Factors Associated with Non-Adherence to Drugs in Patients with Chronic Diseases Who Go to Pharmacies in Spain

Background. Pharmacological non-adherence in chronic diseases is 40–65%. No predictive profile of non-adherence exists in patients with multiple chronic diseases. Our study aimed to quantify the prevalence of non-adherence to pharmacological treatment and its associated factors in patients who visit pharmacies in Spain. Methods. This observational cross-sectional study included patients with one or more chronic diseases. The variables analyzed were demographics, diseases involved, self-medication, information about disease, and lifestyle. The main variable was adherence using the Morisky–Green test. A total of 132 pharmacies collaborated, providing 6327 patients representing all Spain regions (April–December 2016). Bivariate and multivariate analyses were performed and the area under the receiver operating characteristic (ROC) curve was calculated. Results. Non-adherence was 48.4% (95% confidence interval (CI): 47.2–49.7%). The variables that reached significance in the multivariate model were: difficulty in taking medication, self-medication, desire for more information, smoking, lower physical activity, younger age and number of chronic treatments. Discrimination was satisfactory (area under the ROC curve = 70%). Our study found that 50% patients was non-adherent and we obtained a profile of variables associated with therapeutic non-adherence. Conclusions. It is cause for concern that in patients with multiple diseases and taking multiple medications, there is an association between non-adherence, self-medication and worse lifestyle

Validation of self-reported adherence in chronic patients visiting pharmacies and factors associated with the overestimation and underestimation of good adherence

Background Studies validating indirect methods to identify nonadherence in chronic patients who visit pharmacies are lacking. The aim of this study was to validate self-reported adherence and assess the variables associated with both overestimation and underestimation of good adherence when using this method. Materials and methods An observational, cross-sectional study was undertaken to validate self-reported adherence in 132 community pharmacies throughout Spain in 6237 chronic patients. The Morisky-Green test was used as the validation method and through a 2 × 2 table, the validity indicators, predictive values, and likelihood ratios were calculated. To assess the variables associated with both overestimation and underestimation of good adherence, multivariate logistic regression analysis and calculation of the area under the ROC curve were used to evaluate discriminatory capacity. Results Sensitivity was 27.8% (95% CI: 26.2–29.4) and specificity was 93.9% (95% CI: 93.1–94.7). Discrepancy analysis obtained a significant overestimation of good adherence (p < 0.001). The factors associated with overestimating good adherence were performing a mnemonic trick (p < 0.001), not self-medicating (p < 0.001), a high level of physical activity (p < 0.001), and an older age (p = 0.014). Factors associated with underestimation were self-medication (p < 0.001), desiring more information (p < 0.001), smoking (p = 0.014), not engaging in physical activity in the low (p = 0.006) or high (p < 0.001) categories, having a younger mean age (p = 0.007), and taking two to three (p = 0.029) or four or more (p < 0.001) chronic treatments. Conclusion Self-reported adherence has good specificity but poor sensitivity. The associated profiles of the discrepancies were obtained to identify both good and poor adherence