International phase IV validation study of an EORTC quality of life questionnaire for testicular cancer patients: the EORTC QLQ-TC26

Abstract

BackgroundGiven the high cure-rate for testicular cancer (TC) and the patients’ young age, comprehensive evaluation of health-related quality of life (HRQOL) is an important consideration in this patient population. The EORTC QLQ-TC26 questionnaire module has been developed to supplement the EORTC QLQ-C30 in assessing TC-specific HRQOL in clinical trials and routine clinical practice. This international, multicentre phase IV validation study evaluated the psychometric properties of the new module.MethodsThis international, multicentre phase IV validation study enrolled testicular cancer patients from seven European countries. Patients completed the EORTC quality of life core questionnaire EORTC QLQ-C30 and the QLQ-TC26 at two consecutive time points and a debriefing questionnaire regarding the QLQ-TC26 after baseline assessment. Psychometric evaluation included examination of the hypothesized module scale structure, internal consistency and test-retest reliability, known-groups validity, responsiveness to change over time and cross-cultural acceptability.ResultsData from 313 patients (mean age 38.6, SD 9.5) were analysed. All items exhibited a high completion rate with less than 2.4% missing values except for the sexuality items (up to 8.8%). The confirmatory factor analysis supported the hypothesised scale structure of the QLQ-TC26. Test-retest reliability was good for 8 of 12 scales (intraclass correlation: R t1|t2 ranged from 0.71–0.91) and four scales did not meet the acceptable criteria. Internal consistency was good for all twelve scales (Cronbach alpha = 0.79–0.90), except Communication (alpha = 0.67) and Sexual Functioning (alpha = 0.62). The module was able to distinguish clearly between patients with differing clinical status. Responsiveness to change over time was acceptable.ConclusionThe EORTC QLQ-TC26 is a valid, reliable and well-accepted condition-specific questionnaire, supplementing the EORTC QLQ-C30, for the assessment of testicular cancer patients’ HRQOL in clinical trials.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-5036-8) contains supplementary material, which is available to authorized users.

Validation study of the Japanese version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire‐Testicular Cancer 26 for patients with testicular cancer

“…However, the reliability of physical limitations and family problems was fair. These tendencies were similar to the previous validation study 15 . This might reflect the pressure of business or relationships with family at the interview.…”

“…The response rate of each item from 31 to 51, except sex‐related questions, was similar to that of the international phase IV study of the EORTC QLQ‐TC26 15 . However, the percentages of missing data for items 52–56 were relatively high (34.0−36.5%) compared with the previous report (6.1–8.8%) 15,17 .…”

“…Internal consistency was evaluated by Cronbach’s alpha coefficients, and four scales (treatment side effects, treatment satisfaction, future perspective and sexual enjoyment) showed acceptable internal consistency (range 0.62–0.91). However, the coefficients for sexual functioning were relatively low, and the scores were similar to those (range 0.36–0.62) in the previous reports using the EORTC QLQ‐TC26 10,15,18 . The coefficient of communication was also low in the present study, different from the previous reports (range 0.62–0.76) 10,15,18 .…”

“…The psychometric properties of the Japanese version including test–retest reliability, internal consistency and concurrent validity were evaluated. Each of the 26 items (items 31–56) of the EORTC QLQ‐TC26 was answered using a 4‐point scale: “1: not at all,” “2: a little,” “3: quite a bit” and “4: very much.” Each subscale was scored from 0 to 100 according to the international phase 4 validation study of the EORTC QLQ‐TC26, which consists of seven symptom scales (treatment side effect, job and education problems, physical limitations, family problems, infertility, body image problems and sexual functioning) and six functional scales (treatment satisfaction, future perspective, communication, sexual activity, sexual enjoyment and testicular implant satisfaction) 15 . On the symptom scale, high scores indicate high impairment, and on the functional scale, low scores indicate high impairment 10 …”

Assessing Health-Related Quality of Life Among Survivors of Testicular Cancer: A Systematic Review

“…No formal systematic search has identified all existing survivors of TC- specific HRQoL tools to conduct a comprehensive review of the methodological soundness and practical fitness of each identified tool, although there have been one-off’s in the past for one select scale ( Sztankay et al, 2018 ). There is a lack of critique on the methodological quality of the seminal studies conducted to produce such tools.…”