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Biomedical subjects

G D Wozniak

Publications and source records attributed to G D Wozniak.

6 recordsLinked to original sources
PubMed2000

HMO penetration and the geographic mobility of practicing physicians.

In this study, we assessed the influence of changes in health maintenance organization (HMO) penetration on the probability that established patient care physicians relocated their practices or left patient care altogether. For physicians who relocated their practices, we also assessed the impact of HMO penetration on their destination choices. We found that larger increases in HMO penetration decreased the probability that medical/surgical specialists in early career stayed in patient care in the same market, but had no impact on generalists, hospital-based specialists, or mid career medical/surgical specialists. We also found that physicians who relocated their practices were much more likely to choose destination markets with the same level of HMO penetration or lower HMO penetration compared with their origin markets than they were to choose destination markets with higher HMO penetration. The largely negligible impact of changes in HMO penetration on established physicians' decisions to relocate their practices or leave patient care is consistent with high relocation and switching costs. Relocating physicians' attraction to destination markets with the same level of HMO penetration as their origin markets suggests that, while physicians' styles of medical practice may adapt to changes in market conditions, learning new practice styles is costly.

Career Mobility↗
PubMed2000

HMO growth and the geographical redistribution of generalist and specialist physicians, 1987-1997.

OBJECTIVE: To assess the impact of the growth in HMO penetration in different metropolitan areas on the change in the number of generalists, specialists, and total physicians, and on the change in the proportion of physicians who are generalists. DATA SOURCES/STUDY SETTING: The American Medical Association Physician Masterfile, to obtain the number of patient care generalists and specialists in 1987 and in 1997 who were practicing in each of 316 metropolitan areas in the United States. Additional data for each metropolitan area were obtained from a variety of sources, and included HMO penetration in 1986 and 1996. STUDY DESIGN: We estimated multivariate regression models in which the change in the number of physicians between 1987 and 1997 was a function of HMO penetration in 1986, the change in HMO penetration between 1986 and 1996, population characteristics and physician fees in 1986, and the change in population characteristics and fees between 1986 and 1996. Each model was estimated using ordinary least squares (OLS) and two-stage least squares (TSLS). PRINCIPAL FINDINGS: HMO penetration did not affect the number of generalist physicians or hospital-based specialists, but faster HMO growth led to smaller increases in the numbers of medical/surgical specialists and total physicians. Faster HMO growth also led to larger increases in the proportion of physicians who were generalists. Our best estimate is that an increase in HMO penetration of .10 between 1986 and 1996 reduced the rate of increase in medical/surgical specialists by 10.3 percent and reduced the rate of increase in total physicians by 7.2 percent. CONCLUSIONS: The findings of this study support the notion that HMOs reduce the demand for physician services, particularly for specialists' services. The findings also imply that, during the past decade, there has been a redistribution of physicians-especially medical/surgical specialists-from metropolitan areas with high HMO penetration to low-penetration areas.

Catchment Area, Health↗
PubMed2000

The effect of HMO penetration on physician retirement.

OBJECTIVE: To examine the effect of HMO penetration on physician retirement. STUDY DESIGN: We linked together historical data from the Physician Masterfile of the American Medical Association for successive years to track changes in physicians' activity status between 1980 and 1997. We used a multivariate discrete-time survival model to examine how the probability of physician retirement was affected by the level of HMO penetration in the physician's market area, controlling for other physician and market characteristics. The study population included all active allopathic patient-care physicians in the United States who reached age 55 between the years of 1980 and 1996. The main outcome measure was physician retirements as reported on the Physician Masterfile. PRINCIPAL FINDINGS: HMO penetration had a statistically significant positive effect on the retirement probabilities of generalists and medical/surgical specialists, but it s effect on hospital-based specialists and psychiatrists was not significant . For generalists regression-adjusted retirement probabilities were roughly 13 percent greater in high-penetration markets (HMO penetration of 45 percent ) than in low-penetration markets (HMO penetration of 5 percent ). For medical/surgical specialist s regression-adjusted retirement probabilities were roughly 17 percent greater in high-penetration markets than in low-penetration markets. CONCLUSIONS: Our findings suggest that many older physicians have found it preferable to retire rather than adapt their practices to an environment with a high degree of managed care penetration . Because the number of physicians entering the older age categories will increase rapidly over the next 20 years, the growth of managed care and other influences on physician retirement will play an increasingly important role in determining the size of the physician workforce.

Aged↗
PubMed1999

Self-reported physician specialties and the primary care content of medical practice: a study of the AMA physician masterfile. American Medical Association.

BACKGROUND: Many internal medicine physicians report both primary and secondary specialties in the American Medical Association (AMA) Physician Masterfile. Usually, those represent combinations of general internal medicine and medical subspecialty practice. Whether reported specialty combinations can be used to assess the contribution of specialists to primary care is unknown. OBJECTIVES: To examine whether internists' primary and secondary specialties reported in the Masterfile reflect the amount of primary care that they provide, and whether changes over time in internists' reported specialties reflect changes in primary care provision. DESIGN: The Masterfile was used to identify internists' reported specialties in 1992 and in 1996. A mail questionnaire was used to assess the primary care content of physicians' practices. The association between reported specialties and the amount of primary care provided was evaluated using analysis of variance. SUBJECTS: A stratified random sample of internists in active clinical practice. MEASURES: The percentage of visits which were for the general medical care of patients for whom the physicians maintained ongoing responsibility. In addition, how often the physicians initiated the provision of preventive care for their regular patients, provided general medical care to these patients, and organized and coordinated the care received by these patients from other providers. RESULTS: There was a strong association between the internists' primary and secondary specialties reported in the Masterfile and measures of the primary care content of physicians' practices (P < 0.0001). In contrast, changes over time in internists' reported specialties were not associated with physicians' assessments of changes in the primary care content of their practices. CONCLUSIONS: Aggregate estimates of the availability of primary care in the US could be adjusted by taking into account the primary and secondary specialties reported by internal medicine physicians in the AMA Physician Masterfile.

American Medical Association↗
PubMed1998

Health maintenance organization penetration and the practice location choices of new physicians: a study of large metropolitan areas in the United States.

OBJECTIVES: The rapid growth of health maintenance organizations is reshaping the practice opportunities available to physicians. The practice location decisions of new physicians provide a sensitive bellwether of these changes. This study assessed the effect of health maintenance organization penetration on practice location for physicians completing graduate medical education (GME). METHODS: Conditional logit regression analysis was used to determine the effect of health maintenance organization penetration on practice location, controlling for other market characteristics. Subjects were physicians who finished GME between 1989 and 1994 and who located in one of the 98 US metropolitan areas with more than 500,000 population. The outcome measure was the particular metropolitan area chosen by each new physician. RESULTS: Early in the study period, new generalists were significantly more likely to locate in metropolitan areas with high health maintenance organization penetration than in low penetration areas, whereas new specialists' practice location choices were not associated with health maintenance organization penetration. The likelihood of choosing a high penetration relative to a low penetration area declined with time, however, for both generalists and specialists. Consequently, by the end of the study period, health maintenance organization penetration had a weak but significant negative effect on practice location for generalists and a strong negative influence on practice location for specialists. CONCLUSIONS: New generalists who completed graduate medical education between 1989 and 1994 were more likely than new specialists to locate in market areas with high health maintenance organization penetration; however, the proportions of both generalists and specialists who chose high penetration areas decreased during the study period. This finding may reflect reduced practice opportunities in high penetration areas relative to low penetration areas as health maintenance organizations' systems for controlling utilization began to yield results. Alternatively, new physicians may have become more hesitant to accept available positions in high penetration areas.

Adult↗