Determining clinically important differences in health status measures: a general approach with illustration to the Health Utilities Index Mark II.

The objective of this article was to describe and illustrate a comprehensive approach for estimating clinically important differences (CIDs) in health-related quality-of-life (HR-QOL). A literature review and pilot study were conducted to determine whether effect size-based benchmarks are consistent with CIDs obtained from other approaches. CIDs may be estimated based primarily upon effect sizes, supplemented by more traditional anchor-based methods of benchmarking (i.e. direct, cross-sectional or longitudinal approaches). A literature review of articles discussing CIDs provided comparative data on effect sizes for various chronic conditions. A pilot study was then conducted to estimate the minimum CID of the Health Utilities Index (HUI) Mark II, and to compare the observed between-group differences observed in a recent randomised trial of an acute stroke intervention with this benchmark. The use of standardised effect size benchmarks has a number of advantages-for example, effect sizes are efficient, widely accepted outside HR-QOL, and have well accepted benchmarks based upon external anchors. In addition, our literature review and pilot study suggest that effect size-based CID benchmarks are similar to those which would be obtained using more traditional methods. For most HR-QOL instruments, we do not know the changes in score which constitute CIDs of various magnitudes. This makes interpretation of HR-QOL results from clinical trials difficult, and having a benchmarking process which is relatively straightforward would be highly desirable.

Cost effectiveness of the multichannel cochlear implant.

Although most third-party payors presently fund cochlear implantation, some do not, and many cite the current lack of cost-effectiveness data as a major concern. Cost-utility analysis is a widely used method of medical technology assessment that permits cost-effectiveness comparisons between medical interventions by determining the cost per quality-adjusted life-year (QALY) they provide. The cost per QALY for the cochlear implant was determined using clinical cost data and a health-utility outcome model based on the established communication gains attained with the device. Cochlear implantation costs approximately $15,600 per QALY provided. Sensitivity analysis, a technique that systematically varies the assumptions underlying the calculations, favorably with other medical interventions, such as coronary artery bypass grafting ($10,431) for three-vessel disease, $64,033 for single-vessel disease), the implantable defibrillator ($29,200), and cardiac transplantation ($38,970). This analysis indicates that the cochlear implant lies well within the cost-effectiveness range currently accepted by the American medical system.

Implications of the Adult Day Health Care Evaluation Study for program revision and research.

With no additional effort to revise adult day health care (ADHC) services or the types of patients who receive them, it would appear that adding an ADHC program to a VA Medical Center would not achieve the desired objectives. The authors discuss here the advantages, disadvantages, and feasibility of 2 options for program revision. The first is to target ADHC to those types of patients who may be most likely to benefit. A targeting scheme should use the most objective criteria possible and may need to be implemented as part of a case-managed package of community-based services. The second option for program revision is to reduce the costs of ADHC services. A cost model developed as a part of the study demonstrated the effect of possible revisions, including increasing enrollment, reducing staffing costs, decreasing length of stay in ADHC, and increasing substitution of ADHC for other services. These changes differ in the level of administrative support and clinician behavior change needed for their implementation. This report then concludes with a discussion of the implications of the results for implementation of VA-ADHC versus contract ADHC, and a discussion of possible directions for future research.

Data collection in the Adult Day Health Care Evaluation Study.

This report presents data collection measures and methods for the evaluation of Adult Day Health Care (ADHC) in the Department of Veterans Affairs (VA). Measures of patient health were survival, the Sickness Impact Profile, self-rated health, the Mini-Mental State Exam, Psychological Distress Scale, Social Support Scale, and Problem Behaviors Scale. Measures of health for the care giver were: Activities of Daily Living, Instrumental Activities of Daily Living, health perceptions, Psychological Distress Scale, life satisfaction, Social Support Scale, and Caregiver Burden Scale. We also assessed patient and care giver satisfaction with the care received by the patient. Measures of health status and outcomes were assessed primarily through patient and care giver interview at study enrollment, 6 months, and 12 months. Utilization and cost both within and outside VA were assessed for hospital, ambulatory care, nursing home, ADHC, home care, pharmacy, laboratory, and other forms of health care. Sources of utilization data included VA's computerized patient database, VA medical records, patient questionnaires, care giver questionnaires, and health care providers outside VA. Costs were obtained from VA's cost accounting system, VA Central Office, VA's contracts with outside providers, and directly from outside providers. Utilization and cost were assessed for each patient for a period of 1 year after entry into the study.

Overview and patient recruitment in the Adult Day Health Care Evaluation Study.

Although Adult Day Health Care (ADHC) is increasingly prominent in the continuum of long-term care services, the results from previous studies of the effects of ADHC are mixed. The objectives of the ADHC Evaluation Study were to determine the effect of ADHC on health status, utilization, and cost of care. The first phase was a randomized controlled trial evaluating ADHC provided directly by the VA. Patients at four medical centers (n = 826) were randomly assigned to receive either ADHC or customary care, and outcomes were compared for the two groups. The second phase was a prospective cohort study evaluating ADHC provided under contract to community agencies in which patients at four additional medical centers (n = 163) were assigned to contract ADHC programs. Outcomes were compared with those of similar patients in the randomized trial. Patients and care givers were assessed at intake and 6 and 12 months after intake. To be admitted to the study, patients must have met one of the following criteria: residence in a nursing home; dependence in ambulation, dressing, or toileting; bowel incontinence; or significant cognitive impairment. Patients at intake demonstrated major impairment in function and high levels of prior use of health care services.

Effects of VA adult day health care on health outcomes and satisfaction with care.

It was hypothesized that ADHC would have a positive effect on the health of patients and their care givers and result in greater satisfaction with care than customary care. Measurement of health outcomes for patients included assessment of overall, psychological, and social health, and survival. Care giver assessment concentrated on psychosocial health. Findings indicated no difference in health outcomes between patients assigned to ADHC or their care givers and their counterparts assigned to customary care. Further analysis of subgroups found that there were 3 subgroups of patients for whom those assigned to ADHC had better outcomes (as indicated by lower Sickness Impact Profile scores) than those assigned to customary care. These subgroups included those who were 1) not married, 2) most satisfied with their social support network, and 3) not hospitalized at the time of enrollment in the study. Patients and their care givers assigned to ADHC were more satisfied with their care than those in nursing homes, but not more satisfied than those in hospital-based home care. Care givers reported significantly greater satisfaction with patient care in ADHC than did care givers of patients receiving care in nursing homes or ambulatory care clinics.

Effects of adult day health care on utilization and cost of care for subgroups of patients.

An important goal of the Adult Day Health Care (ADHC) Evaluation Study was to identify subgroups of patients assigned to ADHC for whom the health care costs were less than, or not higher than, the costs of similar patients assigned to customary care. Patients eligible for VA services because of a severe disability that occurred during military service had significantly lower costs when assigned to ADHC compared with customary care. For several types of patients, total health care costs were not significantly higher for those assigned to ADHC compared with those assigned to customary care: patients who at study intake 1) were at highest risk of going to a nursing home, 2) had high levels of physical dysfunction as measured by the Sickness Impact Profile, 3) had multiple behavior problems, and 4) were eligible for VA services because of a less severe service-connected disability but admitted to the ADHC for treatment of that disability. Two types of patients were found to have particularly high costs when assigned to ADHC compared with customary care: patients with low levels of physical dysfunction and patients with few behavior problems. Significant differences in the relative costs of ADHC versus customary care also were found between the 4 study sites.

Effects of contract adult day health care on health outcomes and satisfaction with care.

The second phase of the ADHC Evaluation Study was designed to assess ADHC provided under contract by community ADHC programs. Outcomes for the 163 patients enrolled in this prospective cohort evaluation were compared with those of patients assigned to ADHC provided directly by VA (VA-ADHC) and customary care in the randomized trial phase of the study. In spite of identical admission criteria, contract ADHC patients were significantly different from VA-ADHC and customary care patients on several characteristics and were more impaired in health status at study intake. They were also more impaired in physical health status at 12 months, even after controlling for baseline differences. There were no significant differences in any other patient or care giver health outcomes. Contract ADHC patients were more satisfied than customary care patients in nursing homes (but not more satisfied than patients in home care), whereas VA-ADHC patients were more satisfied than those in contract ADHC. It is suggested that differences in physical function are due to differences in patient health status at intake rather than a detrimental effect of contract ADHC.

Summary and discussion of methods and results of the Adult Day Health Care Evaluation Study.

This article summarizes the study results and presents an evaluative summary of the implementation of study methods designed to provide guidance in the degree of confidence with which the results may be accepted and generalized to other situations. Patients who were offered VA-ADHC services in the first phase of this study had significantly higher VA health care costs on average than patients assigned to customary care, with no apparent incremental health benefit to themselves or their care givers. One can have a high level of confidence in these results. The ADHC clinical services were implemented as planned, the randomized controlled trial was implemented successfully, and such threats to validity as insufficient numbers of patients and differential attrition were not present. Certain subgroups of patients assigned to VA-ADHC had VA costs of care that were not significantly higher than those assigned to customary care, although these results must be interpreted with caution. The findings of the second phase of the study evaluating contract ADHC provide no support for choosing to provide either contract ADHC or VA-ADHC over the other. The nonrandomized design and smaller sample size suggest that inferences from the contract ADHC evaluation should be drawn with more caution than those from the VA-ADHC evaluation.

Issues in the measurement of health status in asthma research.

Asthma is a chronic condition of increasing prevalence and high cost to patients, their families, and society. Research into the causes and consequences of asthma has increased during the last few years, but the use of health status measures to help characterize patient outcomes is infrequent. Those studies that have included health status measures have focused on different dimensions of health status, making comparisons across studies difficult. The purpose of this article is to provide information about the selection of health status measures in studies of persons with asthma and to review applications of and make recommendations for health status assessment in asthma research. These recommendations include: use of both generic and specific instruments where appropriate, the development of new asthma-specific measures and rigorous testing of the several new measures that have been reported recently, and the development and inclusion of utility measures in studies of asthma.

Adult day health care evaluation study: methodology and implementation. Adult Day Health Care Evaluation Development Group.

The Adult Day Health Care Evaluation Study was developed in response to a congressional mandate to study the medical efficacy and cost effectiveness of the Adult Day Health Care (ADHC) effort in the Department of Veterans Affairs (VA). Four sites providing ADHC in VA facilities are participating in an ongoing randomized controlled trial. Three years of developmental work prior to the study addressed methodological issues that were problematic in previous studies. This developmental work resulted in the methodological approaches described here: (1) a patient recruitment process that actively recruits and screens all potential candidates using empirically developed admission criteria based on predictors of nursing home placement in VA; (2) the selection and development of measures of medical efficacy that assess a wide range of patient and caregiver outcomes with sufficient sensitivity to detect small but clinically important changes; and (3) methods for detailed, accurate, and efficient measurement of utilization and costs of health care within and outside VA. These approaches may be helpful to other researchers and may advance the methodological sophistication of long-term care program evaluation.

The validity of proxy-generated scores as measures of patient health status.

This study examines the validity of proxy assessments as substitutes for patient assessments of patient physical and psychosocial health status. Data were obtained from 275 patient-proxy pairs who were enrolled in a national study of Adult Day Health Care. Patients and proxies (informal caregivers such as spouses) were asked to complete the Sickness Impact Profile (SIP) based on the patients health status. Findings showed that patient-generated and proxy-generated physical scores were highly correlated, although proxies rated patients as slightly more impaired than the patient's rated themselves. The correlation between psychosocial scores was not high enough to consider proxy responses as valid substitutes for patient responses. We explored these differences in response by comparing regression equations predicting patient-generated and proxy-generated physical and psychosocial SIP dimension scores. Variance in the patient-generated psychosocial score was explained by physical function, psychological distress, cognitive status and patient age. Proxy-generated psychosocial scores were primarily explained by the caregiver's psychological distress and perceived burden. These findings point out the importance of considering the source of patient health status estimates when interpreting the results of research studies.

The Sickness Impact Profile as a measure of the health status of noncognitively impaired nursing home residents.

The Sickness Impact Profile (SIP) is a multidimensional, behaviorally based measure of the health status that has been successfully used in a wide range of applications. The characteristics of this measure have not been assessed with nursing home residents. The purpose of this study was to assess the feasibility, reliability (internal consistency), validity, and comprehensiveness of the SIP as a measure of the health status of a selected group of nursing home residents. One hundred sixty-eight veterans residing in community and VA nursing homes responded to a questionnaire consisting of the SIP, Index of Activities of Daily Living, Barthel Index, Life Satisfaction Index Z, and the Philadelphia Geriatric Center Morale Scale. In general, the respondents correctly interpreted instructions; reliability and validity were supported; and the SIP was found to provide a comprehensive assessment of physical function. Adding a measure of psychologic well-being to a study protocol involving this population may, however, provide additional useful information regarding this construct.

Prophylactic knee braces and injury to the lower extremity.

Five hundred and eighty high-school football players were studied over a period of two seasons to determine the effect of so-called prophylactic knee braces on the lower extremity. Two hundred and forty-seven athletes who wore single-hinged braces and eighty-three who wore double-hinged braces were paired for the same season of play with 250 athletes who were similar in height, weight, and playing position but who did not wear braces. The fifty-three injuries of the knee that occurred were significantly more frequent (p less than 0.001) in the group that wore single-hinged braces than in the matched, non-braced group. While there were more injuries of the knee in the participants who were double-hinged braces than in the matched controls, who did not wear braces, the increase in the number of injuries was not significant. There was also a dramatic increase (p less than 0.01) in the number of injuries of the ankle and foot in the athletes who wore braces. Our results question the efficacy of the braces that were studied and call attention to the potentially adverse effect of the braces on adjacent joints in the ipsilateral limb.

The Veterans Administration Northwest Regional Health Services Research and Development Field Program: organization, activities, and early outcomes.

In 1982, the Veterans Administration established Health Services Research field programs in each of the six VA regions. Herein, we describe the historical origins, organization, responsibilities, activities, and early accomplishments of one of these programs--the Northwest Regional HSR&D field program. Special reference is made to this program's commitment to health services research relevant to geriatrics and gerontology, including the development of a system-wide agenda for research, information syntheses in geriatrics-relevant health services research topics, and the conduct of funded projects pertinent to care of the elderly. The importance of a medical center location for the field programs is discussed, and early indications of institutional impact are described.