Work ability of workers in western China: reference data.

BACKGROUND The Work Ability Index (WAI) is a validated and widely used research tool. Reference data for Chinese workers by age, gender and work content are poorly documented or lacking. OBJECTIVE To provide reference data for work ability among workers in western China. METHODS A random sample of 10 218 workers (including manual, professional, clerical and semi-skilled workers) in western China, aged 16-69 years, was taken from several studies and the WAI questionnaire was administered. RESULTS All the WAI scores were distributed continuously and nearly normally. The WAI for female workers was significantly higher than for males (P < 0.01) and the 'poor' WAI category only accounted for 3% of females, against 6% of males. WAI scores declined with age and changed variably among workers according to work content and age. Mean WAI scores of manual workers declined rapidly beyond the age of 35 years, and beyond age 45 years for professional and clerical workers. WAI scores were distributed differently according to work content and age group (P < 0.01). WAI categories differed by work content and age group both for male and female workers. CONCLUSION WAI is validated in Chinese occupational practices. Some reference data are different from Finnish data. This study provides gender, age and work-content-specific WAI reference values that will help enable comparison and intervention evaluation in further studies.