Browsing by Author "Johnson LF"

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Associations of inter-annual rainfall decreases with subsequent HIV outcomes for persons with HIV on antiretroviral therapy in Southern Africa: a collaborative analysis of cohort studies.
(2023-Dec-19) Trickey A; Johnson LF; Fung F; Bonifacio R; Iwuji C; Biraro S; Bosomprah S; Chirimuta L; Euvrard J; Fatti G; Fox MP; Von Groote P; Gumulira J; Howard G; Jennings L; Kiragga A; Muula G; Tanser F; Wagener T; Low A; Vickerman P
BACKGROUND: Periods of droughts can lead to decreased food security, and altered behaviours, potentially affecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa. METHODS: Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981-2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre's latitude/longitude. In individual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associations between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts < 200 cells/mm RESULTS: Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32-46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07-1.32] per 10 percentile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01-1.09]). Levels of rainfall were not strongly associated with CD4 counts < 200 cell/mm CONCLUSIONS: Decreased rainfall could negatively impact on HIV treatment behaviours and outcomes. Further research is needed to explore the reasons for these effects. Interventions to mitigate the health impact of severe weather events are required.
Extending Visit Intervals for Clinically Stable Patients on Antiretroviral Therapy: Multicohort Analysis of HIV Programs in Southern Africa.
(2019-Aug-01) Haas AD; Johnson LF; Grimsrud A; Ford N; Mugglin C; Fox MP; Euvrard J; van Lettow M; Prozesky H; Sikazwe I; Chimbetete C; Hobbins M; Kunzekwenyika C; Egger M
BACKGROUND: The World Health Organization recommends differentiated antiretroviral therapy (ART) delivery with longer visit intervals for clinically stable patients. We examined time trends in visit frequency and associations between criteria for clinical stability and visit frequency in ART programs in Southern Africa. METHODS: We included adults on ART from 4 programs with viral-load monitoring, 2 programs with CD4 monitoring, and 4 programs with clinical monitoring of ART. We classified patients as clinically stable based on virological (viral load <1000 copies/mL), immunological (CD4 >200 cells/µL), or clinical (no current tuberculosis) criteria. We used Poisson regression and survival models to examine associations between criteria for clinical stability and the rate of clinic visits. RESULTS: We included 180,837 patients. There were trends toward fewer visits in more recent years and with longer ART duration. In all ART programs, clinically stable patients were seen less frequently than patients receiving failing ART, but the strength of the association varied. Adjusted incidence rate ratios comparing visit rates for stable patients with patients on failing ART were 0.82 (95% confidence interval: 0.73 to 0.90) for patients classified based on the virological criterion, 0.81 (0.69 to 0.93) for patients classified based on the clinical criterion, and 0.90 (0.85 to 0.96) for patients classified based on the immunological criterion for stability. CONCLUSION: Differences in visit rates between stable patients and patients failing ART were variable and modest overall. Larger differences were seen in programs using virological criteria for clinical stability than in programs using immunological criteria. Greater access to routine viral-load monitoring may increase scale-up of differentiated ART delivery.
Global Trends in CD4 Count Measurement and Distribution at First Antiretroviral Treatment Initiation.
(2025-Jul-18) de Waal R; Wools-Kaloustian K; Brazier E; Althoff KN; Jaquet A; Duda SN; Kumarasamy N; Savory T; Byakwaga H; Murenzi G; Justice A; Ekouevi DK; Cesar C; Pasayan MKU; Thawani A; Kasozi C; Babakazo P; Karris M; Messou E; Cortes CP; Kunzekwenyika C; Choi JY; Owarwo NC; Niyongabo A; Marconi VC; Ezechi O; Castilho JL; Petoumenos K; Johnson LF; Ford N; Kassanjee R
BACKGROUND: While people with human immunodeficiency virus (PWH) start antiretroviral treatment (ART) regardless of CD4 count, CD4 measurement remains crucial for detecting advanced human immunodeficiency virus (HIV) disease and evaluating ART programs. We explored CD4 measurement (proportion of PWH with a CD4 result available) and prevalence of CD4 <200 cells/µL (hereafter "CD4 <200") at ART initiation within the International epidemiology Databases to Evaluate AIDS (IeDEA) global collaboration. METHODS: We included PWH at participating ART programs who first initiated ART at age 15-80 years during 2005-2019. We described proportions of PWH with a CD4 result (measured within 6 months before to 2 weeks after ART initiation) and, among those with a CD4 result, with CD4 <200, by year of ART initiation and region. RESULTS: We included 1 355 104 PWH from 42 countries in 7 regions; 63% were female. The median (interquartile range) age at ART initiation was 37 (3144) years in males and 32 (26-39) years in females. CD4 measurement initially increased, or remained stable over time until around 2013, but then declined to low levels in some regions (Southern Africa, except South Africa: from 54% to 13%; East Africa: 85% to 31%; Central Africa: 72% to 20%; West Africa: 91% to 53%; and Latin America: 87% to 56%). Prevalence of CD4 <200 declined over time in all regions, but plateaued after 2015 at ≥30%. CONCLUSIONS: CD4 measurement has declined sharply in recent years, especially in sub-Saharan Africa. Among those with a CD4 measurement, the prevalence of CD4 <200 remains concerningly high. Scaling up CD4 testing and securing adequate funding are urgent priorities.