Analysis of the difference in perinatal mortality rate between white- and blue-collar workers in Japan, 1995–2015

Abstract

Objective: The current study aimed to analyze the differences in perinatal mortality rate between whiteand blue-collar workers Methods: Data from the "Report of Vital Statistics: Occupational and Industrial Aspects" in Japan covering 1995 to 2015 were used. Five-year maternal age groups from 15-19 to 45-49 years were analyzed according to work type, and perinatal mortality rate for each age group and age-standardized perinatal mortality rate according to maternal age were calculated in each analyzed year. Bayesian ageperiod-cohort analysis was used to estimate age, period, and cohort effects for perinatal mortality rate according to work type. Moreover, perinatal mortality rate ratios between types of workers were estimated for each age group, period, and cohort. Results: The estimated perinatal mortality rate ratios of blue-to white-collar workers were above 1 most of the time. Moreover, age effect for perinatal mortality rate among white-collar workers was the largest in the 15-19-year age group, whereas that among blue-collar workers was the largest in the 45-49-year age group. Furthermore, the estimated perinatal rate ratio between white-and blue-collar workers tended to increase with maternal age. The degree of decrease of the cohort effects on perinatal mortality rate was rather larger in blue-collar workers in the cohorts born between 1946-1950 and 1996-2000. Conclusion: The degree of the disparity particularly increased with maternal age, and middle-aged blue-collar workers need more prenatal care and preventive measures for perinatal mortality than white-collar workers.