Impact of the Chronic Care Model on medication adherence when patients perceive cost as a barrier

Abstract

Aims

Cost burdens represent a significant barrier to medication adherence among chronically ill patients, yet financial pressures may be mitigated by clinical or organizational factors, such as treatment aligned with the Chronic Care Model (CCM). This study examines how perceptions of chronic illness care attenuate the relationship between adherence and cost burden.

Methods

Surveys were administered to patients at 40 small community-based primary care practices. Medication adherence was assessed using the 4-item Morisky scale, while five cost-related items documented recent pharmacy restrictions. CCM experiences were assessed via the 20-item Patient Assessment of Chronic Illness Care (PACIC). Nested random effects models determined if chronic care perceptions modified the association between medication adherence and cost-related burden.

Results

Of 1823 respondents reporting diabetes and other chronic diseases, one-quarter endorsed intrapersonal adherence barriers, while 23% restricted medication due of cost. Controlling for age and health status, the relationship between medication cost and CCM with adherence was significant; including PACIC scores attenuated cost-related problems patients with adequate or problematic adherence behavior.

Conclusions

Patients experiencing treatment more consistent with the CCM reported better adherence and lower cost-related burden. Fostering highly activated patients and shared clinical decision making may help alleviate medication cost pressures and improve adherence.

Introduction

Poor adherence to prescribed medications is a significant problem for patients with chronic illness. Most estimates suggest that only 50% of patients with diabetes or other conditions take their medication regularly [1], [2], [3]. Using electronic pharmacy records, a recent study found that 22% of patients with type 2 diabetes prescribed a new medication either never picked up the initial prescription or only filled it once [4]. Medication non-adherence contributes to deteriorating symptoms, worsens overall disease burden, and leads to unnecessary hospital admissions and higher health care costs [5].

Previous studies demonstrate that patient characteristics such as age, sex, race, and education are associated with medication adherence [1], [5]. In addition, financial burdens such as low income or socioeconomic status, lack of prescription drug coverage, and high out-of-pocket costs are also significant adherence barriers across a variety of physical and mental health conditions [6], [7], [8]. There is some evidence that non-economic factors may help mitigate the likelihood of reducing medication use in response to financial pressures [2], [6], [9], [10]. Piette and colleagues have proposed a conceptual framework to describe the influence of patient, medication, clinician, and health system factors on individuals’ responses to medication costs [2]. This framework suggests that cost-related medication non-adherence should be evaluated within a broader context that takes into account the role of organizational and social dimensions such as health system factors, patient self-efficacy and patient–provider communication.

The Chronic Care Model (CCM) describes a set of 6 clinical practice elements designed to optimize management of chronic illness – community linkages, organizational support, self-management support, delivery system design, decision support, and clinical information systems. The CCM was developed out of a perceived need to address the gap in evidence-based medicine regarding chronic illness care and effective clinical practice [11]. The goal of treatment aligned with CCM principles is to create “an informed, activated patient interacting with a prepared, proactive practice team, resulting in productive encounters and improved outcomes” [12]. Such activated patients can potentially overcome cost burdens and improve their medication adherence [2], as suggested by recent work in patients with both diabetes and bipolar disorder [13], [14].

Evidence to date suggests that interventions based on the CCM are associated with improved clinical outcomes in terms of quality of life, symptom reduction, and biological markers [15]. A few prior studies have examined whether specific features of the CCM, such as self-management support and improved patient–provider communication, are positively associated with medication adherence [14], [16], [17], [18]. However, limited evidence has addressed whether implementation of the CCM as a whole might positively influence medication adherence or the interaction with perceived medication cost barriers. To the best of our knowledge, no studies of the CCM have used medication adherence as a primary outcome. We hypothesized that the CCM targets and reflects several of the non-cost factors proposed by Piette et al. and therefore modify patients’ decisions regarding medication use due to perceived cost pressures. The purpose of this study is to determine whether receipt of services more consistent with the CCM is positively associated with better medication adherence among patients with chronic disease. Furthermore, we wished to examine whether experiences of better chronic illness care attenuated the relationship between medication adherence and cost burdens.