Appraisal of: Hinde S, Spackman E. Bidirectional citation searching to completion: an exploration of literature searching methods. Pharmacoeconomics 2015; 33(1): 5-11.

Short description: 

This paper discusses the relative merits of a systematic citation searching approach as both an alternative and a concurrent method to keyword searching. A method of citation searching, both forwards and backwards, which is iterated to form a closed loop solution, is discussed. An illustrative example is presented of both methods, applying them to the topic of the UK National Institute for Health and Care Excellence (NICE) cost-effectiveness threshold. The case study finds the citation searching approach dominates the traditional keyword searching approach, finding 76 papers of relevance, including all 15 found by the alternative approach. 

Limitations stated by the author(s): 

No limitations stated regarding study methods.But limitations stated regarding search techniques under investigation:

Citation searching faces two major limitations which, it could be argued, have limited its implementation: (1) the ability to extract a paper’s references (backward citation searching) and identify those that have since cited it (forward); and (2) the completeness of citation networks and low efficiency of the search (p. 8) 

Limitations stated by the reviewer(s): 
Not stated whether study selection was performed by 2 people independent from each other; no information about performance of each search technique separately (forward and backward searching); no information about time; high number of hits (n = 4.529); results only compared to a very simple Boolean search (n = 36).
Study Type: 
Single study