MEASUREMENT OF QUALITY-OF-LIFE IN PATIENTS WITH LUNG-CANCER IN MULTICENTER TRIALS OF NEW THERAPIES - PSYCHOMETRIC ASSESSMENT OF THE LUNG-CANCER-SYMPTOM-SCALE

Background. This study continued the development and psychometric test ing of the Lung Cancer Symptom Scale (LCSS), a disease- and site-speci fic instrument primarily measuring the physical and functional dimensi ons of quality of life for individuals with lung cancer. The instrumen t contains two scales, one for patients and a counterpart for health p rofessionals as observers. Methods. Feasibility, reliability, construc t validity, and criterion-related validity were evaluated with 207 pat ients with non-small cell lung cancer (NSCLC) from six cancer centers. Within an interview with an observer, patients completed part of a ba ttery of instruments by self-report and were interviewed for the remai ning measures. Observers also completed measures after the interview. Results. Feasibility, reliability, and validity were well supported fo r this lung cancer population. Feasibility was demonstrated by patient and staff compliance in completion at all six cancer centers. Interna l consistency was good, with coefficient alphas of 0.82 for the patien t scale and 0.75 for the observer scale. Construct validity was suppor ted by 1. contrasted groups approach: regression lines (with 95% confi dence bands) were obtained between the Karnofsky performance scale (KP S) and each of the two LCSS scales; 2. as a refinement, relationship t esting: significant correlations between the LCSS and KPS for each ite m (except hemoptysis for the patient scale); and 3. multitrait-multime thod approach: good reliability (alphas ranging from 0.75 to 0.93), go od convergent validity for the two LCSS scales (r = 0.77), and a good discriminant validity pattern from the Brief Symptom Inventory (BSI). Criterion-related validity with relevant gold standard measures (Ameri can Thoracic Society Questionnaire [ATS] and McGill Pain questionnaire , KPS, Profiles of Mood States [POMS], and Sickness Impact Profile [SI P]) was supported with significant correlations (0.40-0.67 for the LCS S patient scale; 0.54-0.65 for the LCSS observer scale). Conclusions. These psychometric properties demonstrate that the LCSS patient and ob server scales are feasible, reliable, and valid quality of life measur es that are ready for research and clinical use with lung cancer popul ations.