Clinical and pharmacoeconomic impact of patient medication adherence

This thesis addresses what is considered to be an important, yet often neglected aspect of pharmacoeconomic analyses: patient adherence with pharmacotherapy.;The objective of this thesis was to provide evidence that patient medication adherence is suboptimal which has implications on the effectiveness and economics of pharmacotherapy. The hypothesis was that patient adherence was suboptimal and this would decrease the clinical effectiveness of pharmacotherapy and would increase overall health care resource utilization.;The thesis reviewed the definitions, measurements, and epidemiology of non-adherence and its clinical and economic consequences. In achieving the first goal a systematic literature review on adherence with biologic DMARDs in RA therapy found decreased compliance and persistence rates. To address the second goal, the literature review on the impact of non-adherence on results of pharmacoeconomic evaluations showed that medication adherence was rarely incorporated into such evaluations, and when it was, there was a wide variation in the definitions and methods used.;For the third goal it was shown in a large retrospective study that lower levels of gastro-protective (GPA) co-therapy with nsNSAIDs, used as a proxy for adherence with GPA co-therapy, were associated with increasing rates of gastrointestinal-related hospitalization, hence greater health care resource utilization. These findings supported the hypothesis that patient adherence is suboptimal and it decreases the clinical effectiveness of pharmacotherapy and increases overall health care resource utilization.;The thesis calls for a standardization of definitions and an improvement in measurement methods so that findings of studies analyzing medication adherence can be compared. The thesis also provides recommendations on how to incorporate adherence in pharmacoeconomic evaluations. This will eventually allow for designing interventions to improve patient adherence which will allow for better clinical and economic outcomes with pharmacotherapy.