motor and cognitive functional status subscales as measured by the Functional Independence Measure, and patient age. The system contains 53 FRGs and explains 31.3% of the variance in the natural logarithm length of stay for patients in a validation sample. The FIM-FRG classification system is conceptually simple and stable when tested on a validation sample. The classification system contains a manageable number of groups, and may represent a solution to the problem of classifying medical rehabilitation patients for payment, facility planning, and research on the outcomes, quality, and cost of rehabilitation.     

Application of functional independence measure-function related groups and resource utilization groups-version III systems across post acute settings

OBJECTIVES: The present study evaluated alternative patient classification systems for skilled nursing facility and rehabilitation facility patients. METHODS: Medicare patients were selected from a random sample of 27 rehabilitation facilities and 65 skilled nursing facilities participating in a national longitudinal study of subacute care. Detailed casemix and resource use data was obtained on 513 patients with hip fracture and 483 stroke patients. The Functional Independence Measure-Function Related Groups (FIM-FRGs) classification system for rehabilitation facilities was replicated on length of stay and tested on resource use for rehabilitation facility patients as well as for skilled nursing facility patients. Modifications to the FIM-FRGs also were tested. The Resource Utilization Groups-Version III classification was tested on rehabilitation facility patients. RESULTS: The FIM-FRGs explained the same amount of variance in length of stay as in the original FIM-FRGs development sample (R2 hip fracture = 0.14, R2 stroke = 0.28), and similar variance in resource use. A modified version of the FIM-FRGs explained more variance in length of stay (R2 hip fracture = 0.19, R2 stroke = 0.39) and resource use (R2 hip fracture = 0.20, R2 stroke = 0.41). Neither model adequately predicted length of stay or resource use in skilled nursing facility patients. The Resource Utilization Groups-Version III rehabilitation groups accounted for little variance in rehabilitation facility patients' per-diem resource use (R2 = 0.11). CONCLUSIONS: The FIM-FRGs are valid for resource use as well as length of stay for rehabilitation facility patients, but are not valid for skilled nursing facility patients. Similarly, the Resource Utilization Groups-Version III system does not apply to rehabilitation facility patients. Related work, however, suggests that development of a single episode-based patient classification system for skilled nursing facility and rehabilitation facility patients is possible and should be pursued.     

A comparative study of postmortem MR imaging and pathological examination of human brain specimens

OBJECTIVE: To determine typical outcome "benchmarks" for 18 functional tasks in patients undergoing stroke rehabilitation. The benchmarks are intended to serve as points of reference to which the outcomes of patients with similar impairments and degrees of disability can be compared. SUBJECTS: Records from 26,339 stroke patients discharged from 252 inpatient facilities across the United States that submitted 1992 data to the Uniform Data System for Medical Rehabilitation. METHODS: Stroke impairment was detailed as the presence or absence of hemiparesis resulting from stroke and the side(s) of involvement. Within each of five stroke impairment categories, patients were further classified by the Functional Independence Measure-Function-Related Groups (FIM-FRGs) into nine syndromes by degree of disability (admission motor and cognitive FIM scores) and by age. Outcomes were determined for each stroke syndrome at patients' discharge from medical rehabilitation. MAIN OUTCOME MEASURES: Patients' median performance levels on each of the 18 items making up the FIM, length of stay, and community discharge rates. RESULTS: The majority of patients whose admission motor FIM scores were above 37 were able to eat, groom, dress the upper body, and manage bladder and bowel functions independently by discharge. In addition to these tasks, most of those whose motor FIM scores were above 55 were able to dress the lower body, bathe, and transfer onto a chair/bed or toilet. The majority of patients whose initial motor FIM scores were above 62 points and whose cognitive FIM scores were above 30 gained independence in most tasks, including stair climbing and tub transfers. Community discharge rates ranged from 51.6% for the group of patients with the most severe disabilities to 99.2% for the group with the least severe disabilities. CONCLUSION: The clinician can apply these benchmarks to guideline development and quality improvement, and in establishing patient goals.     

Discharge destination and motor function outcome in severe stroke as measured by the functional independence measure/function-related group classification system

OBJECTIVES: Function-related groups based on the Functional Independence Measure have been proposed as a model for a prospective payment system for medical rehabilitation. This study describes discharge destination and motor function outcomes in a sample of patients with stroke from the FIM-FRG STR1 classification. STUDY DESIGN: A retrospective review of 293 cases of stroke from the years 1993 to 1995. The demographic and outcome characteristics of this sample were described. RESULTS/CONCLUSIONS: Forty-five percent of the patients were discharged to home after a mean length of stay of 23.8 days in acute medical rehabilitation. Patients who were discharged home had higher admission and discharge motor FIM scores than those discharged to a subacute facility or long-term care facility, although the correlation between motor FIM score and discharge destination was low to moderate. Median discharge motor FIM scores indicate considerable residual disability in this classification after rehabilitation. Research problems that address methods to improve the usefulness of the FIM-FRG system in a prospective payment system are discussed.     

Prospective payment per case and length of stay at coordinated private hospitals

BACKGROUND: In 1991 the Valencian Health Service (SVS) introduced a system of prospective payment per process to reimburse some surgical interventions to coordinated private hospitals which, until then, had invoiced by retrospective payment per hospital stay. The impact of this change on the mean length of stay in seven groups of surgical interventions is evaluated. METHODS: Retrospective analysis of the mean stay of 2025 admissions in private hospitals coordinated under both systems of payment (payment per process 66%, October 91 to February 92; payment by stay 64%, March 91 to February 92) for seven groups of surgical procedures: cataract surgery, cholecystectomy, hernioraphy, prostate resection, tonsillectomy-adenoidectomy, varicose vein and proctologic procedures was carried out. RESULTS: Mean hospital stay decreased (mean = 5.4 days; p < 0.001) in all the groups reimbursed under PRP (from 72% in proctologic conditions to 43% for adenoidectomy-tonsillectomy) avoiding 8727 stays. The coinciding period under both systems demonstrated a decrease of mean hospital stay similar to the total period. CONCLUSIONS: The coordinated hospitals demonstrated a surprisingly rapid capacity to modify their organizative behaviour or influence the styles of clinical practice or both to adopt the patterns of length of stay which optimize profits according to the system of payment used by the SVS.     

Functional status outcomes in rehabilitation. Implications for prospective payment

Previous studies have demonstrated that functional status is a significant predictor of resource utilization for rehabilitation patients. Before implementing a prospective payment system (PPS) for rehabilitation, it is important to first: 1) develop an underlying conceptual framework of rehabilitation resource use; and 2) understand how the role of functional status may vary by rehabilitation condition. In this study, a theoretical model of rehabilitation is presented that proposes relationships between patient and provider characteristics, rehabilitation treatment, costs, and clinical outcomes of rehabilitation. Also presented are regression analyses based on this model for a key outcome of rehabilitation, change in functional status, for nine rehabilitation conditions using variables that minimize adverse incentives by providers in selecting patients for admission to rehabilitation. The change-in-functional-status model explained the most variance for back injury, cardiopulmonary, and arthritis, and less variance for stroke, spinal cord injury, and neurologic impairment. The significant predictors of change in functional status varied by condition. Results support the use of functional status measurements in a PPS for rehabilitation services, the need to refine the measurement of functional status, and the use of condition-specific activities of daily living (ADL) items to include in summary indices.     

The effect of Medicare's payment system for rehabilitation hospitals on length of stay, charges, and total payments

BACKGROUND: Medicare's system for the payment of rehabilitation hospitals is based on limits derived from a hospital's average allowable charges per patient discharged during a base year. Thereafter, payments are capped but hospitals receive incentive payments if charges per patient are reduced in succeeding years. We hypothesized that per-patient charges would increase during the base year and then decrease in subsequent years. Hospitals would thus have higher reimbursement limits and receive incentive payments for reducing their charges. METHODS: We analyzed Medicare claims data for 190,921 discharges from 69 rehabilitation hospitals from 1987 through 1994. We compared total charges, length of stay, and interim payments before, during, and after each hospital's base year. RESULTS: After we controlled for inflation and temporal and seasonal trends, mean charges per patient discharged increased from $25,131 for patients discharged before the base year to $32,167 for patients discharged in the base year (a 28 percent increase, P<0.001) and the mean length of stay increased from 22.1 to 26.7 days (a 21 percent increase, P<0.001). After the base year, mean charges decreased to $29,307 (a 9 percent decrease) and the mean length of stay decreased to 24.0 days (a 10 percent decrease) (P<0.001 for both comparisons). Analysis of data on patients according to diagnosis -- for example, spinal cord injury, brain injury, stroke, amputations and deformities, hip fracture, and arthritis and joint disorders -- showed similar findings for each, with increases in charges and length of stay in the base year, followed by smaller reductions thereafter. For-profit hospitals had greater increases than nonprofit hospitals in their per-patient charges (mean increase, $7,434 vs. $2,929; P<0.001) and length of stay (mean increase, 4.6 vs. 2.3 days, P<0.001) during the base year. CONCLUSIONS: Although Medicare's reimbursement system for rehabilitation hospitals put an upper limit on total payments, its design was associated with substantial extra costs, including significantly increased payments to hospitals and doctors and increased numbers of hospital days for the average patient.     

Functional outcome after brain tumor and acute stroke: a comparative analysis

OBJECTIVE: To compare the functional outcome, length of stay, and discharge disposition of patients with brain tumors and those with acute stroke. DESIGN: Case-controlled, retrospective study at a tertiary care medical center inpatient rehabilitation unit. SUBJECTS: Sixty-three brain tumor patients matched with 63 acute stroke patients according to age, sex, and location of lesion. MAIN OUTCOME MEASURES: The functional independence measure (FIM) was measured on admission and discharge. The FIM change and FIM efficiency were also calculated. The FIM was analyzed in three subsets: activities of daily living (ADL), mobility (MOB), and cognition (COG). Discharge disposition and rehabilitation length of stay were compared. RESULTS: Demographic variables of race, marital status, and payer source were comparable for the two groups. No significant difference was found between the brain tumor and stroke populations with respect to total admission FIM, total discharge FIM, change in total FIM, or FIM efficiency. The admission MOB-FIM was found to be higher in the brain tumor group (13.6 vs 11.1, p = .04), whereas the stroke group had a greater change in ADL-FIM score (10.8 vs 8.3, p = .03). The two groups had similar rates of discharge to community at greater than 85%. The tumor group had a significantly shorter rehabilitation length of stay than the stroke group (25 vs 34 days, p < .01). CONCLUSION: Brain tumor patients can achieve comparable functional outcome and rates of discharge to community and have a shorter rehabilitation length of stay than stroke patients.     

Impact of an all-inclusive diagnosis-related group payment system on inpatient utilization

OBJECTIVES: Although case-based payment is one of the main reimbursement mechanisms for hospitals, little is known about its effects in the general population. Prior studies have focused on Medicare or on all-payer systems in particular states. This study estimates the effect of a prospective payment system based on diagnosis-related groups (DRGs) nationwide in the Department of Veterans Affairs. METHODS: Multiple regression analysis was used to estimate the effect of Department of Veterans Affairs's diagnosis-related group system separately for 22 diagnoses. The dependent variables were length of stay, inpatient days per patient, and discharges per patient. Covariates included patient, hospital, and area characteristics. RESULTS: Department of Veterans Affairs's diagnosis-related group system reduced lengths of stay and inpatient days per patient. The largest impacts were for the psychiatric diagnoses and several surgical procedures. The magnitudes of the effects were generally moderate. Department of Veterans Affairs's case-based system had a negligible effect on discharges per patient. CONCLUSIONS: Per case reimbursement is a potentially useful tool for improving the efficiency of inpatient care for all types of diagnoses and age groups. The effect may be larger than estimated here because of institutional barriers and caps on financial impact.     

A longitudinal study of hospitalization rates for patients with chronic disease: results from the Medical Outcomes Study

OBJECTIVE: To prospectively compare inpatient and outpatient utilization rates between prepaid (PPD) and fee-for-service (FFS) insurance coverage for patients with chronic disease. DATA SOURCE/STUDY SETTING: Data from the Medical Outcomes Study, a longitudinal observational study of chronic disease patients conducted in Boston, Chicago, and Los Angeles. STUDY DESIGN: A four-year prospective study of resource utilization among 1,681 patients under treatment for hypertension, diabetes, myocardial infarction, or congestive heart failure in the practices of 367 clinicians. DATA COLLECTION/EXTRACTION METHODS: Insurance payment system (PPD or FFS), hospitalizations, and office visits were obtained from patient reports. Disease and severity indicators, sociodemographics, and self-reported functional status were used to adjust for patient mix and to compute expected utilization rates. PRINCIPAL FINDINGS: Compared to FFS, PPD patients had 31 percent fewer observed hospitalizations before adjustment for patient differences (p = .005) and 15 percent fewer hospitalizations than expected after adjustment (p = .078). The observed rate of FFS hospitalizations exceeded the expected rate by 9 percent. These results are not explained by system differences in patient mix or trends in hospital use over four years. Half of the PPD/FFS difference in hospitalization rate is due to intrinsic characteristics of the payment system itself. CONCLUSIONS: PPD patients with chronic medical conditions followed prospectively over four years, after extensive patient-mix adjustment, had 15 percent fewer hospitalizations than their FFS counterparts owing to differences intrinsic to the insurance reimbursement system.     

Effect of inpatient rehabilitation measures on patients with total hip endoprostheses--evaluation 15 months after operation

159 patients were examined approximately 15 months after hip arthroplasty. 116 of these patients have had at that time point a postoperative 4 week hospital stay for rehabilitation. A score that considered pain at motion and at rest, maximal walking capacity and activity of daily living was used for evaluation. The preoperative conditions did not differ between patients that had their postoperative hospital stay for rehabilitation (n = 116) and those that did not (n = 43). The results at the time of examination were regarded as excellent (group 1; score 3) in 64 (40.3%) patients, as good (group 2; score 4) in 56 (35.2%) patients and as poor (group 3; score > or = 5) in 39 (24.5%) patients. The amount of patients with a hospital stay for rehabilitation was significantly (p = 0.025) higher in the patient groups with excellent or good results in comparison with the patients with poor postoperative outcome. The most excellent results were obtained in patients who had their rehabilitation within the first two months after surgery (p = 0.008). Apart from the above mentioned score the following-additionally assessed-parameters differed significantly between the 3 groups: hip mobility; pain elicited by pressure on the operated joint; pain in the contralateral hip or knee joints; consumption of analgetics; walking time for 15 meters; degree of handicap as assessed by the patient or the occupational therapist or the physician; coping with household activities (for females only). We conclude that a poor result of hip arthroplasty may be due not only to degenerative joint disease of the lower limbs but also (or in combination) to the lack of a postoperative hospital stay for rehabilitation.     

Impact of a function-based payment model on the financial performance of acute inpatient medical rehabilitation providers: a simulation analysis

OBJECTIVES: To operationalize research findings about a medical rehabilitation classification and payment model by building a prototype of a prospective payment system, and to determine whether this prototype model promotes payment equity. This latter objective is accomplished by identifying whether any facility or payment model characteristics are systematically associated with financial performance. DESIGN: This study was conducted in two phases. In Phase 1 the components of a diagnosis-related group (DRG)-like payment system, including a base rate, function-related group (FRG) weights, and adjusters, were identified and estimated using hospital cost functions. Phase 2 consisted of a simulation analysis in which each facility's financial performance was modeled, based on its 1990-1991 case mix. A multivariate regression equation was conducted to assess the extent to which characteristics of 42 rehabilitation facilities contribute toward determining financial performance under the present Medicare payment system as well as under the hypothetical model developed. PARTICIPANTS: Phase 1 (model development) included 61 rehabilitation hospitals. Approximately 59% were rehabilitation units within a general hospital and 48% were teaching facilities. The number of rehabilitation beds averaged 52. Phase 2 of the stimulation analysis included 42 rehabilitation facilities, subscribers to UDS in 1990-1991. Of these, 69% were rehabilitation units and 52% were teaching facilities. The number of rehabilitation beds averaged 48. MAIN OUTCOME MEASURE: Financial performance, as measured by the ratio of reimbursement to average costs. RESULTS: Case-mix index is the primary determinant of financial performance under the present Medicare payment system. None of the facility characteristics included in this analysis were associated with financial performance under the hypothetical FRG payment model. CONCLUSIONS: The most notable impact of an FRG-based payment model would be to create a stronger link between resource intensity and level of reimbursement, resulting in greater equity in the reimbursement of inpatient medical rehabilitation hospitals.     

Stroke rehabilitation: clinical predictors of resource utilization

OBJECTIVE: To identify predictors of rehabilitation hospital resource utilization for patients with stroke, using demographic, medical, and functional information available on admission. DESIGN: Statistical analysis of data prospectively collected from stroke rehabilitation patients. SETTING: Large, urban, academic freestanding rehabilitation facility. PARTICIPANTS: A total of 945 stroke patients consecutively admitted for acute inpatient rehabilitation. MAIN OUTCOME MEASURES: Resource utilization was measured by rehabilitation length of stay (LOS) and mean hospital charge per day (CPD). METHODS: Independent variables were organized into categories derived from four consecutive phases of clinical assessment: (1) patient referral information, (2) acute hospital record review and patient history, (3) physical examination, and (4) functional assessment. Predictors for LOS and CPD were identified separately using four stepwise multiple linear regression analyses starting with variables from the first category and adding new category data for each subsequent analysis. RESULTS: Severe neurologic impairment, as measured by Rasch-converted NIH stroke scale and lower Rasch-converted motor measure of the Functional Independence Measure (FIM) instrument predicted longer LOS (F2,824 = 231.9, p < .001). Lower Rasch-converted motor FIM instrument measure, tracheostomy, feeding tube, and a history of pneumonia, coronary artery disease, or renal failure predicted higher CPD (F6,820 = 90.2, p < .001). CONCLUSION: Stroke rehabilitation LOS and CPD are predicted by different factors. Severe impairment and motor disability are the main predictors of longer LOS; motor disability and medical comorbidities predict higher CPD. These findings will help clinicians anticipate resource needs of stroke rehabilitation patients using medical history, physical examination, and functional assessment.     

Effects of Medicare's prospective payment system on service use by depressed elderly inpatients

OBJECTIVE: To determine the effects of Medicare's prospective payment system (PPS) on hospital care, changes in length of stay and intensity of clinical services received by 2,746 depressed elderly patients in 297 acute care general medical hospitals were studied. METHODS: A pre-post design was used, and differences in sickness at admission were controlled for. Data on length of stay and use of specific clinical services were obtained from the medical record using a medical record abstraction form. Care provided on units exempt from PPS was compared with care provided in nonexempt units. RESULTS: After implementation of PPS, the average length of stay fell by up to three days within the different types of acute care settings studied, but this decline was partially offset by proportionately more admissions to psychiatric units, which had longer lengths of stay. Intensity of clinical services increased after PPS implementation, especially in nonexempt psychiatric units. CONCLUSION: Despite financial incentives for hospitals to reduce clinical services under PPS, its implementation was not associated with a marked decline in length of stay, when averaged across all treatment settings, and was associated with an increase in the intensity of many clinical services used by depressed elderly patients in general hospitals.     

Predicting length of stay, functional outcome, and aftercare in the rehabilitation of stroke patients. The dominant role of higher-order cognition

BACKGROUND AND PURPOSE: Research in recent years has revealed factors that are important predictors of physical and functional rehabilitation: demographic variables, visual and perceptual impairments, and psychological and cognitive factors. However, there is a remaining uncertainty about prediction of outcome and a need to clinically apply research findings. This study was designed to identify the relative importance of medical, functional, demographic, and cognitive factors in predicting length of stay in rehabilitation, functional outcome, and recommendations for postdischarge continuation of services. METHODS: The influence of these factors was determined by comparing diagnostic, medical, demographic, functional, and neuropsychological information that was retrospectively obtained by reviewing the records of 86 patients admitted for comprehensive rehabilitation due to stroke (n = 36) or orthopedic injury (n = 50). Multiple linear regression with statistical adjustment to control for overprediction of variance was used to predict outcomes. RESULTS: The study revealed the primary importance of higher-order cognitive impairments (comprehension, judgment, short-term verbal memory, and abstract thinking) in extending length of stay and increasing referrals for outpatient therapies and home services after discharge for the cerebrovascular accident patients in comparison with orthopedic cohorts. CONCLUSIONS: The need is discussed for early, comprehensive assessment of deficits in cognition that affect a stroke survivor's ability to participate in a rehabilitation program and remediation that facilitates functional improvement by building on residuals of impaired abilities or teaching compensatory behaviors.     

Effect of prospective reimbursement on nursing home costs

OBJECTIVE: This study evaluates the effect of Maine's Medicaid nursing home prospective payment system on nursing home costs and access to care for public patients. DATA SOURCES/STUDY SETTING: The implementation of a facility-specific prospective payment system for nursing homes provided the opportunity for longitudinal study of the effect of that system. Data sources included audited Medicaid nursing home cost reports, quality-of-care data from state facility survey and licensure files, and facility case-mix information from random, stratified samples of homes and residents. Data were obtained for six years (1979-1985) covering the three-year period before and after implementation of the prospective payment system. STUDY DESIGN: This study used a pre-post, longitudinal analytical design in which interrupted, time-series regression models were estimated to test the effects of prospective payment and other factors, e.g., facility characteristics, nursing home market factors, facility case mix, and quality of care, on nursing home costs. PRINCIPAL FINDINGS: Prospective payment contributed to an estimated $3.03 decrease in total variable costs in the third year from what would have been expected under the previous retrospective cost-based payment system. Responsiveness to payment system efficiency incentives declined over the study period, however, indicating a growing problem in achieving further cost reductions. Some evidence suggested that cost reductions might have reduced access for public patients. CONCLUSIONS: Study findings are consistent with the results of other studies that have demonstrated the effectiveness of prospective payment systems in restraining nursing home costs. Potential policy trade-offs among cost containment, access, and quality assurance deserve further consideration, particularly by researchers and policymakers designing the new generation of case mix-based and other nursing home payment systems.     

The referral of hospitalized patients with cerebrovascular pathology. Where, when and why. A cross-sectional multicenter study of the referral of patients with ischemia and predisposing factors

OBJECTIVES: Referral of patients with ictus on discharge from hospital is a daily problem for neurologists, both because of the suitability of one place or another for maximum recovery of the patient and because of the effect on average stay, complications and use of resources. The aim of this study was to determine where and when patients with ictus were referred and what factors affect whether a patient goes to one place or another. PATIENTS AND METHODS: A transversal multicentric study (3 months) using a questionnaire was sent to all Insalud hospitals in Aragon, recording data of 128 patients from four hospitals. There were questions on medical, functional, demographic and socio-economic factors which might affect referral. RESULTS: On discharge 20% of the patients did not return to their own homes. In 50% of the cases where patients went to a supporting hospital (SH) socio-economic factors were decisive and in 20% were the only cause. Referral to SH was related to functional state and type of ictus, need for nursing care or rehabilitation, age, sex, marital status and place of residence. CONCLUSIONS: Apart from clinical criteria, many socio-economic factors determine the need for referral of patients to one place or another.