SOS created a population based community survey to understand the incidence and prevalence of surgically treatable conditions in low-resource settings. The survey tool, Surgeons OverSeas Assessment of Surgical Need (SOSAS), has been undertaken in Rwanda (2011) and Sierra Leone (2012). SOSAS was recently used in Nepal, a low-income South Asian country, in the summer of 2014.

One hundred Nepali physicians, interns and medical students throughout Nepal were trained in surgical care needs assessment and served as interviewers for the study. Fifteen of the 75 districts of Nepal were surveyed, which provided a nationwide representative sample of 2,695 individuals. This study revealed a large current unmet surgical need in the Nepali population, 10.0%. The Nepal study improved on the SOSAS tool with the addition of a visual physical examination, which validated the SOSAS tool and justified the previous estimates of unmet surgical need in Rwanda (6.4%) and Sierra Leone (25%).