Self-reported measures of medication adherence in adults with type 2 diabetes are valid, although some self-reports are moderated by depression, according to a study published online Nov. 30 inDiabetes Care.
Jeffrey S. Gonzalez, PhD, from Yeshiva University in Bronx, NY, and colleagues assessed the validity of self-reported measures of medication adherence in 170 adults with type 2 diabetes (57% male) treated with oral medications. Patients were also interviewed for depression and provided blood samples. Medication Event Monitoring System (MEMS) bottle caps were given to patients with clinically significant depression and hemoglobin A1c (HbA1c) ≥7.0%.
The researchers found that adherence self-reports correlated significantly with lower HbA1c. In the subsample of 88 patients receiving MEMS, all self-reports correlated significantly with MEMS-measured adherence. The relationship between three of six self-reports and HbA1c was significantly moderated by depression. At high levels of depression, the correlations with HbA1c were no longer significant.
"Results support the validity of easily administered self-reports for diabetes medication adherence," the authors write. "One-week self-ratings and measures that require respondents to record the number of missed doses appear to be vulnerable to bias from depression severity."