The Quality of Research Methods in Studies Quantifying the Association Between Cancer Diagnosis to Treatment Interval and Overall Survival
TL;DR
A systematic review of observational studies published from 2020 onward that examine the association between DTI and OS in seven cancers with global relevance to provide a comprehensive assessment of methodological validity and consistency in recent studies investigating the association between cancer DTI and OS.
Abstract
Background and Objective: Studies examining the association between cancer diagnosis to treatment interval (DTI) and overall survival (OS) are important to help inform clinical practice guidelines. Recent international consensus-based recommendations defined best practices for this area of research and raised concerns about the poor validity and inconsistent methodologies in the available literature. Our objective is to systematically assess the quality of studies investigating the association between DTI and OS using consensus-based methodological recommendations. Methods: We are conducting a systematic review of observational studies published from 2020 onward that examine the association between DTI and OS in seven cancers with global relevance: bladder, breast, colon, rectal, lung, cervical, and head and neck cancers. We developed thorough search strategies to search Ovid MEDLINE, EMBASE, and Web of Science databases. Two rounds of screening will be performed in tandem using Covidence following predefined exclusion criteria and reliability procedures. Data extraction will be performed using Covidence with considerations for reliability and reconciliation. Methodological components will be evaluated against international consensus-based recommendations across domains including variable definition and measurement, cohort creation, confounder control, bias management, analytic techniques, and responsible data interpretation. Findings will be synthesized and presented using descriptive statistics. Anticipated Applications: This review will provide a comprehensive assessment of methodological validity and consistency in recent studies investigating the association between cancer DTI and OS. The findings will highlight areas for improvement and support wider adoption of the consensus-based recommendations to strengthen future research in this area (Jalink et al., 2025). References: Jalink M, King WD, Anderson BO, et al. Recommendations for studying the association of the cancer diagnosis to treatment interval with overall survival: a modified Delphi process. Br J Cancer. 2025;133:1526-1534. doi:10.1038/s41416-025-03158-3.