Evaluating the effectiveness of IPTi on malaria using routine health information from sentinel health centres in southern Tanzania

Willey, Barbara; Schellenberg, Joanna; Maokola, Werner; Shirima, Kizito; Chemba, Mwajuma; Mshinda, Hassan; Alonso, Pedro L.; Tanner, Marcel; Schellenberg, David

doi:10.1186/1475-2875-10-41

Cited by 7 publications

(19 citation statements)

References 27 publications

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“…Programmatic changes such as adoption of RDTs at facilities, stock-outs, changes in RDT brand or antigen combination, introduction of systematic quality assurance and quality control approaches for monitoring RDT users, or even timing of refresher training for health workers on malaria case management are additional contextual factors which could be incorporated into impact evaluation. 67 …”

Section: Further Considerations For Impact Evaluation Design Using Hmmentioning

confidence: 99%

Methodological Considerations for Use of Routine Health Information System Data to Evaluate Malaria Program Impact in an Era of Declining Malaria Transmission

Ashton

Bennett

Yukich

et al. 2017

The American Journal of Tropical Medicine and Hygiene

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Abstract.Coverage of malaria control interventions is increasing dramatically across endemic countries. Evaluating the impact of malaria control programs and specific interventions on health indicators is essential to enable countries to select the most effective and appropriate combination of tools to accelerate progress or proceed toward malaria elimination. When key malaria interventions have been proven effective under controlled settings, further evaluations of the impact of the intervention using randomized approaches may not be appropriate or ethical. Alternatives to randomized controlled trials are therefore required for rigorous evaluation under conditions of routine program delivery. Routine health management information system (HMIS) data are a potentially rich source of data for impact evaluation, but have been underused in impact evaluation due to concerns over internal validity, completeness, and potential bias in estimates of program or intervention impact. A range of methodologies were identified that have been used for impact evaluations with malaria outcome indicators generated from HMIS data. Methods used to maximize internal validity of HMIS data are presented, together with recommendations on reducing bias in impact estimates. Interrupted time series and dose-response analyses are proposed as the strongest quasi-experimental impact evaluation designs for analysis of malaria outcome indicators from routine HMIS data. Interrupted time series analysis compares the outcome trend and level before and after the introduction of an intervention, set of interventions or program. The dose-response national platform approach explores associations between intervention coverage or program intensity and the outcome at a subnational (district or health facility catchment) level.

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Section: Further Considerations For Impact Evaluation Design Using Hmmentioning

confidence: 99%

Methodological Considerations for Use of Routine Health Information System Data to Evaluate Malaria Program Impact in an Era of Declining Malaria Transmission

Ashton

Bennett

Yukich

et al. 2017

The American Journal of Tropical Medicine and Hygiene

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“…Our search retrieved only one study aiming to evaluate the PE of IPTi. It was a CCS conducted among infants in Tanzania and its main result was that the PE against occurrence of clinical malaria cases was 18% and not significant (95% CI -129–71% 165 ).…”

Section: Resultsmentioning

confidence: 99%

The protective effectiveness of control interventions for malaria prevention: a systematic review of the literature

2017

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Background: Thanks to a considerable increase in funding, malaria control interventions (MCI) whose efficacy had been demonstrated by controlled trials have been largely scaled up during the last decade. Nevertheless, it was not systematically investigated whether this efficacy had been preserved once deployed on the field. Therefore, we sought the literature to assess the disparities between efficacy and effectiveness and the effort to measure the protective effectiveness (PE) of MCI. Methods: The PubMed database was searched for references with keywords related to malaria, to control interventions for prevention and to study designs that allow for the measure of the PE against parasitemia or against clinical outcomes. Results: Our search retrieved 1423 references, and 162 articles were included in the review. Publications were scarce before the year 2000 but dramatically increased afterwards. Bed nets was the MCI most studied (82.1%). The study design most used was a cross-sectional study (65.4%). Two thirds (67.3%) were conducted at the district level or below, and the majority (56.8%) included only children even if the MCI didn’t target only children. Not all studies demonstrated a significant PE from exposure to MCI: 60.6% of studies evaluating bed nets, 50.0% of those evaluating indoor residual spraying, and 4/8 showed an added PE of using both interventions as compared with one only; this proportion was 62.5% for intermittent preventive treatment of pregnant women, and 20.0% for domestic use of insecticides. Conclusions: This review identified numerous local findings of low, non-significant PE –or even the absence of a protective effect provided by these MCIs. The identification of such failures in the effectiveness of MCIs advocates for the investigation of the causes of the problem found. Ideal evaluations of the PE of MCIs should incorporate both a large representativeness and an evaluation of the PE stratified by subpopulations.

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“…The last step in the model was that there should be some evidence of reduced malaria morbidity, which was indeed the case in the study [ 8 , 9 ]. Taking all these elements together, it seems likely that a combination of (i) lack of power combined with (ii) suboptimal coverage and (iii) increasing levels of drug resistance undermined this attempt to estimate the impact of IPTi on child survival.…”

Section: Discussionmentioning

confidence: 97%

“…The current study included household surveys in 2006 which suggested a modest impact of IPTi on malaria parasitaemia (from 38% to 31%, p = 0.06) and anaemia (from 88% to 80%, p = 0.02), despite coverage which was lower than anticipated [ 8 ]. Morbidity monitoring of malaria in 11 sentinel health facilities suggested that IPTi was associated with a reduction in clinical malaria of between 18% and 54%, depending on the scope of the analysis, although no differences reached statistical significance [ 9 ]. A recent pooled analysis of the efficacy of IPTi in six individually randomized studies in infants from Tanzania, Mozambique, Ghana and Gabon concluded that IPTi prevented 30% of clinical malaria episodes (95% CI 20-39) and 23% of all-cause hospital admissions (95%CI 10-34) [ 1 ].…”

Section: Discussionmentioning

confidence: 99%

“…The development of the strategy for the IPTi intervention, and specifically acceptability, and results on safety, costs and community effectiveness for malaria parasitaemia, anaemia, and clinical episodes are presented elsewhere [ 3 - 9 ]. This paper presents the evidence of the impact of IPTi on survival in children aged two-11 months from a cluster-randomized trial in 243,000 households.…”

Section: Introductionmentioning

confidence: 99%

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Cluster-randomized study of intermittent preventive treatment for malaria in infants (IPTi) in southern Tanzania: evaluation of impact on survival

Schellenberg

Maokola

Shirima

et al. 2011

Malar J

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BackgroundIntermittent Preventive Treatment for malaria control in infants (IPTi) consists of the administration of a treatment dose of an anti-malarial drug, usually sulphadoxine-pyrimethamine, at scheduled intervals, regardless of the presence of Plasmodium falciparum infection. A pooled analysis of individually randomized trials reported that IPTi reduced clinical episodes by 30%. This study evaluated the effect of IPTi on child survival in the context of a five-district implementation project in southern Tanzania. [Trial registration: clinical trials.gov NCT00152204].MethodsAfter baseline household and health facility surveys in 2004, five districts comprising 24 divisions were randomly assigned either to receive IPTi (n = 12) or not (n = 12). Implementation started in March 2005, led by routine health services with support from the research team. In 2007, a large household survey was undertaken to assess the impact of IPTi on survival in infants aged two-11 months through birth history interviews with all women aged 13-49 years. The analysis is based on an "intention-to-treat" ecological design, with survival outcomes analysed according to the cluster in which the mothers lived.ResultsSurvival in infants aged two-11 months was comparable in IPTi and comparison areas at baseline. In intervention areas in 2007, 48% of children aged 12-23 months had documented evidence of receiving three doses of IPTi, compared to 2% in comparison areas (P < 0.0001). Over the three years of the study there was a marked improvement in survival in both groups. Between 2001-4 and 2005-7, mortality rates in two-11 month olds fell from 34.1 to 23.6 per 1,000 person-years in intervention areas and from 32.3 to 20.7 in comparison areas. In 2007, divisions implementing IPTi had a 14% (95% CI -12%, 49%) higher mortality rate in two-11 month olds in comparison with non-implementing divisions (P = 0.31).ConclusionThe lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management. This study raises important questions for programme evaluation design.

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Evaluating the effectiveness of IPTi on malaria using routine health information from sentinel health centres in southern Tanzania

Cited by 7 publications

References 27 publications

Methodological Considerations for Use of Routine Health Information System Data to Evaluate Malaria Program Impact in an Era of Declining Malaria Transmission

Methodological Considerations for Use of Routine Health Information System Data to Evaluate Malaria Program Impact in an Era of Declining Malaria Transmission

The protective effectiveness of control interventions for malaria prevention: a systematic review of the literature

Cluster-randomized study of intermittent preventive treatment for malaria in infants (IPTi) in southern Tanzania: evaluation of impact on survival

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