Increasing rural-urban gradients in US suicide mortality, 1970-1997.

Objectives: This study examined rural-urban gradients in US suicide mortality and the extent to which such gradients varied across time, sex, and age.
Methods: Using a 10-category rural-urban continuum measure and 1970-1997 county mortality data, we estimated rural-urban differentials in suicide mortality over time by multiple regression and Poisson regression models.
Results: Significant rural-urban gradients in age-adjusted male suicide mortality were found in each time period, indicating rising suicide rates with increasing levels of rurality. The gradient increased consistently, suggesting widening rural-urban differentials in male suicides over time. When controlled for geographic variation in divorce rate and ethnic composition, rural men, in each age cohort, had about twice the suicide rate of their most urban counterparts. Observed rural-urban differentials for women diminished over time. In 1995 to 1997, the adjusted suicide rates for young and working-age women were 85% and 22% higher, respectively, in rural than in the most urban areas.
Conclusions: The slope of the relationship between rural-urban continuum and suicide mortality varied substantially by time, sex, and age. Widening rural-urban disparities in suicide may reflect differential changes over time in key social integration indicators.