Cancer-related Dysfunctional Beliefs and Attitude about Sleep-6 (C-DBAS-6): a practical and accurate shortened version using XGBoost and SymScore.

We aimed to develop a practical, data-driven, shortened version of the Cancer-related Dysfunctional Beliefs and Attitudes about Sleep (C-DBAS) scale that maintains diagnostic accuracy while minimizing assessment time and efforts for both patients and clinicians. A sample dataset of 564 cancer patients was collected. Responses to 18 items were organized into six groups based on response similarity using exploratory factor analysis and K-means clustering. The most representative item from each group was then selected utilizing eXtreme Gradient Boosting (XGBoost). Subsequently, a symbolic regression-based clinical score generator (SymScore), a newly developed clinical score generator, was employed to assign optimized weights to the selected items, enabling accurate prediction of the total scores for the Dysfunctional Beliefs and Attitudes about Sleep-16 items (DBAS-16) and 2-item Cancer-related Dysfunctional Beliefs about Sleep (C-DBS) questionnaires. Six key items (items 4, 5, 7, 9, and 15 from DBAS-16 and item C2 from C-DBS) were identified, allowing close estimation of the total score for the combined DBAS-16 and C-DBS, referred to as C-DBAS-6. XGBoost applied to C-DBAS-6 demonstrated strong predictive performance, achieving an R