Change in type A behaviour among medical students: a 4-year longitudinal study.

Medical students were administered a measure of Type A behaviour at first-year orientation (n = 178), and about 9 months into their first (n = 169), second (n = 122), third (n = 73), and fourth (n = 86) years. Type A behaviour decreased over the course of the first year and from the start of the first year to the second year; however, no differences were found between the first (at 9 months) and second years. From the first (at 9 months) year and from the combined preclinical years to the third year, however, Type A behaviour increased. Type A behaviour peaked during the fourth year and was significantly higher than the level in the first year (at 9 months). Also, Type A behaviour was higher during the clinical years relative to the first year (at 9 months). The results were interpreted in the context of the developmental stresses experienced by students during each year. The relative ranking of the Type A scores was reasonably stable (test-retest) during an interval of 3 years 8 months.