Context matters for disability and priority setting for musculoskeletal diseases: revisiting the egalitarian approach to disability weights and disability-adjusted life-years.

Health metrics have evolved with increasing sophistication. The disability-adjusted life-year (DALY) has emerged as a widely used metric. While DALYs vary between countries, the global disability weights (DWs) that are integral to the DALY ignore the potential impact of local factors on the burden of disease. Developmental dysplasia of the hip (DDH), a spectrum of hip pathologies, typically develops during early childhood and is a leading cause of early hip osteoarthritis. This paper explores the variability in the DW for DDH in relation to to local health environments using select health system indicators.The DW for DDH increases with decreasing income level of countries. The Human Development Index and the Gross Domestic Product per capita are both negatively correlated with (p<0.05) the DW for DDH per country. For the indicators surgical workforce, surgical procedures and hospital beds per 1000 population, there is a significant negative correlation in countries not meeting the minimum standard of that indicator (p<0.05), while for countries meeting that minimum standard, the correlation between DW for DDH and the respective indicator is not significantly different from zero.Consideration should be given to re-establishing the DWs for health entities in countries that do not meet the minimum standards of a functional health system. This would more accurately reflect the burden of disease from a functional perspective in LMICs, and perhaps allow for more informed priority setting within LMICs and for donors. The establishment of these DWs should not start from scratch; our data suggest that the variability in DWs due to context can most likely be modelled using health system and financial protection indicators already in use today.