Minimally important differences for interpreting the EORTC QLQ-C30 in patients with advanced colorectal cancer treated with chemotherapy.

AIM: The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) assesses the health-related quality of life of patients in cancer trials. There are currently no minimally important difference (MID) guidelines for the EORTC QLQ-C30 for colorectal cancer (CRC). This study aims to estimate MIDs for the EORTC QLQ-C30 scales in patients with advanced CRC treated with chemotherapy and enrolled in clinical trials. METHOD: The data were obtained from three published EORTC trials that treated CRC patients using chemotherapy. Potential anchors were selected from clinical variables based on their correlation with EORTC QLQ-C30 scales. Anchor-based MIDs for within-group change and between-group change were estimated via the mean change method and linear regression, respectively, and summarized using weighted correlation. Distribution-based MIDs were also examined. RESULTS: Anchor-based MIDs were determined for deterioration in 8 of the 14 EORTC QLQ-C30 scales and in 9 scales for improvement, and varied by scale, direction of change and anchor. MIDs for improvement (deterioration) ranged from 6 to 18 (-11 to -5) points for within-group change and 5 to 15 (-10 to -4) for between-group change. Summarized MIDs (in absolute values) per scale mostly ranged from 5 to 10 points. CONCLUSIONS: These findings have clinical relevance for the interpretation of treatment efficacy and the design of clinical trials by informing sample size requirements.

Sexual quality of life in Hodgkin Lymphoma: a longitudinal analysis by the German Hodgkin Study Group.

BACKGROUND: Health-related quality of life (HRQoL) comprises different domains of physical, mental, and social well-being. In this analysis, we focus on sexual quality of life in Hodgkin Lymphoma (HL) patients. METHODS: Four-thousand one-hundred and sixty patients enroled in the HD10-HD12 trials underwent HRQoL assessment. Instruments included the Quality of Life Questionnaire for survivors (QLQ-S), combining the European Organisation for Research and Treatment of Cancer QLQ-C30, Multidimensional fatigue (FA) inventory (MFI-20) and an additional sexual functioning (SX) scale. We describe SX up to 27 months after therapy and analyse relationship to stage, age, gender, FA, social functioning, and therapy. Statistical methods range from descriptive statistics to a classification of SX courses, and a longitudinal structural equations model with full information maximum likelihood estimation of missing data. In the analysis, a score below 50 was used to describe severe sexual dysfunction. RESULTS: Three-thousand two-hundred and eight patients provided data on SX. Patients in advanced stages reported lower SX than patients in early stages both, before and after the treatment. During follow-up, an improvement of SX compared with baseline was detected, except for those ≥50 years. Patients in early stages reached normal SX, whereas advanced-stage patients remained below the reference value for healthy controls. Sexual functioning during follow-up was significantly and strongly related to previous SX, other HRQoL measures, age, and stage, and to lesser degree with gender and chemotherapy. CONCLUSION: Overall, HL patients have a decreased sexual quality of life at baseline, which improves after therapy and normalises in early-stage patients. Importantly, long-term SX is more closely related to patient characteristics and SX at baseline than to the intensity of treatment.

Effect of completion-time windows in the analysis of health-related quality of life outcomes in cancer patients.

BACKGROUND: We examined if cancer patients' health-related quality of life (HRQoL) scores on the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 are affected by the specific time point, before or during treatment, at which the questionnaire is completed, and whether this could bias the overall treatment comparison analyses. PATIENTS AND METHODS: A 'completion-time window' variable was created on three closed EORTC randomised control trials in lung (non-small cell lung cancer, NSCLC) and colorectal cancer (CRC) to indicate when the QLQ-30 was completed relative to chemotherapy cycle dates, defined as 'before', 'on' and 'after'. HRQoL mean scores were calculated using a linear mixed model. RESULTS: Statistically significant differences (P<0.05) were observed on 6 and 5 scales for 'on' and 'after' comparisons in the NSCLC and two-group CRC trial, respectively. As for the three-group CRC trial, several statistical differences were observed in the 'before' to 'on' and the 'on' to 'after' comparisons. For all three trials, including the 'completion-time window' variable in the model resulted in a better fit, but no substantial changes in the treatment effects were noted. CONCLUSIONS: We showed that considering the exact timing of completion within specified windows resulted in statistical and potentially clinically significant differences, but it did not alter the conclusions of treatment comparison in these studies.