Formulae for calculating the comprehensiveness and efficiency of Pubmed searches
| Search result | Relevant articles* | Nonrelevant articles |
|---|---|---|
| Articles found | a | b |
| Articles not found | c | d |
| Comprehensiveness† = a/(a+c) Efficiency‡ = a/(a+b) | ||
↵* For each search, relevant articles were defined as the primary studies included in the original systematic review from which the clinical question was derived.
↵† Measured by search recall (the number of relevant articles found as a proportion of the total number of relevant articles). Also called sensitivity.
↵‡ Measured by search precision (the number of relevant articles found as a proportion of the total number of articles found). Also called positive predictive value.