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Whilst not disputing the originality of the review of community-based participatory research by Cook, and published in the August 2008 edition of JECH, it does raise questions about what the agreed minimum methodological requirements are for JECH to describe a review as “systematic”.
Specifically, the Cook review meets none of the criteria which are widely considered to differentiate systemati...
Specifically, the Cook review meets none of the criteria which are widely considered to differentiate systematic reviews (SRs) from traditional literature reviews (Table 1). Most notably, the Cook study employed a very minimalist search strategy not least as in terms of the electronic searches, only MEDLINE was searched. This is widely considered as inadequate for SRs, particularly public health ones, as many relevant studies are missed.[3, 4] Further, citation follow-ups, hand searching and author contact, all considered important aspects of a sound SR search strategy, are absent.[2, 5] Clear descriptions of study inclusion, data extraction and quality appraisal were similarly lacking. Indeed, quality appraisal seems limited to a description of the various study designs employed by the included studies. No quality appraisal criteria are presented. As table 1 demonstrates, transparency is lacking in many other aspects of the review methodology and it is unclear why studies are included (or indeed excluded). In addition, there is only one author of the review (Cook). This is very rare for a SR, as having a second reviewer to independently check judgements is an important component of the rigour of SRs – minimising bias and enhancing reproducibility. [2, 5] Indeed all other SRs published in JECH since 2000 have had more than two reviewers.
It is therefore highly misleading to describe the Cook literature review as a “systematic” review. Doing so within the pages of JECH undermines the extensive efforts (time, cost, management) put in by actual SR teams, ignores the evidence of the benefits of taking a systematic approach to evidence synthesis,[2-5] and brushes aside the extensive guidelines developed about the good conduct of SRs. The essential methodological elements of SRs (transparency, rigour, reproducibility, quality appraisal), not only differentiate them from traditional reviews, but they are also what gives SRs their high status within the hierarchy of evidence and makes them such a valuable source of research evidence. The Cook review lacks the methodological rigour which characterises a SR and cannot be fairly described as such: it is a traditional literature review and JECH readers should re-consider its findings in this context.
1. Cook, WK. Integrating research and action: a systematic review of community-based participatory research to address health disparities in environmental and occupational health in the USA. J Epidemiol Comm Heal. 2008, 62: 668-676.
2. Petticrew, M. Systematic reviews from astronomy to zoology: myths and misconceptions. Brit Med J. 2001, 322;98-101.
3. Suarez-Almazor, ME., Belseck, E., Homik, J., et al. Identifying clinical trials in the medical literature with electronic databases: MEDLINE alone is not enough. Control Clin Trials 2000, 21: 476.87.
4. Ogilivie, D., Hamilton, V., Egan, M., et al Systematic reviews of health effects of social interventions: How far should you go? J Epidemiol Comm Heal. 2005, 59: 804-808.
5. Higgins, JPT., Green, S. (eds). Cochrane Handbook for Systematic Reviews of Intervention Studies (v5.0). 2008. Available at: http://www.cochrane-handbook.org/ [accessed 20/08/08]