Cancer Prevention Group, School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
Int J Cancer. 2023 May 15;152(10):2061-2068. doi: 10.1002/ijc.34441. Epub 2023 Feb 1.
Extending screening intervals in ongoing cancer screening programmes can lead to challenging year-on-year variations in the number of screening tests. We explored how such variation could be diminished with a managed transition to the extended interval. We defined three extension scenarios: immediate extension for the entire target population; stepped transition by birth cohort; and gradual transition by reducing the number of available screening appointments. These were compared to a situation in which the interval remains unchanged in a demographic model covering a 15-year period. The model was populated with observed parameters from England, a real-world setting recommending cervical screening with 3-year intervals at age 25-49 and 5-year intervals at age 50-64. Informed by typical changes currently considered by several European programmes including the programme in England, we explored the effect on screening test numbers of an extension of the 3-year interval to 5 years for women younger than 50. All three extension scenarios resulted in similar cumulative numbers of screening tests, which were about 30% lower compared to a situation in which the interval would remain unchanged. However, the year-on-year variation in the number of screening tests varied between the scenarios. This variation was around 4-fold for the immediate scenario. In the stepped scenario, the yearly numbers could differ by around 20%, whereas in the gradual scenario they were virtually constant. A managed interval extension, transitioning different groups of the target population at different times, can substantially reduce the yearly variation in screening workload without increasing the total number of screening tests in the long term.
在正在进行的癌症筛查计划中延长筛查间隔可能会导致每年筛查测试数量的显著变化。我们探讨了如何通过管理过渡到延长的间隔来减少这种变化。我们定义了三种扩展方案：对整个目标人群立即扩展；按出生队列逐步过渡；以及通过减少可用筛查预约数量逐步过渡。这些方案与在涵盖 15 年的人口模型中保持不变的间隔情况进行了比较。该模型使用来自英格兰的观察参数进行了填充，这是一个现实世界的背景，建议 25-49 岁女性每 3 年进行一次宫颈癌筛查，50-64 岁女性每 5 年进行一次。根据目前包括英格兰计划在内的几个欧洲计划正在考虑的典型变化，我们探讨了将 3 年间隔延长至 5 年对 50 岁以下女性筛查测试数量的影响。所有三种扩展方案都导致了相似的累积筛查测试数量，与间隔不变的情况相比，大约降低了 30%。然而，筛查测试数量的逐年变化在不同的方案之间存在差异。对于立即扩展的情况，这种变化大约是 4 倍。在逐步扩展的方案中，每年的数量可能相差约 20%，而在逐步扩展的方案中，数量几乎是恒定的。通过管理间隔扩展，在不同时间过渡目标人群的不同群体，可以在不增加长期总筛查测试数量的情况下，大幅减少筛查工作量的年度变化。
