Journal Article > ResearchFull Text
Am J Epidemiol. 2011 March 4; Volume 173 (Issue 8); DOI:10.1093/aje/kwq436
Isanaka S, Grais RF, Briend A, Checchi F
Am J Epidemiol. 2011 March 4; Volume 173 (Issue 8); DOI:10.1093/aje/kwq436
Expected incidence of acute malnutrition is the most appropriate measure for projecting the needs of a nutritional treatment program over time in terms of staffing, food, and other treatments, but direct estimation of incidence is rarely feasible at the onset of an intervention. While incidence may be approximated as prevalence/average duration, ethical constraints preclude measurement of the duration of acute malnutrition in the absence of treatment. The authors used a compartmental model to estimate the duration of untreated moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) in children aged 6-60 months. The model was informed by data from a community-based cohort of children in Niger followed from August 2006 to March 2007. Maximum likelihood estimates for the duration of untreated MAM, defined by weight-for-height z score and middle upper arm circumference, were 75-81 days and 101-116 days, respectively. The duration of untreated SAM, defined by weight-for-height z score, was 45 days. The duration of untreated MAM appears to have been shorter among children aged 6-35 months compared with those aged 36-60 months. Such estimates of the duration, and thus incidence, of untreated malnutrition can be used to improve projections of program needs and estimates of the global burden of acute malnutrition.
Journal Article > ResearchFull Text
Am J Epidemiol. 2021 February 12; Volume 190 (Issue 8); 1519-1532.; DOI:10.1093/aje/kwab032
Kerschberger B, Boulle AM, Kuwengwa R, Ciglenecki I, Schomaker M
Am J Epidemiol. 2021 February 12; Volume 190 (Issue 8); 1519-1532.; DOI:10.1093/aje/kwab032
Rapid initiation of antiretroviral therapy (ART) is recommended for people living with HIV, with the option to start treatment on the day of diagnosis (same-day-ART). However, the effect of same-day-ART remains unknown in realistic public sector settings. We established a cohort of ≥16-year-old patients who initiated first-line ART under Treat-All in Nhlangano (Eswatini) between 2014-2016, either on the day of HIV care enrolment (same-day-ART) or 1–14 days thereafter (early-ART). Directed acyclic graphs, flexible parametric survival analysis and targeted maximum likelihood estimation (TMLE) were used to estimate the effect of same-day-ART initiation on the composite unfavourable treatment outcome (loss to follow-up;death;viral failure). Of 1328 patients, 839 (63.2%) initiated same-day ART. The adjusted hazard ratio of the unfavourable outcome was increased by 1.48 (95% CI:1.16–1.89) for same-day-ART compared with early-ART. TMLE suggested that after 1 year, 28.9% of patients would experience the unfavourable outcome under same-day-ART compared with 21.2% under early-ART (difference: 7.7%; 1.3–14.1%). This estimate was driven by loss to follow-up and varied over time, with a higher hazard during the first year after HIV care enrolment and a similar hazard thereafter. We found an increased risk with same-day-ART. A limitation was possible silent transfers that were not captured.
Journal Article > ResearchFull Text
Am J Epidemiol. 2014 January 15; Volume 179 (Issue 2); 245-251.; DOI:10.1093/aje/kwt236
Minetti A, Hurtado N, Grais RF, Ferrari MJ
Am J Epidemiol. 2014 January 15; Volume 179 (Issue 2); 245-251.; DOI:10.1093/aje/kwt236
Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals.