Evaluating the content of a patient-reported outcome measure for people with multimorbidity: a Delphi consensus.

Purpose: Evidence supporting multimorbidity-adapted interventions is scarce, mostly due to a lack of adapted outcome measures. Measurement constructs for a novel patient-reported outcome measure (PROM) were defined in previous studies using a literature review, a qualitative description from stakeholders, and an item pool identification process. The aim of this study was to attain consensus on the content of this novel PROM.

Methods: A three-round electronic modified Delphi technique was conducted using an academic and clinical expert panel. Using a Likert scale, the panel rated the relevance, improvability, and self-ratability of each construct and item of the preliminary version of the PROM. The main outcome was consensus attainment, defined as strong (≥ 70%), moderate (50-69%) or low agreement (< 50%). Constructs and items with strong consensus were kept, moderate were sent to the next round and low agreement were rejected.

Results: From the 61 experts contacted, 39 participated in the first round of the Delphi, with a 12.8% attrition at the second round (n = 34) and 38.2% at the third round (n = 21). The panel included mostly female academic experts from nursing and medicine backgrounds. The preliminary PROM included 19 constructs and 70 items; from these, 16 constructs and 50 items attained consensus. The consensus attainment process excluded three constructs and their items: awareness, weight control and social integration.

Conclusion: Consensus was reached for a patient-reported outcome measure adapted for people with multimorbidity including 50 relevant, improvable and self-ratable items categorized under 16 constructs. As more interventions tailored to multimorbidity are implemented, there is an increasing need for a valid measure of the effectiveness of these interventions.