Showing papers in "Medical Care in 1995"

Comparison of methods for the scoring and statistical analysis of SF-36 health profile and summary measures: summary of results from the Medical Outcomes Study

Abstract: Physical component summary (PCS) and mental component summary (MCS) measures make it possible to reduce the number of statistical comparisons and thereby the role of chance in testing hypotheses about health outcomes. To test their usefulness relative to a profile of eight scores, results were compared across 16 tests involving patients (N = 1,440) participating in the Medical Outcomes Study. Comparisons were made between groups known to differ at a point in time or to change over time in terms of age, diagnosis, severity of disease, comorbid conditions, acute symptoms, self-reported changes in health, and recovery from clinical depression. The relative validity (RV) of each measure was estimated by a comparison of statistical results with those for the best scales in the same tests. Differences in RV among scales from the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) were consistent with those in previous studies. One or both of the summary measures were significant for 14 of 15 differences detected in multivariate analyses of profiles and detected differences missed by the profile in one test. Relative validity coefficients ranged from .20 to .94 (median, .79) for PCS in tests involving physical criteria and from .93 to 1.45 (median, 1.02) for MCS in tests involving mental criteria. The MCS was superior to the best SF-36 scale in three of four tests involving mental health. Results suggest that the two summary measures may be useful in most studies and that their empiric validity, relative to the best SF-36 scale, will depend on the application. Surveys offering the option of analyzing both a profile and psychometrically based summary measures have an advantage over those that do not.

The role of the primary care physician in patients' adherence to antidepressant therapy

Abstract: In this study, the authors attempted to determine predictors of adherence to antidepressant therapy and to identify specific educational messages, side effects, and features of doctor-patient collaboration that influence adherence. Patients newly prescribed antidepressants for depression at a health maintenance organization were identified by using automated pharmacy data and medical records review. Patients (n = 155) were interviewed 1 and 4 months after starting antidepressant medication. Approximately 28% of patients stopped taking antidepressants during the first month of therapy, and 44% had stopped taking them by the third month of therapy. Patients who received the following five specific educational messages--1) take the medication daily; 2) antidepressants must be taken for 2 to 4 weeks for a noticeable effect; 3) continue to take medicine even if feeling better; 4) do not stop taking antidepressant without checking with the physician; and 5) specific instructions regarding what to do to resolve questions regarding antidepressants--were more likely to comply during the first month of antidepressant therapy. Asking about prior experience with antidepressants and discussions about scheduling pleasant activities also were related to early adherence. Side effects, only at severe levels, were associated with early noncompliance. Neuroticism, depression severity, and other patient characteristics did not predict adherence. Primary care physicians may be able to enhance adherence to antidepressant therapy by simple and specific educational messages easily integrated into primary care visits.

A chronic disease score with empirically derived weights.

Abstract: Different types of medication prescribed during a 6-month period for the treatment and management of chronic conditions were utilized in the refinement and validation of a chronic disease score Prescription data, in addition to age and sex, were utilized to develop a chronic disease score based on empirically derived weights for each of three outcomes: total cost, outpatient cost, and primary care visits The ability of the revised chronic disease score to predict health care utilization, costs, hospitalization, and mortality was compared to an earlier version of the chronic disease score (original) that was derived through clinical judgments of disease severity The predictive validity of the chronic disease score is also compared to ambulatory care groups, which utilize outpatient diagnoses to form mutually exclusive diagnostic categories Models based on a concurrent 6-month period and a 6-month prospective period (ie, the 6-month period after the chronic disease score or ambulatory care group derivation period) were estimated using a random one half sample of 250,000 managed-care enrollees aged 18 and older The remaining one half of the enrollee population was used as a validation sample The revised chronic disease score showed improved estimation and prediction over the original chronic disease score The difference in variance explained prospectively by the revised chronic disease score versus the ambulatory care groups, conversely, was small The revised chronic disease score was a better predictor of mortality than the ambulatory care groups The combination of revised chronic disease score and ambulatory care groups showed only marginally greater predictive power than either one alone These results suggest that the revised chronic disease score and ambulatory care groups with empirically derived weights provide improved prediction of health care utilization and costs, as well as hospitalization and mortality, over age and sex alone We recommend the revised chronic disease score with total cost weights for general use as a severity measure because of its relative advantage in predicting mortality compared to the outpatient cost and primary care visit weights

Patient and visit characteristics related to physicians' participatory decision-making style. Results from the Medical Outcomes Study.

Abstract: This article identifies the characteristics of patients and office visits associated with decreased mutual decision-making between physicians and patients. In the baseline cross-sectional survey of the Medical Outcomes Study we measured specific patient characteristics hypothesized to influence participatory decision-making (PDM) styles of physicians. We related these characteristics to the PDM style scores for their physicians. The study was conducted in solo practices, multi-specialty groups, and health maintenance organizations in Boston, Chicago, and Los Angeles. Over a 9-day period in 1986, 8,316 patients were sampled from the practices of 344 participating Medical Outcome Study physicians, representing general internal medicine, family practice, cardiology and endocrinology. Physicians' PDM style was measured using a 3-item scale included on the baseline questionnaire completed by patients after office visits to their Medical Outcome Study physicians. We found that the elderly (age 75 and older) and young adult (younger than age 30) patients, patients with high school education or less, minority patients, and male patients had the least participatory visits with their physicians. We also found that male patients seeing male physicians had the least participatory visits compared with male patients seeing female physicians, and compared with female patients seeing physicians of either gender. Our data indicated that PDM style increased as duration or tenure of the physician-patient relationship increased. Participatory decision-making style also increased with increasing length of office visits. The role of effective interpersonal care in optimizing patients' health outcomes may be underappreciated. We have identified seven patient and visit characteristics that maximize or compromise the effectiveness of interpersonal care. Recognizing those at risk for suboptimal interpersonal care may be a first step in improving the management of chronic disease. Key words: participatory decision-making style; interpersonal care; doctor-patient communication.

What information do consumers want and how will they use it

Abstract: Long before I entered the field of health policy analysis, I was a methodologist. Methods, therefore, are important to me when discussing health care information and its uses. This view is shared by some of the other speakers. We must understand the reliability, validity, strengths, and weaknesses of the measures we already have or we must plan to develop so that we do not misinterpret these measures. I shall talk about the usefulness of this in-

Patient reactions to a program designed to facilitate patient participation in treatment decisions for benign prostatic hyperplasia

Abstract: Patients often want considerable information about their conditions, and enhanced patient participation might reduce unwanted practice variation and improve medical decisions. The authors assessed how men with benign prostatic hyperplasia reacted to an educational program designed to facilitate part

The influence of gender on physician practice style.

Abstract: As more women enter medicine, intriguing questions arise about how physician gender impacts practice style. To measure this influence in primary care encounters, 118 male and 132 female adult new patients, having no stated preference for a specific physician, were randomly assigned to university hospital primary care residents, and their initial encounters were videotaped. Forty-eight male and 33 female physicians participated. Patient health status was assessed before the visit with the Medical Outcomes Study Short-Form General Health Survey. Physician practice style was evaluated by using the Davis Observation Code to analyze videotapes of each initial visit. Patient satisfaction with medical care was assessed with satisfaction questionnaires. Contrary to prior reports, the difference between male and female physicians in total time spent with patients was small and statistically insignificant, and diminished further when controlling for patient gender and health status. Female physicians, however, were observed to engage in more preventive services and to communicate differently with their patients. These differences in practice style appear to explain partially the observed higher patient satisfaction scores for female physicians. This study underscores the importance of careful measurement and control of potential confounding factors in clarifying the impact of physician gender on practice style.

Medicare payments from diagnosis to death for elderly cancer patients by stage at diagnosis.

Abstract: Although extensive resources go to cancer care, national population-based data on the costs of such care at the patient level have been unavailable. Medicare payments subsequent to diagnosis of cancer for elderly enrollees with five common cancers were estimated using tumor registry data from the Surveillance, Epidemiology, and End Results Program linked to Medicare claims from 1984 to 1990. The time between diagnosis and death was divided into four phases corresponding to the clinical course of solid tumors, average payments for each phase were estimated (including payments for services not related to cancer), then phase-specific payment data were aggregated. Average payments by phase varied among cancer sites, especially in the initial care phase, where payments were highest for lung and colorectal cancers ($17,500 in 1990 dollars) and lowest for female breast cancer ($8,913). Total Medicare payments from diagnosis to death were highest for persons with bladder cancer ($57,629) and lowest for those with lung cancer ($29,184). Low payments for persons with lung cancer corresponded to brief survival times. Persons diagnosed at earlier stages incurred higher total payments between diagnosis and death than those diagnosed at later stages, reflecting their longer survival. This implies that early detection may increase total Medicare expenditures by extending beneficiaries' lives. However, Medicare payments per year of survival were lower for earlier stages. Data on Medicare payments subsequent to diagnosis of cancer are useful for identifying the cost implications of differences in treatment patterns by demographic characteristics, geography, and delivery systems; comparing the financial impact of alternative therapies; evaluating the long-term cost impacts of screening and prevention programs; and risk-adjusting payments to health plans.

Measuring disease-specific health status in men with benign prostatic hyperplasia. Measurement Committee of The American Urological Association.

Abstract: In preparation for an outcomes study of benign prostatic hyperplasia (BPH), two measures of disease-specific health status were developed to supplement a symptom score and overall health status measures. The symptom problem index (SPI) captures how troublesome patients find their urinary symptoms. The BPH impact index (BII) measures how much their urinary problems affect various domains of health. A prospective revalidation of the refined instruments (N = 108 BPH patients and 50 controls) documented that both indices had good internal consistency (Cronbach's alpha = 0.88 and 0.79, respectively) and test-retest (r = 0.88 for both) reliabilities, correlated strongly with symptom scores (r = 0.86 and 0.77), and discriminated between BPH and control subjects (receiver-operating characteristic areas = 0.87 and 0.85, respectively). These indices were nearly as responsive as symptom scores in 50 men actively treated for BPH, and much more responsive than a non-disease-specific General Health Index (GHI), a Mental Health Index (MHI), and an Activity Index (AI). Finally, these measures capture most of the health status significance of BPH symptoms. In linear regression models constructed to predict scores on the GHI, MHI, and AI, symptom scores added little explanatory power to the SPI and, particularly, to the BII. These measures help clarify how BPH affects overall health status and function. Such measures have an important role to play in studies of the outcomes of treatment for BPH, and probably for other conditions that interfere with health status and function.

Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery

Abstract: Generic and disease-specific health status instruments are commonly used to assess patients' outcomes. The hypothesis that they measure distinct but complementary aspects of patients' quality of life was tested using a sample of patients aged 67 to 99 years who had undergone knee replacement surgery 2 to 7 years previously. Patients' scores on a generic health-related quality-of-life (HRQOL) measure, the SF-36, were compared to those of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index; the WOMAC was developed specifically for patients with lower extremity arthritis, whereas the SF-36 is aimed at all conditions. A stratified sample of 1,750 Medicare beneficiaries was surveyed and an overall response rate of 80.3% achieved, resulting in 1,193 usable surveys (after adjustment for ineligible, incapacitated, and deceased individuals). The distribution of scores on the three dimensions common to both instruments (i.e., pain, physical function, and overall score) showed consistently higher scores on the WOMAC, on a scale of 0 (worst) to 100 (best), than on the SF-36, indicating less disability from arthritis than from other conditions after knee surgery in this elderly population. Statistically significant differences in the number of people with perfectly healthy scores were detected between the instruments; with regard to pain, 32.2% of the sample reported no pain due to arthritis on the WOMAC, compared with only 13.6% reporting no pain due to any conditions on the SF-36. The figures for physical function and overall score were 9.6% versus 1.4%, and 6.9% versus 0.2%, respectively. Examination for discriminant validity showed that the scores on the two scales followed hypothesized patterns: the WOMAC discriminated better among subjects with varying severity of knee problems, whereas the SF-36 discriminated better among subjects with varying levels of self-reported health status and comorbidity. The results of this study support the inclusion of both a generic and a disease-specific HRQOL measure to assess patient outcomes fully.

The adolescent child health and illness profile. A population-based measure of health.

Abstract: This study was designed to test the reliability and validity of an instrument to assess adolescent health status. Reliability and validity were examined by administration to adolescents (ages 11-17 years) in eight schools in two urban areas, one area in Appalachia, and one area in the rural South. Integrity of the domains and subdomains and construct validity were tested in all areas. Test/retest stability, criterion validity, and convergent and discriminant validity were tested in the two urban areas. Iterative testing has resulted in the final form of the CHIP-AE (Child Health and Illness Profile-Adolescent Edition) having 6 domains with 20 subdomains. The domains are Discomfort, Disorders, Satisfaction with Health, Achievement (of age-appropriate social roles), Risks, and Resilience. Tested aspects of reliability and validity have achieved acceptable levels for all retained subdomains. The CHIP-AE in its current form is suitable for assessing the health status of populations and subpopulations of adolescents. Evidence from test-retest stability analyses suggests that the CHIP-AE also can be used to assess changes occurring over time or in response to health services interventions targeted at groups of adolescents.

Oral Health, Health, and Health-Related Quality of Life

Abstract: Health-related quality of life is a multidimensional concept with five broad domains: opportunity/resilience, health perception, functional states, impairments/diseases, and duration of life. It addresses the tradeoff between how long and how well people live. The health-related quality of life approach has provided greater opportunity for investigation of the interrelations among oral health, health, and related outcomes. The inclusion of patient-driven measures, such as perceptions and functional status, is critical. Oral health-related quality of life measures are being developed and used in research on aging populations. Clinical measures of oral health, perceptions of general and oral well-being, and reported physical, social, and psychological functioning are independent, but correlated, components of overall oral health-related quality of life. An oral health-related quality of life approach benefits 1) clinical practitioners in selecting treatments and monitoring patient outcomes; 2) researchers in identifying determinants of health, tracking levels of health risk factors, and determining use of services in populations; and 3) policy-makers establishing program and institutional priorities, policies, and funding decisions. This overview indicates substantial value in pursuing several recommendations. A theoretical framework from which concepts, measures, and models can be derived must be developed to address oral health, oral health-related quality of life, health, and health-related quality of life. Oral health outcomes or states must be identified and classified along some continuum of impairment, function, disability, and opportunity. Indicators of appropriate concepts and domains must be adapted or established. Extended analyses on the relations among oral health, oral health-related quality of life, health, and health-related quality of life should be conducted with use of the Boston VA Normative Aging Study and other appropriate data sets.

A comparative study of seven measures of patient satisfaction.

Abstract: The acceptability of satisfaction as a quality indicator is qualified by several well known measurement problems This study examines the variability in satisfaction evaluations related to different measurement methods and the effect of response biases on reported satisfaction Satisfaction evaluations using seven different, commonly used measures of patient satisfaction were obtained from the same sample of respondents The seven measures were: 1) a global measure of satisfaction using a visual analogue scale; 2) a multidimensional measure of satisfaction based on the Patient Satisfaction Questionnaire using an evaluation response format (poor, fair, good, very good, excellent); 3) a two-item overall evaluation of quality using the evaluation response format; 4) a six-item attitude measure of general satisfaction using a five-point Likert agree-disagree response format; 5) a four-item attitude measure of satisfaction with physician, using the agree-disagree response format; 6) a four-item measure of behavioral intention; and 7) willingness-to-pay in dollars The percentage of favorable evaluations of care ranged from 63% to 82% across six of the seven measures Willingness-to-pay does not appear to be a valid measure of satisfaction Correlations were highest between measures with similar response formats Although an oppositional response bias was not found, a very substantial acquiescent response bias was detected Acquiescence reduced the internal consistency of three multiple-item measures, the general and physician attitude and behavioral intention measures, to levels unacceptable even for group comparisons Between highly and nonacquiescent respondents, levels of satisfaction were somewhat lower for the multidimensional measure of satisfaction and significantly lower for the two attitude satisfaction measures Highly acquiescent respondents were older, less well educated, and in poorer health than nonacquiescent subjects Results of satisfaction evaluations dependent on the measurement method used, and unreliability of measurement may be a significant problem in satisfaction measurement, especially for the oldest and most ill patients

Construction and Validation of an Alternate Form General Mental Health Scale for the Medical Outcomes Study Short-Form 36-Item Health Survey

Abstract: Alternate-form health measures are useful for clinical trials or health services research requiring repeated administrations over a short interval of time. Further, by using alternate-form methodology, they can be utilized to estimate score reliability. Data from the Medical Outcomes Study were used to evaluate five alternate forms of the Short-Form 36-Item Health Survey (SF-36) general mental health scale (MHI-5). Well-established psychometric criteria were used to select the best alternate form and to estimate the reliability of the MHI-5 using the alternate-form methodology. Although a considerable degree of comparability across the five alternate forms was observed for criteria pertaining to estimates of item-internal consistency and reliability, distributional characteristics of scales, tests of empirical validity, and score equivalence at the individual level, we recommend one alternate form that satisfied all evaluation criteria and did so better than any other alternate form. Using the alternate-form methodology of estimating reliability, results suggest that the internal-consistency method underestimates the reliability of the MHI-5 by 3%. The methodology presented here should prove useful to others interested in constructing and evaluating alternate forms, and the alternate form recommended here (MHI-5AF) should prove useful across many health status assessment applications.

Measuring disease-specific health status in men with benign prostatic hyperplasia

Abstract: In preparation for an outcomes study of benign prostatic hyperplasia (BPH), two measures of disease-specific health status were developed to supplement a symptom score and overall health status measures. The symptom problem index (SPI) captures how troublesome patients find their urinary symptoms. The BPH impact index (BII) measures how much their urinary problems affect various domains of health. A prospective revalidation of the refined instruments (N = 108 BPH patients and 50 controls) documented that both indices had good internal consistency (Cronbach's alpha = 0.88 and 0.79, respectively) and test-retest (r = 0.88 for both) reliabilities, correlated strongly with symptom scores (r = 0.86 and 0.77), and discriminated between BPH and control subjects (receiver-operating characteristic areas = 0.87 and 0.85, respectively). These indices were nearly as responsive as symptom scores in 50 men actively treated for BPH, and much more responsive than a non-disease-specific General Health Index (GHI), a Mental Health Index (MHI), and an Activity Index (AI). Finally, these measures capture most of the health status significance of BPH symptoms. In linear regression models constructed to predict scores on the GHI, MHI, and AI, symptom scores added little explanatory power to the SPI and, particularly, to the BII. These measures help clarify how BPH affects overall health status and function. Such measures have an important role to play in studies of the outcomes of treatment for BPH, and probably for other conditions that interfere with health status and function.

Variations in the utilization of coronary angiography for elderly patients with an acute myocardial infarction. An analysis using hierarchical logistic regression.

Abstract: This article reports a study of variations in the utilization of angiography for Medicare recipients who had an acute myocardial infarction. The study cohort consisted of 1987 Medicare beneficiaries who had a recent acute myocardial infarction. Variations were examined from three perspectives: patient characteristics, regional practice patterns, and on-site availability of the procedure. Factors associated with variation within and among states were incorporated into the analysis using hierarchical logistic regression models. The probability of angiography during the first 90 days after an acute myocardial infarction was estimated as a function of patient age, gender, race, and comorbidity for patients in 51 states (including the District of Columbia). Interstate differences were examined in relation to geographic region and on-site availability of angiography. Observed rates of angiography ranged between 13.8% and 38.3% (median, 24.7%). Variation was nearly threefold based on estimated state probabilities of angiography for a patient with characteristics set at the national average. Observed and estimated rates were lower in northeastern states than in other parts of the United States. States with more extensive onsite availability of angiography tended to have higher angiography rates after adjusting for patient characteristics and geographic region. Adjusted angiography rates were on average higher for younger patients, males, and nonblacks. There was substantial interstate variation in race differences, with states in the Southeast generally having the largest differences. The adjusted black-to-nonblack odds ratio ranged from a low of 0.41 to a high of 0.94. Interstate variation in age and gender differences was moderate. The work reported in this article illustrates the potential of hierarchical regression modeling as a framework for the analysis of variations and some methodologic issues connected with its implementation. Our results show that large variations in the utilization of procedures can exist, despite uniform insurance coverage and a relatively homogeneous patient cohort. Aggressive use of angiography was highly variable across states as was the degree of access to the procedure for blacks and nonblacks. The state rate of on-site availability of angiography facilities was an important predictor of utilization. Increased on-site availability of angiography, however, was not associated with a reduction of differences in access to the procedure.

Change in clinical status, health status, and health utility outcomes in HIV-infected patients.

Abstract: Psychometric health status scales and health utility scales were compared to measure the impact of changes in clinical status in patients infected with the human immunodeficiency virus (HIV). The data used included the first two waves of a longitudinal study of 160 HIV-infected patients, a population that was 34% women and 65% African American. The Medical Outcome Study-HIV Health Survey (MOS-HIV); sleep, cognitive function, and depression scales; the Sickness Impact Profile Home Management Scale; and questions on HIV-related clinical symptoms were administered. Standard gamble utilities and categorical rating scale preferences were assessed for current health state. The MOS-HIV scale scores of asymptomatic patients were significantly higher than those of symptomatic patients and patients with acquired immune deficiency syndrome. No differences were observed for utilities. Increases in clinical symptoms over 4 months were associated with changes in health perception, pain, physical role function, social function, mental health, depression, energy, cognitive function, and categorical rating scale preferences. The MOS-HIV and other health status measures discriminated between HIV disease stages and were associated with clinical status. Standard gamble utilities did not discriminate among the three groups and were not correlated with clinical status.

The effect of physician factors on the cesarean section decision.

Abstract: The number of deliveries by cesarean section (c-section) has increased dramatically. Clinical and demographic factors have not adequately explained the increased rate, however. This study investigates the role of nonclinical (i.e., physician) factors in explaining variations in c-section rates, including the physician's training/experience, financial and convenience incentives, and practice characteristics. The study measures the impact of these factors on the decision to perform a c-section rather than opting for vaginal delivery, controlling for a host of patient and hospital characteristics. Physician effects are evaluated in terms of their overall contribution to the explanatory power of logistic regression models, as well as in terms of specific hypotheses to be tested. The analyses are based on 33,233 deliveries performed by 441 physicians in 36 hospitals in 1 state during 1989. As a set, physician factors contribute more to the explanatory power of the model than do hospital factors, despite being added last to the equation. Parameter estimates provide more support for the hypothesized effects of physician convenience incentives than background/training. The log odds of performing a c-section increase with the physician's rate of c-sections in the prior year, delivery on a Friday, and delivery between 6 AM and 6 PM, and decrease with the concentration of the physician's hospital practice. Patient factors appear much more important than both physician and hospital factors, however. Efforts to reduce unnecessary c-sections should focus on identifying the appropriate clinical indications for c-section and disseminating this information to physicians.

The effects of ownership, operating environment, and strategic choices on nursing home efficiency.

Abstract: This article reports on a study of the labor efficiency of 461 nursing homes located in Pennsylvania. Data envelopment analysis was used to estimate efficiency scores. Tobit equations were estimated for the entire sample and for subsamples consisting of for-profit (FP) and not-for-profit (NFP) nursing homes. The authors found that the major factors explaining efficiency were managerial and environmental characteristics such as ownership, occupancy rate, size, payment source, wage rate, and per capita income, rather than quality characteristics of nursing homes. Analysis of the FP and NFP subsamples suggests that many NFP homes may respond to environmental pressures by increasing their efficiency, whereas FP homes tend to operate at a high level of efficiency irrespective of environmental and regulatory pressures.

The proximal-distal continuum of multiple health outcome measures: the case of cataract surgery.

Abstract: This paper presents the concept of a proximal-distal continuum in health outcome measures. It indicates how this continuum can be used in the selection of outcome measures in health technology evaluation studies. Finally, it demonstrates several ways in which the placement of a specific health outcome measure in the proximal-distal continuum determines the overall statistical model of treatment and nontreatment variables. We identify five principles that relate to the above issues. The first three principles state that a larger effect of treatment on health outcomes will be seen when the following occur: 1) more proximal (e.g., signs and symptoms, disease-specific outcomes) measures are examined, 2) the initial illness is more severe; and 3) pretreatment distal (e.g., role functioning, life satisfaction) outcome measures show relatively high impairment. Principle four indicates that distal outcomes are influenced more heavily by external (i.e., nontreatment) factors. Principle five states that a causal chain links each outcome measure in the continuum to the next more distal outcome measure. This last principle enables the determination of indirect relationships between treatment and outcomes. These principles are illustrated with data from a study on the effects of cataract surgery with intraocular lens implantation on patient outcome variables across the proximal-distal continuum.

Development and testing of a new measure of case mix for use in office practice.

Abstract: Case mix has been shown to be of critical importance in studies of effectiveness and quality of care using health outcomes. How these variables are defined, combined, and used to adjust or increase precision in tests for differences in health outcomes has been a source of controversy. Because existing measures were developed to adjust mortality and have marginal relevance for the adjustment of functional status outcomes, especially in ambulatory settings, the authors developed a measure of case (or patient) mix that is specifically designed to adjust functional status outcomes measured in office practice or out-of-hospital settings. This measure, developed as part of Type II Diabetes Patient Outcomes Research Team project, uses patients' reports of symptoms and conditions, as well as patients' ratings of symptom intensity to characterize total disease burden. It differs from other measures of case mix in lack of dependence on diagnoses. Separate measures were developed for each of 15 different disease categories (e.g., chronic lung disease) grouped by body system affected. Within each measure, questionnaire items were combined to rate the severity of that disease on a 1 to 4 scale, according to definitions provided by clinicians. A single, global measure was developed by aggregating the 15 measures, weighted according to the expected impact of each disease category on functional outcomes and disability. In a sample of 1,738 patients, significant relationships were observed between the global case mix measure and functional status, disability days, and service utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Methodological issues of patient utility measurement. Experience from two clinical trials.

Abstract: This article explores various methodological issues of patient utility measurement in two randomized controlled clinical trials involving 85 patients with fibromyalgia and 144 with ankylosing spondylitis. In both trials one baseline and two follow-up measurements of the patients' preferences for their own health state and several hypothetical states were performed using the rating scale and the standard gamble methods. It was confirmed that standard gamble scores are consistently higher than rating scale scores for both the experienced and the hypothetical states. The 3-month test-retest reliability for hypothetical states measured by intraclass correlation coefficients ranged from 0.24 to 0.33 for the rating scale and from 0.43 to 0.70 for the standard gamble. Although the reproducibility is not high, the group mean scores are fairly stable over time. Mean standard gamble scores tend to differ depending on the way the measurements are undertaken. Utilities elicited with chained gambles were significantly higher than utilities elicited with basic reference gambles. At the individual level some inconsistent responses occurred. However, more than 70% of these fell within the bounds of the measurement error, which ranged from 0.11 to 0.13 on the standard gamble (0-1 scale) and from 8 to 10 on the rating scale (0-100 scale). The large number of negative utilities for the severe hypothetical state, which was used as an anchor point in the chained gambles, and the magnitude of these negative utilities (down to -19) calls for intensified research efforts to handle these responses in utility calculations

Access to medical care and health-related quality of life for low-income persons with symptomatic human immunodeficiency virus

Abstract: Despite growing interest in the accessibility of medical care and health-related quality of life for persons infected with human immunodeficiency virus, an association between these variables has not been documented. The authors conducted a cross-sectional study of access to care and its association with health-related quality of life among 205 persons of low income infected with the human immunodeficiency virus with constitutional symptoms and/or diarrhea at one public and one Veterans Administration hospital, using a 9-item measure of perceived access and a 55-item health-related quality of life instrument. Problems with access were widespread: 55% traveled for longer than 30 minutes to their usual source of care (compared with 9% to 12% of general populations in national surveys), 49% had problems meeting costs of care, and 48% had problems with clinic hours (compared with 23% in national surveys). In multivariate analyses, uninsured patients reported worse access than patients with Medicaid or Veterans Administration insurance, particularly for meeting the cost of care (P < 0.01). Adjusted health-related quality of life scores in this sample were far lower (by about 1 SD) than those of subjects in a large national acquired immune deficiency syndrome clinical trial. For 8 of 11 health-related quality of life subscales, worse perceived access was significantly (P < 0.05) associated with poorer health-related quality of life, even after controlling for T-4 lymphocyte count, symptoms and other factors. Access and health-related quality of life measures similar to those used in this study may prove useful in future evaluations of medical care systems serving poor, clinically ill populations infected with human immunodeficiency virus.

Geographic variation in utilization of cataract surgery.

Abstract: Cataract surgery is the most frequently performed surgical procedure on Medicare beneficiaries, with an annual cost to the Medicare program of more than $3.4 billion. In this study, the relationship between demographic, environmental, and provider-related factors, and the likelihood that cataract surgery will be performed on a Medicare beneficiary were assessed. The association between likelihood of cataract surgery and patient age, sex, race, income, and latitude of residence was examined, as was the association with the supply of ophthalmologists and optometrists in each region, and the allowed charge for cataract surgery and cost of practice in a region. This cross-sectional, population-based study used administrative data. Both regional models, using least-squares regression and person-based models, using logistic regression were employed. A random 5% sample of 1986 and 1987 Medicare beneficiaries, 65 years of age and older, were included in the study. Medicare beneficiaries who lacked continuous Part A and Part B coverage during 1986 and 1987, or who were enrolled in a health maintenance organization at any time during this 2-year period of observation were excluded from the study to make certain that complete utilization data were available for each individual. Rate of cataract surgery per 1,000 Medicare beneficiaries in each Bureau of Economic Analysis Economic Area (BEAEA) and the likelihood of an individual with particular characteristics undergoing cataract surgery were determined in separate regression models. The mean annual rate of cataract surgery during 1986 and 1987 in the 181 BEAEAs was 25.4 surgeries per 1,000 persons 65 years of age or older (standard deviation = 6.2, coefficient of variation = 0.24). Both the regional model and the person-based model detected an association between a higher rate of and personal likelihood of cataract surgery and female gender, more southerly latitude, higher concentration of optometrists per 1,000 Medicare beneficiaries, and higher allowed charge for cataract surgery, after adjusting for variation in practice expense. The person-based model additionally demonstrated that increased likelihood of undergoing cataract surgery was associated with increasing age from 65 to 94 years, white race, and living in a zip-code area with mean income greater than $15,000. Neither analysis detected a statistically significant association between the concentration of ophthalmologists per 1,000 Medicare beneficiaries and the regional rate of, or an individual's likelihood of, cataract surgery. Compared with the geographic variation in provision of other surgical procedures, the variation in cataract surgery across large geographic areas observed in this analysis was relatively low.(ABSTRACT TRUNCATED AT 400 WORDS)

Predicting in-hospital mortality. The importance of functional status information.

Abstract: Monitoring risk-adjusted outcomes is the centerpiece of efforts to ensure health care quality. Because data collection is expensive, questions arise concerning what information is essential to adjust for risk. This investigation used retrospective analysis of existing, computerized clinical database

Measuring the success of treatment in patient terms

Abstract: Measuring the success of major surgeries such as total hip and total knee replacement is important for both case selection and public policy. Patients, purchasers, and practitioners must choose among clinical scoring systems, health status measures, and patient satisfaction ratings to monitor performance and ensure appropriate use of costly procedures. The present study compares results from the Medical Outcomes Study Short Form 36 (SF-36) Health Status Survey and clinical scoring systems to direct patient ratings of success. Data come from a study of 128 total knee-replacement procedure and 211 total hip replacements. Analyses indicate that for both hip and knee patients, success is related closely to posttreatment physical function and bodily pain. Patient ratings of success also are related to the clinical scores used by physicians. Success is related less to change from pretreatment function for knee patients than for hip patients. Although patient ratings of success are generally consistent with other outcome measures, their relationship to patient expectations, satisfaction, and attributions need to be understood before they can become a useful tool for performance monitoring and case selection.

Measuring effectiveness. What to expect without a randomized control group.

Abstract: Randomized controlled trials or studies are often considered the ideal way to evaluate the effectiveness of a treatment compared to a control. In such a study, the randomization procedure ensures that the subjects receiving the treatment and control are equal with respect to all conditions except for receiving the treatment or the control. Differences found by statistical comparisons of the results of such a study can be attributed to the effect of the treatment or how much the treatment differs from the control when all other things are held constant. Randomized controlled trials are not always possible, and even when possible they are often performed with such restrictions that they do not provide the true measure of the effectiveness of the treatment in the "real world" or under "conditions of usual practice." This article reviews the use of nonrandomized studies to measure effectiveness when a randomized control group is not available. Various types of nonrandomized studies are reviewed, along with their advantages and disadvantages. Often, these studies require statistical adjustments such as matching or covariance analysis to adjust for inequalities or to remove biases between the treatment and control groups; these are reviewed as well.

Why it is important to demonstrate linkages between outcomes of care and processes and structures of care.

Abstract: This first article of the supplement describes the rationale for the Department of Veterans Affairs Cooperative Study, Processes, Structures, and Outcomes in Cardiac Surgery, which was designed to demonstrate statistically and clinically meaningful linkages between processes and structures of care and the outcomes of that care. United States health care is in an era of great enthusiasm for the use of health care outcomes to assess and improve quality of care. An important reason for this enthusiasm is the concern that processes and structures of care, which traditionally have been selected arbitrarily without valid linkages to favorable outcomes, may not result in the desired outcomes of care. Furthermore, health care outcomes are intrinsic to the definition of quality of care and should be relatively free of preconceived biases about how care should be provided. However, the limitations to outcomes-directed quality improvement have been inadequately recognized. These limitations include the following: (1) mortality, the most commonly used outcome, is usually sufficiently rare, resulting in inadequate statistical power; (2) nonfatal outcomes are much more difficult to measure reliably; (3) outcomes may not be measurable for an extended period of time after the care episode, making linkage to quality improvement inefficient; and (4) patients often desire good processes of care as well as favorable outcomes. A review of the literature found relatively few reports linking processes and structures of care to favorable outcomes. Significant relationships between processes of care and outcomes have been reported for several medical conditions (congestive heart failure, acute myocardial infarction, pneumonia, and stroke) when the patient has been considered the unit of analysis. However, there is a paucity of published meaningful process-outcome or structure-outcome linkages for surgical conditions or for any conditions when the hospital has been the focus of analysis. The authors concluded that quality improvement will proceed most efficiently and effectively if all three elements of Donabedian's quality triad (processes, structures, and outcomes) are used and if the processes and structures chosen have been demonstrated to be associated with desired outcomes of care.

Evaluation of screening criteria for adverse events in medical patients.

Abstract: The goals of this study were to evaluate the sensitivity and specificity of 15 screening criteria for adverse events, preventable adverse events, and severe adverse events in medical patients, and to evaluate combinations of these criteria, including those available through hospital billing data, to determine whether a small subset of generic screens might efficiently identify adverse events. The authors studied 3,137 consecutive admissions to a medical service over a 4-month period at an urban tertiary care hospital. Chart reviews were performed after discharge by reviewers blinded to the eventual determination of presence of an adverse event. Judgments regarding presence, severity, and preventability of adverse events were made using guided implicit reviews by physicians. Of all admissions, 341 (11%) were judged to include an adverse event, of which 274 were severe and 145 were preventable. Sensitivity and specificity of individual screens varied widely, with prior hospitalization the most sensitive (68%) but least specific (56%). Death was specific (97%) but not sensitive (9%); readmission was intermediate (sensitivity 28%, specificity 80%). In analyses using severe and preventable adverse events as the outcome, results were generally similar. Combinations of screens also were compared, including some using only screens available through billing data; the most sensitive billing strategy detected just 47% of adverse events, but cost only $3 per admission reviewed and $57 per adverse event, versus $13 per admission and $116 per adverse event for a strategy in which all records were reviewed. It is concluded that no small subset of screens identified a high percentage of adverse events. Using screens available through billing data, although insensitive, would be much less costly.