Neural tube defects burden from 1992 to 2021: a global, regional, and national age-period-cohort analysis of disability-adjusted life years

Neural tube defects (NTDs) remain a persistent global health concern; however, the complex drivers of their epidemiological trends are not fully understood. This study investigated three-decade trends in NTDs-related disability-adjusted life years (DALYs) using an age-period-cohort (APC) modeling framework across global, regional, and national settings. Leveraging data from the Global Burden of Disease Study 2021, we analyzed trends in the number, all-age rate, and age-standardized rate (ASR) of NTDs-related DALYs. We assessed the ecological association between ASR and the Socio-demographic Index (SDI) using Spearman’s correlation and employed an APC model to disentangle the underlying effects of age, time period, and birth cohort. Globally, NTDs-related DALYs and their ASR declined by approximately 47% between 1992 and 2021. A significant inverse correlation was found between ASR and national SDI levels, yet the annual net drift revealed a striking disparity, being negative in low-SDI regions (-1.18%) but positive in high-SDI regions (0.78%). Furthermore, the burden of DALYs shifted over time from neonates towards older age groups (≥ 5 years). APC analysis confirmed that while the protective age effect (risk declining with age) was universal, period and cohort effects varied substantially across regions. In conclusion, despite a marked global decline in the NTDs burden over three decades, substantial disparities persist, closely linked to socioeconomic development. The shifting burden towards older ages and the divergent trends uncovered by APC analysis underscore the need for tailored public health strategies that move beyond one-size-fits-all approaches to effectively address NTDs in diverse settings.