Background:
For systematic reviews providing evidence for policy decisions in specific geographicalregions, there is a need to minimise regional bias when seeking out relevant research studies.Studies on people’s views tend to be dispersed across a range of bibliographic databases andother search sources. It is recognised that a comprehensive literature search can provideunique evidence not found from a focused search; however, the geographical focus ofdatabases as a potential source of bias on the findings of a research review is less clear. This case study describes search source selection for research about people’s views and howsupplementary searches designed to redress geographical bias influenced the findings of asystematic review. Our research questions are: a) what was the impact of search methodsemployed to redress potential database selection bias on the overall findings of the review?and b) how did each search source contribute to the identification of all the research studiesincluded in the review?
Methods:
The contribution of 25 search sources in locating 28 studies included within a systematicreview on UK children’s views of body size, shape and weight was analysed retrospectively.The impact of utilising seven search sources chosen to identify UK-based literature on thereview’s findings was assessed.
Results:
Over a sixth (5 out of 28) of the studies were located only through supplementary searches ofthree sources. These five studies were of a disproportionally high quality compared with theother studies in the review. The retrieval of these studies added direction, detail and strengthto the overall findings of the review. All studies in the review were located within 21 searchsources. Precision for 21 sources ranged from 0.21% to 1.64%.
Conclusions:
For reducing geographical bias and increasing the coverage and context-specificity ofsystematic reviews of people’s perspectives and experiences, searching that is sensitive andaimed at reducing geographical bias in database sources is recommended.