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1.
Trop Med Int Health ; 29(3): 192-205, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38100203

RESUMEN

OBJECTIVES: Despite declining TB notifications in Southern Africa, TB-related deaths remain high. We describe patient- and population-level trends in TB-related deaths in Eswatini over a period of 11 years. METHODS: Patient-level (retrospective cohort, from 2009 to 2019) and population-level (ecological analysis, 2009-2017) predictors and rates of TB-related deaths were analysed in HIV-negative and HIV-coinfected first-line TB treatment cases and the population of the Shiselweni region. Patient-level TB treatment data, and population and HIV prevalence estimates were combined to obtain stratified annual mortality rates. Multivariable Poisson regressions models were fitted to identify patient-level and population-level predictors of deaths. RESULTS: Of 11,883 TB treatment cases, 1302 (11.0%) patients died during treatment: 210/2798 (7.5%) HIV-negative patients, 984/8443 (11.7%) people living with HIV (PLHIV), and 108/642 (16.8%) patients with unknown HIV-status. The treatment case fatality ratio remained above 10% in most years. At patient-level, fatality risk was higher in PLHIV (aRR 1.74, 1.51-2.02), and for older age and extra-pulmonary TB irrespective of HIV-status. For PLHIV, fatality risk was higher for TB retreatment cases (aRR 1.38, 1.18-1.61) and patients without antiretroviral therapy (aRR 1.70, 1.47-1.97). It decreases with increasing higher CD4 strata and the programmatic availability of TB-LAM testing (aRR 0.65, 0.35-0.90). At population-level, mortality rates decreased 6.4-fold (-147/100,000 population) between 2009 (174/100,000) and 2017 (27/100,000), coinciding with a decline in TB treatment cases (2785 in 2009 to 497 in 2017). Although the absolute decline in mortality rates was most pronounced in PLHIV (-826/100,000 vs. HIV-negative: -23/100,000), the relative population-level mortality risk remained higher in PLHIV (aRR 4.68, 3.25-6.72) compared to the HIV-negative population. CONCLUSIONS: TB-related mortality rapidly decreased at population-level and most pronounced in PLHIV. However, case fatality among TB treatment cases remained high. Further strategies to reduce active TB disease and introduce improved TB therapies are warranted.


Asunto(s)
Infecciones por VIH , Tuberculosis , Humanos , Tuberculosis/epidemiología , Estudios Retrospectivos , Esuatini , Factores de Riesgo , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología
2.
Trop Med Int Health ; 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38961819

RESUMEN

OBJECTIVES: The objective of this study is to assess the outcomes of children, adolescents and young adults with HIV reported as lost to follow-up, correct mortality estimates for children, adolescents and young adults with HIV for unascertained outcomes in those loss to follow-up (LTFU) based on tracing and linkage data separately using data from the International epidemiology Databases to Evaluate AIDS in Southern Africa. METHODS: We included data from two different populations of children, adolescents and young adults with HIV; (1) clinical data from children, adolescents and young adults with HIV aged ≤24 years from Lesotho, Malawi, Mozambique, Zambia and Zimbabwe; (2) clinical data from children, adolescents and young adults with HIV aged ≤14 years from the Western Cape (WC) in South Africa. Outcomes of patients lost to follow-up were available from (1) a tracing study and (2) linkage to a health information exchange. For both populations, we compared six methods for correcting mortality estimates for all children, adolescents and young adults with HIV. RESULTS: We found substantial variations of mortality estimates among children, adolescents and young adults with HIV reported as lost to follow-up versus those retained in care. Ascertained mortality was higher among lost and traceable children, adolescents and young adults with HIV and lower among lost and linkable than those retained in care (mortality: 13.4% [traced] vs. 12.6% [retained-other Southern Africa countries]; 3.4% [linked] vs. 9.4% [retained-WC]). A high proportion of lost to follow-up children, adolescents and young adults with HIV had self-transferred (21.0% and 47.0%) in the traced and linked samples, respectively. The uncorrected method of non-informative censoring yielded the lowest mortality estimates among all methods for both tracing (6.0%) and linkage (4.0%) approaches at 2 years from ART start. Among corrected methods using ascertained data, multiple imputation, incorporating ascertained data (MI(asc.)) and inverse probability weighting with logistic weights were most robust for the tracing approach. In contrast, for the linkage approach, MI(asc.) was the most robust. CONCLUSIONS: Our findings emphasise that lost to follow-up is non-ignorable and both tracing and linkage improved outcome ascertainment: tracing identified substantial mortality in those reported as lost to follow-up, whereas linkage did not identify out-of-facility deaths, but showed that a large proportion of those reported as lost to follow-up were self-transfers.

3.
Am J Epidemiol ; 190(8): 1519-1532, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-33576383

RESUMEN

Rapid initiation of antiretroviral therapy (ART) is recommended for people living with human immunodeficiency virus (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 a treat-all policy in Nhlangano (Eswatini) during 2014-2016, either on the day of HIV care enrollment (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 a composite unfavorable treatment outcome (loss to follow-up, death, viral failure, treatment switch). Of 1,328 patients, 839 (63.2%) initiated same-day ART. The adjusted hazard ratio of the unfavorable outcome was higher, 1.48 (95% confidence interval: 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 unfavorable 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 enrollment and a similar hazard thereafter. We found an increased risk with same-day ART. A limitation was that possible silent transfers that were not captured.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Tuberculosis/epidemiología , Adolescente , Adulto , Antituberculosos/uso terapéutico , Esuatini , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pacientes Desistentes del Tratamiento , Políticas , Sector Público , Estudios Retrospectivos , Análisis de Supervivencia , Tiempo de Tratamiento , Tuberculosis/tratamiento farmacológico , Organización Mundial de la Salud , Adulto Joven
4.
Future Oncol ; 17(21): 2705-2711, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33880956

RESUMEN

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a potentially severe complication of mainly antiresorptive drugs. We evaluated the frequency of dentoalveolar pathologies in patients scheduled for antiresorptive therapy in a 'real-world' setting, also including patients with poor oral health potentially requiring tooth extractions and/or other dentoalveolar surgery. This approach is in contrast to the setting of recent randomized trials with restrictive exclusion criteria. Patients & methods: We prospectively included patients suffering from solid tumors with osseous metastases or multiple myeloma. Screening for dentoalveolar pathologies was done prior to initiation of antiresorptive therapy at the specialized MRONJ clinic of the University Hospital for Cranio-Maxillofacial and Oral Surgery, Innsbruck, Austria. Results: 119 subjects could be included. In 76 patients (63.9%), a dental focus was revealed including deep caries (24.4% of patients), chronic apical periodontitis (26.9%), periodontal disease (45.8%), root remnants (16%), jaw cysts (2.5%), partially impacted teeth (5.0%) and peri-implantitis (5.0%). Conclusion: Considering the high number of dentoalveolar pathologies (63.9%), systematic dental focus screening prior to initiation of antiresorptive therapy is of utmost importance to lower the risk for MRONJ.


Asunto(s)
Osteonecrosis de los Maxilares Asociada a Difosfonatos/prevención & control , Conservadores de la Densidad Ósea/efectos adversos , Neoplasias Óseas/tratamiento farmacológico , Mieloma Múltiple/tratamiento farmacológico , Salud Bucal/estadística & datos numéricos , Anciano , Osteonecrosis de los Maxilares Asociada a Difosfonatos/epidemiología , Osteonecrosis de los Maxilares Asociada a Difosfonatos/etiología , Neoplasias Óseas/secundario , Denosumab/efectos adversos , Caries Dental/diagnóstico , Caries Dental/epidemiología , Caries Dental/cirugía , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Boca/diagnóstico por imagen , Enfermedades Periodontales/diagnóstico , Enfermedades Periodontales/epidemiología , Guías de Práctica Clínica como Asunto , Estudios Prospectivos , Radiografía Panorámica/normas , Radiografía Panorámica/estadística & datos numéricos , Factores de Riesgo , Extracción Dental/efectos adversos , Ácido Zoledrónico/efectos adversos
5.
Am J Epidemiol ; 189(8): 811-819, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32219384

RESUMEN

Little is known about the functional relationship of delaying second-line treatment initiation for human immunodeficiency virus-positive patients and mortality, given a patient's immune status. We included 7,255 patients starting antiretroviral therapy during 2004-2017, from 9 South African cohorts, with virological failure and complete baseline data. We estimated the impact of switch time on the hazard of death using inverse probability of treatment weighting of marginal structural models. The nonlinear relationship between month of switch and the 5-year survival probability, stratified by CD4 count at failure, was estimated with targeted maximum likelihood estimation. We adjusted for measured time-varying confounding by CD4 count, viral load, and visit frequency. Five-year mortality was estimated to be 10.5% (95% CI: 2.2, 18.8) for immediate switch and to be 26.6% (95% CI: 20.9, 32.3) for no switch (51.1% if CD4 count was <100 cells/mm3). The hazard of death was estimated to be 0.37 (95% CI: 0.30, 0.46) times lower if everyone had been switched immediately compared with never. The shorter the delay in switching, the lower the hazard of death-delaying 30-59 days reduced the hazard by 0.53 (95% CI: 0.43, 0.65) times and 60-119 days by 0.58 (95% CI: 0.49, 0.69) times, compared with no switch. Early treatment switch is particularly important for patients with low CD4 counts at failure.


Asunto(s)
Antirretrovirales/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Adulto , Recuento de Linfocito CD4 , Femenino , Estudios de Seguimiento , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Humanos , Masculino , Sudáfrica/epidemiología
7.
Trop Med Int Health ; 24(6): 701-714, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30938037

RESUMEN

OBJECTIVES: To assess long-term antiretroviral therapy (ART) outcomes during rapid HIV programme expansion in the public sector of Eswatini (formerly Swaziland). METHODS: This is a retrospectively established cohort of HIV-positive adults (≥16 years) who started first-line ART in 25 health facilities in Shiselweni (Eswatini) between 01/2006 and 12/2014. Temporal trends in ART attrition, treatment expansion and ART coverage were described over 9 years. We used flexible parametric survival models to assess the relationship between time to ART attrition and covariates. RESULTS: Of 24 772 ART initiations, 6% (n = 1488) occurred in 2006, vs. 13% (n = 3192) in 2014. Between these years, median CD4 cell count at ART initiation increased (113-265 cells/mm3 ). The active treatment cohort expanded 8.4-fold, ART coverage increased 8.0-fold (7.1% in 2006 vs. 56.8% in 2014) and 12-month crude ART retention improved from 71% to 86%. Compared with the pre-decentralisation period (2006-2007), attrition decreased by 5% (adjusted hazard ratio [aHR] 0.95, 95% confidence interval 0.88-1.02) during HIV-TB service decentralisation (2008-2010), by 17% (aHR 0.83, 0.75-0.92) during service consolidation (2011-2012), and by 20% (aHR 0.80, 0.71-0.90) during further treatment expansion (2013-2014). The risk of attrition was higher for young age, male sex, pathological baseline haemoglobin and biochemistry results, more toxic drug regimens, WHO III/IV staging and low CD4 cell count; access to a telephone was protective. CONCLUSIONS: Programmatic outcomes improved during large expansion of the treatment cohort and increased ART coverage. Changes in ART programming may have contributed to better outcomes.


OBJECTIFS: Evaluer les résultats du traitement antirétroviral (ART) à long terme durant l'expansion rapide du programme de lutte contre le VIH dans le secteur public d'Eswatini (anciennement Swaziland). MÉTHODES: Il s'agit d'une cohorte établie de manière rétrospective d'adultes VIH positifs (≥ 16 ans) qui ont commencé un ART de première ligne dans 25 établissements de santé à Shiselweni (Eswatini) entre janvier 2006 et décembre 2014. Les tendances temporelles de l'attrition dans l'ART, de l'extension de la couverture ART ont été décrites sur 9 ans. Nous avons utilisé des modèles de survie paramétriques flexibles pour évaluer la relation entre le temps écoulé avant l'attrition dans l'ART et les covariables. RÉSULTATS: Sur 24.772 initiations à l'ART, 6% (n = 1.488) ont eu lieu en 2006 contre 13% (n = 3.192) en 2014. Entre ces années, le nombre médian de cellules CD4 au début du traitement ART a augmenté (113 à 265 cellules/mm3 ). La cohorte de traitement actif a été multipliée par 8,4, la couverture ART par 8,0 (7,1% en 2006 contre 56,8% en 2014) et la rétention brute sous ART est passée de 71% à 86%. Par rapport à la période antérieure à la décentralisation (2006-2007), l'attrition a diminué de 5% (rapport de risque ajusté [aHR]: 0,95, intervalle de confiance à 95%: 0,88 à 1,02) au cours de la décentralisation des services VIH-TB (2008-2010), de 17% (HR: 0,83; 0,75-0,92) lors de la consolidation du service (2011-2012) et de 20% (HR: 0,80; 0,71-0,90) lors de la poursuite de l'extension du traitement (2013-2014). Le risque d'attrition était plus élevé pour le jeune âge, le sexe masculin, les résultats pathologiques de l'hémoglobine initiale et biochimiques, des schémas thérapeutiques plus toxiques, un stade III/IV de l'OMS et une faible numération des cellules CD4; l'accès au téléphone était protecteur. CONCLUSIONS: Les résultats programmatiques se sont améliorés au cours de l'expansion importante de la cohorte de traitement et de l'augmentation de la couverture ART. Les changements apportés au programme ART peuvent avoir contribué à de meilleurs résultats.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Tiempo de Tratamiento/estadística & datos numéricos , Adulto , Fármacos Anti-VIH/administración & dosificación , Recuento de Linfocito CD4 , Determinación de la Elegibilidad , Esuatini , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Embarazo , Evaluación de Programas y Proyectos de Salud , Modelos de Riesgos Proporcionales , Sector Público/estadística & datos numéricos , Estudios Retrospectivos , Población Rural
8.
Trop Med Int Health ; 24(9): 1114-1127, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31310029

RESUMEN

OBJECTIVES: This paper assesses patient- and population-level trends in TB notifications during rapid expansion of antiretroviral therapy in Eswatini which has an extremely high incidence of both TB and HIV. METHODS: Patient- and population-level predictors and rates of HIV-associated TB were examined in the Shiselweni region in Eswatini from 2009 to 2016. Annual population-level denominators obtained from projected census data and prevalence estimates obtained from population-based surveys were combined with individual-level TB treatment data. Patient- and population-level predictors of HIV-associated TB were assessed with multivariate logistic and multivariate negative binomial regression models. RESULTS: Of 11 328 TB cases, 71.4% were HIV co-infected and 51.8% were women. TB notifications decreased fivefold between 2009 and 2016, from 1341 to 269 cases per 100 000 person-years. The decline was sixfold in PLHIV vs. threefold in the HIV-negative population. Main patient-level predictors of HIV-associated TB were recurrent TB treatment (adjusted odds ratio [aOR] 1.40, 95% confidence interval [CI]: 1.19-1.65), negative (aOR 1.31, 1.15-1.49) and missing (aOR 1.30, 1.11-1.53) bacteriological status and diagnosis at secondary healthcare level (aOR 1.18, 1.06-1.33). Compared with 2009, the probability of TB decreased for all years from 2011 (aOR 0.69, 0.58-0.83) to 2016 (aOR 0.54, 0.43-0.69). The most pronounced population-level predictor of TB was HIV-positive status (adjusted incidence risk ratio 19.47, 14.89-25.46). CONCLUSIONS: This high HIV-TB prevalence setting experienced a rapid decline in TB notifications, most pronounced in PLHIV. Achievements in HIV-TB programming were likely contributing factors.


OBJECTIFS: Ce document évalue les tendances des notifications de la tuberculose (TB) à l'échelle des patients et de la population lors de l'expansion rapide du traitement antirétroviral à Eswatini, où l'incidence de la TB et du VIH est extrêmement élevée. MÉTHODES: Les prédicteurs et les taux de TB associée au VIH à l'échelle des patients et de la population ont été examinés dans la région de Shiselweni à Eswatini de 2009 à 2016. Les dénominateurs annuels à l'échelle de la population obtenus à partir des données de recensement projetées et des estimations de la prévalence obtenues à partir d'enquêtes de population ont été combinés avec des données de traitement de la TB à l'échelle individuel. Les prédicteurs de la TB associée au VIH à l'échelle du patient et de la population ont été évalués à l'aide de modèles de régression logistique multivariée et binomiale négative multivariée. RÉSULTATS: Sur 11.328 cas de TB, 71,4% étaient coinfectés par le VIH et 51,8% étaient des femmes. Les notifications de TB ont été réduites de 5,0 fois entre 2009 et 2016, passant de 1.341 à 269 cas par 100.000 personnes-années. Le déclin était de 6,0 fois chez les PVVIH contre 3,0 fois dans la population négative pour le VIH. Les principaux prédicteurs de la TB associée au VIH à l'échelle des patients étaient les traitements antituberculeux récurrents (rapport de cotes ajusté [aOR] 1,40; intervalle de confiance à 95% [IC]: 1,19 à 1,65), un statut bactériologique négatif (aOR: 1,31; 1,15 à 1,49) et manquant (aOR: 1,30; 1,11 à 1,53) et le diagnostic au niveau des soins de santé secondaires (AOR 1,18; 1,06 à 1,33). Par rapport à 2009, la probabilité de contracter la TB a diminué pour toutes les années, de 2011 (aOR: 0,69; 0,58 à 0,83) à 2016 (aOR: 0,5; 0,43 à 0,69). Le prédicteur le plus prononcé de la TB à l'échelle de la population était le statut VIH-positif (rapport de risque d'incidence ajusté: 19,47; 14,89 à 25,46). CONCLUSIONS: Ce contexte de prévalence élevée de la TB-VIH a connu un déclin rapide du nombre de notifications de TB, plus prononcé chez les PVVIH. Les réalisations dans la programmation VIH-TB étaient probablement des facteurs contributifs.


Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Tuberculosis/epidemiología , Adolescente , Adulto , Factores de Edad , Fármacos Anti-VIH/uso terapéutico , Esuatini , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Adulto Joven
9.
PLoS Med ; 15(3): e1002514, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29494593

RESUMEN

BACKGROUND: Globally, the population of adolescents living with perinatally acquired HIV (APHs) continues to expand. In this study, we pooled data from observational pediatric HIV cohorts and cohort networks, allowing comparisons of adolescents with perinatally acquired HIV in "real-life" settings across multiple regions. We describe the geographic and temporal characteristics and mortality outcomes of APHs across multiple regions, including South America and the Caribbean, North America, Europe, sub-Saharan Africa, and South and Southeast Asia. METHODS AND FINDINGS: Through the Collaborative Initiative for Paediatric HIV Education and Research (CIPHER), individual retrospective longitudinal data from 12 cohort networks were pooled. All children infected with HIV who entered care before age 10 years, were not known to have horizontally acquired HIV, and were followed up beyond age 10 years were included in this analysis conducted from May 2016 to January 2017. Our primary analysis describes patient and treatment characteristics of APHs at key time points, including first HIV-associated clinic visit, antiretroviral therapy (ART) start, age 10 years, and last visit, and compares these characteristics by geographic region, country income group (CIG), and birth period. Our secondary analysis describes mortality, transfer out, and lost to follow-up (LTFU) as outcomes at age 15 years, using competing risk analysis. Among the 38,187 APHs included, 51% were female, 79% were from sub-Saharan Africa and 65% lived in low-income countries. APHs from 51 countries were included (Europe: 14 countries and 3,054 APHs; North America: 1 country and 1,032 APHs; South America and the Caribbean: 4 countries and 903 APHs; South and Southeast Asia: 7 countries and 2,902 APHs; sub-Saharan Africa, 25 countries and 30,296 APHs). Observation started as early as 1982 in Europe and 1996 in sub-Saharan Africa, and continued until at least 2014 in all regions. The median (interquartile range [IQR]) duration of adolescent follow-up was 3.1 (1.5-5.2) years for the total cohort and 6.4 (3.6-8.0) years in Europe, 3.7 (2.0-5.4) years in North America, 2.5 (1.2-4.4) years in South and Southeast Asia, 5.0 (2.7-7.5) years in South America and the Caribbean, and 2.1 (0.9-3.8) years in sub-Saharan Africa. Median (IQR) age at first visit differed substantially by region, ranging from 0.7 (0.3-2.1) years in North America to 7.1 (5.3-8.6) years in sub-Saharan Africa. The median age at ART start varied from 0.9 (0.4-2.6) years in North America to 7.9 (6.0-9.3) years in sub-Saharan Africa. The cumulative incidence estimates (95% confidence interval [CI]) at age 15 years for mortality, transfers out, and LTFU for all APHs were 2.6% (2.4%-2.8%), 15.6% (15.1%-16.0%), and 11.3% (10.9%-11.8%), respectively. Mortality was lowest in Europe (0.8% [0.5%-1.1%]) and highest in South America and the Caribbean (4.4% [3.1%-6.1%]). However, LTFU was lowest in South America and the Caribbean (4.8% [3.4%-6.7%]) and highest in sub-Saharan Africa (13.2% [12.6%-13.7%]). Study limitations include the high LTFU rate in sub-Saharan Africa, which could have affected the comparison of mortality across regions; inclusion of data only for APHs receiving ART from some countries; and unavailability of data from high-burden countries such as Nigeria. CONCLUSION: To our knowledge, our study represents the largest multiregional epidemiological analysis of APHs. Despite probable under-ascertained mortality, mortality in APHs remains substantially higher in sub-Saharan Africa, South and Southeast Asia, and South America and the Caribbean than in Europe. Collaborations such as CIPHER enable us to monitor current global temporal trends in outcomes over time to inform appropriate policy responses.


Asunto(s)
Antirretrovirales/uso terapéutico , Transmisión de Enfermedad Infecciosa , Salud Global/estadística & datos numéricos , Infecciones por VIH , Adolescente , Niño , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Monitoreo Epidemiológico , Femenino , Estudios de Seguimiento , Infecciones por VIH/epidemiología , Infecciones por VIH/mortalidad , Infecciones por VIH/terapia , Infecciones por VIH/transmisión , Humanos , Recién Nacido , Cooperación Internacional , Internacionalidad , Estudios Longitudinales , Masculino
10.
Epidemiology ; 29(6): 841-847, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30063542

RESUMEN

BACKGROUND: South Africa faced repeated episodes of temporary power shutdowns, or load shedding, in 2014/2015. The effect of load shedding on children's health is unknown. METHODS: We determined periods of load shedding using Twitter, Facebook, and data from the City of Cape Town. We obtained the number of unscheduled hospital admissions between June 2014 and May 2015 from Red Cross Children's Hospital, Cape Town, and weather data from the South African Weather Service. We used quasi-Poisson regression models to explore the relationship between number of hospital admissions and load shedding, adjusted for season, weather, and past admissions. Based on assumptions about the causal process leading to hospital admissions, we estimated the average treatment effect, that is, the difference in expected number of admissions per day had there been load shedding each day or on any of the preceding 2 days compared with if there had not been any load shedding. RESULTS: We found a 10% increase (95% confidence interval: 4%, 15%) in hospital admissions for days where load shedding was experienced on the same day, or no more than 2 days prior, compared with when there was no load shedding in the past 2 days. The increase was more pronounced during weekdays (12% [7%, 18%] vs. 1% [-9%, 11%]), and for specific diagnoses (e.g., respiratory system: 14% [2%, 26%]). The average treatment effect was estimated as 6.50 (5.12, 7.87) highlighting that about 6 additional admissions a day could be attributed to load shedding. CONCLUSIONS: The association we measured is consistent with our hypothesis that failures of the power infrastructure increase risk to children's health. See video abstract at, http://links.lww.com/EDE/B409.


Asunto(s)
Suministros de Energía Eléctrica , Hospitales Pediátricos/estadística & datos numéricos , Admisión del Paciente/estadística & datos numéricos , Adolescente , Niño , Preescolar , Cicloparafinas , Suministros de Energía Eléctrica/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Medios de Comunicación Sociales/estadística & datos numéricos , Sudáfrica/epidemiología , Tiempo (Meteorología)
11.
Stat Med ; 37(14): 2252-2266, 2018 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-29682776

RESUMEN

Many modern estimators require bootstrapping to calculate confidence intervals because either no analytic standard error is available or the distribution of the parameter of interest is nonsymmetric. It remains however unclear how to obtain valid bootstrap inference when dealing with multiple imputation to address missing data. We present 4 methods that are intuitively appealing, easy to implement, and combine bootstrap estimation with multiple imputation. We show that 3 of the 4 approaches yield valid inference, but that the performance of the methods varies with respect to the number of imputed data sets and the extent of missingness. Simulation studies reveal the behavior of our approaches in finite samples. A topical analysis from HIV treatment research, which determines the optimal timing of antiretroviral treatment initiation in young children, demonstrates the practical implications of the 4 methods in a sophisticated and realistic setting. This analysis suffers from missing data and uses the g-formula for inference, a method for which no standard errors are available.


Asunto(s)
Biometría/métodos , Modelos Estadísticos , Antirretrovirales , Simulación por Computador , Infecciones por VIH/tratamiento farmacológico , Humanos
12.
Stat Med ; 37(16): 2530-2546, 2018 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-29687470

RESUMEN

When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In contrast propensity score methods require the correct specification of an exposure model. Double-robust methods only require correct specification of either the outcome or the exposure model. Targeted maximum likelihood estimation is a semiparametric double-robust method that improves the chances of correct model specification by allowing for flexible estimation using (nonparametric) machine-learning methods. It therefore requires weaker assumptions than its competitors. We provide a step-by-step guided implementation of TMLE and illustrate it in a realistic scenario based on cancer epidemiology where assumptions about correct model specification and positivity (ie, when a study participant had 0 probability of receiving the treatment) are nearly violated. This article provides a concise and reproducible educational introduction to TMLE for a binary outcome and exposure. The reader should gain sufficient understanding of TMLE from this introductory tutorial to be able to apply the method in practice. Extensive R-code is provided in easy-to-read boxes throughout the article for replicability. Stata users will find a testing implementation of TMLE and additional material in the Appendix S1 and at the following GitHub repository: https://github.com/migariane/SIM-TMLE-tutorial.


Asunto(s)
Métodos Epidemiológicos , Funciones de Verosimilitud , Algoritmos , Simulación por Computador , Interpretación Estadística de Datos , Humanos , Aprendizaje Automático , Neoplasias/epidemiología , Puntaje de Propensión
13.
PLoS Med ; 14(11): e1002407, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29112692

RESUMEN

BACKGROUND: Retention in care is an essential component of meeting the UNAIDS "90-90-90" HIV treatment targets. In Khayelitsha township (population ~500,000) in Cape Town, South Africa, more than 50,000 patients have received antiretroviral therapy (ART) since the inception of this public-sector program in 2001. Disengagement from care remains an important challenge. We sought to determine the incidence of and risk factors associated with disengagement from care during 2013-2014 and outcomes for those who disengaged. METHODS AND FINDINGS: We conducted a retrospective cohort study of all patients ≥10 years of age who visited 1 of the 13 Khayelitsha ART clinics from 2013-2014 regardless of the date they initiated ART. We described the cumulative incidence of first disengagement (>180 days not attending clinic) between 1 January 2013 and 31 December 2014 using competing risks methods, enabling us to estimate disengagement incidence up to 10 years after ART initiation. We also described risk factors for disengagement based on a Cox proportional hazards model, using multiple imputation for missing data. We ascertained outcomes (death, return to care, hospital admission, other hospital contact, alive but not in care, no information) after disengagement until 30 June 2015 using province-wide health databases and the National Death Registry. Of 39,884 patients meeting our eligibility criteria, the median time on ART to 31 December 2014 was 33.6 months (IQR 12.4-63.2). Of the total study cohort, 592 (1.5%) died in the study period, 1,231 (3.1%) formally transferred out, 987 (2.5%) were silent transfers and visited another Western Cape province clinic within 180 days, 9,005 (22.6%) disengaged, and 28,069 (70.4%) remained in care. Cumulative incidence of disengagement from care was estimated to be 25.1% by 2 years and 50.3% by 5 years on ART. Key factors associated with disengagement (age, male sex, pregnancy at ART start [HR 1.58, 95% CI 1.47-1.69], most recent CD4 count) and retention (ART club membership, baseline CD4) after adjustment were similar to those found in previous studies; however, notably, the higher hazard of disengagement soon after starting ART was no longer present after adjusting for these risk factors. Of the 9,005 who disengaged, the 2 most common initial outcomes were return to ART care after 180 days (33%; n = 2,976) and being alive but not in care in the Western Cape (25%; n = 2,255). After disengagement, a total of 1,459 (16%) patients were hospitalized and 237 (3%) died. The median follow-up from date of disengagement to 30 June 2015 was 16.7 months (IQR 11-22.4). As we included only patient follow-up from 2013-2014 by design in order to maximize the generalizability of our findings to current programs, this limited our ability to more fully describe temporal trends in first disengagement. CONCLUSIONS: Twenty-three percent of ART patients in the large cohort of Khayelitsha, one of the oldest public-sector ART programs in South Africa, disengaged from care at least once in a contemporary 2-year period. Fifty-eight percent of these patients either subsequently returned to care (some "silently") or remained alive without hospitalization, suggesting that many who are considered "lost" actually return to care, and that misclassification of "lost" patients is likely common in similar urban populations. A challenge to meeting ART retention targets is developing, testing, and implementing program designs to target mobile populations and retain them in lifelong care. This should be guided by risk factors for disengagement and improving interlinkage of routine information systems to better support patient care across complex care platforms.


Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Cumplimiento de la Medicación/estadística & datos numéricos , Adulto , Factores de Edad , Femenino , Infecciones por VIH/mortalidad , Humanos , Incidencia , Masculino , Aceptación de la Atención de Salud , Sistema de Registros , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Sudáfrica/epidemiología
14.
J Virol ; 89(10): 5264-75, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25673728

RESUMEN

UNLABELLED: The membrane-proximal external region (MPER), the V2/glycan site (initially defined by PG9 and PG16 antibodies), and the V3/glycans (initially defined by PGT121-128 antibodies) are targets of broadly neutralizing antibodies and potential targets for anti-HIV-1 antibody-based vaccines. Recent evidence shows that antibodies with moderate neutralization breadth are frequently attainable, with 50% of sera from chronically infected individuals neutralizing ≥ 50% of a large, diverse set of viruses. Nonetheless, there is little systematic information addressing which specificities are preferentially targeted among such commonly found, moderately broadly neutralizing sera. We explored associations between neutralization breadth and potency and the presence of neutralizing antibodies targeting the MPER, V2/glycan site, and V3/glycans in sera from 177 antiretroviral-naive HIV-1-infected (>1 year) individuals. Recognition of both MPER and V3/glycans was associated with increased breadth and potency. MPER-recognizing sera neutralized 4.62 more panel viruses than MPER-negative sera (95% prediction interval [95% PI], 4.41 to 5.20), and V3/glycan-recognizing sera neutralized 3.24 more panel viruses than V3/glycan-negative sera (95% PI, 3.15 to 3.52). In contrast, V2/glycan site-recognizing sera neutralized only 0.38 more panel viruses (95% PI, 0.20 to 0.45) than V2/glycan site-negative sera and no association between V2/glycan site recognition and breadth or potency was observed. Despite autoreactivity of many neutralizing antibodies recognizing MPER and V3/glycans, antibodies to these sites are major contributors to neutralization breadth and potency in this cohort. It may therefore be appropriate to focus on developing immunogens based upon the MPER and V3/glycans. IMPORTANCE: Previous candidate HIV vaccines have failed either to induce wide-coverage neutralizing antibodies or to substantially protect vaccinees. Therefore, current efforts focus on novel approaches never before successfully used in vaccine design, including modeling epitopes. Candidate immunogen models identified by broadly neutralizing antibodies include the membrane-proximal external region (MPER), V3/glycans, and the V2/glycan site. Autoreactivity and polyreactivity of anti-MPER and anti-V3/glycan antibodies are thought to pose both direct and indirect barriers to achieving neutralization breadth. We found that antibodies to the MPER and the V3/glycans contribute substantially to neutralization breadth and potency. In contrast, antibodies to the V2/glycan site were not associated with neutralization breadth/potency. This suggests that the autoreactivity effect is not critical and that the MPER and the V3/glycans should remain high-priority vaccine candidates. The V2/glycan site result is surprising because broadly neutralizing antibodies to this site have been repeatedly observed. Vaccine design priorities should shift toward the MPER and V3/glycans.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Vacunas contra el SIDA/inmunología , Adulto , Secuencia de Aminoácidos , Anticuerpos Neutralizantes/biosíntesis , Especificidad de Anticuerpos , Recuento de Linfocito CD4 , Femenino , Anticuerpos Anti-VIH/biosíntesis , Proteína gp120 de Envoltorio del VIH/genética , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp41 de Envoltorio del VIH/genética , Proteína gp41 de Envoltorio del VIH/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Infecciones por VIH/virología , VIH-1/genética , VIH-2/genética , VIH-2/inmunología , Humanos , Masculino , Datos de Secuencia Molecular , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Polisacáridos/inmunología
15.
Epidemiology ; 27(2): 237-46, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26479876

RESUMEN

BACKGROUND: There is limited evidence regarding the optimal timing of initiating antiretroviral therapy (ART) in children. We conducted a causal modeling analysis in children ages 1-5 years from the International Epidemiologic Databases to Evaluate AIDS West/Southern-Africa collaboration to determine growth and mortality differences related to different CD4-based treatment initiation criteria, age groups, and regions. METHODS: ART-naïve children of ages 12-59 months at enrollment with at least one visit before ART initiation and one follow-up visit were included. We estimated 3-year growth and cumulative mortality from the start of follow-up for different CD4 criteria using g-computation. RESULTS: About one quarter of the 5,826 included children was from West Africa (24.6%).The median (first; third quartile) CD4% at the first visit was 16% (11%; 23%), the median weight-for-age z-scores and height-for-age z-scores were -1.5 (-2.7; -0.6) and -2.5 (-3.5; -1.5), respectively. Estimated cumulative mortality was higher overall, and growth was slower, when initiating ART at lower CD4 thresholds. After 3 years of follow-up, the estimated mortality difference between starting ART routinely irrespective of CD4 count and starting ART if either CD4 count <750 cells/mm³ or CD4% <25% was 0.2% (95% CI = -0.2%; 0.3%), and the difference in the mean height-for-age z-scores of those who survived was -0.02 (95% CI = -0.04; 0.01). Younger children ages 1-2 and children in West Africa had worse outcomes. CONCLUSIONS: Our results demonstrate that earlier treatment initiation yields overall better growth and mortality outcomes, although we could not show any differences in outcomes between immediate ART and delaying until CD4 count/% falls below 750/25%.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Desarrollo Infantil , Intervención Médica Temprana , Infecciones por VIH/tratamiento farmacológico , Burkina Faso , Recuento de Linfocito CD4 , Causalidad , Preescolar , Estudios de Cohortes , Côte d'Ivoire , Bases de Datos Factuales , Femenino , Ghana , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Humanos , Lactante , Malaui , Masculino , Senegal , Sudáfrica , Factores de Tiempo , Togo , Zimbabwe
17.
Epidemiology ; 26(5): 628-36, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26214336

RESUMEN

BACKGROUND: Both CD4 count and viral load in HIV-infected persons are measured with error. There is no clear guidance on how to deal with this measurement error in the presence of missing data. METHODS: We used multiple overimputation, a method recently developed in the political sciences, to account for both measurement error and missing data in CD4 count and viral load measurements from four South African cohorts of a Southern African HIV cohort collaboration. Our knowledge about the measurement error of ln CD4 and log10 viral load is part of an imputation model that imputes both missing and mismeasured data. In an illustrative example, we estimate the association of CD4 count and viral load with the hazard of death among patients on highly active antiretroviral therapy by means of a Cox model. Simulation studies evaluate the extent to which multiple overimputation is able to reduce bias in survival analyses. RESULTS: Multiple overimputation emphasizes more strongly the influence of having high baseline CD4 counts compared to both a complete case analysis and multiple imputation (hazard ratio for >200 cells/mm vs. <25 cells/mm: 0.21 [95% confidence interval: 0.18, 0.24] vs. 0.38 [0.29, 0.48], and 0.29 [0.25, 0.34], respectively). Similar results are obtained when varying assumptions about measurement error, when using p-splines, and when evaluating time-updated CD4 count in a longitudinal analysis. The estimates of the association with viral load are slightly more attenuated when using multiple imputation instead of multiple overimputation. Our simulation studies suggest that multiple overimputation is able to reduce bias and mean squared error in survival analyses. CONCLUSIONS: Multiple overimputation, which can be used with existing software, offers a convenient approach to account for both missing and mismeasured data in HIV research.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Sesgo , Interpretación Estadística de Datos , Infecciones por VIH/tratamiento farmacológico , Modelos Estadísticos , Análisis de Supervivencia , Recuento de Linfocito CD4 , Simulación por Computador , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Infecciones por VIH/virología , Humanos , Modelos de Riesgos Proporcionales , Resultado del Tratamiento , Carga Viral
18.
Eur J Epidemiol ; 30(4): 331-41, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25630563

RESUMEN

Higher placental weight relative to birthweight has been described as an adaptive mechanism to fetal hypoxia in small for gestational age (SGA) infants. However, placental weight alone may not be a good marker reflecting intrauterine growth restriction. We hypothesized that fetoplacental ratio (FPR)-the ratio between birthweight and placental weight-may serve as a good marker of SGA after adjustment for surrogates of fetal hypoxemia (maternal iron deficiency anemia, smoking and choriodecidual necrosis). We conducted a within-sibling analysis using data from the US National Collaborative Perinatal Project (1959-1966) of 1,803 women who delivered their first two (or more) consecutive infants at term (n = 3,494). We used variance-component fixed-effect linear regression models to explore the effect of observed time-varying factors on placental weight and conditional logistic regression to estimate the effects of the tertiles of FPRs (1st small, 2nd normal and 3rd large) on the odds of SGA infants. We found placental weights to be 15 g [95 % confidence interval (CI) 8, 23] higher and -7 g (95 % CI -13, -2) lower among women that had anemia and choriodecidual necrosis, respectively. After multivariable adjustment, newborns with a small FPR (1st-tertile ≤7) had twofold higher odds of being SGA (OR 2.0, 95 % CI 1.2, 3.5) than their siblings with a large FPR (3nd-tertile ≥9). A small FPR was associated with higher odds of SGA, suggesting that small FPR may serve as an indicator suggestive of adverse intrauterine environment. This observation may help to distinguish pathological from constitutional SGA.


Asunto(s)
Peso al Nacer/fisiología , Desarrollo Fetal/fisiología , Retardo del Crecimiento Fetal/fisiopatología , Placentación , Adulto , Femenino , Edad Gestacional , Humanos , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Masculino , Edad Materna , Tamaño de los Órganos/fisiología , Placenta/anatomía & histología , Embarazo , Estudios Prospectivos , Análisis de Regresión , Hermanos
19.
AIDS Res Ther ; 12: 35, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26448780

RESUMEN

BACKGROUND: Identifying those at increased risk of death during TB treatment is a priority in resource-constrained settings. We performed this study to determine predictors of mortality during TB treatment. METHODS: We performed a retrospective analysis of a TB surveillance population in a high HIV prevalence area that was recorded in ETR.net (Electronic Tuberculosis Register). Adult TB cases initiated TB treatment from 2007 through 2009 in Khayelitsha, South Africa. Cox proportional hazards models were used to identify risk factors for death (after multiple imputations for missing data). Model selection was performed using Akaike's Information Criterion to obtain the most relevant predictors of death. RESULTS: Of 16,209 adult TB cases, 851 (5.3 %) died during TB treatment. In all TB cases, advancing age, co-infection with HIV, a prior history of TB and the presence of both pulmonary and extra-pulmonary TB were independently associated with an increasing hazard of death. In HIV-infected TB cases, advancing age and female gender were independently associated with an increasing hazard of death. Increasing CD4 counts and antiretroviral treatment during TB treatment were protective against death. In HIV-uninfected TB cases, advancing age was independently associated with death, whereas smear-positive disease was protective. CONCLUSION: We identified several independent predictors of death during TB treatment in resource-constrained settings. Our findings inform resource-constrained settings about certain subgroups of TB patients that should be targeted to improve mortality during TB treatment.

20.
PLoS Med ; 11(9): e1001718, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25203931

RESUMEN

BACKGROUND: High early mortality in patients with HIV-1 starting antiretroviral therapy (ART) in sub-Saharan Africa, compared to Europe and North America, is well documented. Longer-term comparisons between settings have been limited by poor ascertainment of mortality in high burden African settings. This study aimed to compare mortality up to four years on ART between South Africa, Europe, and North America. METHODS AND FINDINGS: Data from four South African cohorts in which patients lost to follow-up (LTF) could be linked to the national population register to determine vital status were combined with data from Europe and North America. Cumulative mortality, crude and adjusted (for characteristics at ART initiation) mortality rate ratios (relative to South Africa), and predicted mortality rates were described by region at 0-3, 3-6, 6-12, 12-24, and 24-48 months on ART for the period 2001-2010. Of the adults included (30,467 [South Africa], 29,727 [Europe], and 7,160 [North America]), 20,306 (67%), 9,961 (34%), and 824 (12%) were women. Patients began treatment with markedly more advanced disease in South Africa (median CD4 count 102, 213, and 172 cells/µl in South Africa, Europe, and North America, respectively). High early mortality after starting ART in South Africa occurred mainly in patients starting ART with CD4 count <50 cells/µl. Cumulative mortality at 4 years was 16.6%, 4.7%, and 15.3% in South Africa, Europe, and North America, respectively. Mortality was initially much lower in Europe and North America than South Africa, but the differences were reduced or reversed (North America) at longer durations on ART (adjusted rate ratios 0.46, 95% CI 0.37-0.58, and 1.62, 95% CI 1.27-2.05 between 24 and 48 months on ART comparing Europe and North America to South Africa). While bias due to under-ascertainment of mortality was minimised through death registry linkage, residual bias could still be present due to differing approaches to and frequency of linkage. CONCLUSIONS: After accounting for under-ascertainment of mortality, with increasing duration on ART, the mortality rate on HIV treatment in South Africa declines to levels comparable to or below those described in participating North American cohorts, while substantially narrowing the differential with the European cohorts. Please see later in the article for the Editors' Summary.


Asunto(s)
Terapia Antirretroviral Altamente Activa/mortalidad , Terapia Antirretroviral Altamente Activa/tendencias , Conducta Cooperativa , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/mortalidad , VIH-1 , Adulto , Fármacos Anti-VIH/uso terapéutico , Estudios de Cohortes , Europa (Continente)/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mortalidad/tendencias , América del Norte/epidemiología , Estudios Prospectivos , Sudáfrica/epidemiología
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