Lack of correlation of the health assessment questionnaire disability index with lung parameters in systemic sclerosis associated pulmonary arterial hypertension.

OBJECTIVE: Pulmonary arterial hypertension (PAH) affects the quality of life (QoL) and the ability to perform the activities of daily living (ADLs) in patients with systemic sclerosis (SSc). We determined whether the Health Assessment Questionnaire-Disability Index (HAQ-DI), a self-assessment measure of function, correlates with a patient's PAH status in a population of SSc patients with PAH.
METHODS: Forty-one patients from one centre with systemic scleroderma, dyspnea and PAH were included. All patients filled in a HAQ-DI, and underwent evaluation with pulmonary function tests (PFTs), 6-minute walk distance (6MWD), degree of dyspnea (Borg dyspnea index), NYHA functional class, and expert PAH physician global assessment every 6 months. Change in HAQ DI was studied to determine relationship to changes in PAH.
RESULTS: The HAQ-DI scores had no significant correlation with PAH, including NYHA functional class (r=0.38, p=0.39), Borg dyspnea index (r=0.60, p=0.37), 6MWD (r=-0.04, p=0.86), % predicted DLCO (r=0.31, p=0.25), % predicted FVC (r=0.02, p=0.93), and expert PAH physician global assessment (r=0.06, p=0.97).
CONCLUSION: HAQ-DI is not an adequate measure of PAH status in SSc patients with PAH. Although PAH causes severe morbidity and death, changes in PAH severity were not reflected in an overall functional status change as assessed by the HAQ-DI. Thus, HAQ-DI changes do not reflect PAH status in SSc.