Welcome to the PAH Risk Calculator

The PAH risk calculator is a tool for all physicians dealing with systemic sclerosis (SSc). The calculator was developed and validated in the DETECT study. The DETECT study was designed and carried out by a group of experts, all of whom are physicians practising in different countries, and was supported by Actelion Pharmaceuticals Ltd.

The calculator was developed for your daily clinical practice. It will help you to identify and diagnose SSc patients with pulmonary arterial hypertension (PAH), which is a serious condition that develops in 8-13% of SSc patients and is the leading cause of death in patients with this disease. The calculator is based on an algorithm with a high sensitivity and specificity and can help you to decide which of your SSc patients should be evaluated using echocardiography, and of those patients who should be referred for right heart catheterization.

Start Calculator

Developing the PAH risk calculator

Screening for PAH can lead to early diagnosis and beneficial early intervention. Due to a paucity of data current screening is based on consensus rather than robust evidence, and is not always reliable, leading to a substantial number of false positive and false negative results.

The DETECT study was carried out to develop an evidence-based screening algorithm for PAH in SSc patients. The goals of the screening algorithm were to minimize the number of missed PAH diagnoses while at the same time optimizing the use of diagnostic right heart catheterization (RHC).

Starting with 112 variables, a series of sophisticated statistical analyses were carried out to determine the most appropriate screening variables. The result was the identification of 8 variables, which form the basis of a 2-step algorithm. The first step assesses the need for a patient to be referred for echocardiographic evaluation; the second step assesses the need for a patient to be referred for RHC. Based on the RHC results a patient may be diagnosed with PAH.

Professor Dinesh Khanna

Department of Internal Medicine, University of Michigan Health System, Michigan, USA

A short introductory video with Professor Dinesh Khanna, a member of the Study Scientific Committee that developed the PAH risk calculator, about PAH in SSc and the development of the DETECT Tool.

Loading the player ...

Professor Oliver Distler

Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland.

An interview with Professor Oliver Distler, a member of the Study Scientific Committee that developed the PAH risk calculator, about the first evidence-based screening algorithm for the detection of PAH in SSc patients.

Loading the player ...

Calculator for mobile devices

PAH risk calculator applications are available for iPhone/iPad and Android phones. For more details about these applications, please refer to the dedicated page PAH risk calculator apps in the SUPPORTING INFORMATION section of this website.


The DETECT Study