A cohort study on the relation between health status evaluated by occupational health survelliance and mortality

Abstract

Objectives To study the relation between the health status(healthy,fairly healthy,follow up and abnormal) evaluated by Guangzhou occupational health surveillance(OHS) and the mortality. Methods Individual health records of 78 785 workers, aged≥35,from 399 factories were established by the Guangzhou OHS system in 1989～1992 as baseline informaiton.Prospective cohort study was used and the study was followed up to 31 Dec,1998.Chi squared test and Cox regression model were used for data analysis. Results (1)This cohort of 78 785 workers were followed up for 8 years,with a total of 627 635 person years(389 240 person years in men).1 525 deaths had occurred and the total mortality rate was 243.0 per 100?000 person years(men:330.4,women:100.3).(2)46.1% of men workers and 34.4% of women workers had a history of occupational exposure,while 70.3% and 1.5% of men and women workers respectively had smoking history.(3)OHS health status was significantly related with total mortality in both men and women.After adjusting for age,education,smoking and occupational exposure,using healthy and fairly healthy workers as the reference,the relative risks(RR) for workers with follow up and abnormal status were 1.85(95%CI1.58～2.18) and 2.71(95%CI2.39～3.08) in men,and 1.80 (95% CI 1.22～2.64) and 2.89(95%CI2.17～3.86) in women,respectively.Further analysis for neoplastic and cardio cerebral vascular deaths showed similar relation with OHS status.(4)In men with follow up or abnormal OHS status,the RR for cardio cerebral vascular deaths was significantly greater in middle age(35～49) than in older age(50～59). Conclusion The workers’ individual occupational health surveillance records provide readily available data for epidemiologic studies at low costs,and follow up observation is possible.The occupational health surveillance status,being closely related with all deaths,is valuable to predict mortality.It is important to adopt early preventive health measures and clinical treatment to prevent early deaths from cardio cerebral vascular diseases in middle aged men.