Analysis of age-period-cohort effects on overall mortality in Andalusia (Southern Spain)

Abstract

Objectives: To evaluate the age-period-cohort effects on overall mortality in Andalusia (Spain).

Study design: An ecological study was implemented with a Lexis diagram triangle comprising each annual age group, year of death and year of birth as the unit of analysis.

Methods: In all 1,384,899 deaths from all causes were analysed for individuals between the ages of 1 and 84 years who died in Andalusia in the period 1981-2008. A non-linear regression model was estimated for each gender group and geographical area. The effects of age, year of death and birth cohort were parameterized using B-spline smoothing functions.

Results: There is a downward trend in mortality by age to around the age of 15 years, from which point the trend turned upwards. For cohorts born between 1945 and 1965, the rate climbed steadily. From 1965, the rate turned downwards. Death rates increased between 1995 and 2000, only to turn down again until the end of the period. Broadly, these results were similar for both men and women, in all the provinces of Andalusia and for Andalusia as a whole.

Conclusions: This study points to an age-period-cohort effect on deaths from all causes in all the geographic areas studied.

Keywords: Age–period–cohort; Andalusia; Mortality; Non-linear regression; Spain.