Measuring mobility in HIV research in sub-Saharan Africa: a scoping review

Mobility-from overnight travel to permanent migration-can reduce service access and increase HIV risk, driving the epidemic in sub-Saharan Africa (SSA). This scoping review described mobility measures used in HIV research to identify gaps and guide research on mobility to strengthen HIV responses in SSA.

Literature from three databases (PubMed, Embase, Web of Science) were systematically screened to identify research articles examining relationships between mobility and individual-level HIV-related outcomes in SSA from 2014 through 2023. Key terms for mobility included "mobility," "movement," "migration" and "travel." Measures were first extracted according to International Organization of Migration definitions of migration (a change in the place of usual residence) and travel (movement between geographies). Then, metrics used to categorize or quantify mobility were organized by the stage (origin, transit, destination, return) and dimension (spatial, temporal, socio-structural) of the movement captured. Measures were analysed within three research contexts: the HIV outcome(s) of interest, study population and local geographies. Outcomes included HIV acquisition, AIDS-related death, and indicators along the prevention, care and treatment cascade.

We identified 69 studies after screening 5343 titles/abstracts and 200 full texts for eligibility. Studies included research from 16 countries, mostly representing general adult populations in eastern and southern Africa. Most studies measured migration (51) versus travel (21) and examined relationships with HIV prevalent infection (29) or care and treatment indicators (44) compared to other epidemiological and programmatic outcomes. Studies employed a range of metrics, mostly of the duration of stay at the destination (28), the number of mobility events (12) or the geographic boundaries across which individuals moved (14). Socio-structural dimensions like the motivation for movement were measured less often. Only 15 studies examined more than one dimension.

Mobility measures varied widely and were inconsistently studied across research contexts. Future studies should fill evidence gaps, standardize reporting and develop multidimensional mobility measures tailored to local settings and HIV outcomes.

People on the move are a vast and diverse group, yet they are often labelled as a monolith. Improved measures can disentangle how different forms of mobility relate to HIV, generating actionable evidence to enhance HIV programming for ending the epidemic.