Incorporating data from dissertations in systematic reviews.
OBJECTIVE
To determine whether unpublished dissertations are an important source of trials for systematic reviews.


METHODS
In a review of infant massage, we identified 17 dissertations. We recorded whether each dissertation was included in the review and, if so, whether it contributed data to any analyses.


RESULTS
Thirteen dissertations were excluded, 11 because of poor reporting of methodology. Three dissertations were also published as journal papers. The data from the remaining dissertation were not included in any analysis. Reviewing data on the Cochrane Library, only one of 878 reviews included data from a dissertation that might have changed a review's conclusions.


CONCLUSIONS
Searching for and retrieving unpublished dissertations involves considerable time and effort and appears to influence the conclusions of a review only rarely.
King's College School of Medicine and Dentistry.
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AJ
Vickers
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Smith
D004212:Academic Dissertations as Topic; D015706:Bibliometrics; D003625:Data Collection; D005069:Evaluation Studies as Topic; D006801:Humans; D007223:Infant; D008405:Massage; D015201:Meta-Analysis as Topic; D012196:Review Literature as Topic