Epidemiology of Adult Pleural Disease in the United States.

Background: Comprehensive US epidemiologic data for adult pleural disease are not available.

Research Question: What are the epidemiologic measures related to adult pleural disease in the United States?

Study Design And Methods: Retrospective cohort study using Healthcare Utilization Project databases (2007-2016). Adults (≥ 18 years of age) with malignant pleural mesothelioma, malignant pleural effusion, nonmalignant pleural effusion, empyema, primary and secondary spontaneous pneumothorax, iatrogenic pneumothorax, and pleural TB were studied.

Results: In 2016, ED treat-and-discharge (T&D) visits totaled 42,215, accounting for charges of $286.7 million. In 2016, a total of 361,270 hospitalizations occurred, resulting in national costs of $10.1 billion. A total of 64,174 readmissions contributed $1.16 billion in additional national costs. Nonmalignant pleural effusion constituted 85.5% of ED T&D visits, 63.5% of hospitalizations, and 66.3% of 30-day readmissions. Contemporary sex distribution (male to female ratio) in primary spontaneous pneumothorax (2.1:1) differs from older estimates (6.2:1). Decadal analyses of annual hospitalization rates/100,000 adult population (2007 vs 2016) showed a significant (P < .001) decrease for malignant pleural mesothelioma (1.3 vs 1.09, respectively), malignant pleural effusion (33.4 vs 31.9, respectively), iatrogenic pneumothorax (17.9 vs 13.9, respectively), and pleural TB (0.20 vs 0.09, respectively) and an increase for empyema (8.1 vs 11.1, respectively) and nonmalignant pleural effusion (78.1 vs 100.1, respectively). Empyema hospitalizations have high costs per case ($38,591) and length of stay (13.8 days). The mean proportion of readmissions attributed to a pleural cause varied widely: malignant pleural mesothelioma, 49%; malignant pleural effusion, 45%; nonmalignant pleural effusion, 31%; empyema, 27%; primary spontaneous pneumothorax, 27%; secondary spontaneous pneumothorax, 27%; and iatrogenic pneumothorax, 20%. Secondary spontaneous pneumothorax had the shortest time to readmission in 2016 (10.3 days, 95% CI, 8.8-11.8 days).

Interpretation: Significant epidemiologic trends and changes in various pleural diseases were observed. The analysis identifies multiple opportunities for improvement in management of pleural diseases.