Diagnostic accuracy and predictive value in differentiating the severity of dengue infection.

OBJECTIVE: To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection. METHODS: Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (complete), PubMed and Scopus. Eligible studies to be included in this review were cohort studies with participants confirmed by laboratory test for dengue infection and comparison among the different severity of dengue infection by using statistical models. The methodological quality of the paper was assessed by independent reviewers using QUADAS-2. RESULTS: Twenty-six studies published from 1994 to 2017 were included. Most diagnostic models produced an accuracy of 75% to 80% except one with 86%. Two models predicting severe dengue according to the WHO 2009 classification have 86% accuracy. Both of these logistic regression models were applied during the first three days of illness, and their sensitivity and specificity were 91-100% and 79.3-86%, respectively. Another model which evaluated the 30-day mortality of dengue infection had an accuracy of 98.5%. CONCLUSION: Although there are several potential predictive or diagnostic models for dengue infection, their limitations could affect their validity. It is recommended that these models be revalidated in other clinical settings and their methods be improved and standardised in future.

OBJECTIF: Analyser la précision des tests de diagnostic et la valeur prédictive des modèles statistiques pour différencier la sévérité de l'infection par la dengue. MÉTHODES: Des recherches électroniques ont été effectuées dans la base de données de revues systématiques Cochrane, le registre central des essais contrôlés Cochrane, MEDLINE (complète), PUBMED et Scopus. Les études éligibles à inclure dans cette revue étaient des études de cohorte avec des participants confirmés par un test de laboratoire pour l'infection par la dengue et une comparaison entre les différentessévérités de l'infection par la dengue à l'aide de modèles statistiques. La qualité méthodologique des articles a été évaluée par des scientifiques indépendants à l'aide de QUADAS-2. RÉSULTATS: 26 études publiées de 1994 à 2017 ont été incluses. La plupart des modèles de diagnostic ont produit une précision de 75% à 80%, sauf un avec 86%. Selon la classification de l'OMS 2009, deux modèles prédisant la dengue sévère présentent une précision de 86%. Ces deux modèles de régression logistique ont été appliqués au cours des trois premiers jours de la maladie. Leur sensibilité et leur spécificité étaient respectivement de 91% à 100% et de 79,3% à 86%. Un autre modèle évaluant la mortalité à 30 jours de la dengue présentait une précision de 98,5%. CONCLUSION: Bien qu'il existe plusieurs modèles prédictifs ou diagnostiques potentiels de l'infection par la dengue, leurs limites pourraient affecter leur validité. Il est recommandé que ces modèles soient revalidées dans d'autres milieux cliniques et leurs méthodes améliorées et normalisées dans le futur.

Evidence for causal links between education and maternal and child health: systematic review.

OBJECTIVE: Numerous studies have documented an inverse association between years of schooling attained, particularly by women, and reduced maternal, infant and child mortality. However, if factors affecting educational attainment - many of which are unobservable, e.g. motivation and genetic endowment - also affect the likelihood of engaging in behaviours that enhance health, then assumed effects of schooling will be inflated in analyses that do not address this endogeneity. This systematic review assesses evidence for a causal link between education and maternal and child health in low and middle-income countries. METHODS: Eligible studies controlled for observable and unobservable factors affecting both education and health. Reported effects were converted into partial correlations. When possible, we also conducted meta-analyses to estimate mean effects by outcome. RESULTS: Of 4952 papers identified, 16 met the inclusion criteria. The 15 child health papers examined neonatal, infant and child mortality, stunting and wasting. Significant effects of education on infant and child health were observed for 30 of 33 models that did not account for endogeneity. In contrast, only 18 of 46 effects were significant in models that addressed endogeneity. Notably, for only one outcome -child mortality measured dichotomously -was the effect of maternal educational attainment significant in a meta-analysis. The one maternal morbidity paper found significant effects for the two preventable outcomes considered. CONCLUSION: While we find evidence for a causal link between education and health, effects are weaker in models that address endogeneity compared to naïve models that do not account for unobservable factors affecting both education and health. Advances in women's educational outcomes have undoubtedly played a role in improving health in many settings; however, the effect is not as strong as some researchers and advocates have claimed.

OBJECTIF: De nombreuses études ont montré une association inverse entre le nombre d'années de scolarité atteintes, en particulier par les femmes, et la réduction de la mortalité maternelle, infantile et des nourrissons. Cependant, si les facteurs affectant le niveau d'éducation - dont beaucoup sont non observables, tels que la motivation et le patrimoine génétique - affectent également la probabilité d'adopter des comportements qui améliorent la santé, les effets supposés de la scolarité seront alors gonflés dans des analyses ne traitant pas de cette endogénicité. Cette analyse systématique évalue la preuve d'un lien de causalité entre l'éducation et la santé maternelle et infantile dans les pays à revenu faible ou intermédiaire. MÉTHODES: Les études éligibles contrôlaient les facteurs observables et non observables affectant à la fois l'éducation et la santé. Les effets rapportés ont été convertis en corrélations partielles. Dans la mesure du possible, nous avons également effectué des méta-analyses pour estimer les effets moyens par résultat. RÉSULTATS: Sur 4.952 articles identifiés, 16 répondaient aux critères d'inclusion. Les 15 articles sur la santé infantile ont examiné la mortalité néonatale, infantile et du nourrisson, le retard de croissance et l'émaciation. Des effets significatifs de l'éducation sur la santé du nourrisson et de l'enfant ont été observés pour 30 des 33 modèles qui n'ont pas tenu compte de l'endogénicité. En revanche, seuls 18 des 46 effets étaient significatifs dans les modèles traitant de l'endogénicité. Notamment, pour un seul résultat - la mortalité infantile mesurée de manière dichotomique - dans une méta-analyse, l'effet du niveau d'éducation de la mère était significatif. Le seul article sur la morbidité maternelle a révélé des effets significatifs sur les deux résultats évitables considérés. CONCLUSION: Bien que nous trouvons des preuves d'un lien de causalité entre l'éducation et la santé, les effets des modèles qui traitent de l'endogénicité sont plus faibles que ceux des modèles naïfs qui ne tiennent pas compte de facteurs non observables affectant à la fois l'éducation et la santé. Les progrès dans les résultats scolaires des femmes ont incontestablement joué un rôle dans l'amélioration de la santé dans de nombreux contextes; cependant, l'effet n'est pas aussi puissant que certains chercheurs et défenseurs le prétendent.

Sustained adoption of water, sanitation and hygiene interventions: systematic review.

OBJECTIVE: To understand factors that influence sustained adoption of water, sanitation and hygiene (WASH) technologies or behaviours. METHODS: Systematic review of the current literature. Articles were gathered from databases of peer-reviewed articles and grey literature, and screened for relevance. After exclusion, we created a descriptive map of 148 articles and analysed in-depth 44 articles that had an explicit focus on promoting or evaluating sustained adoption or programme sustainability. Twenty-two of these articles met our definition of measuring sustained adoption. RESULTS: Definitions of sustained adoption varied widely and were often inadequate, making comparison of sustained adoption across studies difficult. The time frame for measurements of sustained adoption is frequently inadequate for examination of longer-term behaviour change. CONCLUSIONS: Ideally, an evaluation should specify the project period and describe the context surrounding adoption, make measurements at multiple time points, diversify measurement methods and describe and measure a range of factors affecting sustained adoption. Additional consideration needs to be given to developing behaviour change models that emphasise factors related to sustained adoption, and how they differ from those related to initial adoption.

Is hearing impairment associated with HIV? A systematic review of data from low- and middle-income countries.

OBJECTIVES: To systematically review evidence on the prevalence and characteristics of hearing impairment among children and adults living with HIV in low- and middle-income countries (LMIC). METHODS: Articles were identified up to January 2016 through searching four electronic databases. Epidemiological studies conducted in LMIC that explored the association between HIV status and hearing loss, with or without an HIV-uninfected comparison group, were eligible for inclusion. Results were screened and assessed for eligibility, and data were extracted by two reviewers, with discussion in the case of disagreement. Findings were narratively synthesised. RESULTS: The search identified 638 unique references, of which 21 studies were included in the review, including 3491 people with HIV from 13 LMIC. There was lack of consistency in the definition used for hearing loss, making comparability across studies difficult. Among children with HIV, across the three studies that used a cut-off of >15 dB in either ear, the prevalence of hearing loss ranged from 22 to 37%. Among the three studies that used >25 dB in either ear, the prevalence ranged from 32 to 39%. Among adults with HIV, for the five studies that used a threshold of >25 dB for either ear, the prevalence ranged from 10 to 43%. The prevalence of hearing impairment was significantly higher among people with HIV than in controls in eight of the ten studies that assessed this comparison. Conductive hearing loss was the most common type of hearing loss in children with HIV, while sensorineural hearing loss was more common in adults with HIV. There was a lack of evidence for an association between ART use and hearing loss, although there was some suggestion that late stage of HIV disease or low CD4 count was related to hearing loss. There were concerns about the quality of the studies included in the review. CONCLUSIONS: The current evidence is suggestive of a high prevalence of hearing loss among people living with HIV compared to people without HIV, or to WHO estimates for the general population. More research is needed to better understand the aetiology of hearing loss in relation to HIV, and whether screening for and treatment of hearing loss can be effectively integrated into HIV treatment services needs further research.

Barriers to obstetric fistula treatment in low-income countries: a systematic review.

OBJECTIVE: To identify the barriers faced by women living with obstetric fistula in low-income countries that prevent them from seeking care, reaching medical centres and receiving appropriate care. METHODS: Bibliographic databases, grey literature, journals, and network and organisation websites were searched in English and French from June to July 2014 and again from August to November 2016 using key search terms and specific inclusion and exclusion criteria for discussion of barriers to fistula treatment. Experts provided recommendations for additional sources. RESULTS: Of 5829 articles screened, 139 were included in the review. Nine groups of barriers to treatment were identified: psychosocial, cultural, awareness, social, financial, transportation, facility shortages, quality of care and political leadership. Interventions to address barriers primarily focused on awareness, facility shortages, transportation, financial and social barriers. At present, outcome data, though promising, are sparse and the success of interventions in providing long-term alleviation of barriers is unclear. CONCLUSION: Results from the review indicate that there are many barriers to fistula treatment, which operate at the individual, community and national levels. The successful treatment of obstetric fistula may thus require targeting several barriers, including depression, stigma and shame, lack of community-based referral mechanisms, financial cost of the procedure, transportation difficulties, gender power imbalances, the availability of facilities that offer fistula repair, community reintegration and the competing priorities of political leadership.

Clostridium difficile infection in low- and middle-human development index countries: a systematic review.

OBJECTIVE: To describe the impact and epidemiology of Clostridium difficile infection (CDI) in low- and middle-human development index (LMHDI) countries. METHOD: Prospectively registered, systematic literature review of existing literature in the PubMed, Ovid and Web of Science databases describing the epidemiology and management of C. difficile in LMHDI countries. Risk factors were compared between studies when available. RESULTS: Of the 218 abstracts identified after applying search criteria, 25 studies were reviewed in detail. The weighted pooled infection rate among symptomatic non-immunosuppressed inpatients was 15.8% (95% CI 12.1-19.5%) and was 10.1% (95% CI 3.0-17.2%) among symptomatic outpatients. Subgroup analysis of immunosuppressed patient populations revealed pooled infection rates similar to non-immunosuppressed patient populations. Risk factor analysis was infrequently performed. CONCLUSIONS: While the percentages of patients with CDI in LMHDI countries among the reviewed studies are lower than expected, there remains a paucity of epidemiologic data evaluating burden of C. difficile infection in these settings.

Critical interpretive synthesis of barriers and facilitators to TB treatment in immigrant populations.

OBJECTIVE: To systematically review studies of TB treatment experiences in immigrant populations, using Critical Interpretive Synthesis (CIS). METHODS: On 26 October 2014, MEDLINE, CINAHL, Embase, LILACS, and PsycINFO were systematically searched. Grey literature and reference lists were hand-searched. Initial papers included were restricted to studies of immigrant patient perspectives; after a model was developed, a second set of papers was included to test the emerging theory. RESULTS: Of 1761 studies identified in the search, a total of 29 were included in the synthesis. Using those studies, we developed a model that suggested treatment experiences were strongly related to the way both individuals and societies adjusted to immigration ('acculturation strategies'). Relationships with healthcare workers and immigration policies played particularly significant roles in TB treatment. CONCLUSIONS: This review emphasised the roles of repatriation policy and healthcare workers in forming experiences of TB treatment in immigrant populations.

Impact of ART on the fertility of HIV-positive women in sub-Saharan Africa.

OBJECTIVE: Understanding the fertility of HIV-positive women is critical to estimating HIV epidemic trends from surveillance data and to planning resource needs and coverage of prevention of mother-to-child transmission services in sub-Saharan Africa. In the light of the considerable scale-up in antiretroviral therapy (ART) coverage over the last decade, we conducted a systematic review of the impact of ART on the fertility outcomes of HIV-positive women. METHODS: We searched Medline, Embase, Popline, PubMed and African Index Medicus. Studies were included if they were conducted in sub-Saharan Africa and provided estimates of fertility outcomes (live births or pregnancies) among women on ART relative to a comparison group. RESULTS: Of 2070 unique references, 18 published papers met all eligibility criteria. Comparisons fell into four categories: fertility of HIV-positive women relative to HIV-negative women; fertility of HIV-positive women on ART compared to those not yet on ART; fertility differences by duration on ART; and temporal trends in fertility among HIV-positive women. Evidence indicates that fertility increases after approximately the first year on ART and that while the fertility deficit of HIV-positive women is shrinking, their fertility remains below that of HIV-negative women. These findings, however, were based on limited data mostly during the period 2005-2010 when ART scaled up. CONCLUSIONS: Existing data are insufficient to characterise how ART has affected the fertility of HIV-positive women in sub-Saharan Africa. Improving evidence about fertility among women on ART is an urgent priority for planning HIV resource needs and understanding HIV epidemic trends. Alternative data sources such as antenatal clinic data, general population cohorts and population-based surveys can be harnessed to understand the issue.

Effectiveness of demand generation interventions on use of modern contraceptives in low- and middle-income countries.

OBJECTIVES: To synthesise evidence on the implementation, costs and cost-effectiveness of demand generation interventions and their effectiveness in improving uptake of modern contraception methods. METHODS: A Cochrane systematic review was conducted. Searches were performed in electronic databases (MEDLINE, EMBASE) and the grey literature. Randomised controlled trials, cluster randomised trials and quasi-experimental studies, including controlled before-after studies (CBAs) and cost and cost-effectiveness studies that aimed to assess demand interventions (including community- and facility-based interventions, financial mechanisms and mass media campaigns) in low- and middle-income countries were considered. Meta-analyses and narrative synthesis were conducted. RESULTS: In total, 20 papers meeting the inclusion criteria were included in this review. Of those, 13 were used for meta-analysis. Few data were available on implementation and on the influence of context on demand interventions. Involving family members during counselling, providing education activities and increasing exposure to those activities could enhance the success of demand interventions. Demand generation interventions were positively associated with increases in current use (pooled OR 1.57; 95% CI: 1.46-1.69, P < 0.01). Financial mechanism interventions (vouchers) appeared effective to increase use of modern contraceptive methods (pooled OR 2.16; 95% CI: 1.91-2.45, P < 0.01; I2 = 0%). Demand interventions improved knowledge (pooled OR 1.02; 95% CI 0.63-1.64, P = 0.93) and attitudes towards family planning and improved discussion with partners/husbands around modern contraceptive methods. However, given the limited number of studies included in each category of demand generation interventions, the dates of publication of the studies and their low quality, caution is advised in considering the results. Very limited evidence was available on costs; studies including data on costs were old and inconsistent. CONCLUSION: Demand generation interventions contribute to increases in modern contraceptive methods use. However, more studies with robust designs are needed to identify the most effective demand generation intervention to increase uptake of modern contraceptive methods. More evidence is also needed about implementation, costs and cost-effectiveness to inform decisions on sustainability and scaling-up.

Self-transfer and mortality amongst adults lost to follow-up in ART programmes in low- and middle-income countries: systematic review and meta-analysis.

OBJECTIVE: To ascertain estimates of adult patients, recorded as lost to follow-up (LTFU) within antiretroviral treatment (ART) programmes, who have self-transferred care, died or truly stopped ART in low- and middle-income countries. METHODS: PubMed, EMBASE, Web of Science, Science Direct, LILACS, IndMed and AIM databases (2003-2013) and IAS/AIDS conference abstracts (2011-2013) were searched for tracing studies reporting the proportion of traced patients found to have self-transferred, died or stopped ART. These estimates were then combined using random-effects meta-analysis. Risk of bias was assessed through subgroup and sensitivity analyses. RESULTS: Twenty eight studies were eligible for inclusion, reporting true outcomes for 10,806 traced patients attending approximately 258 ART facilities. None were from outside sub-Saharan Africa. Twenty three studies reported 4.5-54.4% traced LTFU patients self-transferring care, providing a pooled estimate of 18.6% (95% CI 15.8-22.0%). A significant positive association was found between rates of self-transfer and LTFU in the ART cohort. The pooled estimates for unreported deaths were 38.8% (95% CI 30.8-46.8%; 27 studies) and 28.6% (95% CI 21.9-36.0%; 20 studies) for patients stopping ART. A significant decrease in unreported deaths from 50.0% (95% CI 41.5-58.4%) to 30.0% (95% CI 21.1-38.9%) was found comparing study periods before and after 31 December 2007. CONCLUSIONS: Substantial unaccounted for transfers and deaths amongst patients LTFU confirms that retention and mortality is underestimated where the true outcomes of LTFU patients are not ascertained.