Global burden and risk factors of musculoskeletal disorders among adolescents and young adults in 204 countries and territories, 1990-2019

Background: Current studies on musculoskeletal (MSK) disorders mainly focus on the elderly, while adolescents and young adults (AYAs) are often neglected despite their unique epidemiology, healthcare needs and societal implications. To bridge this gap, we evaluated the global burden and temporal trends of MSK disorders among AYAs from 1990 to 2019, as well as their common categories and main risk factors.Methods: Data on the global burden and risk factors of MSK disorders were obtained from the Global Burden of Diseases study 2019. Age standardized rates for incidence, prevalence and disability-adjusted life-years (DALYs) were calculated using the world population age standard, and their temporal trends were evaluated by estimated annual percentage changes (EAPC). Locally estimated scatterplot smoothing (LOESS) regression was used to explore the association between two variables.Results: Over the past 30 years, MSK disorders have become the third leading cause of global DALYs among AYAs, with 36.2%, 39.3%, and 21.2% of increases in incident cases, prevalent cases and DALYs, respectively. In 2019, age standardized incidence, prevalence and DALY rates for MSK disorders were positivity associated with socio-demographic index (SDI) among AYAs in 204 countries and territories. The global age-standardized prevalence and DALY rates of MSK disorders began to increases among AYAs since 2000. In the last decade, countries with high SDI not only presented the only increase in age-standardized incidence rate across all SDI quintiles (EAPC = 0.40, 0.15 to 0.65), but also displayed the most rapid increases in age-standardized prevalence and DALY rates (EAPC = 0.41, 0.24 to 0.57; 0.39, 0.19 to 0.58, respectively). Low back pain (LBP) and neck pain (NP) were the most common MSK disorders among AYAs, accounting for 47.2% and 15.4% of global DALYs of MSK disorders in this population, respectively. Rheumatoid arthritis (RA), osteoarthritis (OA), and gout exhibited increasing trends in global age-standardized incidence, prevalence, and DALY rates among AYAs over the past 30 years (all EAPC >0), whereas LBP and NP showed declining trends (all EAPC <0). Occupational ergonomic factors, smoking and high BMI accounted for 13.9%, 4.3%, and 2.7% of global DALYs for MSK disorders among AYAs, respectively. The proportion of DALYs attributable to occupational ergonomic factors was negatively associated with SDI, whereas the proportions attributable to smoking and high BMI increased with SDI. Over the last 30 years, both the proportions of DALYs attributable to occupational ergonomic factors and smoking have consistently decreased globally and across all SDI quintiles, while the proportion attributable to high BMI has increased.Conclusions: MSK disorders have emerged as the third leading cause of global DALYs among AYAs over the past three decades. Countries with high SDI should make more efforts to tackle the dual challenges posed by the high levels and rapid increases in age standardized incidence, prevalence, and DALY rates in the last decade.