Understanding the growing burden of Malignant Pleural Effusion - epidemiology, health care utilization and cost, a Canadian perspective.

Introduction: Malignant Pleural Effusion (MPE) is common in advanced malignancy. Data are needed on health care utilization and costs.

Methods: This population-based retrospective cohort study included patients aged ≥18 years with an MPE diagnosed between January 1, 2004 and December 31, 2018. We described the incidence and prevalence of MPE from 2004 to 2018, and trends in hospital admissions, emergency department (ED) visits, and pleural-based procedures. In patients diagnosed with MPE from 2006 to 2016 we estimated 2-year health care costs (2018 US dollars) from the public payer perspective.

Results: The annual incidence and prevalence of MPE increased from 5,090 and 14,579 in 2004 to 6,977 and 23,204 in 2018, respectively. Annual mortality among prevalent patients decreased from 32% to 28%. In 2004, 57% of patients were hospitalized, decreasing to 50% in 2018. ED visits increased (59% to 61%). From 2004 to 2018, the number of patients who had insertions of thoracostomy tube (2,211 to 3,664) and tunnelled pleural catheter (383 to 1,164) increased. The number of patients receiving pleurodesis declined (565 to 284). No change occurred in the number of patients receiving video-assisted thoracoscopy (range 140 - 208/year). Between 2004 and 2016, 76,190 patients were diagnosed with MPE (mean age 71.2; 52% female). The median (interquartile range) health care cost during follow-up was $45,641 ($23,237-$86,700), with $19,753 ($9,590-$38,746) for inpatient hospitalization.

Conclusion: Hospitalization and temporizing MPE procedures are associated with high costs. This population-based study may guide clinicians and policy makers to improve MPE management and reduce health care costs.