Incidence and prevalence of pulmonary hypertension in chronic lung disease: insights from a retrospective cohort study using a UK nationwide health database

Objectives Pulmonary hypertension (PH) associated with lung disease (Group 3 PH) is a serious complication that negatively impacts patient outcomes. This study aimed to assess the epidemiology and disease burden of Group 3 PH in the UK, focusing on interstitial lung disease (ILD-PH). Design Retrospective cohort study. Setting Electronic medical records from the Clinical Practice Research Datalink Aurum, linked to Hospital Episode Statistics. Participants 6690 incident cases of Group 3 PH, including 1561 ILD-PH cases, were identified from a sample of approximately 33 million individuals between January 2017 and December 2019. Primary and secondary outcome measures Primary outcomes included prevalence and incidence of Group 3 PH and ILD-PH. Secondary outcomes included patient characteristics, overall survival, hospitalisations, outpatient visits and healthcare costs. Results Over the 3-year period, prevalence and annual incidence were 139/million (95% CI 134 to 142) and 73/million/year (95% CI 70 to 76) for Group 3 PH and 36/million (95% CI 33 to 37.3) and 17/million/year (95% CI 16 to 19) for ILD-PH. Median overall survival was 19.3 (95% CI 17.77 to 20.8) for Group 3 PH and 15.1 months (95% CI 12.66 to 18.2) for ILD-PH. Following a PH diagnosis, all-cause inpatient visits increased by 33.6% from baseline. The all-cause annual hospitalisation rate was 1.63 (95% CI 1.6 to 1.65) for Group 3 PH and 1.36 (95% CI 1.31 to 1.4) for ILD-PH, with about half linked to PH diagnosis. Pulmonologists were the most consulted specialists, averaging 1.78 (95% CI 1.76 to 1.81) and 2.31 (95% CI 2.25 to 2.37) visits per patient per year for Group 3 PH and ILD-PH, respectively. Annual per-patient costs were £7761 (95% CI 7759 to 7762) for Group 3 PH and £7170 (95% CI 7167.17 to 7173.69) for ILD-PH. Conclusion Incidence and prevalence of Group 3 PH in the UK are consistent with other European countries. Patients had poor survival, with PH associated with half of hospital admissions, highlighting the negative impact of PH in chronic lung disease.