Geert Kleinnibbelink

Chapter 9 188 (CR program, non-physician provider, per diem), or CPT code 1013171 (Physician or other qualified health care professional services for outpatient CR). Correspondingly, these CR- related codes were excluded in the propensity score-matched controls. At the time of the search, 27 participating healthcare organizations had data available for patients meeting the study inclusion criteria. Thus, following propensity score matching, the cohort consisted of patients with primary PH, who either were referred for CR or did not receive CR (control). Information on 1-year mortality was also retrieved from the data set. As an exploratory aim, we also compared re-hospitalisation between patients with primary PH who were referred for CR or did not receive CR. Baseline characteristics were compared using chi-squared tests or independent- sample t-tests. Using logistic regression, patients with PH with an EMR of CR were 1:1 propensity score-matched with PH patients without CR for age, sex, race, diseases of the respiratory system, disease of the circulatory system, hypertensive disease, heart failure, diabetes mellitus, chronic kidney disease, cerebrovascular disease, cardiovascular procedures (e.g. cardiography, echocardiography, cardiac catheterization, cardiac devices, electrophysiological procedures), and cardiovascular medications (e.g. beta- blockers, antiarrhythmics, diuretics, antilipemic agents, antianginals, calcium channel blockers, ACE inhibitors). These variables were chosen because they are established risk factors for mortality or were significantly different between the two cohorts. Logistic regression produced odds ratios (OR) with 95% confidence intervals (CI) for mortality and hospitalisation at 1-year following PH diagnosis, comparing CR with propensity score- matched controls. Statistical significance was set at p < 0.05. RESULTS In total, 70,875 and 637 patients with primary PH met the inclusion criteria for the control group and the CR and exercise cohort, respectively. Compared to controls, the CR and exercise cohort were older, had less females, and reported more comorbidities ( Table 1 ). Following propensity score-matching, cohorts were well balanced for age, race, sex, comorbidities, cardiovascular medications and cardiovascular procedures (p > 0.05; Table 1 ). Using the propensity score-matched cohort, and excluding patients with outcomes outside the measurement window, mortality at 1-year from CR was proportionally lower