Excess autoimmune disease mortality among school teachers.

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.