Illness Perceptions, Self-efficacy, and Self-reported Medication Adherence in Persons Aged 50 and Older With Type 2 Diabetes.

The cross-sectional design cannot show whether illness perceptions caused higher self-efficacy or medication adherence, or whether the reverse was true. All key variables were self-reported and may be affected by response bias. The medication adherence scale had low internal consistency in this sample (0.40). The sample was 67.1% white and averaged 13.97 years of education, so results may not apply to less educated or non-white populations. The analysis excluded 20 participants younger than 50 and 1 participant with missing illness-perception data, leaving 146 participants. Diabetes duration was not collected, so it could not be considered as a possible explanation. Only the number of comorbid conditions was analyzed, not the type or impact of each condition. Extreme values for years of education and number of comorbid conditions were altered to reduce their influence on the regression results.

The study used baseline data from the Habit Study, supported by NIH grant P01-NR010949. The supplied text does not include a conflicts-of-interest declaration.

Do not conclude that changing illness perceptions causes better diabetes confidence or medication adherence. This was a cross-sectional self-report analysis, and the medication adherence measure had low internal consistency (0.40) in this sample.