Background: More than a billion people have some form of disabilities worldwide. Persons living with a disability have many needs (including physically, mentally, and socially needs). Estimating the size of disabled population is a challenge in health systems. An innovative indirect method to estimate the size of populations is network scale up (NSU) having widely used for hidden populations. The method is based-on the social network of individuals. We assessed the capability of NSU to estimate persons living with a disability being a middle population (neither non-hidden nor hidden populations) in the Southeast of Iran (Kerman City, southeast Iran).

Methods: A total of 3052 of Kermanian people over 20 year old were interviewed by simple random sampling. We asked them whether they knew acquaintances with complete blindness, severe visual impairment, deafness, severe hearing impairment, limb defects, and mental retardation, if yes; we wanted them to count them.

Results: Based on the network scale up method, the prevalence of the populations was estimated at 5.21/1000 in Kerman City where severe visual impairment was 1.35, mental retardation was 1.039, severe hearing impairment was 1.005, limb defects was 0.78, deafness was 0.59, and complete blindness was 0.56 (per 1000 inhabitants).

Conclusions: The results were not exactly comparable to previous studies using different methods such as surveys. Although the method has some limitations, considering its easiness and cost-effectiveness, modified NSU could be used when direct methods are not practicable.