Locating qualitative studies in dementia on MEDLINE, EMBASE, CINAHL and PsycINFO: a comparison of search strategies.

BACKGROUND: Qualitative research in dementia improves understanding of the experience of people affected by dementia. Searching databases for qualitative studies is problematic. Qualitative specific search strategies might help with locating studies. OBJECTIVE: To examine the effectiveness of five strategies across four major databases for retrieving qualitative studies in dementia. examine the effectiveness (sensitivity and precision) of five qualitative strategies on locating qualitative research studies in dementia in four major databases (MEDLINE, EMBASE, PsycINFO and CINAHL) METHODS: Qualitative dementia studies were checked for inclusion on MEDLINE, EMBASE, PsycINFO and CINAHL. Five qualitative search strategies (subject headings; simple free-text terms; complex free-text terms; two broad based strategies) were tested for study retrieval. Specificity, precision and number needed to read were calculated. RESULTS: 214 qualitative studies in dementia were included. PsycINFO and CINAHL held the most qualitative studies out the four databases studied (N=171 and 166 respectively) and both held unique records (N=14 and 7 respectively). The controlled vocabulary strategy in in CINAHL returned 96% (N=192) of studies held; by contrast, controlled vocabulary in PsycINFO returned 7% (N=13) of studies held. The broad based strategies returned more studies (93-99%) than the other free text strategies (22-82%). Precision ranged from 0.061-0.004 resulting in a number needed to read in order to obtain one relevant study ranging from 16 (simple free text search in CINAHL) to 239 (broad based search in EMBASE) CONCLUSION: MEDLINE and EMBASE offered little benefit for locating qualitative dementia research when CINAHL and PSYCINFO were also searched. Qualitative search strategies using three broad terms were more sensitive than long complex searches. The controlled vocabulary for qualitative research in CINAHL was particularly effective. Furthermore, results indicate that MEDLINE and EMBASE offer little benefit for locating qualitative dementia research if CINAHL and PSYCINFO are also searched.