Core items for a standardized resource-use measure (ISRUM): expert Delphi consensus survey

Background: Resource-use measurement by patient recall is characterized by inconsistent methods and a lack of validation. A validated standardized resource-use measure could increase data quality, improve comparability between studies and reduce research burden.
Aim: To identify a minimum set of core resource-use items that should be included in a standardized adult instrument for UK health economic evaluation from a provider perspective.
Methods: Health economists with experience of UK-based economic evaluations were recruited to participate in an electronic Delphi survey. Respondents were asked to rate 60 resource-use items (e.g. medication names) on a scale of 1 to 9 according to the importance of the item in a generic context. Items considered less important according to predefined consensus criteria were dropped and a second survey was developed. In the second round, respondents received the median score and their own score from round 1 for each item alongside summarized comments and were asked to re-rate items. A final project team meeting was held to determine the recommended core set.
Results: 45 participants completed round 1. 26 items were considered less important and dropped, 34 items were retained for the second round and no new items were added. 42 respondents completed round 2 (93.3%), and greater consensus was observed. Following the final meeting, a list of 10 core items was selected with further items identified as suitable for ‘bolt-on’ questionnaire modules.
Conclusions: The consensus on 10 items considered important in a generic context suggests that a standardized instrument for core resource-use items is feasible.