CRD summary

This review concluded that there was no benefit of vitamin A supplementation for the prevention and treatment of childhood community acquired pneumonia. However, due to problems with the conduct and reporting of the review, the author's conclusion may not be reliable.

Authors' objectives

To evaluate the effectiveness of supplementation with vitamin A for the prevention and treatment of childhood pneumonia

Searching

The Cochrane Library and MEDLINE were searched. Search terms were reported, but no search dates were given. Bibliographies of included trials were handsearched.

Study selection

To be eligible for the review, studies need to be randomised controlled trials (RCTs) of vitamin A for the prevention or treatment of pneumonia in children. Trials including children with pre-existing pneumonia or other pre-existing illness were excluded, as were those that recruited specific subgroups. Those evaluating a respiratory outcome not consistent with pneumonia were also excluded.

Most of the included trials were conducted in developing country populations, except one which included Australian indigenous children. Across the trials, ages ranged from newborn to up to 10 years old (where reported). Doses and duration of supplementation varied. In prevention and treatment trials, a range of outcomes were examined including mortality due to pneumonia and all-cause mortality.

The author did not state how many reviewers were involved in the selection of studies for the review.

Assessment of study quality

The author appeared to assess risk of bias, but the tool used was not specified. The involvement of a second reviewer was not apparent.

Data extraction

The author did not state how data were extracted for the review.

Methods of synthesis

A series of meta-analyses were conducted on subsets of trials. Data were pooled for each reported outcome for prevention and therapeutic trials. Methods of pooling were not reported. Statistical heterogeneity was assessed using the X² and I² tests.

Results of the review

Twenty trials were included in the review; the overall number of participants was not stated. One of the nine prevention trials was classed as having a low risk of bias, whilst six were at high risk of bias. Seven of nine treatment trials had a low risk of bias. Follow-up in the prevention trials ranged from 90 days to 15 months (where reported).

Pneumonia prevention: When vitamin A was compared with placebo for prevention, there were no significant differences in numbers of children with pneumonia (four trials), incidence of pneumonia (five trials), pneumonia mortality (two trials) and all-cause mortality (four trials). The only outcome that showed evidence of heterogeneity was all-cause mortality (I²=65.6%).

Pneumonia treatment: When vitamin A was compared with placebo for treatment of pneumonia, there were no significant differences in mortality (eight trials), duration of hospitalisation (two trials), duration of illness (two trials), complications (four trials), side effects (two trials), absence of cure (one trial) and hospitalisation of outpatients (one trial). The only outcome that showed evidence of heterogeneity was occurrence of side effects (I²=61.1%).

Authors' conclusions

There was neither therapeutic nor prophylactic benefit of vitamin A supplementation for childhood community acquired pneumonia.

CRD commentary

This review was underpinned by basic inclusion criteria for study design, participants, intervention and outcomes. Searching covered a small range of sources. It was unclear if foreign language and unpublished research were eligible for inclusion, introducing the possibility of language and publication bias. Search dates were not stated, so the search could not be replicated. It was unclear whether more than one reviewer was involved in the selection of studies, data extraction and validity assessment in order to minimise the potential for error and bias.

The methods for assessing trial quality were unclear. The effect of trial quality on results did not appear to have been investigated. The methods of meta-analysis were not clearly explained.

Given these methodological and reporting issues, the author's conclusion may not be reliable.

Implications of the review for practice and research

Practice: The author stated that there was no benefit of vitamin A supplementation for the prevention and treatment of childhood community acquired pneumonia.

Research: The author did not state any implications for research.

Funding

None.

Bibliographic details

Mathew JL. Vitamin A supplementation for prophylaxis or therapy in childhood pneumonia: a systematic review of randomized controlled trials. Indian Pediatrics 2010; 47(3): 255-261. [PubMed: 20371893]

Original Paper URL

http://www.indianpediatrics.net/mar2010/255.pdf

Indexing Status

Subject indexing assigned by NLM

MeSH

Child; Community-Acquired Infections /diet therapy /prevention & control; Dietary Supplements; Humans; Pneumonia /diet therapy /prevention & control; Vitamin A /administration & dosage

AccessionNumber

12010003319

Database entry date

01/12/2010

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.