Santos, Yolanda Martínez

PURPOSE Patients with cancer take different types of medications with varying schedules and settings. They are also sometimes instructed to stop medications due to toxicity. To measure self-reported nonadherence in this heterogeneous population, we modified and evaluated a measure originally developed to assess nonadherence to daily oral antihypertensives, the Domains of Subjective Extent of Nonadherence (DOSE-Nonadherence). METHODS The measure was refined in an iterative process incorporating feedback from patient investigators and participant interviews in English and Spanish. Branching logic was added for participant selection of medication administration setting: (1) only home, (2) only clinic, or (3) partly home/partly clinic. Participants reported their adherence to medications taken over a setting-specific reference period (1 week for home, 1 month for clinic medications). Participants who missed medications then reported on reasons for nonadherence. Adherence was dichotomized for analysis (complete adherence v any nonadherence). For participants who received clinic-administered medications, concordance between chart-abstracted and self-reported adherence was evaluated. RESULTS Seventy-three participants completed the measure (68% English; 32% Spanish; 86% female; 44% age ≥60 years). The majority had breast cancer; 64% had metastatic disease. Twenty-six percent (15/58) of participants who received medication in clinic and 24% (11/46) of those who took medication at home reported nonadherence. Participants felt able to respond accurately to both reference periods and perceived all reasons for nonadherence to be relevant. Among participants who completed the final version of the measure for clinic-administered medication, 96% (26/27) accurately reported their adherence compared with chart-abstracted data. CONCLUSION Our results support the validity of the DOSE-Nonadherence-Cancer for assessing cancer treatment nonadherence. This measure can be used to assess nonadherence in patients with cancer receiving a broad array of systemic therapies.

11106 Background: Patients with cancer take different types of medication (e.g., enteral, parenteral), with varying treatment schedules, in various settings. They are also sometimes instructed to stop medication in response to toxicity. To measure medication nonadherence in this heterogenous population, we modified and pilot-tested a self-report measure originally developed to assess nonadherence to daily oral medication, the Domains of Subjective Extent of Nonadherence (DOSE-Nonadherence), in adults with cancer. Methods: Participants were ≥21 years, on active cancer treatment at Memorial Sloan Kettering, and spoke English and/or Spanish. A branching logic was added to allow participants to select the setting where they take cancer medication: 1) only at home, 2) only in clinic, or 3) partly at home/partly in clinic. Based on administration setting, participants reported nonadherence to medications their clinician expected them to take over a given reference period (1 week for home and 1 month for clinic medications). Participants then reported on setting-relevant reasons for nonadherence. Survey instructions/items were refined in an iterative process using feedback from a patient investigator committee and participant cognitive interviews. During interviews, we asked participants about the interpretation of instructions/items, recall period, and comprehensiveness of reasons for nonadherence, regardless of their own adherence. After initial testing in English, a Spanish version was developed through transcreation. Adherence was dichotomized for analysis (complete adherence vs. any nonadherence). For all participants who received clinic medications, concordance between chart abstracted and self-reported adherence was evaluated. Results: Of 55 participants who completed the surveys and interviews (67% in English; 33% in Spanish), 87% were female and 44% identified as Latino. The majority (73%) had breast cancer; 60% had metastatic disease. 12 of 45 who received medication in clinic reported nonadherence as did 8 of 35 who took medication at home. Participants felt able to respond accurately to both recall periods. All reasons for nonadherence were perceived as relevant to themselves or other patients. There was 89% concordance between self-reported and chart abstracted adherence for clinic-administered medication. To improve concordance, changes were made to the formatting and instructions. Of 12 participants who completed the final version of the survey for clinic-administered medication, there was 100% concordance between self-reported and chart abstracted nonadherence. Conclusions: Our results support the reliability and validity of modified DOSE-Nonadherence for cancer patients. This instrument can be used to better identify nonadherence to cancer medications in a population of adult patients with cancer receiving various treatment regimens.