Evaluation of quality of life questionnaire in patients with colorectal cancer

Background: The quality of life (QoL) of colorectal cancer patients has growing importance. The aim of the current study was to construct a colorectal cancer specific QoL questionnaire (CRC_QoL) and to test its reliability and validity.

Patients-Methods: 372 patients with rectal cancer were included on a voluntary basis in this prospective study. The CRC_QoL was prepared to analyze the correlation between the characteristics of the colorectal cancer and its treatment versus the physical and psychological state, somatic sensations and social connections of the patients. The questionnaire consists of 62 questions. There are 2–5 possible answers in a simple choice system. Bigger numbers mean worse, the smaller mean better quality of life. The scale can also be seen as a percent distribution, where -in turn- the best quality is 100. The results were evaluated by question and by patient group too. Statistical routines were administered with the use of MiniStat.

Results: Internal consistency of each factor was assessed by calculating Cronbach alpha values and was found satisfactory [Physical state indicators 0.779, General state indicators 0.844, Gastrointestinal indicators 0.445, Stool and defecation indicators 0.758, Gender specific indicators 0.940, Emotional state indicators 0.845, Social indicators 0.281]. For the test-retest reliability analysis the questionnaires were re-assessed. Correlation analysis showed that the answers were consistent, Pearson values ranging from 0.991–1.00. Discriminative validity analysis of the factors showed a significant difference in all cases which proves that these items discriminate between patients operated for colorectal cancer and the healthy population.

Conclusion: This questionnaire can be used to detect changes in QoL over time to patients with colorectal cancer. Its use as an additional outcome measure in surgery, chemotherapy and radiotherapy should be encouraged.