PAH-SYMPACT^®: A Reliable Instrument for PAH Symptom Assessment

The Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT^®) questionnaire proved to have good psychometric properties and can be administered in clinical practice and used in clinical studies, according to the results of a study published in Chest.

Disease-specific patient-reported outcome instruments are essential to the evaluation of disease and treatment. PAH-SYMPACT is the first instrument to assess PAH symptoms and effects. It was developed in accordance with the 2009 US Food and Drug Administration patient-reported outcome guidance.

Kelly M. Chin, MD, from the University of Texas Southwestern in Dallas, and colleagues used data from SYMPHONY (ClinicalTrials.gov Identifier: NCT01841762), a 16-week study of macitentan 10-mg therapy in patients with PAH.

The investigators used item performance, Rasch, and factor analyses to determine item content of the patient-reported outcome and delineate its domain structure. They evaluated internal consistency, test-retest reliability, known group and construct validity, sensitivity to change, and influence of oxygen on item performance. A Steering Committee of clinical experts provided advice on item retention and removal.

The investigators analyzed data from 278 patients, 79% of whom were women. The final questionnaire contained 11 symptom items across 2 domains (cardiopulmonary and cardiovascular symptoms) and 11 impact items across 2 domains (physical and cognitive/emotional impacts). Scores ranged from 0 to 4, with higher scores indicating greater symptom severity or worse impact. One-third of patients reported using oxygen on a given day; however, oxygen use did not affect patient-reported outcome scoring, as determined by differential item function analysis. 

Confirmatory factor analysis demonstrated an acceptable model fit for symptom items and a good model fit for impact items. Internal consistency reliability was high for all 4 domains, with a Cronbach’s alpha >0.80, which indicates that the items are situated within the correct domain.

Limitations of SYMPHONY include the lack of untreated patients and the relative lack of patients with heritable PAH, PAH associated with congenital heart disease or HIV, and severe disease.

Disclosures: Dr Chin has received consultant fees from Actelion and United Therapeutics, as well as research support from Actelion, Bayer, and United Therapeutics. Other authors also reported financial relationships with pharmaceutical companies.

Reference

Cin K, Gomberg-Maitland M, Channick RN, et al. Psychometric validation of the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT®) questionnaire: results of the SYMPHONY trial [published online April 2, 2018]. CHEST. doi: 10.1016/j.chest.2018.04.027