Shea, B., Andersson, N. And Henry, D. (2009) Increasing the demand for childhood vaccination in developing countries: a systematic review. BMC International Health and Human Rights, 9 (Suppl 1): S5Link to Source
The review authors attempted to synthesise a diverse and wide-reaching set of studies. They took care to use two reviewers to screen studies and extract data and provide some important information about the included studies. However, the review has some major limitations. Specifically, it is not clear if studies in any language were included and if authors were not contacted for unpublished studies. The time period covered by the search is also not fully justified. The review cites a well-known and validated checklist for assessing RCTs, but the exact criteria are not reported. The criteria used for assessing other studies are not reported, although these are describes as more ‘informal’. The results of the critical appraisal for each study by each criterion are not reported. The authors provide descriptive results, but it is not clear from the methods how this information was derived or how it was best reported. In addition, it is not clear if included studies suffered from unit of analysis errors, and if so, whether this was addressed in the review.