Reliability and validity of the Cancer Therapy Satisfaction Questionnaire in lung cancer

PURPOSE: To test the reliability and validity of the Cancer Treatment Satisfaction Questionnaire (CTSQ), to assess its relation with quality of life (QoL), and to assess the interpretability of the domain scores in lung cancer patients receiving intravenous chemotherapy. METHODS: Patients with stage IIIB and IV non-squamous non-small cell lung carcinoma treated with pemetrexed were enrolled in our study. They completed the 16-item CTSQ and two other (health-related) QoL questionnaires. Information about sociodemographic characteristics, cancer stage, and the experience of adverse events was collected. Internal consistency, construct validity, and clinical interpretability were calculated. RESULTS: Fifty-five patients completed the CTSQ. Correlations of the CTSQ items with its domain were all above 0.40. A high correlation between item 8 and the expectations of therapy and satisfaction with therapy domain was observed (0.50 and 0.48, respectively). The CTSQ domains demonstrated good internal consistency and low to moderate correlations of the CTSQ with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 and World Health Organization Quality of Life-BREF. No significant differences in mean domain scores were observed in relation to the number and severity of different adverse events and chemotherapy-related adverse events. CONCLUSIONS: The Dutch version of the CTSQ was found to be a reliable and valid instrument to assess satisfaction and expectations of treatment in lung cancer patients receiving intravenous chemotherapy. Furthermore, the CTSQ proved to be of additional informative value as not all of its domains correlated with the various domains of the existing HRQoL instruments.