Biomedical subjects

A M Zaslavsky

Publications and source records attributed to A M Zaslavsky.

At least 19 recordsLinked to original sources

PubMed2002

Short screening scales to monitor population prevalences and trends in non-specific psychological distress.

BACKGROUND: A 10-question screening scale of psychological distress and a six-question short-form scale embedded within the 10-question scale were developed for the redesigned US National Health Interview Survey (NHIS). METHODS: Initial pilot questions were administered in a US national mail survey (N = 1401). A reduced set of questions was subsequently administered in a US national telephone survey (N = 1574). The 10-question and six-question scales, which we refer to as the K10 and K6, were constructed from the reduced set of questions based on Item Response Theory models. The scales were subsequently validated in a two-stage clinical reappraisal survey (N = 1000 telephone screening interviews in the first stage followed by N = 153 face-to-face clinical interviews in the second stage that oversampled first-stage respondents who screened positive for emotional problems) in a local convenience sample. The second-stage sample was administered the screening scales along with the Structured Clinical Interview for DSM-IV (SCID). The K6 was subsequently included in the 1997 (N = 36116) and 1998 (N = 32440) US National Health Interview Survey, while the K10 was included in the 1997 (N = 10641) Australian National Survey of Mental Health and Well-Being. RESULTS: Both the K10 and K6 have good precision in the 90th-99th percentile range of the population distribution (standard errors of standardized scores in the range 0.20-0.25) as well as consistent psychometric properties across major sociodemographic subsamples. The scales strongly discriminate between community cases and non-cases of DSM-IV/SCID disorders, with areas under the Receiver Operating Characteristic (ROC) curve of 0.87-0.88 for disorders having Global Assessment of Functioning (GAF) scores of 0-70 and 0.95-0.96 for disorders having GAF scores of 0-50. CONCLUSIONS: The brevity, strong psychometric properties, and ability to discriminate DSM-IV cases from non-cases make the K10 and K6 attractive for use in general-purpose health surveys. The scales are already being used in annual government health surveys in the US and Canada as well as in the WHO World Mental Health Surveys. Routine inclusion of either the K10 or K6 in clinical studies would create an important, and heretofore missing, crosswalk between community and clinical epidemiology.

Adult↗

PubMed2001

Racial disparity in influenza vaccination: does managed care narrow the gap between African Americans and whites?

CONTEXT: Substantial racial disparities exist in use of some health services. Whether managed care could reduce racial disparities in the use of preventive services is not known. OBJECTIVE: To determine whether the magnitude of racial disparity in influenza vaccination is smaller among managed care enrollees than among those with fee-for-service insurance. DESIGN, SETTING, AND PARTICIPANTS: The 1996 Medicare Current Beneficiary Survey of a US cohort of 13 674 African American and white Medicare beneficiaries with managed care and fee-for-service insurance. MAIN OUTCOME MEASURES: Percentage of respondents (adjusted for sociodemographic characteristics, clinical comorbid conditions, and care-seeking attitudes) who received influenza vaccination and magnitude of racial disparity in influenza vaccination, compared among those with managed care and fee-for-service insurance. RESULTS: Eight percent of the beneficiaries were African American and 11% were enrolled in managed care. Overall, 65.8% received influenza vaccination. Whites were substantially more likely to be vaccinated than African Americans (67.7% vs 46.1%; absolute disparity, 21.6%; 95% confidence interval [CI], 18.2%-25.0%). Managed care enrollees were more likely than those with fee-for-service insurance to receive influenza vaccination (71.2% vs 65.4%; difference, 5.8%; 95% CI, 3.6%-8.3%). The adjusted racial disparity in fee-for-service was 24.9% (95% CI, 19.6%-30.1%) and in managed care was 18.6% (95% CI, 9.8%-27.4%). These adjusted racial disparities were both statistically significant, but the absolute percentage point difference in racial disparity between the 2 insurance groups (6.3%; 95% CI, -4.6% to 17.2%) was not. CONCLUSION: Managed care is associated with higher rates of influenza vaccination for both whites and African Americans, but racial disparity in vaccination is not reduced in managed care. Our results suggest that additional efforts are needed to adequately address this disparity.

Black or African American↗

PubMed2001

Statistical issues in reporting quality data: small samples and casemix variation.

PURPOSE: To present two key statistical issues that arise in analysis and reporting of quality data. SUMMARY: Casemix variation is relevant to quality reporting when the units being measured have differing distributions of patient characteristics that also affect the quality outcome. When this is the case, adjustment using stratification or regression may be appropriate. Such adjustments may be controversial when the patient characteristic does not have an obvious relationship to the outcome. Stratified reporting poses problems for sample size and reporting format, but may be useful when casemix effects vary across units. Although there are no absolute standards of reliability, high reliabilities (interunit F > or = 10 or reliability > or = 0.9) are desirable for distinguishing above- and below-average units. When small or unequal sample sizes complicate reporting, precision may be improved using indirect estimation techniques that incorporate auxiliary information, and 'shrinkage' estimation can help to summarize the strength of evidence about units with small samples. CONCLUSIONS: With broader understanding of casemix adjustment and methods for analyzing small samples, quality data can be analysed and reported more accurately.

Data Interpretation, Statistical↗

PubMed2001

National quality monitoring of Medicare health plans: the relationship between enrollees' reports and the quality of clinical care.

BACKGROUND: The clinical quality of health plans varies. The associations between different measures of health plan quality are incompletely understood. OBJECTIVE: To assess the relationships between enrollee reports on the quality of health plans as measured by the Consumer Assessment of Health Plans Study (CAHPS 2.0) survey and the clinical quality of care measured by the Medicare Health Plan Employer Data and Information Set (HEDIS). DESIGN: Observational cohort study. SAMPLE: National sample of 233 Medicare health plans that reported data using the CAHPS 2.0 survey and Medicare HEDIS during 1998. MEASURES: Five composite measures and four ratings derived from the CAHPS survey and six measures of clinical quality from Medicare HEDIS. RESULTS: Two composite measures ("getting needed care" and "health plan information and customer service") were significantly associated with most of the HEDIS clinical quality measures. The proportion of enrollees having a personal doctor was also significantly associated with rates of mammography, eye exams for diabetics, beta-blocker use after myocardial infarction, and follow-up after mental health hospitalization. Enrollees' ratings of health plan care were less consistently associated with HEDIS performance. In multivariable analyses, the measure of health plan communication ("health plan information and customer service") was the most consistent predictor of HEDIS performance. CONCLUSIONS: The pattern of associations we observed among some of the measures suggests that the CAHPS survey and HEDIS are complementary quality monitoring strategies. Our results suggest that health plans that provide better access and customer service also provide better clinical care.

Aged↗

PubMed2001

Physician incentives and disclosure of payment methods to patients.

OBJECTIVE: There is increasing public discussion of the value of disclosing how physicians are paid. However, little is known about patients' awareness of and interest in physician payment information or its potential impact on patients' evaluation of their care. DESIGN: Cross-sectional survey SETTING: Managed care and indemnity plans of a large, national health insurer. PARTICIPANTS: Telephone interviews were conducted with 2,086 adult patients in Atlanta, Ga; Baltimore, Md/Washington DC; and Orlando, Fla (response rate, 54%). MEASUREMENTS AND MAIN RESULTS: Patients were interviewed to assess perceptions of their physicians' payment method, preference for disclosure, and perceived effect of different financial incentives on quality of care. Non-managed fee-for-service patients (44%) were more likely to correctly identify how their physicians were paid than those with salaried (32%) or capitated (16%) physicians. Just over half (54%) wanted to be informed about their physicians' payment METHOD: Patients of capitated and salaried physicians were as likely to want disclosure as patients of fee-for-service physicians. College graduates were more likely to prefer disclosure than other patients. Many patients (76%) thought a bonus paid for ordering fewer than the average number of tests would adversely affect the quality of their care. About half of the patients (53%) thought a particular type of withhold would adversely affect the quality of their care. White patients, college graduates, and those who had higher incomes were more likely to think that these types of bonuses and withholds would have a negative impact on their care. Among patients who believed that these types of bonuses adversely affected care, those with non-managed fee-for-service insurance and college graduates were more willing to pay a higher deductible or co-payment in order to get tests that they thought were necessary. CONCLUSIONS: Most patients were unaware of how their physicians are paid, and only about half wanted to know. Most believed that bonuses or withholds designed to reduce the use of services would adversely affect the quality of their care. Lack of knowledge combined with strong attitudes about various financial incentives suggest that improved patient education could clarify patient understanding of the nature and rationale for different types of incentives. More public discussion of this important topic is warranted.

Adult↗

PubMed2000

Unmet health needs of uninsured adults in the United States.

CONTEXT: In 1998, 33 million US adults aged 18 to 64 years lacked health insurance. Determining the unmet health needs of this population may aid efforts to improve access to care. OBJECTIVE: To compare nationally representative estimates of the unmet health needs of uninsured and insured adults, particularly among persons with major health risks. DESIGN AND SETTING: Random household telephone survey conducted in all 50 states and the District of Columbia through the Behavioral Risk Factor Surveillance System. PARTICIPANTS: A total of 105,764 adults aged 18 to 64 years in 1997 and 117,364 in 1998, classified as long-term (>/=1 year) uninsured (9.7%), short-term (<1 year) uninsured (4.3%), or insured (86.0%). MAIN OUTCOME MEASURES: Adjusted proportions of participants who could not see a physician when needed due to cost in the past year, had not had a routine checkup within 2 years, and had not received clinically indicated preventive services, compared by insurance status. RESULTS: Long-term- and short-term-uninsured adults were more likely than insured adults to report that they could not see a physician when needed due to cost (26.8%, 21.7%, and 8.2%, respectively), especially among those in poor health (69.1%, 51.9%, and 21.8%) or fair health (48.8%, 42.4%, and 15.7%) (P<.001). Long-term-uninsured adults in general were much more likely than short-term-uninsured and insured adults not to have had a routine checkup in the last 2 years (42.8%, 22.3%, and 17.8%, respectively) and among smokers, obese individuals, binge drinkers, and people with hypertension, elevated cholesterol, diabetes, or human immunodeficiency virus risk factors (P<.001). Deficits in cancer screening, cardiovascular risk reduction, and diabetes care were most pronounced among long-term-uninsured adults. CONCLUSIONS: In our study, long-term-uninsured adults reported much greater unmet health needs than insured adults. Providing insurance to improve access to care for long-term-uninsured adults, particularly those with major health risks, could have substantial clinical benefits. JAMA. 2000;284:2061-2069

Adult↗

PubMed2000

Physicians' reports of focused expertise in clinical practice.

Little is known about the prevalence of focused expertise (special areas of expertise within a clinical field) among physicians, yet such expertise may influence how care is delivered. We surveyed general internists, pediatricians, cardiologists, infectious disease specialists, and orthopedic surgeons to describe the prevalence of focused expertise and identify associated physician and practice characteristics. About one quarter of generalists and three quarters of specialists reported a focused expertise within their primary specialty. Hospital-based physicians more often reported such expertise, and physicians reimbursed by capitation less often reported expertise. Learning how focused expertise affects processes and outcomes of care will contribute to decisions about physician training and staffing of medical groups.

Cardiology↗

PubMed2000

Dimensions of consumer-assessed quality of Medicare managed-care health plans.

OBJECTIVES: We investigated relationships at the health-plan level among member ratings of and reports on plans in the Consumer Assessment of Health Plans Survey (CAHPS). We sought a more parsimonious description of the reports that can be used in analyses of the distribution and correlates of consumer-assessed quality. SUBJECTS: There were 89,419 Medicare beneficiaries enrolled in 212 Medicare managed-care health plans who responded to CAHPS in 1998. MEASURES: There were 39 survey items measuring consumer ratings of and reports on care. METHODS: We adjusted correlations for sampling variability in the plan means and performed a principal factor analysis of the report items with oblique rotation. We grouped items that loaded heavily on the different factors, formed composites, and regressed rating items on the report composites. RESULTS: Four factors explained 75% of the variance in the reports. The corresponding groups of items were concerned with the following subjects: (1) interactions around delivery of care in the doctor's office; (2) customer service from the plan; (3) access to medical services provided by the plan, such as specialist care, equipment, therapy, or drugs; and (4) advice on health-promoting activities. Corrected Cronbach alpha for composites were 0.97, 0.93, 0.86, and 0.60. The "delivery" composite was strongly predictive of overall ratings of care, doctor, and specialist; the "customer" composite was strongly predictive of overall ratings of the plan. CONCLUSIONS: CAHPS distinguishes among dimensions of between-plan variability of consumer-assessed quality. Different global ratings are related to distinct groups of consumer reports on their experiences.

Adult↗

PubMed2000

Impact of sociodemographic case mix on the HEDIS measures of health plan quality.

BACKGROUND: The widely used Health Plan Employer Data and Information Set (HEDIS) measures may be affected by differences among plans in sociodemographic characteristics of members. OBJECTIVE: The objective of this study was to estimate effects of geographically linked patient sociodemographic characteristics on differential performance within and among plans on HEDIS measures. RESEARCH DESIGN: Using logistic regression, we modeled associations between age, sex, and residential area characteristics of health plan members and results on HEDIS measures. We then calculated the impact of adjusting for these associations on plan-level measures. SUBJECTS: This study included 92,232 commercially insured members with individual-level HEDIS data and an additional 20,615 members whose geographic distribution was provided. MEASURES: This study used 7 measures of screening and preventive services. RESULTS: Performance was negatively associated with percent receiving public assistance in the local area (6 of 7 measures), percent black (5 measures), and percent Hispanic (2 measures) and positively associated with percent college educated (6 measures), percent urban (2 measures), and percent Asian (1 measure) after controlling for plan and product type. These effects were generally consistent across plans. When measures were adjusted for these characteristics, rates for most plans changed by less than 5 percentage points. The largest change in the difference between plans ranged from 1.5% for retinal exams for people with diabetes to 20.2% for immunization of adolescents. CONCLUSIONS: Performance on quality indicators for individual members is associated with sociodemographic context. Adjustment has little impact on the measured performance of most plans but a substantial impact on a few. Further study with more plans is required to determine the appropriateness and feasibility of adjustment.

Adolescent↗

PubMed2000

Does the effect of respondent characteristics on consumer assessments vary across health plans?

Responses to the Consumer Assessments of Health Plans Survey (CAHPS) are related to respondent characteristics. CAHPS procedures include casemix adjustment to remove effects of difference in respondent characteristics on comparative plan ratings, under the assumption that casemix coefficients are homogeneous across plans. The authors analyzed data from the Washington state CAHPS demonstration, fitting hierarchical models in which coefficients of casemix variables and intercepts could vary by plan. They estimated the impact of variability in casemix coefficients on plan adjustments and also assessed the implications for differential effects of individual characteristics at different plans. Estimated between-plan variability of coefficients was small, but the data are consistent with substantially larger variability. The potential impact of this variability on adjustments for plans was small relative to the magnitude of the adjustments. Comparisons between plans for individuals, however, could be affected substantially. This methodology could be useful wherever casemix adjustment is applied.

Adult↗

PubMed2000

How consumer assessments of managed care vary within and among markets.

This study investigated the extent to which the Consumer Assessments of Health Plans Survey (CAHPS) distinguishes performance of Medicare managed care (MMC) health plans. Results indicate that CAHPS ratings and report composites distinguish among plans both nationally and within markets. Global ratings of a health plan and reports on customer services varied strongly at the individual plan level, with smaller effects seen at regional and Metropolitan Statistical Area (MSA) levels. Ratings of doctors and health care, and reports on experiences in the doctor's office varied more among regions and among MSAs than among plans within the same MSA. These patterns are consonant with our hypotheses about the determinants of these ratings: customer service is a distinct plan function, but medical services are provided by networks that often overlap for plans in the same area. We conclude that the CAHPS-MMC survey can inform consumers choosing among plans as well as policymakers and researchers.

Adult↗

PubMed1999

Applying the Cox proportional hazards model for analysis of latency data with interval censoring.

The latency time of an infectious disease is defined as the time from infection to disease onset. This paper applies the proportional hazards model to estimate the effect of covariates on latency when the time of disease onset is exact or right-censored but the time of infection is interval-censored. We use a Monte Carlo EM algorithm to estimate parameters of the joint distribution of infection times and latency times. At each EM iteration, exact infection times are multiply imputed from the density determined by the parameters of the infection and latency time distributions. The methodology is tested using a simulation study and is applied to data from a cohort of haemophiliacs with HIV disease.

Algorithms↗

PubMed1999

Sample allocation for overlapping domains in a physician survey with a limited population.

We consider an analytic survey in which each survey unit can respond with respect to one or more domains to which it belongs. In this situation, the optimal sample allocation is constrained by the number of available units in each stratum defined by a set of domains. We present optimal sample allocation rules for this situation, and other rules that apply when there are additional constraints on sample sizes or variances by domain. We apply these rules to our motivating example, the design of a survey of physicians on their experiences with health plans, in which each physician can only be asked about her experience with one plan regardless of her number of affiliations.

Algorithms↗

PubMed1999

Use of hormone replacement therapy by postmenopausal women in the United States.

BACKGROUND: The benefits and risks of hormone replacement therapy (HRT) in postmenopausal women are not fully defined, and individual characteristics and preferences may influence decisions to use this therapy. Previous studies of postmenopausal women who use HRT have been conducted in local or highly selected cohorts or have not focused on current use. OBJECTIVE: To examine sociodemographic, clinical, and psychological factors associated with current use of HRT in a national population-based cohort. DESIGN: Random-digit telephone survey. SETTING: Probability sample of U.S. households with a telephone. PARTICIPANTS: 495 postmenopausal women 50 to 74 years of age in 1995. MEASUREMENTS: Current use of HRT. RESULTS: Current use of HRT was reported by 37.6% of women (58.7% of those who underwent hysterectomy and 19.6% of those who did not undergo hysterectomy; P = 0.001). In multivariable analyses, use of HRT was more common among women in the South (adjusted odds ratio, 2.67 [95% CI, 1.08 to 6.59]) and West (odds ratio, 2.76 [CI, 1.01 to 7.53]) than the Northeast. Use was more common among college graduates (odds ratio, 3.72 [CI, 1.29 to 10.71]) and less common among women with diabetes mellitus (odds ratio, 0.17 [CI, 0.05 to 0.51]). Other cardiac risk factors and most psychological characteristics were not associated with HRT use. CONCLUSIONS: Sociodemographic factors, such as region and education, may be more strongly associated with use of HRT than clinical factors, such as risk for cardiovascular disease. Future efforts should focus on understanding sociodemographic variations, defining which women are most likely to benefit, and targeting therapy to them.

Aged↗

PubMed1999

The impact of having parents report about both their own and their children's experiences with health insurance plans.

OBJECTIVES: The aim of this study was to determine whether parents rate their children's care differently when they also rate their own care than when they do not. METHODS: Subjects were employees of Washington State who had been enrolled in a health plan for at least 6 months and who had at least one covered child. Subjects were randomly assigned to four study groups that were surveyed using different protocols. To assess the stability of responses over time, a follow-up telephone interview was conducted with individuals in two of the groups. RESULTS: Parents or guardians who received both the Adult and Child Surveys were less likely to complete a survey than those who received only one survey. Responses to selected survey questions were quite stable between survey administrations. Parents who rated only their child's health care experiences generally gave more positive responses than those who also rated their own care, although few of these differences were statistically significant. This may have been due, in part, to the lower response rates in the latter group. The pairs of survey questions that ask about the adult's and child's experiences with the same aspects of care had moderate to high levels of association. The pair with the weakest association asked how clearly the doctor or nurse explained things to the adult or the child. CONCLUSIONS: Sending both an adult and child survey to an adult could have an effect on the pattern of responses and result in lower response rates, but this might be a cost-effective way to collect reports about both adult and child health care.

Adult↗

PubMed1999

Physician experiences with, and ratings of, managed care organizations in Massachusetts.

BACKGROUND: Physicians can provide important information about how managed care plans affect the delivery of health care. Assessments of the quality of managed care plans have rarely used physician evaluations. OBJECTIVES: To elicit physician evaluations of managed care plans and to determine factors associated with those evaluations. RESEARCH DESIGN: Physicians were asked in a mail survey to evaluate a managed care plan they were associated with. SUBJECTS: Probability sample of 1,336 physicians associated with the five largest managed care health plans in Massachusetts. MEASURES: Physicians were asked about the extent to which the management strategies used by a plan influenced their clinical behavior and about the quality of care available to their patients. RESULTS: Evaluations of the plans were significantly different among the eight units evaluated. Some differences between divisions within plans were as large as differences among plans. Physicians reported that the use of education and peer influence influenced their clinical behavior and facilitated the provision of high quality care more than did rules and regulations or financial incentives. Physicians evaluated most positively plans, which they said used educational strategies more than other plans and which used rules and regulations and financial incentives less. Physicians tended to rate staff and group model plans more positively than did other plans. CONCLUSIONS: Physicians can provide important information about the extent to which the organization and operation of managed care plans affect the provision of high quality care.

Attitude of Health Personnel↗

PubMed1999

Applying the Cox proportional hazards model when the change time of a binary time-varying covariate is interval censored.

This paper develops methodology for estimation of the effect of a binary time-varying covariate on failure times when the change time of the covariate is interval censored. The motivating example is a study of cytomegalovirus (CMV) disease in patients with human immunodeficiency virus (HIV) disease. We are interested in determining whether CMV shedding predicts an increased hazard for developing active CMV disease. Since a clinical screening test is needed to detect CMV shedding, the time that shedding begins is only known to lie in an interval bounded by the patient's last negative and first positive tests. In a Cox proportional hazards model with a time-varying covariate for CMV shedding, the partial likelihood depends on the covariate status of every individual in the risk set at each failure time. Due to interval censoring, this is not always known. To solve this problem, we use a Monte Carlo EM algorithm with a Gibbs sampler embedded in the E-step. We generate multiple completed data sets by drawing imputed exact shedding times based on the joint likelihood of the shedding times and event times under the Cox model. The method is evaluated using a simulation study and is applied to the data set described above.

AIDS-Related Opportunistic Infections↗

PubMed1998

The relationship between method of physician payment and patient trust.

CONTEXT: Trust is the cornerstone of the patient-physician relationship. Payment methods that place physicians at financial risk have raised concerns about patients' trust in physicians to act in patients' best interests. OBJECTIVE: To evaluate the extent to which methods of physician payment are related to patient trust. DESIGN: Cross-sectional telephone interview survey done between January and June 1997. SETTING: Health plans of a large national insurer in Atlanta, Ga, the Baltimore, Md-Washington, DC, area, and Orlando, Fla. PARTICIPANTS: A total of 2086 adult managed care and indemnity patients. MAIN OUTCOME MEASURE: A 10-item scale (alpha = .94) assessing patients' trust in physicians. RESULTS: More fee-for-service (FFS) indemnity patients (94%) completely or mostly trust their physicians to "put their health and well-being above keeping down the health plan's costs" than salary (77%), capitated (83%), or FFS managed care patients (85%) (P<.001 for pairwise comparisons). In multivariate analyses that adjusted for potentially confounding factors, FFS indemnity patients also had higher scores on the 10-item trust scale than salary (P<.001), capitated (P<.001), or FFS managed care patients (P<.01). The effects of payment method on patient trust were reduced when a measure based on patients' reports about physician behavior (eg, Does your physician take enough time to answer your questions?) was included in the regression analyses, but the differences remained statistically significant, except for the comparison between FFS managed care and FFS indemnity patients (P=.08). Patients' perceptions of how their physicians were paid were not independently associated with trust, but the 37.7% who said they did not know how their physicians were paid had higher levels of trust than other patients (P<.01). A total of 30.2% of patients were incorrect about their physicians' method of payment. CONCLUSIONS: Most patients trusted their physicians, but FFS indemnity patients have higher levels of trust than salary, capitated, or FFS managed care patients. Patients' reports of physician behavior accounted for part of the variation in patients' trust in physicians who are paid differently. The impact of payment methods on patient trust may be mediated partly by physician behavior.

Attitude to Health↗