[A comparison of three health-related quality of life measures in COPD patients].

INTRODUCTION: Chronic Obstructive Pulmonary Disease (COPD) is one of the most disabling diseases today, and a good assessment of Health Related Quality of Life (HRQoL) allows the clinicians to identify the critical areas where is possible to cure in order to improve the well-being of the patient.

OBJECTIVE: The aim of this study was to compare different questionnaires used for the evaluation of HRQoL, in order to assess their psychometric properties and their abilities to discriminate the different severity levels of COPD.

METHODS: This research was conducted using the Medical Research Council (MRC) dyspnoea scale for grading the degree of a patient's breathlessness, St. George's Respiratory Questionnaire (SGRQ), Italian Health Status Questionnaire (IHSQ) and Maugeri Respiratory Failure-26 (MRF-26) were filled by 102 patients affected by COPD.

RESULTS: We observed high internal and external correlations between the instruments, showing a good level of internal consistency. Results did not show any correlations between medical and psychological evaluation, in particular a lack of correlation (r = 0.321) between GOLD categorization and the evaluation of dyspnoea made by patients (MRC scale). Even the correlations between GOLD categorization, SGRQ (r = 0.226), MRF-26 (r = 0.237) and IHSQ (r = 0.239) did not show any correlations. The evaluation of discriminating properties of questionnaires had shown, for all the instruments, a good discrimination between higher levels, but more difficulties in the discrimination of lower levels (not only in MRC scale, but even in GOLD classification).

CONCLUSIONS: The study confirms the high psychometric properties of the psychological instruments used in Italy to examine Health Related Quality of Life (HRQoL) indexes. It is observed that there isn't a direct correlation between severity of illness and self-perceived quality of life, so we can conclude that the construct of "quality of life" is more connected with self-perceived disability (dyspnoea and obstruct activities), than with the medical parameters. We can consider worthy of a psychological and clinical close examination the patients that are included in the first two GOLD categories, in case that they report scores connected with a high sense of limitation of Quality of Life. In short, clinicians have to distinguish and consider the concepts of physical health and HRQoL, composed by the multiple psychological factors that influenced the self-perceived well-being.