What are validated self-report adherence scales really measuring?: a systematic review.

AIMS: Medication non-adherence is a significant health problem. There are numerous methods for measuring adherence, but no single method performs well on all criteria. The purpose of this systematic review is to (i) identify self-report medication adherence scales that have been correlated with comparison measures of medication-taking behaviour, (ii) assess how these scales measure adherence and (iii) explore how these adherence scales have been validated. METHODS: Cinahl and PubMed databases were used to search articles written in English on the development or validation of medication adherence scales dating to August 2012. The search terms used were medication adherence, medication non-adherence, medication compliance and names of each scale. Data such as barriers identified and validation comparison measures were extracted and compared. RESULTS: Sixty articles were included in the review, which consisted of 43 adherence scales. Adherence scales include items that either elicit information regarding the patient's medication-taking behaviour and/or attempts to identify barriers to good medication-taking behaviour or beliefs associated with adherence. The validation strategies employed depended on whether the focus of the scale was to measure medication-taking behaviour or identify barriers or beliefs. CONCLUSIONS: Supporting patients to be adherent requires information on their medication-taking behaviour, barriers to adherence and beliefs about medicines. Adherence scales have the potential to explore these aspects of adherence, but currently there has been a greater focus on measuring medication-taking behaviour. Selecting the 'right' adherence scale(s) requires consideration of what needs to be measured and how (and in whom) the scale has been validated.

Validated adherence scales used in a measurement-guided medication management approach to target and tailor a medication adherence intervention: a randomised controlled trial.

OBJECTIVE: To determine if a targeted and tailored intervention based on a discussion informed by validated adherence scales will improve medication adherence. DESIGN: Prospective randomised trial. SETTING: 2 community pharmacies in Brisbane, Australia. METHODS: Patients recently initiated on a cardiovascular or oral hypoglycaemic medication within the past 4-12 weeks were recruited from two community pharmacies. Participants identified as non-adherent using the Medication Adherence Questionnaire (MAQ) were randomised into the intervention or control group. The intervention group received a tailored intervention based on a discussion informed by responses to the MAQ, Beliefs about Medicines Questionnaire-Specific and Brief Illness Perception Questionnaire. Adherence was measured using the MAQ at 3 and 6 months following the intervention. RESULTS: A total of 408 patients were assessed for eligibility, from which 152 participants were enrolled into the study. 120 participants were identified as non-adherent using the MAQ and randomised to the 'intervention' or 'control' group. The mean MAQ score at baseline in the intervention and control were similar (1.58: 95% CI (1.38 to 1.78) and 1.60: 95% CI (1.43 to 1.77), respectively). There was a statistically significant improvement in adherence in the intervention group compared to control at 3 months (mean MAQ score 0.42: 95% CI (0.27 to 0.57) vs 1.58: 95% CI (1.42 to 1.75); p<0.001). The significant improvement in MAQ score in the intervention group compared to control was sustained at 6 months (0.48: 95% CI (0.31 to 0.65) vs 1.48: 95% CI (1.27 to 1.69); p<0.001). CONCLUSIONS: An intervention that targeted non-adherent participants and tailored to participant-specific reasons for non-adherence was successful at improving medication adherence. TRIAL REGISTRATION NUMBER: ACTRN12613000162718; Results.