Evaluation of urban–rural difference in breast cancer mortality among Chinese women during 1987–2021: A hierarchical age-period-cohort analysis

Abstract

BackgroundBreast cancer mortality varies in urban and rural areas in China. Studies have reported urban–rural difference across time period, however, the evaluation on urban–rural differences in age and birth cohort effects is limited. Our aim was to quantitatively assess urban–rural disparities in age, period and cohort effects in breast cancer mortality in China. MethodsWe collected age-specific breast cancer mortality rates for urban and rural females aged 20–84 years from 1987 to 2021. Hierarchical age-period-cohort (HAPC) models were used to evaluate the effect of area (urban, rural) on breast cancer mortality and investigate urban–rural differences in age, time period and birth cohort effects. ResultsWe found a significant area (urban, rural) effect on breast cancer mortality in that rural females had a lower mortality risk than urban females [−0.25 (95 % confidence interval (CI): −0.32, −0.17)]. Age trajectories of mortality based on the HAPC model showed nonlinear trends with adjustment for area variable. The urban–rural difference in age effect appeared to be divergent with age, and urban women had higher mortality risk in the senior age group. The urban–rural difference in birth cohort effect indicated a reversal around the birth cohort group of 1962–1966, after which rural females had a higher mortality risk than urban females. ConclusionThe area (urban, rural) could affect breast cancer mortality among women, and the effect of urban–rural difference varies with age and birth cohort. To promote the health of urban and rural females, the gap between urban and rural areas should be shorten.