Evidence map›Paper›PMID 24948745›Full record

SynthesisBMJ open2014

Preventive zinc supplementation for children, and the effect of additional iron: a systematic review and meta-analysis.

Evan Mayo-Wilson, Aamer Imdad, Jean Junior, Sohni Dean, Zulfiqar A Bhutta

Open access · goldAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in BMJ open, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 36 papers, 9 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
36citing papers in PubMed, 9 pooled it
4.0field-weighted citation impact, top 7% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

36 citing papers in PubMed, 9 syntheses or guidelines pooled it, 68 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 5 institutions in 3 countries.

Evan Mayo-WilsonDepartment of Epidemiology, Center for Clinical Trials and Evidence Synthesis, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.ORCID http://orcid.org/0000-0001-6126-2459
Aamer ImdadDepartment of Pediatrics, SUNY Upstate Medical University, Syracuse, New York, USA.
Jean JuniorHarvard Medical School, Boston, Massachusetts, USA.
Sohni DeanAlbert Einstein Medical Center, Philadelphia, Pennsylvania, USA.
Zulfiqar A BhuttaSickKids Center for Global Child Health, Toronto, Canada Center of Excellence in Women and Child Health, The Aga Khan University, Karachi, Pakistan.
Aga Khan University · PKEinstein Medical Center Philadelphia · USHarvard University · USJohns Hopkins University · USSUNY Upstate Medical University · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveZinc deficiency is widespread, and preventive supplementation may have benefits in young children. Effects for children over 5 years of age, and effects when coadministered with other micronutrients are uncertain. These are obstacles to scale-up. This review seeks to determine if preventive supplementation reduces mortality and morbidity for children aged 6 months to 12 years.

designSystematic review conducted with the Cochrane Developmental, Psychosocial and Learning Problems Group. Two reviewers independently assessed studies. Meta-analyses were performed for mortality, illness and side effects. DATA SOURCES: We searched multiple databases, including CENTRAL and MEDLINE in January 2013. Authors were contacted for missing information. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised trials of preventive zinc supplementation. Hospitalised children and children with chronic diseases were excluded.

results80 randomised trials with 205 401 participants were included. There was a small but non-significant effect on all-cause mortality (risk ratio (RR) 0.95 (95% CI 0.86 to 1.05)). Supplementation may reduce incidence of all-cause diarrhoea (RR 0.87 (0.85 to 0.89)), but there was evidence of reporting bias. There was no evidence of an effect of incidence or prevalence of respiratory infections or malaria. There was moderate quality evidence of a very small effect on linear growth (standardised mean difference 0.09 (0.06 to 0.13)) and an increase in vomiting (RR 1.29 (1.14 to 1.46)). There was no evidence of an effect on iron status. Comparing zinc with and without iron cosupplementation and direct comparisons of zinc plus iron versus zinc administered alone favoured cointervention for some outcomes and zinc alone for other outcomes. Effects may be larger for children over 1 year of age, but most differences were not significant.

conclusionsBenefits of preventive zinc supplementation may outweigh any potentially adverse effects in areas where risk of zinc deficiency is high. Further research should determine optimal intervention characteristics and delivery strategies.

Indexed as

Dietary SupplementsChildChild, PreschoolDeficiency DiseasesDrug Therapy, CombinationHumansIronRandomized Controlled Trials as TopicZincIronZincPreventive MedicinePublic Health

Identifiers

PMID24948745
PMCPMC4067863
OpenAlexW2049228659

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.