Development and content validation of measures assessing adherence barriers and behaviors for use in clinical care.

BACKGROUND: Providers are often unaware of poor adherence to prescribed medications for their patients with chronic diseases. OBJECTIVE: To develop brief, computer-administered patient-reported measures in English and Spanish assessing adherence behaviors and barriers. Design, Participants, and Main Measures: Item pools were constructed from existing measures of medication adherence behaviors and barriers, which informed development of a patient concept elicitation interview guide to identify medication adherence behavior and barrier-related concepts. Two hundred six patients either living with HIV (PLWH) or without were interviewed. Interviews were coded, concepts matched to item pool content, and new items were developed for novel concepts. A provider/investigator team highlighted clinically relevant items. Cognitive interviews were conducted with patients on final candidate items (n = 37). The instruments were administered to 2081 PLWH. KEY RESULTS: Behavioral themes from concept elicitation interviews included routines incorporating time of day, placement, visual cues, and intentionality to miss or skip doses. Barrier themes included health-related (e.g. depressed mood, feeling ill), attitudes/beliefs (e.g., need for medication), access (e.g., cost/insurance problems), and circumstantial barriers (e.g., lack of privacy, disruption of daily routine). The final instruments included 6 behavior items, and 1 barrier item with up to 23 response options. PLWH endorsed a mean (SD) of 3.5 (1.1) behaviors. The 201 PLWH who missed ≥2 doses in the previous week endorsed a mean (SD) of 3.1 (2.5) barriers. The intraclass correlation coefficient (ICC) for the numbers of behaviors endorsed in 61 PLWH after 4-16 days was 0.54 and for the number of barriers for the 20 PLWH with ≥2 missed doses the ICC was 0.89, representing fair and excellent test-retest reliability. CONCLUSION: Measures of medication adherence behaviors and barriers were developed for use with patients living with chronic diseases focusing on clinical relevance, brevity, and content validity for use in clinical care.

Medication understanding among patients living with multiple chronic conditions: Implications for patient-reported measures of adherence.

BACKGROUND: Low health literacy is associated with poor medication adherence and poor health outcomes. Limited understanding of prescribed medications may decrease validity of patient-reported adherence measures. OBJECTIVES: To assess knowledge of names and purposes of prescribed medications among patients with multiple chronic conditions. METHODS: Individual interviews were conducted with a convenience sample of patients from six U.S. primary care clinics. Participants (n = 57) were English and/or Spanish-speaking patients prescribed 3+ medications for chronic conditions, for which non-adherence may lead to disability or death. In individual interviews, patients were asked to name their medications, explain the purpose of each, and to explain how they distinguish them from one another. Interviews were audio recorded, transcribed, and coded; coded content was quantified by 1) whether or not the patient could name medications; 2) method of categorizing medications; 3) whether or not the purpose of the medication was understood. Descriptive statistics were compiled using Fisher's exact test to determine the relationship between patient knowledge and medication characteristics. RESULTS: Thirty percent of patients could not name at least one of their medications; 19% did not know their purpose; 30% held misconceptions about the purpose of one or more medications. There was no significant difference in ability to name medications or state their medication's purpose between patients using medi-sets, pre-packaged rolls, or blister packs, and patients who stored pills in their original containers (p = 0.56 and p = 0.73, respectively), or across demographic groups (p = 0.085 to 0.767). CONCLUSIONS: Many patients demonstrated difficulty identifying the name and purpose of prescribed medications; this did not differ by demographic group or medication storage type. Patients may benefit from routine review of medications with their provider in order to improve health literacy, outcomes, and patient-reported adherence measurement.