EORTC QLQ-C30
European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 · Also known as: QLQ-C30, EORTC QLQ-C30, Cancer Quality of Life Scale
The EORTC QLQ-C30 is the most widely used international instrument for assessing quality of life in cancer patients. Developed by the European Organisation for Research and Treatment of Cancer in 1993, it measures physical, emotional, cognitive, and social functioning alongside cancer-specific symptoms and financial impact, making it the standard outcome measure in oncology clinical trials and patient care.
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When to use it
The QLQ-C30 is indicated for measuring quality of life in adult cancer patients across all cancer types and disease stages. It is particularly valuable in randomized controlled trials comparing treatments, in clinical practice to monitor patient well-being and guide supportive care decisions, in health economic analyses to evaluate cost-effectiveness, and in observational studies tracking outcomes over time. It is suitable for both curative and palliative contexts. It is less appropriate for very young children (use EORTC QLQ-C30 Peds for ages 8-18) or for non-cancer populations.
Strengths & limitations
- Multidimensional coverage—measures five functional domains and nine symptom dimensions, capturing the full impact of cancer on patients' lives
- Extensively validated—used in thousands of clinical trials, demonstrating strong psychometric properties (Cronbach's α typically 0.70-0.92 across scales), reliability over time (test-retest r > 0.70), and sensitivity to clinical change
- Internationally standardized—validated in 80+ languages with translation guidelines, enabling cross-cultural comparisons and global research
- Free for research—EORTC provides no-cost licensing for academic research and clinical use, with downloadable forms and scoring algorithms
- Patient-centered—derived from patient interviews and focus groups, ensuring items reflect outcomes that matter to cancer patients themselves
- Modest symptom specificity—does not probe depth into individual symptoms (e.g., pain location, quality, temporal pattern), limiting utility for detailed symptom assessment without supplementary measures
- Requires literacy—relies on written comprehension; interviewer administration necessary for patients with low literacy or severe cognitive impairment
- Limited data on clinical cutoffs—while reference ranges exist, specific cutoff scores for intervention thresholds are not universally defined; interpretation relies more on individual and group comparisons than diagnostic cutoffs
- Not a diagnostic tool—screens and tracks quality of life but does not diagnose depression, anxiety, or other comorbidities; supplementary mental health measures may be needed
Frequently asked
How do I interpret a 10-point change on the Physical Functioning scale?
A 10-point change is conventionally regarded as clinically meaningful. For example, if a patient's Physical Functioning score improves from 60 to 70 during or after treatment, this suggests a noticeable improvement in their ability to engage in daily activities. However, the clinical relevance depends on context: a 10-point improvement from 20 to 30 indicates recovery from severe limitation but still substantial impairment; a change from 80 to 90 represents modest incremental gain in an already high-functioning patient.
Should I use the QLQ-C30 alone, or do I need cancer-specific modules?
The QLQ-C30 alone provides comprehensive assessment of generic cancer impact. EORTC cancer-specific modules (e.g., QLQ-BR23 for breast cancer, QLQ-LC13 for lung cancer) should be added when you need detailed measurement of disease-specific symptoms or toxicities. Many major trials combine the QLQ-C30 with a relevant module for complete coverage.
Can proxy respondents (family members or clinicians) complete the QLQ-C30 on behalf of patients?
Proxy completion is not recommended as standard practice. Patient self-report is the gold standard because quality of life is inherently subjective. However, in cases of severe cognitive impairment, extreme illness, or imminent death, proxy data may provide valuable information when patient completion is not feasible. Document proxy status in the data and interpret cautiously, as proxies often underestimate patients' quality of life.
Is the QLQ-C30 free to use in my research or clinic?
Yes. The EORTC provides unrestricted, free access to the QLQ-C30 for academic research, quality improvement, and clinical care. You can download the questionnaire, user manual, and scoring algorithms from eortc.org. Commercial use requires licensing; contact EORTC for terms.
Sources
- Aaronson, N. K., Ahmedzai, S., Bergman, B., Bullinger, M., Cull, A., Duez, N. J., ... & Takeda, F. (1993). The European Organisation for Research and Treatment of Cancer QLQ-C30: A quality-of-life instrument for use in international clinical trials in oncology. Journal of the National Cancer Institute, 85(5), 365-376. DOI: 10.1093/jnci/85.5.365 ↗
- Fayers, P. M., & Bottomley, A. (2001). Quality of life research within the EORTC-the EORTC QLQ-C30. European Journal of Cancer, 38(4), 427-431. DOI: 10.1016/s0959-8049(01)00448-8 ↗
- Cella, D. (1998). The Functional Assessment of Cancer Therapy Scale: Development and validation. Journal of Clin Oncol, 11(3), 570-579. link ↗
How to cite this page
ScholarGate. (2026, June 3). European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30. ScholarGate. https://scholargate.app/en/health-outcomes/eortc-qlq-c30
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