System factors as correlates of medication adherence in transplant and HIV populations: A systematic review

Purpose: Medication adherence (MA) is influenced not only by characteristics of the individual patient, but also by factors at the healthcare system level, i.e., micro- (e.g. healthcare worker, social support), meso- (e.g. factors related to the healthcare organization or setting in which care is received) and macrolevel factors (e.g. regulations on reimbursement for medication). To date most research has focused on factors at the patient level which offer limited explanation of the broad variability in MA. The aim of this study is to identify and summarize quantitative studies addressing factors at the micro-, meso-, and macro-level of the healthcare system that are associated with MA in individuals who have received an organ transplant (Tx) or who have HIV, two populations necessitating strict adherence to prevent poor outcomes. Methods: Searches were conducted in PubMed, EMBASE and Cinahl databases. Quantitative studies, published in English between January 1999 and December 2009, were included. To be eligible, studies had to investigate MA as an outcome, have described the MA measurement used, and have reported on the relationship between micro-, meso-, and/or macro-level healthcare system characteristics and MA in adults with a Tx or HIV. Results: The electronic searches returned 5,341 citations. Seven articles in the Tx literature and 55 in the HIV literature met all inclusion criteria. The microlevel factor most consistently related to adherence was trust in the healthcare provider. At the meso-level, it was drug access/dispensing. Cost-related characteristics (macro-level) were significantly associated (p<.05) with adherence 50% of the times they were studied. Conclusions: While the findings of studies examining the relationship between the system level factors and MA are inconsistent, this systematic review provides preliminary evidence to suggest that some of the system level factors are important contributors to MA

• Population(s)
  • General HIV+ population
• Engagement and Care Cascade
  • Treatment
• Co-morbidities
  • Other