Browsing by Author "MacPhail, Patrick"

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    Correcting mortality for loss to follow-up: a nomogram applied to antiretroviral treatment programmes in sub-Saharan Africa
    (Public Library of Science, 2011) Egger, Matthias; Spycher, Ben D; Sidle, John; Weigel, Ralf; Geng, Elvin H; Fox, Matthew P; MacPhail, Patrick; van Cutsem, Gilles; Messou, Eugène; Wood, Robin
    Background: The World Health Organization estimates that in sub-Saharan Africa about 4 million HIV-infected patients had started antiretroviral therapy (ART) by the end of 2008. Loss of patients to follow-up and care is an important problem for treatment programmes in this region. As mortality is high in these patients compared to patients remaining in care, ART programmes with high rates of loss to follow-up may substantially underestimate mortality of all patients starting ART. Methods and Findings: We developed a nomogram to correct mortality estimates for loss to follow-up, based on the fact that mortality of all patients starting ART in a treatment programme is a weighted average of mortality among patients lost to follow-up and patients remaining in care. The nomogram gives a correction factor based on the percentage of patients lost to follow-up at a given point in time, and the estimated ratio of mortality between patients lost and not lost to follow-up. The mortality observed among patients retained in care is then multiplied by the correction factor to obtain an estimate of programme-level mortality that takes all deaths into account. A web calculator directly calculates the corrected, programme-level mortality with 95% confidence intervals (CIs). We applied the method to 11 ART programmes in sub-Saharan Africa. Patients retained in care had a mortality at 1 year of 1.4% to 12.0%; loss to follow-up ranged from 2.8% to 28.7%; and the correction factor from 1.2 to 8.0. The absolute difference between uncorrected and corrected mortality at 1 year ranged from 1.6% to 9.8%, and was above 5% in four programmes. The largest difference in mortality was in a programme with 28.7% of patients lost to follow-up at 1 year. Conclusions: The amount of bias in mortality estimates can be large in ART programmes with substantial loss to follow-up. Programmes should routinely report mortality among patients retained in care and the proportion of patients lost. A simple nomogram can then be used to estimate mortality among all patients who started ART, for a range of plausible mortality rates among patients lost to follow-up.
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    Monitoring the South African National Antireteoviral Treatment Programme, 2003-2007: The IeDEA Southern Africa Collaboration
    (2009) Cornell, Morna; Technau, Karl; Fairall, Lara; Wood, Robin; Moultrie, Harry; Van Cutsem, Gilles; Giddy, Janet; Mohapi, Lerato; Eley, Brian; MacPhail, Patrick; Prozesky, Hans; Rabie, Helena; Davies, Mary-Ann; Maxwell, Nicola; Boulle, Andrew
    Objectives: To introduce the combined South African cohorts of the International Epidemiologic Databases to Evaluate AIDS-Southern Africa (IeDEA-SA) collaboration as reflecting the South African national antiretroviral treatment (ART) programme; to characterize patients accessing these services; and to describe changes in services and patients 2003-2007. Design & setting Multi-cohort study of 11 ART programmes in Gauteng, Western Cape, Free State and KwaZulu-Natal. Subjects ART-naïve adults and children (<16 years old) who initiated ART with ≥3 antiretroviral drugs before 2008. Results: Most sites were offering free treatment to adults and children in the public sector, ranging from 264 to 17,835 patients per site. Among 45,383 adults and 6,198 children combined, median (IQR) range was 35.0 years (29.8-41.4) and 42.5 months (14.7-82.5) respectively. Of adults, 68% were female. Median CD4 cell count was 102 cells/µL (44-164) and was lower among males than females (86, 34-150 vs 110, 50-169, p<0.001). Median CD4% among children was 12% (7-17.7). Between 2003 and 2007, enrolment increased 11-fold in adults and 3-fold in children. Median CD4 count at enrolment increased for all adults (67-111 cells/µL, p<0.001) and for those in Stage IV (39-89 cells/µL, p<0.001). Among children <5 years, baseline CD4% increased over time (11.5%-16.0%, p<0.001). Conclusions: IeDEA-SA provides a unique opportunity to report on the national ART programme. The study describes dramatically increasing enrolment. Late presentation, especially of men and children, remains a concern. Investment in sentinel sites ensures good individual-level data while freeing most sites to continue with simplified reporting.
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    Treatment response and mortality among patients starting antiretroviral therapy with and without Kaposi sarcoma: a cohort study
    (Public Library of Science, 2013) Maskew, Mhairi; Fox, Matthew P; Cutsem, Gilles van; Chu, Kathryn; MacPhail, Patrick; Boulle, Andrew; Egger, Matthias; Africa, for IeDEA Southern
    BACKGROUND: Improved survival among HIV-infected individuals on antiretroviral therapy (ART) has focused attention on AIDS-related cancers including Kaposi sarcoma (KS). However, the effect of KS on response to ART is not well-described in Southern Africa. We assessed the effect of KS on survival and immunologic and virologic treatment responses at 6- and 12-months after initiation of ART. METHODS: We analyzed prospectively collected data from a cohort of HIV-infected adults initiating ART in South Africa. Differences in mortality between those with and without KS at ART initiation were estimated with Cox proportional hazard models. Log-binomial models were used to assess differences in CD4 count response and HIV virologic suppression within a year of initiating treatment. RESULTS: Between January 2001-January 2008, 13,847 HIV-infected adults initiated ART at the study clinics. Those with KS at ART initiation (n = 247, 2%) were similar to those without KS (n = 13600,98%) with respect to age (35 vs. 35yrs), presenting CD4 count (74 vs. 85cells/mm 3 ) and proportion on TB treatment (37% vs. 30%). In models adjusted for sex, baseline CD4 count, age, treatment site, tuberculosis and year of ART initiation, KS patients were over three times more likely to have died at any time after ART initiation (hazard ratio[HR]: 3.62; 95% CI: 2.71-4.84) than those without KS. The increased risk was highest within the first year on ART (HR: 4.05; 95% CI: 2.95-5.55) and attenuated thereafter (HR: 2.30; 95% CI: 1.08-4.89). Those with KS also gained, on average, 29 fewer CD4 cells (95% CI: 7-52cells/mm 3 ) and were less likely to increase their CD4 count by 50 cells from baseline (RR: 1.43; 95% CI: 0.99-2.06) within the first 6-months of treatment. CONCLUSIONS: HIV-infected adults presenting with KS have increased risk of mortality even after initiation of ART with the greatest risk in the first year. Among those who survive the first year on therapy, subjects with KS demonstrated a poorer immunologic response to ART than those without KS.