Global, Regional, and National Impact of Pelvic Inflammatory Disease: Changing Landscape from 1990 to 2021

Background: Pelvic inflammatory disease (PID) is a polymicrobial infection of the upper female genital tract affecting women globally. The study aimed to assess the global prevalence and years lived with disability (YLDs) of PID from 1990 to 2021 and analyze influencing factors. Methods: The 2021 Global Burden of Disease (GBD) dataset provided data on the PID statistics of women of childbearing age (15-49 years), including case counts and age-standardized rates (ASRs). Trends were assessed using estimated annual percentage changes (EAPCs), while the relation of regions, nations and Socio-demographic Index (SDI) was examined using local weighted regression (Lowess). To predict the burden, the Bayesian age-period-cohort (BAPC) model was devised. Results: The GBD data show PID burden negatively correlated with SDI: the age-standardized prevalence rate (ASPR) and the agestandardized years lived with disability rate (ASYR) were higher in low-SDI regions (eg, sub-Saharan Africa) and lower in high-SDI regions (eg, Western Europe). In 2021, rates were 27.02 and 3.68 per 100,000, respectively. Country disparities are marked (Guinea-Bissau highest). Burden peaks at ages 30-39. Projections show persistent increases in both rates across childbearing ages through 2050. Conclusion: Through severity-stratified estimations, detailed cause-specific burden analysis, and BAPC projection modeling, this study provides a comprehensive and detailed description of the global burden and epidemiological trends of PID. Despite overall progress, persistent disparities remain notably the disproportionately high burden in low-SDI regions such as sub-Saharan Africa and Eastern Europe. These projections underscore an urgent need for context-specific prevention strategies, including strengthened STI screening and treatment, improved antibiotic access, and community-based sexual health education tailored to local health system capacity.