The Evolution of Mobile Phone Surveys in Low- and Middle-Income Countries: A Study of Coverage Structure

Mobile phone interviews are becoming an increasingly appealing mode of data collection in low- and middle-income countries. Therefore, we used data from 36 countries to examine mobile phone coverage of adults aged 15-49 years. We paid special attention to the (1) coverage rate (percentage of individuals who own at least one mobile phone) versus penetration rate (mobile phone subscriptions per 100 inhabitants), and (2) proxy-covered population (i.e., persons who do not own mobile phones but are potentially accessible through devices owned by other household members). Study findings suggest that (1) penetration rates notably overestimate mobile phone coverage of the population; (2) mobile phone coverage structure varies substantially; (3) mobile phone owners are more likely to be males, urban residents, literate, married, and relatively wealthy; and (4) proxy-covered adults are distinct with regard to demographic characteristics and survey outcomes in comparison to directly covered and not-covered adults. This study informs practitioners about the current coverage structure in several low- and middle-income countries and promotes proper procedures for studying coverage structure before implementing mobile phone interviews in those countries. Finally, this study introduces the term proxy-coverage and advocates for approaching the proxy-covered population to reduce noncoverage bias, especially in settings where mobile phone sharing among family members is common.