Description

The EORTC Quality of Life Questionnaire (QLQ-C30) is a multidimensional assessment instrument developed by the European Organisation for Research and Treatment of Cancer (EORTC) to measure quality of life among patients with cancer.

The questionnaire covers a broad range of dimensions related to patients’ health, functioning, symptoms, and well-being. Its multidimensional structure allows the impact of both cancer and its treatment on different aspects of patients’ lives to be assessed.

According to the available source, the QLQ-C30 is one of the most widely used quality-of-life instruments in oncology clinical trials and clinical practice.

Objective

The primary objective of the QLQ-C30 is to assess quality of life among patients with cancer, taking into account the effects of the disease and its treatment on different aspects of their lives.

The questionnaire provides information on both functional status and symptom burden, as well as patients’ overall perception of their health and quality of life.

This approach allows quality of life to be assessed as a multidimensional outcome rather than relying exclusively on conventional clinical indicators.

Structure and Dimensions

The QLQ-C30 consists of 30 items covering several dimensions of health-related quality of life.

It includes five functional scales:

Physical Functioning: Assesses aspects of physical functioning and the patient’s ability to perform everyday physical activities.

Role Functioning: Evaluates the extent to which health status affects the performance of usual daily roles and activities.

Emotional Functioning: Addresses emotional aspects of the patient’s experience.

Cognitive Functioning: Examines aspects of cognitive functioning.

Social Functioning: Evaluates the impact of health status on social functioning.

The questionnaire also contains three symptom scales:

Fatigue

Pain

Nausea/Vomiting

In addition, the QLQ-C30 includes a Global Health Status/Quality of Life scale, providing an overall assessment of the patient’s perceived health and quality of life.

Scoring

Most QLQ-C30 items are rated using a 4-point Likert scale, ranging from:

1 = Not at all to 4 = Very much.

Some questions are rated using a 7-point Likert scale, ranging from:

1 = Very poor to 7 = Excellent.

According to the source document, scores for the individual items within each scale are combined and subsequently transformed to a standardized 0–100 scale.

Score Interpretation

The interpretation of QLQ-C30 scores depends on the type of scale being examined.

For the functional scales, higher scores indicate better functional status.

For the symptom scales, higher scores indicate greater symptom severity.

The direction of scoring should therefore be considered carefully when interpreting and comparing results across the different dimensions of the questionnaire.

Data Analysis and Use

QLQ-C30 data can be analyzed separately for the functional scales, symptom scales, and global health status/quality-of-life scale.

Descriptive statistical methods can be used to summarize scores within a study population, while comparisons may be conducted between different clinical or demographic groups.

The instrument may also be used to investigate associations between quality-of-life dimensions and other relevant clinical variables.

Repeated administration can facilitate the assessment of changes in functioning, symptoms, and overall quality of life during the course of cancer treatment or follow-up.

Applications

The QLQ-C30 can be used in oncology research, clinical trials, and clinical practice to assess different dimensions of quality of life among patients with cancer.

Its multidimensional structure allows researchers and healthcare professionals to examine functional status, symptom burden, and overall perceived health and quality of life within the same assessment framework.

The questionnaire can therefore contribute to evaluating the impact of cancer and its treatment on patients’ everyday lives and to comparing quality-of-life outcomes across different groups or assessment periods.

References

Aaronson NK, Ahmedzai S, Bergman B, Bullinger M, Cull A, Duez NJ, et al. The European Organization 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. 1993;85(5):365-376.

Fayers P, Aaronson N, Bjordal K, Groenvold M, Curran D, Bottomley A. The EORTC QLQ-C30 Scoring Manual. 3rd ed. Brussels: European Organisation for Research and Treatment of Cancer; 2001.