Development and validation of the 15-STARS - A novel self-report pharmacy-based questionnaire to screen for medication non-adherence

Background Published scales measuring medication adherence are myriad. There is a need for a tool that guides towards downstream adherence interventions. Objective To develop and validate a self-report questionnaire able to detect modifiable determinants of medication non-adherence. Methods Workshops, surveys and meetings were used to identify items. Validation was performed in French and German (Switzerland) between March and April 2022. Face validation, content validation, construct validation, internal consistency and test-retest reliability were assessed. The questionnaire was finalized in August 2022. Results The first draft in English included 13 items divided into four areas. Following translation, validation was performed with 144 patients (63 German-, 81 French-speaking) who were recruited in 35 community pharmacies. Acceptability was good (<5% missing data). Psychometric properties were acceptable with good content validity and moderate construct validity. Internal consistency was acceptable for the French version (Cronbach’s alpha = 0.71 [item 1–5] - 0.61 [item 6–9]) and less acceptable for the German version (Cronbach’s alpha = 0.43 [item 1–5] - 0.45 [item 6–9]). Test-retest was given for all items (r = 0.52 to 1.0) except item 10 in French (r = 0.25). The final instrument is a 15-item questionnaire called the 15-STARS (Screening Tool for AdheRence to medicineS) that assesses practical difficulties with medicine use, reasons for non-adherence, doses missed, and need for further help. Conclusions Our findings support the validity and clinical utility of the 15-STARS questionnaire. Reliability was inconclusive due to incoherent internal consistency, but explainable by the single-item nature of the scale. This new tool will enable the detection of patients who experience difficulties that negatively influence medication adherence. Pharmacists will be able to propose specific and tailored adherence interventions to the patients. Next steps will focus on evaluating its usefulness for developing targeted interventions that optimize medication adherence in routine care and research settings

Individual factors increasing complexity of drug treatment—a narrative review

Purpose!#!Complexity of drug treatment is known to be a risk factor for administration errors and nonadherence promoting higher healthcare costs, hospital admissions and increased mortality. Number of drugs and dose frequency are parameters often used to assess complexity related to the medication regimen. However, factors resulting from complex processes of care or arising from patient characteristics are only sporadically analyzed. Hence, the objective of this review is to give a comprehensive overview of relevant, patient-centered factors influencing complexity of drug treatment.!##!Methods!#!A purposeful literature search was performed in MEDLINE to identify potential complexity factors relating to the prescribed drug (i.e. dosage forms or other product characteristics), the specific medication regimen (i.e. dosage schemes or additional instructions), specific patient characteristics and process characteristics. Factors were included if they were associated to administration errors, nonadherence and related adverse drug events detected in community dwelling adult patients.!##!Results!#!Ninety-one influencing factors were identified: fourteen in 'dosage forms', five in 'product characteristics', twelve in 'dosage schemes', nine in 'additional instructions', thirty-one in 'patient characteristics' and twenty in 'process characteristics'.!##!Conclusions!#!Although the findings are limited by the non-systematic search process and the heterogeneous results, the search shows the influence of many factors on the complexity of drug treatment. However, to evaluate their relevance for individual patients, prospective studies are necessary