Validity, reliability, and responsiveness of a new short Visual Simplified Respiratory Questionnaire (VSRQ©) for health-related quality of life assessment in chronic obstructive pulmonary disease

Abstract

The Visual Simplified Respiratory Questionnaire (VSRQ) was designed to assess health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD). It contains eight items: dyspnea, anxiety, depressed mood, sleep, energy, daily activities, social activities and sexual life. Psychometric properties were assessed during a clinical trial that evaluated the impact of tiotropium on HRQoL of COPD patients. These included the determination of structure, internal consistency reliability, concurrent validity with the St George's Respiratory Questionnaire (SGRQ), test - retest reliability, clinical validity and responsiveness to change over two weeks. Minimal important difference (MID) was calculated; cumulative response curves (CRC) were based on the dyspnea item. Psychometric analyses showed that VSRQ structure was unidimensional. The questionnaire demonstrated good internal consistency reliability (Cronbach's alpha = 0.84), good concurrent validity with SGRQ (Spearman = -0.70) and clinical validity, good test-retest reproducibility (ICC = 0.77), and satisfactory responsiveness (standardized response mean = 0.57; Guyatt's statistic = 0.63). MID was 3.4; CRC median value of the 'minimally improved' patients was 3.5. In conclusion, VSRQ brevity and satisfactory psychometric properties make it a good candidate for large studies to assess HRQoL in COPD patients. Further validation is needed to extend its use in clinical practice. © 2009 Perez et al, publisher and licensee Dove Medical Press Ltd.