Evidence map›Paper›PMID 21769305›Full record

ArticleThe open respiratory medicine journal2011

Zinc lozenges may shorten the duration of colds: a systematic review.

Harri Hemilä

Open access · hybridAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in The open respiratory medicine journal, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
41citing papers in PubMed, 5 pooled it
2.9field-weighted citation impact, top 10% 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

41 citing papers in PubMed, 5 syntheses or guidelines pooled it, 90 citations in OpenAlex.

  1. Zinc for prevention and treatment of the common cold.The Cochrane database of systematic reviews · 2024
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  5. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials.CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2012
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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

1 author at 1 institution in 1 country.

Harri HemiläDepartment of Public Health, University of Helsinki, Helsinki, Finland.
University of Helsinki · FI

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundA number of controlled trials have examined the effect of zinc lozenges on the common cold but the findings have diverged. The purpose of this study was to examine whether the total daily dose of zinc might explain part of the variation in the results.

methodsThe Medline, Scopus and Cochrane Central Register of Controlled Trials data bases were searched for placebocontrolled trials examining the effect of zinc lozenges on common cold duration. Two methods were used for analysis: the P-values of the trials were combined by using the Fisher method and the results of the trials were pooled by using the inverse-variance method. Both approaches were used for all the identified trials and separately for the low zinc dose and the high zinc dose trials.

resultsThirteen placebo-controlled comparisons have examined the therapeutic effect of zinc lozenges on common cold episodes of natural origin. Five of the trials used a total daily zinc dose of less than 75 mg and uniformly found no effect. Three trials used zinc acetate in daily doses of over 75 mg, the pooled result indicating a 42% reduction in the duration of colds (95% CI: 35% to 48%). Five trials used zinc salts other than acetate in daily doses of over 75 mg, the pooled result indicating a 20% reduction in the duration of colds (95% CI: 12% to 28%).

conclusionsThis study shows strong evidence that the zinc lozenge effect on common cold duration is heterogeneous so that benefit is observed with high doses of zinc but not with low doses. The effects of zinc lozenges should be further studied to determine the optimal lozenge compositions and treatment strategies.

Indexed as

Meta-analysisrandomized controlled trialsrespiratory infectionszinc.

Identifiers

PMID21769305
PMCPMC3136969
OpenAlexW1568841878

What OpenQuestion holds

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Registered trials

None linked

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.