Effects of social class, sex, and region of residence on age at death from cystic fibrosis.

To determine the time trend in age at death from cystic fibrosis and the independent effects of social class, sex, and region of residence mortality data for England and Wales from 1959 to 1986 were analysed. Median age at death increased from 6 months in 1959 to 17 years in 1986 and was higher in most years from 1970 in male patients (by one to six years) and in social classes with non-manual occupations (by one to 12 years). Independent odds ratios for death above the median age for the year of death (calculated for years from 1974, when regions of residence were coded by regional health authority area) were 1.47 (95% confidence interval 1.16 to 1.87) in male compared with female patients and 2.75 (2.16 to 3.52) in non-manual compared with manual social classes. The independent odds of death at above the median age also varied significantly among regions of residence by a ratio of up to 2.67. Social class, sex, and region of residence are all potential determinants of survival of patients with cystic fibrosis. Social class is particularly likely to confound the effect of management in specialist centres on survival.