Pulmonary arterial hypertension (PAH) is a rare and serious condition characterised by increased growth in blood vessels and structural changes to the small pulmonary arteries. This results in an increase in pulmonary arterial pressure, and typically leads to many serious conditions such as right-sided heart failure and premature death.
Little is currently known about the epidemiology of PAH due to its rarity, and most studies published on patient characteristics are from studies that draw a small patient sample size from PAH registries. However, in GlobalData’s upcoming report, 'Pulmonary Arterial Hypertension – Epidemiology Forecast to 2026', GlobalData epidemiologists estimate that PAH registries may underestimate patient sizes.
GlobalData epidemiologists conducted a thorough review of the literature available on the epidemiology of PAH in key global pharmaceutical markets. When GlobalData epidemiologists compared registry data for PAH in the UK with patient size reported by the UK 2015 Health and Social Care Information Centre (HSCIC) report, they found that the registry underestimated the diagnosed prevalent cases by almost sevenfold.
No large-scale epidemiology studies are available in the US, France, Germany, Italy, and Spain. Therefore, only registry data is available to estimate patient population size. GlobalData epidemiologists believe that solely relying on registry data would severely underestimate the true patient size of PAH.
For the US and the five major European markets (5EU) of France, Germany, Italy, Spain, and the UK, GlobalData epidemiologists provide a forecast for the diagnosed incident cases and a forecast for the diagnosed prevalent cases of PAH. The forecast for diagnosed prevalent cases is based on registry data and then adjusted to compensate for the underestimation of registry based data. The figure below illustrates the difference in estimated cases between these two forecasts.
Figure 1: Diagnosed Prevalent Cases of PAH Using Registry Data and Adjusted Data, 2016, Men and Women, All Ages
PAH registries are instrumental in the advancement of treatment of the disease. However, the calculation of incidence or prevalence of a disease such as PAH using registry data can be difficult, and is more likely to describe a younger, more select group of patients. More epidemiology studies conducted in the general population are necessary to better understand the true burden of this disease.