Evaluating Pharmacist-Led Heart Failure Transitions of Care Clinic: Impact of Analytic Approach on Readmission Rate Endpoints

Abstract

Studies evaluating pharmacist-led transitions of care (TOC) services for heart failure patients reported profound decreases in hospital readmissions. Most studies restricted their analysis to clinic attendees (as-treated analysis), which can introduce selection and immortal time bias. In this study, we evaluated the impact of including only clinic attendees vs all clinic referrals in assessing the effectiveness of a pharmacist-led heart failure transitions of care (PharmD HF TOC) clinic program on 30-day readmissions. This is a retrospective, observational study of patients discharged from a heart failure hospitalization at a large urban academic medical center from August 2016 to December 2018. Primary exposure was the provision of a PharmD HF TOC clinic appointment in the intent-to-treat analysis and the attendance of the clinic in the as-treated analysis. Primary outcome was all-cause readmissions within 30 days of discharge. There were 766 and 1015 patients included in the as-treated and intent-to-treat analyses, respectively. In the as-treated analysis, 30-day all-cause readmissions were significantly lower in the intervention group compared to the control group (12.4% vs 19.6%, P = 0.018). In contrast, the intent-to-treat analysis did not reveal a significant difference in 30-day all-cause readmissions between the intervention group and the control group (18.2% vs 19.6%, P = 0.643). Pharmacist-led heart failure TOC program is associated with a reduction in 30-day all-cause readmissions only when restricting the analysis to clinic attendees. Future studies evaluating the effectiveness of post-discharge TOC services need to carefully consider the biases inherent in the evaluation methods employed.