Aim: To determine predictors of frequent chest pain unit (CPU) users and to identify characteristics and outcomes of their CPU visits.
Patients and methods: Observational prospective case-control study. Frequent CPU user was defined by 3 or more CPU visits within the study year. A control patient and a control visit were randomly selected for each case patient and case visit. Demographic, clinical, and outcome variables were collected from medical record and phone interview performed in a 30-day interval. A multivariate logistic regression analysis was used to identify frequent CPU users' predictors.
Results: Of 1934 patients presenting during the year, 80 (4.1%) met the definition for case patient. They accounted for 352 (13%) of 2709 CPU visits. Sixty-seven (83.7%) case patients and 71 (88.7%) control patients were contacted. The final predictors were the following: Karnofsky Performance Scale of 70 or lesser (odds ratio [OR], 5.24 [95% confidence interval {CI}, 1.71-16.06]), previous hospitalization (OR, 3.76 [95% CI, 1.49-9.49]), previously known coronary artery disease (OR, 3.72 [95% CI, 1.32-10.52]), and symptoms of depression (OR, 2.98 [95% CI, 1.14-7.78]). Case visits were more likely at night (OR, 2.41 [95% CI, 1.64- 3.52]), generated more diagnostic uncertainty (OR, 2.39 [95% CI, 1.71-3.35]), but did not increase the need of hospital admission.
Conclusions: Frequent CPU user is associated with previously known coronary artery disease, previous hospitalization, impaired performance status, and presence of symptoms of depression. They are more likely to arrive on CPU at night and generate more diagnostic uncertainty.