Category: Fellows Posters
Purpose: Warfarin has a narrow therapeutic index, which necessitates patients to have frequent visits to anti-thrombosis clinics for anticoagulation monitoring and management. There is little evidence assessing the impact of missed appointments, potentiated by healthcare access barriers, on anticoagulation outcomes. The purpose of this study was to assess the relationship between missed specialty clinic appointments and anticoagulation control in an inner city, socioeconomically disadvantaged population over a 6-month period.
Methods: This was a prospective cohort study that enrolled patients from a large, inner city academic center (UI Health). Eligible patients were ≥ 21 years old, English-speaking and expected to be on warfarin therapy for ≥ 6 months. The exposure, percent missed appointments, was calculated by dividing the number of missed appointments by the total number of clinic appointments during the 6 months observation period. The outcome, anticoagulation control (AC), was calculated by assessing time spent in therapeutic range (%TTR) for International Normalized Ratio (INR) values using the Rosendaal linear interpolation method. Poor %TTR was defined as < 60%. Logistic regression models with odds ratio (OR) and 95% confidence intervals (CI) were used to evaluate the relationship between missed clinic appointments and anticoagulation outcomes.
Results: Of the 144 recruited patients, mean (SD) age was 60 (14) years, 102 (71%) were African-American, 71 (50%) reported income < $25,000, and 90 (62.5%) had moderate to severe Charlson Comorbidity Index (CCI). The mean (SD) %TTR was 62% (25%), with 57 (43%) patients demonstrating poor AC. Common reasons for missing appointments included time conflicts (18%) and transportation barriers (4%). The mean (SD) percent missed appointments was 20% (24%), with majority of patients (63%) missing at least one appointment. Of the patients with poor AC, 44 (77%) patients missed at least one appointment compared to 38 (50%) patients among those with good AC. Missing appointments was significantly associated with poor AC in crude model (OR 0.30, 95% CI 0.14-0.64, p< 0.01) and in a model adjusted for age, gender, income, and CCI (aOR 0.24, 95% CI 0.10-0.59, p< 0.01).
Missed specialty clinic appointments are associated with poor AC in an inner city, socioeconomically disadvantaged population. Future research is warranted to elucidate reasons for missing appointments and inform interventions aimed at improving anticoagulation control in this high-risk population.