Drosdowsky Allison, Lamb Karen E, Bergin Rebecca J, Boyd Lucy, Milley Kristi, IJzerman Maarten J, Emery Jon D
Department of General Practice and Centre for Cancer Research, The University of Melbourne, Parkville, Australia.
Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Australia.
Cancer Epidemiol. 2023 Apr;83:102323. doi: 10.1016/j.canep.2023.102323. Epub 2023 Jan 24.
Research focusing on timely diagnosis and treatment of colorectal cancer is necessary to improve outcomes for people with cancer. Previous attempts to consolidate research on time to diagnosis and treatment have noted varied methodological approaches and quality, limiting the comparability of findings. This systematic review was conducted to comprehensively assess the scope of methodological issues in this field and provide recommendations for future research. Eligible articles had to assess the role of any interval up to treatment, on any outcome in colorectal cancer, in English, with no limits on publication time. Four databases were searched (Ovid Medline, EMBASE, EMCARE and PsycInfo). Papers were screened by two independent reviewers using a two-stage process of title and abstract followed by full text review. In total, 130 papers were included and had data extracted on specific methodological and statistical features. Several methodological problems were identified across the evidence base. Common issues included arbitrary categorisation of intervals (n = 107, 83%), no adjustment for potential confounders (n = 65, 50%), and lack of justification for included covariates where there was adjustment (n = 40 of 65 papers that performed an adjusted analysis, 62%). Many articles introduced epidemiological biases such as immortal time bias (n = 37 of 80 papers that used survival as an outcome, 46%) and confounding by indication (n = 73, 56%), as well as other biases arising from inclusion of factors outside of their temporal sequence. However, determination of the full extent of these problems was hampered by insufficient reporting. Recommendations include avoiding artificial categorisation of intervals, ensuring bias has not been introduced due to out-of-sequence use of key events and increased use of theoretical frameworks to detect and reduce bias. The development of reporting guidelines and domain-specific risk of bias tools may aid in ensuring future research can reliably contribute to recommendations regarding optimal timing and strengthen the evidence base.
聚焦于结直肠癌及时诊断与治疗的研究对于改善癌症患者的治疗效果十分必要。此前对诊断和治疗时间相关研究进行整合的尝试发现，研究方法和质量各不相同，这限制了研究结果的可比性。本系统评价旨在全面评估该领域方法学问题的范围，并为未来研究提供建议。纳入的合格文章必须评估直至治疗的任何时间段对结直肠癌任何结局的作用，语言为英文，对发表时间无限制。检索了四个数据库（Ovid Medline、EMBASE、EMCARE和PsycInfo）。论文由两名独立评审员进行筛选，采用标题和摘要两阶段筛选流程，随后进行全文评审。总共纳入了130篇论文，并提取了关于特定方法学和统计学特征的数据。在整个证据库中发现了几个方法学问题。常见问题包括对时间段的任意分类（n = 107，83%）、未对潜在混杂因素进行调整（n = 65，50%），以及在进行调整时对纳入的协变量缺乏合理性说明（在65篇进行调整分析的论文中有40篇，62%）。许多文章引入了流行病学偏倚，如不朽时间偏倚（在80篇将生存作为结局的论文中有37篇，46%）和指示性混杂（n =
73，56%），以及因纳入时间顺序之外的因素而产生的其他偏倚。然而，报告不足阻碍了对这些问题全面程度的确定。建议包括避免对时间段进行人为分类，确保不会因关键事件的无序使用而引入偏倚，并增加使用理论框架来检测和减少偏倚。制定报告指南和特定领域的偏倚风险工具可能有助于确保未来的研究能够可靠地为关于最佳时机的建议做出贡献，并加强证据基础。
