Abstract
The objective of this study is to assess global trends and cross-country inequalities in low back pain (LBP) and neck pain (NP) burdens among adolescents and adults aged 15 to 49 years from 1990 to 2021 and project the disease burden through 2036. Data from the 2021 Global Burden of Disease study were used to analyze trends in the prevalence and years lived with disability for LBP and NP from 1990 to 2021. Age-standardized prevalence rates (ASPR) and years lived with disabilities were calculated, and trends were assessed using the average annual percent change (AAPC). Disparities across sociodemographic index (SDI) quintiles, regions, and countries were analyzed, with inequality examined through slope and concentration indices. A Bayesian age-period-cohort model was used to project the disease burden of LBP and NP through 2036. From 1990 to 2021, global ASPR for LBP showed a modest decline with an AAPC of -0.38%, while NP ASPR exhibited a slight reduction (-0.05%). The most significant reduction in LBP prevalence occurred in the high-middle SDI quintile (AAPC -0.36%), whereas the low SDI quintile experienced a slight increase in NP (AAPC 0.09%). Regionally, East Asia saw the largest decline in LBP, while Central Latin America showed an increase. Gender differences were evident, with women consistently experiencing higher burdens for both conditions. Cross-country inequalities were marked by widening absolute disparities, especially for NP. The overall burden of LBP and NP in the 15 to 49-year age group was projected to decline through 2036, although ASPR of NP in females was estimated to increase to 3190.49 per 100,000 population (95% uncertainty interval, 2220.92-4160.05). Global LBP prevalence declined while NP stagnated. Regional disparities remain, particularly in lower-resource settings. Gender-specific risk factors and healthcare access need further research and attention.