Calendar time trends of the insulin-dependent diabetes mellitus mortality in Allegheny county, Pennsylvania.

This study applied a Cox proportional hazard model to investigate the calendar time trends of insulin-dependent diabetes mellitus (IDDM) mortality. The study population was the IDDM patients who were diagnosed in the period 1965-1979, less than or equal to 19 years of age at diagnosis, and were residents of Allegheny County, PA. The mortality follow-up for each individual was recorded from the diagnosis of IDDM and till 31 December 1990. There were 999 individuals in this study, and 68 deaths (6.8%) occurred during this 26-year investigation period. Overall, for the patients with the same IDDM duration, non-whites were 1.7 times more likely to die than white group; female IDDM patients had a higher risk of death than male IDDM patients (1.27:1); and the risk of mortality increased as the age at diagnosis increased. When controlling for the gender, ethnic groups and age at onset effect, the risk of dying in different calendar years appeared to be a quadratic form. The highest mortality appeared in the late 60's, and the lowest was in the period of 1975-1979. Disappointingly the mortality has begun to rise again in the latest time frame.