Background and objective: The objective of this study was to develop a specific instrument for measuring health-related quality of life (HRQL) in patients receiving home mechanical ventilation (HMV).
Methods: The Severe Respiratory Insufficiency (SRI) Questionnaire was developed and tested for its psychometric properties following a multicentric clinical trial including 226 patients receiving HMV (mean age 57.3+/-14.0 years).
Results: Forty-nine items passed the selection process and were allocated to seven subscales: Respiratory Complaints, Physical Functioning, Attendant Symptoms and Sleep, Social Relationships, Anxiety, Psychologic Well-Being, and Social Functioning. Cronbach's alpha was >0.7 in all subscales and >0.8 in four subscales indicating high internal consistency reliability. Construct validity was confirmed by factor analysis, indicating one summary scale that accounts for 59.8% of the variance. Concurrent validity was confirmed by correlating subscales of the SRI and the SF-36 (0.21<r<0.79). Item-scale correlations revealed a high item discriminant validity. In addition, different diagnostic groups could be discriminated by the SRI. Here, the overall best HRQL was measured in the following order: patients with kyphoscoliosis, miscellaneous disorders, neuromuscular diseases, post-tuberculosis, and chronic obstructive pulmonary disease (P<.05).
Conclusion: The SRI is a new multidimensional instrument with high psychometric properties designed to measure specific HRQL in patients with SRI receiving HMV.