For most analyses, the dependent variable was the PMP at each of the 125 U.S. medical schools during the 1998 to 1999, 1999 to 2000, and 2000 to 2001 academic years. We obtained the PMP for all 125 schools as follows: In July 2001, we e-mailed deans of student affairs at each school and asked them what the PMP was in their school in 1999, 2000, and 2001. Deans who did not respond the first time were e-mailed again. Simultaneously, we obtained the Electronic Residency Admissions System (ERAS) Match results from the NRMP, promising to keep individual schools' PMP confidential.
Independent variables were obtained thus: The PMP at each school from 1975 to 1978 was published in the Journal of Psychiatric Education (
+25). In 1993, the PMP from each school from 1987 to 1992 was presented at the APA Council on Education and Career Development (
+26), which one of us (F.S.S.) attended. The following were obtained from the AMA and the Association of American Medical College's Annual Medical School Questionnaires for 1999 to 2000 and 2000 to 2001: age of the school; admissions preference for applicants from disadvantaged or rural backgrounds or preferring primary care; tuition; and proportion of African American, Asian American, Euro-American, Hispanic and Native American students (27; Barbara Barzansky, personal communication, 2002).
We obtained the proportion of psychiatry IMGs at each school from the APA's 1997 Directory of Psychiatry Residency Programs (
+28), which was the most recent data available. We also obtained the most recent data (also from 1997) on the extent of local managed care penetration from Harvard University's Health System Consortium (29; Eric Campbell, personal communication), as measured by market stage. The components of market stage include: health maintenance organization (HMO) penetration, HMOs with enrollees earning $100,000 or more, percentage of employees in the top three HMOs, hospital occupancy days/1,000 beds in the system, percentage of group specialists capitated, percentage of Medicare population in HMOs, percentage of Medicaid population in HMOs, and commercial HMO premiums (
+29). We ascertained clerkship lengths from the AAMC's 2000 to 2001 curriculum directory (
+30). We obtained information on deans from a listing that was published in
Psychiatric News (
+31).
Geographic region was as such: Northeast—Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont. Southeast—Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia. Midwest—Illinois, Indiana, Iowa, Kansas, Michigan, Missouri, Minnesota, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. Southwest: Arizona, New Mexico, Oklahoma, and Texas. West—Colorado, Nevada, and Utah. West Coast—California, Hawaii, Oregon and Washington. The Puerto Rican (Cayey, Ponce, San Juan) schools comprised another group. Alaska, Montana, Idaho, and Wyoming have no medical schools.
We used an SPSSx 11.0 system (
+32,
+33). The dependent variable, PMP, is interval-ratio. When an independent variable was categorical, we used independent samples t tests or analysis of variance (ANOVA). When an independent variable was interval or ratio and the variables were not normally distributed, we used Spearman product-moment correlations. When we conducted multiple correlation analyses for year-by-year and decade-by-decade variation in PMP (
+Table 2), a Bonferroni correction revised the cutoff level for significance to p < 0.007. For geographic region, we used Tukey's post hoc analysis to identify significant pairwise mean regional PMP differences whenever we discovered a significant main effect of region.
Because we used one dependent variable and multiple independent variables, we used multiple regression analysis with simultaneous entry of predictor variables to control for associations among independent variables. For this analysis, we chose those independent variables for which the association with PMP was statistically significant or showed a statistical trend.