EORTC QOL Thresholds for clinical importance (TCIs)

Definition

A threshold provides information on when a symptom/ functional impairment is clinically important and needs to be discussed by HCPs with patients. The TCIs can vary between the scales. 

Example

Application

• clinical practice and research
• individual and group-based data
• screening and monitoring
• easy interpretation of the scales due to distribution into two categories (clinically relevant/not relevant)
• independent of cancer patient groups (e.g. age, sex, diagnosis)

Limitations

• does not distinguish between severity, therefore additional clinical interpretation of the exact score is necessary
• contextual factors have to be taken into account, e.g., the patient’s personal circumstances, comorbidities

Available thresholds

There are established TCIs for the

• EORTC quality of life core questionnaire (EORTC QLQ-C30)
• EORTC Quality of Life in palliative cancer care patients questionnaire (EORTC QLQ-C15-PAL)
• EORTC computerized adaptive test core questionnaire (EORTC CAT Core)
• EORTC modules (as of June 2026):
  • published: QLQ-FA12 (fatigue)
  • currently in publication: QLQ-LC29 (lung), QLQ-PR25 (prostate), QLQ-ELD14 (older patients with cancer), QLQ-CR29 (colorectal)
  • currently under development: QLQ-EN24 (endometrial), QLQ-H&N43 (head and neck), QLQ-OV28 (ovarian cancer).

Development

The development of the thresholds was based on patients’ input. Three crucial factors (anchors) were defined that are suitable to distinguish patients with and without further need for support in daily clinical practice.

During the past week: 

1. Has your [symptom/problem] limited your daily life?
2. Have you ever needed any help or care because of your [symptom/problem]?
3. Has your [symptom/problem] caused you or your family/partner to worry?

If a patient answers with “quite a bit” or “very much” on at least one of these anchor items, the patient’s symptom burden is categorized as clinically important (i.e. as having a clinically important problem/symptom).

For in depth details, see "A cross-cultural convergent parallel mixed methods study of what makes a cancer-related symptom or functional health problem clinically important": Link