Longest held occupation in a lifetime and risk of disability in activitiesof daily living

Objectives-To examine the association between the longest held occupation i n a Lifetime and risk of disability in activities of daily living (ADL) amo ng elderly people (65 years and older) in northern Taiwan. Methods-A case-control design was used nested within two cohorts of a total of 2198 elderly people who had been followed up either between 1993 and 19 97 or between 1996 and 1997. Cases were 360 elderly people with ADL disabil ity within the study period. For each case, two sex matched controls were r andomly sampled from the pool of elderly people free from ADL disability. O ccupational data were collected through interviews conducted in 1997. Perfo rmed job contents were classified into occupational categories and occupati on based social classes. Unconditional logistic regression techniques were used to estimate relative risk and 95% confidence intervals (95% CIs) of AD L disability. Results-Compared with people who were former legislators, government admini strators, or business executives and managers, workers in agriculture, anim al husbandry, forestry, or fishing (odds ratio (OR) 1.9, 95% CI 1.1 to 3.5) and workers in craft and related trades (OR 1.9, 95% CI 1.1 to 3.4) had si gnificantly increased risks of subsequent ADL disability. Differential risk s of ADL disability were found across social classes, with a significant do se-response trend in which unskilled blue collar workers had an 1.8 times h igher risk of ADL disability than higher social classes of white collar wor kers. Conclusions-After adjustment for education, there was still an inverse rela tion between risk of ADL disability and social class. Although total contro l for all the known risk factors for ADL disability among elderly people wa s impossible, the results tend to suggest a potential for an effect of long est held occupation in a lifetime on risk of ADL disability.