Searching CINAHL did not add value to clinical questions posed in NICE guidelines

This study aims to quantify the unique useful yield from the Cumulative Index to Nursing and Allied Health Literature (CINAHL) database to National Institute for Health and Clinical Excellence (NICE) clinical guidelines. A secondary objective is to investigate the relationship between this yield and different clinical question types. It is hypothesized that the unique useful yield from CINAHL is low, and this database can therefore be relegated to selective rather than routine searching.

A retrospective sample of 15 NICE guidelines published between 2005 and 2009 was taken. Information on clinical review question type, number of references, and reference source was extracted.

Only 0.33% (95% confidence interval: 0.01-0.64%) of references per guideline were unique to CINAHL. Nursing- or allied health (AH)-related questions were nearly three times as likely to have references unique to CINAHL as non-nursing- or AH-related questions (14.89% vs. 5.11%), and this relationship was found to be significant (P<0.05). No significant relationship was found between question type and unique CINAHL yield for drug-related questions.

The very low proportion of references unique to CINAHL strongly suggests that this database can be safely relegated to selective rather than routine searching. Nursing- and AH-related questions would benefit from selective searching of CINAHL.