The impact of an accountable care unit on mortality: an observational study

Background: Despite enthusiasm for inpatient ward redesign, coordinated models require high effort with uncertain return on investment. Objective: We aimed to reduce mortality and achieve a benchmark of zero preventable deaths by committing to an interprofessional model, including partnered nurse-physician unit leadership, geographic localization, and structured interdisciplinary bedside rounds (SIBR). Methods: An observational pre-post design with 5-year follow-up studied the transition of a medical unit to an Accountable Care Unit (ACU). This geographic model enables partnered nurse-physician leadership and patient-centered workflows, including daily interdisciplinary bedside rounds. Potentially additive or confounding hospital-wide safety initiatives were tracked. Yearly mortality was compared using multivariable logistic regression and reported as odds ratio (OR). For the pre-specified goal of no preventable deaths, we report unexpected deaths, defined as those occurring without documentation of comfort as the goal of care. Results: 12,158 inpatients (55.1% female, mean [sd] age 62.2 [19.7]) were observed over 6 years. Reduction in the risk-adjusted mortality was observed following ACU implementation, with Year 2 significantly lower than the pre-implementation year (adjusted odds ratio [aOR] = 0.58 [0.35-0.94]). Risk-adjusted mortality was similar in Year 3 (aOR = 0.64 [0.39-1.0]) but returned to baseline for Years 4 and 5. Unexpected deaths reached zero in Year 3 and plateaued in Years 4 and 5 at a rate below pre-implementation year (~0.1% vs. 0.38%). Conclusions: A geographic ACU with nurse-physician partnered leadership and daily structured interdisciplinary bedside rounds can reduce total and unexpected mortality. However, maintenance requires constant effort and, in the real world, multiple confounders complicate study.