Browsing by Author "Todd, Jim"
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Item Age-Specific Mortality Patterns in HIV-Infected Individuals: A Comparative Analysis of African Community Study Data(Aids, 2007) Zaba, Basia; Marston, Milly; Crampin, Amelia C.; Isingo, Raphael; Biraro, Sam; Ba¨rnighausen, Till; Lopman, Ben; Lutalo, Tom; Glynn, Judith R.; Todd, JimDescribe age-specific mortality patterns of HIV-infected adults in African communities before introduction of HAART.Mortality data (deaths and person-years observed) for HIV-positive subjects aged 15–65 from six African community studies in five different countries were pooled, combining information from 1793 seroconverters and 8534 HIV positive when first tested. Age-specific mortality hazards were modelled using parametric regression based on the Weibull distribution, to investigate effects of sex, and site-specific measures of mean age at incidence, crude mortality rate of uninfected, and measures of epidemic maturity.The combined studies yielded a total of 31 777 person-years of observation for HIV-positive subjects, during which time 2602 deaths were recorded. Mortality rates rose almost linearly with age, from below 50/1000 at ages < 20 years, up to 150/1000 at 50 years +. There was no significant difference between men and women in level or age pattern of mortality. Weibull regression analysis suggested that intersite variation could be explained by HIV prevalence trend, and by the ratio of HIV proportional mortality to current HIV prevalence. A model representation was constructed with a common age pattern of mortality, but allowing the level to be adjusted by specifying HIV prevalence indicators.The linear age trend of mortality in HIV-infected populations was satisfactorily represented by a Weibull function providing a parametric model adaptable for representing different levels of HIV-related mortality. This model might be simpler to use in demographic projections of HIV-affected populations than models based on survival post-infection.Item Correlates of previous couples’ HIV counseling and testing uptake among married individuals in three HIV prevalence strata in Rakai, Uganda(Global health action, 2015) Matovu, Joseph K.B.; Todd, Jim; Wanyenze, Rhoda K.; Wabwire-Mangen, Fred; Serwadda, DavidStudies show that uptake of couples’ HIV counseling and testing (couples’ HCT) can be affected by individual, relationship, and socioeconomic factors. However, while couples’ HCT uptake can also be affected by background HIV prevalence and awareness of the existence of couples’ HCT services, this is yet to be documented. We explored the correlates of previous couples’ HCT uptake among married individuals in a rural Ugandan district with differing HIV prevalence levels. Design: This was a cross-sectional study conducted among 2,135 married individuals resident in the three HIV prevalence strata (low HIV prevalence: 9.7 11.2%; middle HIV prevalence: 11.4 16.4%; and high HIV prevalence: 20.5 43%) in Rakai district, southwestern Uganda, between November 2013 and February 2014. Data were collected on sociodemographic and behavioral characteristics, including previous receipt of couples’ HCT. HIV testing data were obtained from the Rakai Community Cohort Study. We conducted multivariable logistic regression analysis to identify correlates that are independently associated with previous receipt of couples’ HCT. Data analysis was conducted using STATA (statistical software, version 11.2). Results: Of the 2,135 married individuals enrolled, the majority (n 1,783, 83.5%) had been married for five or more years while (n 1,460, 66%) were in the first-order of marriage. Ever receipt of HCT was almost universal (n 2,020, 95%); of those ever tested, (n 846, 41.9%) reported that they had ever received couples’ HCT. There was no significant difference in previous receipt of couples’ HCT between low (n 309, 43.9%), middle (n 295, 41.7%), and high (n 242, 39.7%) HIV prevalence settings (p 0.61). Marital order was not significantly associated with previous receipt of couples’ HCT. However, marital duration [five or more years vis-a`-vis 1 2 years: adjusted odds ratio (aOR): 1.06; 95% confidence interval (95% CI): 1.04 1.08] and awareness about the existence of couples’ HCT services within the Rakai community cohort (aOR: 7.58; 95% CI: 5.63 10.20) were significantly associated with previous receipt of couples’ HCT.Item Estimating Incidence from Prevalence in Generalised HIV Epidemics: Methods and Validation(PLoS medicine, 2008) Hallett, Timothy B.; Zaba, Basia; Todd, Jim; Lopman, Ben; Mwita, Wambura; Biraro, Sam; Gregson, SimonHIV surveillance of generalised epidemics in Africa primarily relies on prevalence at antenatal clinics, but estimates of incidence in the general population would be more useful. Repeated cross-sectional measures of HIV prevalence are now becoming available for general populations in many countries, and we aim to develop and validate methods that use these data to estimate HIV incidence.Two methods were developed that decompose observed changes in prevalence between two serosurveys into the contributions of new infections and mortality. Method 1 uses cohort mortality rates, and method 2 uses information on survival after infection. The performance of these two methods was assessed using simulated data from a mathematical model and actual data from three community-based cohort studies in Africa. Comparison with simulated data indicated that these methods can accurately estimates incidence rates and changes in incidence in a variety of epidemic conditions. Method 1 is simple to implement but relies on locally appropriate mortality data, whilst method 2 can make use of the same survival distribution in a wide range of scenarios. The estimates from both methods are within the 95% confidence intervals of almost all actual measurements of HIV incidence in adults and young people, and the patterns of incidence over age are correctly captured.It is possible to estimate incidence from cross-sectional prevalence data with sufficient accuracy to monitor the HIV epidemic. Although these methods will theoretically work in any context, we have able to test them only in southern and eastern Africa, where HIV epidemics are mature and generalised. The choice of method will depend on the local availability of HIV mortality data.Item Estimating ‘net’ HIV-related Mortality and the Importance of Background Mortality Rates(AIDS, 2007) Marston, Milly; Todd, Jim; Glynn, Judith R.; Nelson, Kenrad E.; Rangsin, Ram; Lutalo, Tom; Urassa, Mark; Biraro, Sam; Paal, Lieve Van der; Sonnenberg, Pam; Żaba, BasiaTo estimate mortality directly attributable to HIV in HIV-infected adults in low and middle income countries and discuss appropriate methodology.Illustrative analysis of pooled data from six studies across sub-Saharan Africa and Thailand with data on individuals with known dates of seroconversion to HIV.Five of the studies also had data from HIV-negative subjects and one had verbal autopsies. Data for HIV-negative cohorts were weighted by the initial age and sex distribution of the seroconverters. Using the survival of the HIV-negative group to represent the background mortality, net survival from HIV was calculated for the seroconverters using competing risk methods. Mortality from all causes and ‘net’ mortality were modelled using piecewise exponential regression. Alternative approaches are explored in the dataset without information on mortality of uninfected individuals.The overall effect of the net mortality adjustment was to increase survivorship proportionately by 2 to 5% at 6 years post-infection. The increase ranged from 2% at ages 15–24 to 22% in those 55 and over. Mortality rate ratios between sites were similar to corresponding ratios for all-cause mortality.Differences between HIV mortality in different populations and age groups are not explained by differences in background mortality, although this does appear to contribute to the excess at older ages. In the absence of data from uninfected individuals in the same population, model life tables can be used to calculate background rates.Item Good adherence to HAART and improved survival in a community HIV/AIDS treatment and care programme: the experience of The AIDS Support Organization (TASO), Kampala, Uganda(BMC health services research, 2008) Abaasa, Andrew M.; Todd, Jim; Ekoru, Kenneth; Kalyango, Joan N.; Levin, Jonathan; Odeke, Emmanuel; Karamagi, Charles A. S.Poor adherence to highly active antiretroviral therapy (HAART) may result in treatment failure and death. Most reports of the effect of adherence to HAART on mortality come from studies where special efforts are made to provide HAART under ideal conditions. However, there are few reports of the impact of non-adherence to HAART on mortality from community HIV/AIDS treatment and care programmes in developing countries. We therefore conducted a study to assess the effect of adherence to HAART on survival in The AIDS Support Organization (TASO) community HAART programme in Kampala, Uganda. Methods: The study was a retrospective cohort of 897 patients who initiated HAART at TASO clinic, Kampala, between May 2004 and December 2006. A total of 7,856 adherence assessments were performed on the data. Adherence was assessed using a combination of self-report and pill count methods. Patients who took ≤ 95% of their regimens were classified as non-adherent. The data was stratified at a CD4 count of 50 cells/mm3. Kaplan Meier curves and Cox proportional hazards regression models were used in the analysis. Results: A total of 701 (78.2%) patients had a mean adherence to ART of > 95%. The crude death rate was 12.2 deaths per 100 patient-years, with a rate of 42.5 deaths per 100 patient-years for non-adherent patients and 6.1 deaths per 100 patient-years for adherent patients. Non-adherence to ART was significantly associated with mortality. Patients with a CD4 count of less than 50 cells/mm3 had a higher mortality (HR = 4.3; 95% CI: 2.22– 5.56) compared to patients with a CD4 count equal to or greater than 50 cells/mm3 (HR = 2.4; 95% CI: 1.79–2.38). Conclusion: Our study showed that good adherence and improved survival are feasible in community HIV/AIDS programmes such as that of TASO, Uganda. However, there is need to support community HAART programmes to overcome the challenges of funding to provide sustainable supplies particularly of antiretroviral drugs; provision of high quality clinical and laboratory support; and achieving a balance between expansion and quality of services. Measures for the early identification and treatment of HIV infected people including home-based VCT and HAART should be strengthened.Item InterVA-4 as a public health tool for measuring HIV/AIDS mortality: a validation study from five African countries(Global Health Action, 2013) Byass, Peter; Calvert, Clara; Nakiyingi-Miiro, Jessica; Lutalo, Tom; Michael, Denna; Crampin, Amelia; Gregson, Simon; Takaruza, Albert; Robertson, Laura; Herbst, Kobus; Todd, Jim; Zaba, BasiaReliable population-based data on HIV infection and AIDS mortality in sub-Saharan Africa are scanty, even though that is the region where most of the world’s AIDS deaths occur. There is therefore a great need for reliable and valid public health tools for assessing AIDS mortality. Objective: The aim of this article is to validate the InterVA-4 verbal autopsy (VA) interpretative model within African populations where HIV sero-status is recorded on a prospective basis, and examine the distribution of cause-specific mortality among HIV-positive and HIV-negative people. Design: Data from six sites of the Alpha Network, including HIV sero-status and VA interviews, were pooled. VA data according to the 2012 WHO format were extracted, and processed using the InterVA-4 model into likely causes of death. The model was blinded to the sero-status data. Cases with known pre-mortem HIV infection status were used to determine the specificity with which InterVA-4 could attribute HIV/AIDS as a cause of death. Cause-specific mortality fractions by HIV infection status were calculated, and a person-time model was built to analyse adjusted cause-specific mortality rate ratios. Results: The InterVA-4 model identified HIV/AIDS-related deaths with a specificity of 90.1% (95% CI 88.7 91.4%). Overall sensitivity could not be calculated, because HIV-positive people die from a range of causes. In a person-time model including 1,739 deaths in 1,161,688 HIV-negative person-years observed and 2,890 deaths in 75,110 HIV-positive person-years observed, the mortality ratio HIV-positive:negative was 29.0 (95% CI 27.1 31.0), after adjustment for age, sex, and study site. Cause-specific HIV-positive:negative mortality ratios for acute respiratory infections, HIV/AIDS-related deaths, meningitis, tuberculosis, and malnutrition were higher than the all-cause ratio; all causes had HIV-positive:negative mortality ratios significantly higher than unity.Item Men are always scared to test with their partners . . . it is like taking them to the Police’’: Motivations for and barriers to couples’ HIV counselling and testing in Rakai, Uganda(Journal of the International AIDS Society, 2014) Wanyenze, Rhoda K; Wabwire-Mangen, Fred; Nakubulwa, Rosette; Sekamwa, Richard; Masika, Annet; Todd, Jim; Serwadda, DavidUptake of couples’ HIV counselling and testing (couples’ HCT) can positively influence sexual risk behaviours and improve linkage to HIV care among HIV-positive couples. However, less than 30% of married couples have ever tested for HIV together with their partners. We explored the motivations for and barriers to couples’ HCT among married couples in Rakai, Uganda. Methods: This was a qualitative study conducted among married individuals and selected key informants between August and October 2013. Married individuals were categorized by prior HCT status as: 1) both partners never tested; 2) only one or both partners ever tested separately; and 3) both partners ever tested together. Data were collected on the motivations for and barriers to couples’ HCT, decision-making processes from tested couples and suggestions for improving couples’ HCT uptake. Eighteen focus group discussions with married individuals, nine key informant interviews with selected key informants and six indepth interviews with married individuals that had ever tested together were conducted. All interviews were audio-recorded, translated and transcribed verbatim and analyzed using Nvivo (version 9), following a thematic framework approach. Results: Motivations for couples’ HCT included the need to know each other’s HIV status, to get a treatment companion or seek HIV treatment together if one or both partners were HIV-positive and to reduce mistrust between partners. Barriers to couples’ HCT included fears of the negative consequences associated with couples’ HCT (e.g. fear of marital dissolution), mistrust between partners and conflicting work schedules. Couples’ HCT was negotiated through a process that started off with one of the partners testing alone initially and then convincing the other partner to test together. Suggestions for improving couples’ HCT uptake included the need for couple- and male-partner-specific sensitization, and the use of testimonies from tested couples. Conclusions: Couples’ HCT is largely driven by individual and relationship-based factors while fear of the negative consequences associated with couples’ HCT appears to be the main barrier to couples’ HCT uptake in this setting. Interventions to increase the uptake of couples’ HCT should build on the motivations for couples’ HCT while dealing with the negative consequences associated with couples’ HCT.Item Reduced morbidity and mortality in the first year after initiating highly active anti-retroviral therapy (HAART) among Ugandan adults(Tropical Medicine & International Health, 2009) Miiro, George; Todd, Jim; Mpendo, Juliet; Watera, Christine; Munderi, Paula; Nakubulwa, Susan; Kaddu, Ismael; Rutebarika, Diana; Grosskurth, HeinerTo evaluate the effect of highly active anti-retroviral therapy (HAART) and cotrimoxazole prophylaxis on morbidity after HAART eligibility. methods Between 1999 and 2006, we collected morbidity data from a community-based cohort of HAART-eligible patients, comparing patients initiating HAART and those non-HAART. Patients aged 15 years or older visited the clinic every 6 months and when ill. Baseline data on patients’ characteristics, WHO stage, haemoglobin and CD4+ T-cell counts, along with follow-up data on morbidity (new, recurrent and drug-related), were collected for the first year after initiating HAART or becoming HAART-eligible. We estimated the overall effect of HAART on morbidity; adjusted for the effect of cotrimoxazole prophylaxis by Mantel–Haenszel methods. A negative binomial regression model was used to assess rate ratios (RR) after adjustment for other confounders, including cotrimoxazole. results A total of 219 HAART patients (median age 37 years; 73% women; 82% using cotrimoxazole prophylaxis, median haemoglobin 11.7 g ⁄ dl and median CD4+ 131 cells ⁄ ll) experienced 94 events in 127 person-years. 616 non-HAART patients (median age 33 years; 70% women; 26% using cotrimoxazole prophylaxis, median haemoglobin 11.2 g ⁄ dl and median CD4+ 130 cells ⁄ ll) experienced 862 events in 474 person-years. The overall morbidity during the first year of HAART was 80% lower than among non-HAART patients (adjusted RR = 0.20, 95% CI: 0.12–0.34). Cotrimoxazole prophylaxis also reduced morbidity (adjusted RR = 0.65, 95% CI: 0.45–0.94). conclusion These results confirm the reduction in morbidity due to HAART, and the additional protection of cotrimoxazole prophylaxis.