Health maintenance organizations and hospital quality for coronary artery bypass surgery.

This study uses hospital discharge data for 1992-1994 to assess differences between HMO and insured non-HMO patients in California and Florida with regard to the quality of the hospitals used for coronary artery bypass graft (CABG) surgery. The authors found that commercially insured HMO patients in California used higher quality hospitals than commercially insured non-HMO patients, controlling for patient distance to the hospital. In contrast, commercially insured HMO and non-HMO patients in Florida were similarly distributed across hospitals of different quality levels, whereas Medicare HMO patients in Florida used lower quality hospitals than patients in the standard Medicare program. The authors conclude that the association between HMO coverage and hospital quality may differ across geographic areas and patient populations, possibly related to the maturity and structure of managed care markets.

Diagnostic coding and medical rehabilitation length of stay: their relationship.

OBJECTIVE: To determine if diagnostic information provided in the form of International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes improves rehabilitation length of stay (LOS) prediction when used in combination with the Functional Independence Measure-Function Related Groups (FIM-FRGs) classification system. DESIGN: Various models characterizing diagnostic information using ICD-9-CM codes were created that included individual ICD-9-CM codes and groupings of those codes by organ or etiology involved. Each method was evaluated using linear regression with the natural logarithm of LOS as the dependent variable. Separate validation data sets were held back to quantify the incremental effect of diagnosis when combined with the FIM-FRG classification system. SETTING: Records from 252 rehabilitation facilities and hospital units across the nation. PATIENTS: Analyses were undertaken using 82,646 records from patients discharged in 1992. RESULTS: The addition of ICD-9-CM diagnostic information to the FIM-FRG classification system increased the variance explained by a maximum of 1.9%, from 31.5% to 33.4%. CONCLUSIONS: Refinement of the FIM-FRGs to include ICD-9-CM diagnoses does not appear warranted on the basis of the small increase in the percentage of explained variance in LOS. We believe the lack of improved prediction with the addition of ICD-9-CM codes relates primarily to incomplete coding practices and to the effect of patients' diagnoses being absorbed in variables as already expressed by the FIM-FRG system. Although ICD-9-CM codes, overall, did not greatly improve LOS prediction, they appeared to have some impact in certain impairment categories.

Development of function-related groups version 2.0: a classification system for medical rehabilitation.

OBJECTIVE: To present a new version (2.0) of the Functional Independence Measure-Function Related Group (FIM-FRG) case-mix measure. DATA SOURCE/STUDY SETTING: 85,447 patient discharges from 252 freestanding facilities and hospital units contained in the 1992 Uniform Data System for Medical Rehabilitation. STUDY DESIGN: Patient impairment category, functional status at admission to rehabilitation, and patient age were used to develop groups that were homogeneous with respect to length of stay. Within each impairment category patients were randomly assigned to one data set to create the system (through recursive partitioning) or a second set for validation. Clinical and statistical criteria were used to increase the percentage of patients classified, expand the impairment categories of FIM-FRGs Version 1.1, and evaluate the incremental predictive ability of coexisting medical diagnoses. Predictive stability over time was evaluated using 1990 discharges. PRINCIPAL FINDINGS: In Version 2.0, the percentage of patients classified was increased to 92 percent. Version 2.0 includes two new impairment categories and separate groups for patients admitted to rehabilitation for evaluation only. Coexisting medical diagnoses did not improve LOS prediction. The system explains 31.7 percent of the variance in the logarithm of LOS in the 1992 validation sample, and 31.0 percent in 1990 discharges. CONCLUSIONS: FIM-FRGs Version 2.0 includes more specific impairment categories, classifies a higher percentage of patient discharges, and appears sufficiently stable over time to form the basis of a payment system for inpatient medical rehabilitation.

Classifying rehabilitation inpatients by expected functional gain.

OBJECTIVES: To create a more suitable payment system for medical rehabilitation, the authors developed a companion classification system to the original functional independence measure-function-related groups (FIM-FRGs), which classify patients having similar lengths of stay in a rehabilitation hospital or inpatient unit. The companion system presented here groups patients according to their gains in functional status during the rehabilitation stay. METHODS: Data from 84,492 patients discharged from 252 rehabilitation facilities in 1992 were provided by the Uniform Data System for Medical Rehabilitation. Classification rules were formed using clinical judgment and a recursive partitioning algorithm. The gain-FRGs system used four predictor variables: (1) diagnosis leading to disability, admission scores on the (2) motor and (3) cognitive subscales of the FIM, and (4) patient age. RESULTS: The gain-FRGs system contained 74 patient groups and explained 21% of the variation in functional gain for patients in a different set of records withheld for validation. CONCLUSIONS: The gain-FRGs system should be considered for prospective payment systems because it gives the provider an incentive to improve patient outcomes, which is missing in a payment system based on FIM-FRGs alone.

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.

The relationship between choice of outcome measure and hospital rank in general surgical procedures: implications for quality assessment.

OBJECTIVE: Institutional complication rates are often used to assess hospital quality of care, particularly for conditions and procedures where mortality rates are not useful because deaths are rare. The objective of this study was to assess the correlation among hospital quality assessment rankings based on adjusted mortality, complication and failure-to-rescue rates. DESIGN: This study used a clinically detailed administrative data set to compare severity and case-mix adjusted hospital outcome rankings for three different measures of quality of care: in-hospital death, complication and failure-to-rescue (in-hospital death following a complication). SETTING AND PATIENTS: Analysis of 74,647 patients who underwent general surgical procedures included in the 1991 and 1992 MedisGroups National Comparative Data Base. MEASUREMENTS: Adjusted outcomes of death, complication and failure to rescue based on multivariable logistic regression models. RESULTS: For 142 hospitals, the correlation between hospital rankings based on the death rate and those ranked by the complication rate was only 0.208 (P = 0.013). A similarly low correlation was present between the complication and failure rate rankings, r = -0.090 (P = 0.287). A higher correlation was observed between the death and failure rate rankings, r = 0.90 (P < 0.001). CONCLUSIONS: For general surgical procedures, hospital rank using the complication rate is poorly correlated with rankings using the death or failure rate. Complication rates should be used with great caution and should not be used in isolation when assessing hospital quality of care.

Routine portable chest radiographs in the medical intensive care unit: effects and costs.

OBJECTIVE: To determine the effects and net costs of routine chest radiographs in a medical intensive care unit (ICU). DESIGN: A prospective, cohort study. A survey of experts in critical care and pulmonary diseases was undertaken to assess the effect of routine radiographs on patient management. SETTING: Medical ICU of a university hospital. PATIENTS: Eighty randomly selected patients admitted to a medical ICU. Two hundred fourteen experts were surveyed; 118 (55%)/214 responded. MEASUREMENTS AND MAIN RESULTS: Daily interviews with medical ICU clinicians were conducted to assess the radiographic findings in the routine radiographs and actions taken based on these findings. Experts evaluated the findings, their importance, the actions taken, and the probability of complications if the actions had not been taken at that time. Experts also predicted increases in length of stay associated with these complications. Presence of radiographic findings, changes in management because of the findings, net costs of routine chest radiographs, cost per finding that prompted an action, and expected changes in length of stay resulting from the actions were also assessed. Seventy-two (33%) of 221 routine radiographs (95% confidence interval: 25% to 39%) had findings, of which 44 (61%) were judged important, and 18 (8%, 95% confidence interval: 5% to 12%) prompted actions. Experts predicted that each action averted, on average, 2.1 +/- 1.7 days (SD) in the medical ICU. Mean savings per routine radiograph was $98. Net savings from routine chest radiographs remained after sensitivity analysis for expected change in length of stay, percentage of patients with routine radiographs, and percentage of routine radiographs that produce changes in management. CONCLUSION: The policy of obtaining routine chest radiographs in the medical ICU is effective and results in net savings.

Measuring hospital outcomes from a buyer's perspective.

This study reports lessons learned from a project to develop a flexible, generalizable, and valid method for corporate buyers of hospital care that would permit them to use available secondary data to rate the outcomes quality of all hospitals in a local market area. As hospitalization insurance has moved from coverage that applied equally to all licensed hospitals to arrangements which selected a certain preferred hospital or hospitals and rejected others, the need to determine the quality of different hospitals (as well as what they would cost the insurer or buyer) has become apparent. The product of this project was the development and demonstration of a set of rating methods that build on the strengths available in large hospital discharge data bases, such as (but by no means limited to) that of the Pennsylvania Health Care Cost Containment Council (PHC4). These measures, or others developed using these methods, deal with uncertainty in the data--its diagnosis and treatment--in a conceptually valid and practically useful way, illustrate a process that might be used in the general development of quality measures, and provide a useful critique of some other measures.

Evaluation of the complication rate as a measure of quality of care in coronary artery bypass graft surgery.

OBJECTIVE: To determine whether hospital rankings based on complication rates provide the same information as hospital rankings based on mortality rates. DESIGN: A retrospective study of in-hospital death, complication, and death following complication (failure to rescue). Hospitals were ranked using residuals based on the difference between the observed and the expected number of events (from logistic regression models); rankings were compared using Spearman rank correlations. SETTING: Hospitals performing coronary artery bypass graft (CABG) surgery in the 1991 and 1992 MedisGroups National Comparative Data Bases. PATIENTS AND DATA SETS: Record abstraction data for 16,673 patients who underwent CABG procedures at 57 hospitals, linked with data from the 1991 American Hospital Association Annual Survey. RESULTS: After adjusting for patient admission severity of illness, there were low correlations between hospital rankings based on death or failure to rescue and those rankings based on complication (death vs complication, r = 0.07, P = .58; failure to rescue vs complication, r = -0.22, P = .11). In addition, many hospital characteristics that are generally associated with a higher quality of care were associated with higher complication rates but with expected or lower-than-expected mortality rates. CONCLUSIONS: Hospital rankings based on complication rates provide different information than those based on mortality rates. Until more is known about these differences, complication rates should not be used to judge hospital quality of care in CABG surgery.

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.

Hospital and patient characteristics associated with death after surgery. A study of adverse occurrence and failure to rescue.

We asked if the factors that predict overall mortality following two common surgical procedures are different from those that predict adverse occurrences (complications) during the hospitalization or death after an adverse occurrence, which we refer to as "failure to rescue." We examined 5,972 Medicare patients undergoing elective cholecystectomy or transurethral prostatectomy using three outcome measures: 1) the death rate (number of deaths/number of patients); 2) the adverse occurrence rate (number of patients who developed an adverse occurrence/number of patients); and 3) the failure rate (number of deaths in patients who developed an adverse occurrence/number of patients with an adverse occurrence). The death rate was associated with both hospital and patient characteristics. The adverse occurrence rate was associated primarily with patient characteristics. In contrast, failure to rescue was associated more with hospital characteristics, and was less influenced by patient admission severity of illness as measured by the MedisGroups score. We concluded that factors associated with hospital failure to rescue are different from factors associated with adverse occurrences or death. Understanding the reasons behind variation in mortality rates across hospitals should improve our ability to use mortality statistics to help hospitals upgrade the quality of care.

Differences in mortality from coronary artery bypass graft surgery at five teaching hospitals.

OBJECTIVE: To measure hospital- and surgeon-specific mortality rates for patients with coronary artery bypass graft (CABG) surgery and to examine possible reasons for any differences. DESIGN: Cohort study using hospital discharge abstracts and itemized bills. SETTING: Five major teaching hospitals in Philadelphia, Pa. PATIENTS: Consecutive sample of all 4613 patients over a 30-month period. MAIN OUTCOME MEASURE: In hospital mortality rates. RESULTS: We observed differences in hospital mortality rates for patients who underwent coronary artery catheterization and CABG surgery during the same admission (diagnosis related group 106) but not for patients who underwent only CABG surgery during the admission (diagnosis related group 107). There were threefold differences in surgeon-specific mortality rates. The hospital mortality rates for coronary artery catheterization and CABG surgery during the same admission changed during the study and coincided with moves of surgeons among study hospitals. Our measures of illness severity did identify patients who were more likely to die, but differences in severity of illness did not explain differences in hospital- or surgeon-specific mortality rates. Patient mortality rates were not associated with the volume of procedures performed by individual surgeons. We found inconclusive evidence for an association with surgeons' clinical skills, and to a lesser extent, with the hospital's volume of procedures and the hospital's organization and staffing. A greater intensity of hospital services was not necessary for a lower mortality rate. CONCLUSIONS: We conclude that studies of CABG mortality should examine mortality rates by diagnosis related group, collect data from more than 1 year, examine associations with surgeons' clinical skills, include information on hospital organization and staffing, and cautiously explore more efficient ways of providing care.

Predicting inpatient rehabilitation length of stay.

Using standardized forms and predefined criteria, information was collected on all 1,238 patients admitted to the inpatient rehabilitation facility at our university hospital between August 1, 1980 and December 30, 1986. Data from 96% of these patients were used retrospectively to create a mathematic model, based on multiple linear regression, that predicts the patient's total rehabilitation length of stay (LOS). The model requires only information about the patient's admitting diagnosis, referral source, admission functional status, and date of admission. The model compared favorably with prospective estimates of LOS made independently by attending physicians at admission to rehabilitation. We conclude that such models could be used to facilitate management of rehabilitation units, forecast patient census, schedule unit personnel, set interim goals for LOS, and facilitate discharge planning. The delivery of rehabilitation services, like the delivery of other medical services, can be defined in part by objective, measurable patient characteristics.

Guiding individual decisions: a randomized, controlled trial of decision analysis.

In early 1983, all 1,280 faculty and resident physicians at one hospital who were eligible to be vaccinated against hepatitis B were divided randomly into three groups: Group 1 physicians received general information about the risks and benefits of alternative vaccine decisions; Group 2 physicians were additionally invited to provide personal information for an individualized decision analysis (12.6 percent responded); and Group 3 physicians, who served as controls, were not contacted. In one year's follow-up, 20 percent of physicians were screened for hepatitis B antibody or vaccinated. More Group 2 physicians whose decision analyses recommended screening or vaccination took these actions (39 percent) than any other group. Group assignment remained significantly associated with vaccine decisions after analyzing results by the "intention to treat" principle, and after adjusting for training status, exposure to blood and blood products, and pre-study intentions about the vaccine. Despite the low overall vaccine acceptance rate, it is concluded that individualized decision analysis can influence the clinical decisions taken by knowledgeable and interested patients.

The impact of DRG-based prospective payment on clinical decision making.

The Medicare Prospective Payment System (PPS) and the financial incentives it creates are likely to influence physician practices, as well as to offer new opportunities for research into clinical decision making. Hospital managers and physicians alike will need to look increasingly to decision analysis for answers regarding technology assessment and the cost-effectiveness of clinical practices. Areas of research in which decision analysis might contribute significantly include: the compromise between cost and quality, the comparative advantages of outpatient versus inpatient procedures, and the appropriate timing of patient discharge or transfer.

Teaching cost-effective diagnostic test use to medical students.

The purpose of this project was to develop and evaluate a program to teach medical students how to order diagnostic tests in a cost-effective manner. The 1-month educational program included a seminar, a simulated patient-care exercise, special case presentations by students, newsletters about diagnostic tests, and concurrent review of patients' bills. Content analysis of answers to open-ended questions and pretests and posttests were used to measure differences in the study and control groups. Although students said the program was useful, no significant differences were found in students' knowledge, attitudes, or simulated test-ordering behavior. The authors conclude that the lack of improvement in objective measures limits the potential effectiveness of restricted efforts such as this one and that the discrepancy between the subjective and objective measures reinforces the need for more rigorous evaluations of programs that teach cost-effective diagnostic test use.

Health insurance under competition: would people choose what is expected?

To determine relative preferences for different cost-sharing options, we asked a 17% random sample of 2,754 nonunion employees to compare health insurance policies that differed in the level of 1) deductible amount, 2) coinsurance rate, 3) coinsurance limit, 4) maximum liability, and 5) price. Using conjoint analysis, we derived preference curves for each of the five components and measured preferences for the compromise between more coverage and the corresponding price increase. In contrast to other studies, our findings suggest that under fair market prices, respondents would choose policies with greater coverage for catastrophic illness, and they would as likely choose cost-sharing policies that contain incentives to reduce utilization as they would choose policies without these incentives.

Methodological limitations in case mix hospital reimbursement, with a proposal for change.

We have found five methodological limitations in the creation and implementation of the diagnosis related group (DRG) patient classification system, which is used to define a hospital's case mix. There are four methodological limitations in the system that Klastorin and Watts have proposed to identify hospital peer groups. We conclude that the effects of these limitations should be sought, and we propose studies to measure their extent. We also propose that these two approaches can be combined to create an improved hospital reimbursement program that accurately measures differences between hospitals caused by case mix and peer group characteristics.