Validation of an instrument to measure patients' experiences of medicine use: the Living with Medicines Questionnaire

Background: Medicine-related burden is an increasingly recognised concept, stemming from the rising tide of polypharmacy, which may impact on patient behaviours, including non-adherence. No instruments currently exist which specifically measure medicine-related burden. The Living with Medicines Questionnaire was developed for this purpose.

Objectives: This study validated the Living with Medicines Questionnaire in a sample of adults using regular prescription medicines in the UK.

Methods: Questionnaires were distributed in community pharmacies and public places in south-east England, or online via UK health websites and social media. A total of 1177 were returned 507 (43.1%) from pharmacy distribution and 670 (56.9%) on-line. Construct validity was assessed by principal components analysis and item reduction undertaken on the original 60-item pool. Known-groups analysis assessed differences in mean total scores between participants using different numbers of medicines and those requiring assistance with medicine use. Internal consistency was assessed by Cronbach’s alpha. Free-text comments were analysed thematically to substantiate underlying dimensions.

Results: A 42-item, 8-factor, structure, comprising inter-correlated dimensions (patient-doctor relationships and communication about medicines; patient-pharmacist communication about medicines; interferences to daily life; practical difficulties; effectiveness; acceptance of medicine use; autonomy/control over medicines; and concerns about medicine use) was derived, which explained 57.4% of the total variation. Six of the eight subscales have acceptable internal consistency (? > 0.7). More positive experiences were observed among patients using eight or fewer medicines compared to nine or more, and those independent with managing/using their medicines versus those requiring assistance. Free-text comments, provided by almost a third of respondents, supported the domains identified.

Conclusions: The resultant Living with Medicines Questionnaire (LMQ-2) is a valid and reliable multidimensional measure of prescription medicine use experiences, which covers more diverse domains than existing questionnaires. However, further validation work is necessary.