Determinants of Primary Nonadherence in Asthma- Controller and Dyslipidemia Pharmacotherapy

The full therapeutic benefit of prescription medications is realized only when the patient follows the healthcare provider’s recommendations, a concept referred to as medication adherence. Premature treatment discontinuation and other forms of poor medication adherence are common and contribute to adverse drug events, worsening disease, increasing healthcare costs, and decreasing quality of life. 1-3 As a result, there is a wealth of scientific evidence documenting risk factors for poor adherence and effectiveness of interventions to improve adherence. 4-11 Yet these studies often rely on secondary data sources, typically administrative pharmacy claims, to identify patients and measure adherence. Though a powerful source of prescription drug information, administrative data can profile only the medication-taking behavior of patients who have already received therapy, and thus have filled at least 1 prescription. In contrast, relatively little is known about the extent and causes of primary nonadherence, prescriptions given by a healthcare provider but never filled by the patient. Without an electronic record, connecting physicians’ handwritten or oral prescriptions with medication-dispensing records is manual and resource intensive. Thus, studies of primary adherence have relied primarily on patient self-reports or on patient populations receiving prescriptions while hospitalized or receiving emergency care, where computer prescription order entry systems exist. These studies routinely report adherence rates across multiple pharmacotherapies, represent the experience of a single pharmacy, enroll only select patient populations, or report the experience of a non-US patient population. As a result, estimates of primary nonadherence vary widely, with international studies reporting rates from 2% to 30% 12-14 and US studies reporting rates from 2% to 20%. 15,16 Electronic prescribing (e-prescribing), a solution formerly available only in hospital settings that had an integrated technology platform connecting physicians with pharmacies, is now gaining acceptance in ambulatory care settings. 17 With the increasing use of e-prescribing, identifying