Factors Associated with Referral to Expert Providers among Patients with Pulmonary Hypertension

<b>Rationale:</b> Guidelines recommend early referral to pulmonary hypertension experts for patients with confirmed or suspected pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH), among others. Yet patients often have advanced disease at the time of referral. The drivers of these referral delays are not well known. <b>Objectives:</b> Building on our prior qualitative findings on barriers to timely pulmonary hypertension care along the care continuum, we sought to identify patient-level factors associated with referral to pulmonary hypertension experts. <b>Methods:</b> We leveraged the Massachusetts All-Payer Claims Database to identify all patients with incident pulmonary hypertension from 2015 to 2017 using a validated algorithm (sensitivity 28%, specificity 100%) and further identified subgroups with risk factors for PAH and CTEPH. Our outcome was the presence or absence of referral to a pulmonary hypertension expert during the study period. On the basis of our prior qualitative work, our three primary exposures were <i>1</i>) Medicaid enrollment, <i>2</i>) mental health diagnoses, and <i>3</i>) distance to the nearest pulmonary hypertension center. We conducted separate multivariable logistic regression models to determine the association between each of our primary exposures and outcome, among our entire cohort and among those with risk factors for PAH and CTEPH. <b>Results:</b> Among our entire cohort (<i>n</i> = 12,505), 704 (5.6%) were seen by pulmonary hypertension experts. Among the subset with risk factors for PAH (<i>n</i> = 2,393) and CTEPH (<i>n</i> = 3,167), 242 (10.1%) and 185 (5.8%) were seen by pulmonary hypertension experts, respectively. Patients less likely to be referred included Medicaid recipients (adjusted odds ratio [aOR], 0.64 [95% confidence interval (CI), 0.53-0.77]), those with mental health diagnoses (aOR, 0.69 [95% CI, 0.58-0.83]), and those living further from a pulmonary hypertension center (aOR, 0.78 [95% CI, 0.74-0.82] for each 10-mile increase in distance to a pulmonary hypertension center). Findings were similar among those with risk factors for PAH and CTEPH. <b>Conclusions:</b> Few patients with pulmonary hypertension are referred to pulmonary hypertension experts, including those with risk factors for PAH and CTEPH. Factors associated with expert referral identified in this study highlight barriers to timely pulmonary hypertension care and offer targeted areas of future study to improve the timeliness of pulmonary hypertension care.