Validity testing of the Long-Term Medication Behavior Self-Efficacy Scale.

Area of Science:

• Health Psychology
• Behavioral Medicine
• Pharmacology

Background:

• Self-efficacy significantly influences health behaviors, including medication adherence.
• Validated measures for self-efficacy in medication taking are crucial for adherence research.
• Existing scales may not adequately capture the nuances of long-term medication behavior self-efficacy.

Purpose of the Study:

• To determine the criterion validity of the Long-Term Medication Behavior Self-Efficacy Scale (LTMBSES).
• To assess the scale's ability to predict medication adherence in diverse patient populations.

Main Methods:

• Pooled individual patient data (n=1021) from six existing adherence studies.
• Included patients with conditions such as transplant, hyperlipidemia, and AIDS/HIV.
• Assessed the relationship between LTMBSES scores and both self-reported and electronically monitored medication adherence.

Main Results:

• A weak correlation was observed between LTMBSES scores and medication adherence.
• A potential ceiling effect due to population homogeneity or scale limitations may explain the weak relationship.
• Generalized Estimating Equations showed self-efficacy predicted reported adherence (p < .0001), but Receiver Operating Characteristic analysis indicated poor predictive capability (AUC=0.67, p < .0001).

Conclusions:

• Current evidence for the criterion validity of the LTMBSES is unconvincing.
• Future research should validate the scale in heterogeneous adherence populations.
• Modifying the scale to include more challenging items, such as "always taking medication without exception," is recommended.