The RAS-24: Development and validation of an adherence-to-medication scale for severe mental illness patients

Area of Science:

• Psychiatry
• Psychometrics
• Health Disparities

Background:

• Medication nonadherence is prevalent in severe mental illness (SMI) patients with comorbid conditions, hindering treatment success and worsening health outcomes.
• Understanding and addressing nonadherence is critical for effective management of psychiatric disorders.

Purpose of the Study:

• To develop and validate the Ralat Adherence Scale, a culturally sensitive instrument for measuring nonadherence behaviors in patients with SMI.
• To provide a reliable tool for assessing medication adherence in diverse patient populations.

Main Methods:

• Developed an initial 147-item pool based on previous research on nonadherence reasons in Puerto Rican patients.
• Expert review and content validity ratio calculation reduced the items to 40.
• Administered the 40-item scale to 160 patients diagnosed with bipolar disorder, major depressive disorder, or schizoaffective disorder.

Main Results:

• The initial 40-item scale showed good internal consistency (Cronbach's alpha = 0.812).
• Factor analysis refined the scale to 24 items, significantly improving internal consistency (Cronbach's alpha = 0.900).

Conclusions:

• The 24-item Ralat Adherence Scale is a self-administered instrument with excellent psychometric properties.
• The scale provides valuable insights into nonadherence behaviors and can aid healthcare professionals and researchers in assessing patient adherence to medication regimens.