The Severe Respiratory Insufficiency Questionnaire was valid for COPD patients with severe chronic respiratory failure.
OBJECTIVE
The Severe Respiratory Insufficiency (SRI) Questionnaire has recently been developed and validated for the assessment of health-related quality of life (HRQL) in patients with severe chronic respiratory failure resulting from a broad spectrum of underlying disorders. The present study was aimed at reexamining the internal structure of the SRI specifically for chronic obstructive pulmonary disease (COPD) patients.


METHODS
Cross-validation was performed in two COPD groups (N=78 and N=84), each receiving home mechanical ventilation in addition to long-term oxygen therapy. The internal consistency reliability was calculated using Cronbach's alpha coefficient. Explorative Factor Analysis was performed followed by Confirmatory Factor Analysis to establish construct validity.


RESULTS
In the total group (N=162) Cronbach's alpha ranged from 0.73 to 0.88. Only one factor could be established which explained 58.5% of the total variance confirming one Summary Scale (SRI-SS). For each of the seven subscales, Confirmatory Factor Analysis revealed two factors, which were substantially correlated (r=0.43-0.80). All scale scores covered a broad range of the questionnaire's scaling range (0-100). The mean SRI-SS score was 52+/-17 indicating a homogenous scaling distribution.


CONCLUSIONS
The SRI is a multidimensional and highly specific tool with high psychometric properties for HRQL assessment in COPD patients with severe chronic respiratory failure.
Windisch
Wolfram
W
Department of Pneumology, University Hospital Freiburg, Killianstrasse 5, D-79106 Freiburg, Germany. wolfram.windisch@uniklinik-freiburg.de
Budweiser
Stephan
S
Heinemann
Frank
F
Pfeifer
Michael
M
Rzehak
Peter
P
D002908:Chronic Disease; D006304:Health Status; D006305:Health Status Indicators; D006699:Home Care Services; D006801:Humans; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D011175:Positive-Pressure Respiration; D011594:Psychometrics / Q000379:methods / Q000592:standards*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000523:psychology*; D011788:Quality of Life; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000209:etiology / Q000523:psychology* / Q000628:therapy; D011795:Surveys and Questionnaires / Q000592:standards*