Objective. To develop and characterize utilization‐based service areas for the United States which reflect the travel of Medicare beneficiaries to primary care clinicians. Data Source/Study Setting. The 1996–1997 Part B and 1996 Outpatient File primary care claims for fee‐for‐service Medicare beneficiaries aged 65 and older. The 1995 Medicaid claims from six states (1995) and commercial claims from Blue Cross Blue Shield of Michigan (1996). Study Design. A patient origin study was conducted to assign 1999 U.S. zip codes to Primary Care Service Areas on the basis of the plurality of beneficiaries' preference for primary care clinicians. Adjustments were made to establish geographic contiguity and minimum population and service localization. Generality of areas to younger populations was tested with Medicaid and commercial claims. Data Collection/Extraction Methods. Part B primary care claims were selected on the basis of provider specialty, place of service, and CPT code. Selection of Outpatient File claims used provider number, type of facility/service, and revenue center codes. Principal Findings. The study delineated 6,102 Primary Care Service Areas with a median population of 17,276 (range 1,005–1,253,240). Overall, 63 percent of the Medicare beneficiaries sought the plurality of their primary care from within area clinicians. Service localization compared to Medicaid (six states) and commercial primary care utilization (Michigan) was comparable but not identical. Conclusions. Primary Care Service Areas are a new tool for the measurement of primary care resources, utilization, and associated outcomes. Policymakers at all jurisdictional levels as well as researchers will have a standardized system of geographical units through which to assess access to, supply, use, organization, and financing of primary care services.

Panic disorder is characterized by spontaneous and recurrent panic attacks, often accompanied by agoraphobia. The results of family, twin, and segregation studies suggest a genetic role in the etiology of the illness. We have genotyped up to 23 families that have a high density of panic disorder with 540 microsatellite DNA markers in a first-pass genomic screen. The thirteen best families (ELOD > 6.0 under the dominant genetic model) have been genotyped with an ordered set of markers encompassing all the autosomes, at an average marker density of 11 cM. Over 110,000 genotypes have been generated on the whole set of families, and the data have been analyzed under both a dominant and a recessive model, and with the program SIBPAIR. No lod scores exceed 2.0 for either parametric model. Two markers give lod scores over 1.0 under the dominant model (chromosomes 1p and 20p), and four do under the recessive model (7p, 17p, 20q, and X/Y). One of these (20p) may be particularly promising. Analysis with SIBPAIR yielded P values equivalent to a lod score of 1.0 or greater (i.e., P < .016, one-sided, uncorrected for multiple tests) for 11 marker loci (2, 7p, 8p, 8q, 9p, 11q, 12q, 16p, 20p and 20q).

In the United States. a debate has existed for decades about whether foreign-trained physicians (known in the US as`international medical graduates' or`IMGs') and US medical graduates (USMGs) have been di erentially distributed such that IMGs were more likely to be found in locales characterized as high in need or medical underservice. This`safety net' hypothesis has been countered by the IMG`surplus exacerbation' argument that IMGs have simply swelled an already abundant supply of physicians without any disproportionate service to areas in need. Through an analysis of the American Medical Association Physician Master®le and the Area Resource File, we classi®ed post-resident IMGs and USMGs into low and high need counties in each of the US states, compared the percentage distributions, and determined whether IMGs were found disproportionately in high need or underserved counties. Using four measures (infant mortality rate, socio-economic status, proportion non-white population, and rural county designation), we show that there were consistently more states having IMG disproportions than USMG disproportions. The magnitude of the di erences was greater for IMGs than for USMGs, and there was a correlation between IMG disproportions and low doctor/100,000 population ratios. These ®ndings are shown to exist simultaneously with two empirical facts: ®rst, not all IMGs were located in high new or underserved counties; second, IMGs were more likely than USMGs to be located in states with a large number of physicians. The juxtaposition of an IMG presence in`safety net' locales and of IMGs' contribution to a physician abundance is discussed within the context of the current debate about a US physician`surplus' and initiatives to reduce the number of IMGs in residency training. #

International medical graduates do help reduce rural physician shortages, but interstate variation points to the role of state policies in influencing international medical graduates' distribution in rural, underserved areas. Such variation also can come about from many different causes, so there is a need for further research to determine why international medical graduates help compensate for physician shortages more so in some states than in others.