Suppressed or unsuppressed HIV in adults on antiretroviral therapy in Zambia: who is at risk?

Purpose of the study To determine factors associated with suppressed or unsuppressed HIV in adults receiving combination antiretroviral therapy (cART) in Zambia. Methods This was a cross‐sectional study conducted between August 2008 and October 2009 in 16 Zambian communities nested within the ZAMSTAR trial [1]. Adult TB cases identified at a TB clinic of each community and their adult household members were invited to participate in the study. A structured interview was used to obtain information on the participants’ social, demographic and clinical characteristics. Socio‐economic position (SEP) was measured using household wealth indices used in demographic health surveys. Principal component analysis was used to determine the cut‐off for high (wealthy) and low (poor) SEP. Depression symptoms were measured using the Center for Epidemiological Studies Depression scale (CES‐D). A cut‐off of≥22 on the CES‐D was used to define current depression [2]. Participants were included in this analysis if they were found to be receiving cART for>90 days at the time of the interview. The outcome was HIV suppression (viral load≤300 copies/ml). In both univariable and multivariable analyses, log Poisson regression models with robust standard errors adjusted for the 16 communities were used to calculate the risk ratios (RR), 95% confidence intervals (CI) and p‐values of factors associated with HIV suppression. In multivariable analysis, each variable was independently assessed for its association with HIV suppression while minimally adjusting for a priori confounders (age, gender and education level). Summary of results There were 520 patients receiving cART for>90 days. The median age was 35 years (inter‐quartile range: 31–41) and 328/520 (63.1%) were married (Table).HIV suppression HIV suppression vs. no suppressionn=520 Yes No Unadjusted AdjustedN (column %) N (row %) N (row %) RR (95% CI) p‐value RR (95% CI) p‐valueAge group, years16 to 25 47 (9.0) 39 (83.0) 8 (17.0) 126 to 35 220 (42.3) 183 (83.2) 37 (16.8) 1.00 (0.85–1.18) 0.97636 to 45 187 (36.0) 162 (86.6) 25 (13.4) 1.04 (0.91–1.20) 0.541Above 45 66 (12.7) 58 (87.9) 8 (12.1) 1.06 (0.90–1.25) 0.503GenderMen 204 (39.2) 169 (82.8) 35 (17.2) 1Women 316 (60.8) 273 (86.4) 43 (13.6) 1.04 (0.97–1.12) 0.261Education levelNone/Primary 241 (46.3) 200 (83.0) 41 (17.0) 1Secondary 279 (53.7) 242 (86.7) 37 (13.3) 1.05 (0.95–1.15) 0.358Socio‐economic position (SEP)Low 287 (55.2) 252 (87.8) 35 (12.2) 1 1High 220 (42.3) 177 (80.5) 43 (19.5) 0.92 (0.86–0.98) 0.009 0.90 (0.84 – 0.96) 0.001 Missing 13 (2.5) 12 (92.3) 1 (7.7)Type of cARTTenofovir (TDF)+emtricitabine (FTC)+nevirapine (NVP) 61 (11.7) 48 (78.7) 13 (21.3) 1 1TDF+FTC+efavirenz (EFV) 182 (35.0) 154 (84.6) 28 (15.4) 1.08 (0.95–1.22) 0.26 1.09 (0.96–1.25) 0.187 Stavudine (d4T)+lamivudine (3TC)+NVP 197 (37.9) 168 (85.3) 29 (14.7) 1.08 (0.97–1.21) 0.158 1.05 (0.94–1.18) 0.379 Zidovudine (ZDV)+3TC+EFV 78 (15.0) 70 (89.7) 8 (10.3) 1.14 (1.01–1.28) 0.027 1.11 (0.99–1.25) 0.071 Missing 2 (0.4) 2 (100.0) 0 (0.0)History of tuberculosisNo 108 (20.8) 92 (85.2) 16 (14.8) 1 1Yes 412 (79.2) 350 (85.0) 62 (15.0) 1.00 (0.89–1.11) 0.961 1.01 (0.91–1.13) 0.818Current depressionNo 416 (80.0) 355 (85.3) 61 (14.7) 1 1Yes 77 (14.8) 63 (81.8) 14 (18.2) 0.96 (0.84–1.09) 0.523 0.96 (0.84–1.09) 0.493 Missing 27 (5.2) 24 (88.9) 3 (11.1)Of the 520 patients, 442 (85.0%) had HIV suppression while 78 (15.0%) did not. At univariable analysis, having high SEP was negatively associated with HIV suppression while receiving ZDV+3TC+EFV was positively associated with HIV suppression. At multivariable analysis, patients with high SEP were less likely to have HIV suppression than those with low SEP. Conclusions Patients with high SEP were found to be at risk of having unsuppressed HIV. There is need for targeted interventions that can improve HIV outcomes in this group of patients receiving cART in Zambia.