ORIGINAL ARTICLE Factors associated with mortality in HIV-infected people in rural and urban South Africa

Background: Factors associated with mortality in HIV-infected people in sub-Saharan Africa are widely reported. However ruralurban disparities and their association with all-cause mortality remain unclear. Furthermore, commonly used classical Cox regression ignores unmeasured variables and frailty. Objective: To incorporate frailty in assessing factors associated with mortality in HIV-infected people in rural and urban South Africa. Design: Using data from a prospective cohort following 6,690 HIV-infected participants from Soweto (urban) and Mpumalanga (rural) enrolled from 2003 to 2010; covariates of mortality were assessed by the integrated nested Laplace approximation method. Results: We enrolled 2,221 (33%) rural and 4,469 (67%) urban participants of whom 1,555 (70%) and 3,480 (78%) were females respectively. Median age (IQR) was 36.4 (31.044.1) in rural and 32.7 (28.238.1) in the urban participants. The mortality rate per 100 person-years was 11 (9.712.5) and 4 (3.64.5) in the rural and urban participants, respectively. Compared to those not on HAART, rural participants had a reduce