ABSTRACT
Background
Outcome measurement instruments (OMIs) are important for evaluating intervention effectiveness and quality. However, adopting OMIs remains challenging. This study aimed to select OMIs for a core outcome set (COS) for use in studies focusing on adherence to appropriate polypharmacy in older people.
Methods
A list of OMIs for COS outcomes and their feasibility information was compiled from the literature to select one OMI per outcome. Two rounds of Delphi questionnaires containing a range of OMIs were distributed to experts [academics, healthcare professionals (HCPs), journal editors and methodologists] who were asked to select OMIs for a subsequent consensus meeting using ‘Yes’, ‘No’, or ‘Uncertain’. The Delphi results were discussed and OMIs were voted on (Yes: important and No: unimportant) in a consensus meeting with experts and an interview with a public member. An OMI was included if ≥ 80% of participants voted on it as critical and ≤ 20% voted it as unimportant.
Results
Twenty-one OMIs were presented to experts (Round 1, n = 42; Round 2, n = 39) in the Delphi exercise to achieve consensus on nine OMIs. Following the consensus meeting and interview (experts, n = 5; public participants, n = 1), agreement was achieved to select four OMIs: the Adherence to Refills and Medications Scale (ARMS, 100%); Multimorbidity Treatment Burden Questionnaire (MTBQ, 100%); Medication-Related Burden Quality of Life questionnaire (MRB-QoL, 83.3%); and ‘the number of undesired consequences of the intervention that result from administering multiple medications in older people (83.3%)’ for measuring medication adherence across multiple medications (subjective); treatment burden; health-related quality of life (HRQoL) and adverse events and side effects (AEs and SEs), respectively. No agreement was reached regarding cost-effectiveness and healthcare utilization.
Conclusion
This study selected OMIs for use with a COS in studies to improve adherence to appropriate polypharmacy in older people. Future research should identify appropriate OMIs for the remaining outcomes.