Background
Medication non-adherence is prevalent in older people taking polypharmacy. Several interventions have been employed to improve adherence in this population. However, inconsistencies in outcomes have impeded comparisons of findings. Accordingly, this work aimed to develop a core outcome set (COS) for use in trials aiming to improve adherence to appropriate polypharmacy in older people.
Methods
A group of stakeholders, including academics, journal editors, healthcare professionals (HCPs) and public participants, evaluated 13 outcomes compiled from the literature in a Delphi study using a nine-point Likert scale ranging from 1 to 9, where higher scores (7–9) indicated critical importance and lower scores (1–3) unimportance. The resultant Delphi consensus list was discussed and voted on (yes: critical and no: unimportant) in two online nominal group technique (NGT) meetings. The NGT followed a five-stage approach: introduction, silent generation, round-robin, clarification and voting. An outcome was included if =80% of participants scored it critical and?=?15% scored it as unimportant.
Results
Of the 13 outcomes originally presented to participants, consensus was achieved to include six outcomes in the COS after the Delphi study (Round 1, n?=?57; Round 2, n?=?53; Round 3, n?=?50, where ‘n’ represents participant numbers) and the NGT meetings (n?=?10) comprising medication adherence across multiple medications, treatment burden, health-related quality of life (HRQoL), healthcare utilisation (HCU), adverse events and side effects (AEs and SEs) and cost-effectiveness.
Conclusion
This COS should be used in intervention studies focusing on improving adherence to appropriate polypharmacy in older people. Future work should identify outcome measurement instruments to be used alongside the COS.
Older people are more likely to be prescribed polypharmacy (many medicines) which may be required for management of multiple long-term conditions. However, older people may find it difficult to adhere to many medications. Previous studies have applied different interventions to improve adherence to polypharmacy, but there is a lack of high-quality studies due to heterogeneity in outcomes, outcome measures and study designs. Therefore, comparing and combining results from previous trials has been challenging. To generate high-quality studies and selectively report outcomes, a Core Outcome Set (COS) is important to provide a standardised list of outcomes related to adherence to appropriate polypharmacy.
Previous COS studies have focused on polypharmacy and adherence separately as indicated below in the brief summary of these studies. Our COS will focus specifically on adherence to appropriate polypharmacy.
Adherence:
1- Developing a Core Outcome Set for trials evaluating medication adherence interventions
The scope of the study is different. Age ranges from 18 – 120 and the COS is not specifically targeting polypharmacy. Our study mainly targets older people aged =65 taking polypharmacy (=4 regular medications).
Polypharmacy:
2- CHARMER (CompreHensive geriAtRician-led Medication Review) - Developing a Core Outcome Set for hospital deprescribing trials: a modified Delphi study
This study targets deprescribing rather than adherence to polypharmacy, and the type of intervention in this study is drugs only.
3- Core Outcome Set for Trials Aimed at Improving the Appropriateness of Polypharmacy in Older People in Primary Care
This COS study targets the appropriateness of polypharmacy rather than adherence to polypharmacy.
4- International core outcome set for clinical trials of medication review in multi-morbid older patients with polypharmacy
This COS study targets medication review in older patients taking polypharmacy, rather than medication adherence to polypharmacy.
5- Core outcome set for interventions aiming to optimize the medication use of patients discharged from the hospital
This study to optimise medication use upon discharge for older patients with multimorbidity or prescribed polypharmacy
Hanadi Al Shaker, Heather Barry, Carmel Hughes
Disease Category: Health care of older people
Disease Name: Medication adherence
Age Range: 65 - 110
Sex: Either
Nature of Intervention: Any
- Clinical experts
- Journal editors
- Patient/ support group representatives
- Researchers
- Service providers
- COS for clinical trials or clinical research
- Recommendations for outcome measures (measurement/how)
- Delphi process
- Interview
- Literature review
- Nominal group technique (NGT)
This COS development research includes a semi-structured interview study, a three-round online Delphi consensus study, an online Nominal group technique study, followed by a study to identify outcome measurement instruments (OMIs) relevant to the developed COS.
The development of this COS will involve three related studies, two of which are completed (Study 1 and Study 2) and one of which is being developed (Study 3).
Study 1 consisted of qualitative interviews with key stakeholders to explore outcomes of importance to be included in the COS. Academics, healthcare professionals (general practitioners and pharmacists), members of patient advocacy groups and older peoples’ carers were interviewed to explore what outcomes might be important for such a COS.
Study 2 followed Study 1 and was a Delphi consensus study with similar stakeholder groups as in Study 1, which used a three-round online questionnaire to reach consensus on outcomes.
Study 3 will use the Nominal Group Technique to finalise and refine the list of outcomes.
Once the COS has been developed, a subsequent study will be undertaken to identify how the core outcomes should be measured, using the COSMIN (Consensus-based Standards for the selection of health Measurement Instruments) approach.