Factors associated with false-positive self-reported adherence to antihypertensive drugs

Abstract

Self-reported medication adherence is known to overestimate true adherence. However, little is known about patient factors that may contribute to the upward bias in self-reported medication adherence. The Objective of this study is to examine whether demographic, behavioral, medication, and mood factors are associated with being a false positive self-reported adherer (FPA) to antihypertensive drug treatment. We studied 175 patients (mean age: 50 years; 57% men) from primary care clinics starting antihypertensive drug treatment. Self-reported adherence was measured with the medication adherence report scale (MARS) and by the number of drug doses missed in the previous week/month and compared to pill count adherence (PCAR) as gold standard. Data on adherence, demographic, behavioral, medication, and mood factors were collected at baseline and every three months up to 1 year. FPA was defined as being non-adherer by PCAR and adherer by self-report. Mixed effect logistic regression was used for the analysis. Twenty percent of participants were FPA. Anxiety increased (odds ratio -OR: 3.00; P=0.01), while smoking (OR: 0.40; P=0.03), and drug side effects (OR: 0.46, P=0.03) decreased the probability for FPA by MARS. An educational below completed high school increased the probability of being a FPA as measured by missing doses in the last month (OR: 1.66; P=0.04) and last week (OR: 1.88; P=0.02). The validity of self-reported adherence varies significantly according to drug side effects, behavioral factors, and patient’s mood. Careful consideration should be given to the use of self-reported measures of adherence among patients likely to be false-positive adherers.

Medication therapy problems identified by pharmacists conducting telephonic comprehensive medication management within a team‐based at‐home care program

“…While the correlation between patient self-report and actual medication taking behavior has been shown to be variable, 22,23 concerns remain due to the possibility of bias in patient reporting of their behavior. 24,25 Additionally, many of the patients opt for multidose packaging provided by pharmacies to help improve their adherence to the large number of medications they may take. 26 This organized approach to receiving their medications aids in improved refill adherence as well.…”

Effectiveness of a targeted and tailored pharmacist‐led intervention to improve adherence to antihypertensive drugs among patients with type 2 diabetes in Indonesia: A cluster randomised controlled trial

“…The MARS-5 has been shown to correlate well with indirect measures of adherence, including pill counts among patients with hypertension and refill rates (using medication possession ratio) among patients with stroke. 26,27 Secondary outcomes were medication beliefs (necessity, concerns, side effects and necessity-…”

Modifiable Factors Associated with Non-adherence to Antihypertensive or Antihyperlipidemic Drugs Are Dissimilar: a Multicenter Study Among Patients with Diabetes in Indonesia

“…The MARS scale has been shown to correlate well with other indirect methods, including pill counts among patients with hypertension and refill rates (using medication possession ratio) among patients with stroke. 43,44 Furthermore, the subtype analyses sometimes included small numbers leading to wide confidence intervals and loss of power. Due to the cross-sectional design, no causal inferences can be made regarding the temporal association between medication beliefs and non-adherence.…”