Congruence between patient characteristics and interventions may partly explain medication adherence intervention effectiveness: An analysis of 190 randomized controlled trials from a Cochrane systematic review

4 years ago

Congruence between patient characteristics and interventions may partly explain medication adherence intervention effectiveness: An analysis of 190 randomized controlled trials from a Cochrane systematic review

Due to the negative outcomes of medication non-adherence, interventions to improve adherence have been the focus of countless studies. The congruence between adherence-related patient characteristics and interventions may partly explain the variability of effectiveness in medication adherence studies. In their latest update of a Cochrane review reporting inconsistent effects of adherence interventions, the authors offered access to their database for sub-analysis. We aimed to use this database to assess congruence between adherence-related patient characteristics and interventions and its association with intervention effects.

Methods

We developed a congruence score consisting of six features related to inclusion criteria, patient characteristics at baseline, and intervention design. Two independent raters extracted and scored items from the 190 studies available in the Cochrane database. We correlated overall congruence score and individual features with intervention effects regarding adherence and clinical outcomes using Kruskal Wallis rank sum test and Fisher’s exact test.

Findings

Interrater-reliability for newly extracted data was almost perfect with a Cohen’s Kappa of 0.92 (95% CI 0.89 – 0.94, p < 0.001). Although present in only six studies, the inclusion of non-adherent patients was the single feature significantly associated with effective adherence interventions (p = 0.003). Moreover, effective adherence interventions were significantly associated with improved clinical outcomes (OR = 6.0, CI95% = 3.1 – 12.0, p < 0.0001). However, neither the overall congruence score, nor any other individual feature (i.e. “determinants of non-adherence as inclusion criteria”, “tailoring of interventions to the inclusion criteria”, “reasons for non-adherence assessed at baseline”, “adjustment of intervention to individual patient needs”, and “theory based interventions”) were significantly associated with intervention effects.

Interpretation

The presence of only six studies that included non-adherent patients and the inter-dependency of this feature with the remaining five might preclude a conclusive assessment of congruence between patient characteristics and adherence interventions. In order to obtain clinical benefits from effective adherence interventions, we encourage researchers to focus on the inclusion of non-adherent patients..

Publisher URL: www.sciencedirect.com/science

DOI: S0895435617301221