Health-related quality of life thresholds of clinical importance at diagnosis can predict longitudinal post-operative health functioning in colorectal cancer patients: A prospective multicentre observational study.

Background: Health-related quality of life (HRQOL) is an increasingly important outcome in colorectal cancer (CRC) treatment. Established thresholds for clinical importance (TCI) permit an absolute interpretation of HRQOL scores but less emphasis has been placed on whether these can be used in a predictive manner. This study aimed to examine if patients' baseline HRQOL functioning scores, subgrouped based on TCI, would significantly predict HRQOL over time.

Methods: 211 CRC patients were prospectively followed up from diagnosis to 18 months after surgery. Patients were administered the EORTC Core Quality of Life Questionnaire (EORTC QLQ-C30) at each timepoint. Baseline demographic and clinical data were extracted from electronic medical records.

Results: Only the physical and emotional functioning scales of the EORTC QLQ-C30 were utilised with their respective TCIs (score of ≤83 for physical; ≤71 for emotional). Physical functioning was below-threshold for most patients at pre-discharge (81.77 %) and 1-month (56.48 %) before stabilising to baseline proportions by 6-month. For emotional functioning, 22.04 %-30.98 % of patients were below-threshold between baseline to 3-month, stabilising to approximately 14.00 % after 6-month. Baseline TCI subgrouping was significantly associated with change in HRQOL scores over time for both the physical (β = 14.09, 95 % CI: 8.22, 19.97) and emotional (β = 25.66, 95 % CI: 18.79, 32.53) functioning scales (p < 0.01).

Conclusion: EORTC QLQ-C30 TCIs can be utilised not just to concretely identify clinically significant impairments in presenting CRC patients, but also as potential predictive tools towards more value-driven delivery of pre- and post-surgical supportive and allied healthcare.