Abstract
OBJECTIVE: To investigate evidence of an association between school teaching and mortality from autoimmune diseases. METHODS: A proportional mortality study using US death certificates from the 1985-95 period was conducted. Death certificates that listed elementary or secondary school teaching as the usual occupation were identified, as were those that cited any of 13 autoimmune diseases as a cause of death. Proportional mortality ratios (PMR) were calculated to compare autoimmune disease mortality among teachers to that among persons in other professional occupations. RESULTS: The PMR for total autoimmune disease mortality among teachers was 113 (p < 0.0001). Rheumatic diseases accounted for 53.1% of the total excess in mortality and multiple sclerosis accounted for 39.9%. Significantly elevated autoimmune disease mortality occurred for female teachers (PMR = 111, p < 0.0001), male teachers (PMR = 124, p < 0.0001), white teachers (PMR = 112, p < 0.0001), non-white teachers (PMR = 118, p = 0.005), elementary teachers (PMR = 111, p < 0.0001), and secondary teachers (PMR = 130, p < 0.0001). There was an inverse trend (p < 0.0001) in the level of excess mortality relative to age. PMR were 149, 144, 127, 118, 108, and 102 for teachers in the 35-44, 45-54, 55-64, 65-74, 75-84, and > or = 85 year age groups, respectively. Excess mortality was significantly greater in secondary teachers than elementary teachers both in total (PMR = 112, p = 0.04) and in the 35-44 age group (PMR = 155, p = 0.03). CONCLUSION: Our results substantiate excess mortality from autoimmune diseases among teachers and suggest that, relatively early in their careers, teachers experience an occupational exposure that increases risk of autoimmune diseases.
