Evaluating the effectiveness, efficiency, cost and value of contacting study authors in a systematic review: a case study and worked example

BACKGROUND: Studies find that identifying additional study data is possible by contacting study authors or experts. What is less certain is the time taken, costs involved and value found by using this supplementary search method. The purpose of this study is to determine the effectiveness, efficiency, cost and value of contacting study authors by e-mail, updating the evidence available for this search method. METHODS: Eighty-eight study authors, whose studies met title/abstract inclusion in a. systematic review, were contacted by e-mail. * effectiveness was assessed by comparing the number of study authors contacted. compared to the number of replies received; * efficiency was assessed by recording the time taken to contact study authors; * cost was assessed by comparing the efficiency of contacting authors with the. effectiveness; and * value was assessed by reading and comparing the published studies with the replies received to see if any unique data was identified. RESULTS: Contacting study authors took 6 h, 54 min and 25 s across 7 weeks. 38 answers (46%) were received from 83 possible contacts. Contacting study authors cost £80.33 or £2.11 per reply. We identified unique data from author replies when compared with data reported in published studies, determining this method as ‘valuable’. CONCLUSIONS: Whilst our effectiveness findings differ from other studies, we believe that this study demonstrates the effectiveness of contacting study authors. By linking effectiveness to value and cost, we offer a new way to interpret the ‘effectiveness’ of this supplementary search method. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12874-019-0685-0) contains supplementary material, which is available to authorized users.