Appraisal of: Linder SK, Kamath GR, Pratt GF, Saraykar SS, Volk RJ. Citation searches are more sensitive than keyword searches to identify studies using specific measurement instruments. J Clin Epidemiol. 2015; 68(4):412-417.
The aim of the study was to compare the effectiveness of two search methods in identifying studies that used the Control Preferences Scale (CPS), a health care decision-making instrument.
The literature was searched using two methods: (1) keyword searching using variations of ‘‘Control Preferences Scale’’ and (2) cited reference searching using two seminal CPS publications. Three bibliographic databases [PubMed, Scopus, and Web of Science (WOS)] and one full-text database (Google Scholar) were searched.
Keyword searches in bibliographic databases yielded high average precision (90%) but low average sensitivity (16%). PubMed was the most precise, followed closely by Scopus and WOS. The Google Scholar keyword search had low precision (54%) but provided the highest sensitivity (70%). Cited reference searches in all databases yielded moderate sensitivity (GS: 54%, WoS: 45%, Scopus 52%), but precision ranged from 35% to 75% with Scopus being the most precise.
When trying to identify many articles using a particular instrument, cited reference searching in Scopus or WOS is preferable to keyword searching in these resources or in PubMed/MEDLINE. However, in Google Scholar, a full-text database, a keyword search for CPS found more studies than the cited reference searches and precision was slightly higher.
If the goal is to identify a few studies that use a specific instrument, keyword searches of a bibliographic database may be the most efficient. When it is important to conduct a comprehensive search to maximize the number of studies found, both cited reference and keyword searches should be conducted in more than one database.