Background Manufacturing industry is the main body of China's national economy, and manufacturing employees provide solid guarantee and support for the vigorous development of China's manufacturing industry. The research on job burnout of manufacturing employees is helpful to prevent or alleviate the health damage and economic loss caused by job burnout.

Objective To investigate the status and influencing factors of job burnout among manufacturing employees in China, and evaluate the potential mediating effect of job burnout between job stress and depressive symptoms.

Methods A cross-sectional study was performed from August to October 2019 and from June to September 2020 in seven provinces of China. Study participants were recruited from 21 manufacturing companies covering 11 manufacturing subdivisions using multistage stratified cluster sampling. General Burnout Scale, Core Occupational Stress Scale, and Patient Health Questionnaire-9 were used to evaluate job burnout, job stress, and depressive symptoms. Mann-Whitney U test and Kruskal-Wallis H test were used to compare data between two independent samples and multiple independent samples of measurement data; Pearson χ² test was used to compare the rate of enumeration data; Spearman rank correlation analysis was used to evaluate correlation between selected variables; binary logistic regression was used for multivariate analysis; stepwise regression and bias-corrected Bootstrap method were used to test potential mediating effect.

Results A total of 10973 valid questionnaires were collected. The M (P₂₅, P₇₅) scores of exhaustions, cynicism, professional efficacy, job burnout, job stress, and depressive symptoms were 1.6 (0.4, 3.0), 1.0 (0.2, 2.2), 4.8 (3.2, 5.7), 1.6 (0.8, 2.5), 45.0 (40.0, 50.0), and 7.0 (4.0, 11.0), respectively. The positive rates of job burnout, job stress, and depressive symptoms were 53.4% (5865/10973), 28.4% (3116/10973), and 29.4% (3231/10973), respectively. The influencing factors of job burnout were gender (versus male; OR for female=0.852), age (versus≤25 years old; ORs for 26-30, 31-40, 41-50, 51-60 years old=0.824, 0.819, 0.738, 0.677), education level (versus junior high school or below; ORs for senior high school/technical secondary school, junior college/vocational college, graduate school or above=1.119, 1.345, 1.331), income per month (versus＜3000 yuan; ORs for 3000-4999, 5000-6999, 7000-8999, 9000-10999, ≥11000 yuan=0.513, 0.470, 0.430, 0.375, 0.411), position (versus assembly line; OR for non-assembly line=0.814), average weekly working hours (versus ≤40 h; ORs for 61-70, ＞70 h=1.199, 1.519), and drinking (versus non-drinking; OR for drinking=1.261). Job burnout was positively correlated with job stress and depressive symptoms (r=0.556, 0.508, P<0.001). Job burnout played a partial mediating role between job stress and depressive symptoms, and its contribution value accounted for 63.2% of the total effect.

Conclusion Manufacturing industry employees' job burnout problem is prominent in China, and there are many factors affecting job burnout. Job burnout may play a partial mediating role between job stress and depressive symptoms in the target group.