Study objectives: Health-related quality of life
associated with interstitial lung disease has received little attention
in clinical studies because there have been no validated methods for
directly measuring it. We have assessed the validity of several generic
and respiratory-specific quality-of-life instruments in patients with
interstitial lung disease.
Setting: Outpatient pulmonary clinic at a
university referral center.
Patients: Fifty patients
with interstitial disease such as idiopathic pulmonary fibrosis,
sarcoidosis, hypersensitivity pneumonitis, and asbestosis.
Interventions: Patients were administered four
quality-of-life questionnaires, the Medical Outcomes Study Short Form
36 (SF-36), the Quality of Well-being scale (QWB), the Chronic
Respiratory Questionnaire (CRQ), and the St. George’s Respiratory
Questionnaire (SGRQ). Patients concomitantly underwent pulmonary
function testing and performed a 6-min walk.
and results: Validation of these instruments was based on testing
an a priori hypothesis that worse quality-of-life scores
should correlate with more severe physiologic impairment demonstrated
by pulmonary function tests, exercise tolerance on the 6-min walk, and
dyspnea scores. Our patients, on average, had a moderate degree of
physiologic impairment and demonstrated moderately decreased
quality-of-life scores. Scores from all four quality-of-life
questionnaires correlated significantly with 6-min walk distance and
dyspnea score. Scores from the SF-36, QWB, and SGRQ showed significant
correlation with FVC, FEV1, and diffusing capacity as well.
The SF-36 and SGRQ consistently showed the strongest correlation with
Conclusions: Our findings
indicate that preexisting quality-of-life instruments can be applied to
patients with interstitial lung disease and suggest that the SF-36 and
the SGRQ, in particular, are sensitive tools for assessing quality of
life in these patients. Future intervention studies of patients with
interstitial lung disease should consider using these