Centre for Cancer Prevention, Queen Mary University of London, Wolfson Institute for Preventive Medicine, London, UK.
J Med Screen. 2012;19 Suppl 1:26-32. doi: 10.1258/jms.2012.012079.
Analysing trends in population breast cancer mortality statistics appears a simple method of estimating the effectiveness of mammographic screening programmes. We reviewed such studies of population-based screening in Europe to assess their value.
A literature review identified 17 papers, of which 12 provided quantitative estimates of the impact of screening. Due to differences in comparisons and outcome measures, no pooled estimate of effectiveness was calculated.
Comparisons included breast cancer mortality before and after the introduction of screening, trends in early and late starting areas and trends in age groups affected and unaffected by screening. Studies that calculated the percentage annual change after the start of screening found reductions of 1-9% per year (1%, 2.3-2.8% and 9% for those with adequate follow-up). Of studies that compared mortality in time periods before and after introduction of screening, three single country studies all had adequate follow-up and estimated mortality reductions ranging from 28% to 36%. Limitations of studies of population mortality rates include the inability to exclude deaths in women with breast cancer diagnosed before invitation to screening, diluting any observable impact of screening, and the gradual implementation of screening in a country or region.
Although analysing population breast cancer mortality rates over time can be a first step in examining changes following the introduction of screening, this method is of limited value for assessment of screening impact. Other methods and individual data are necessary to properly quantify the effect.
分析人群乳腺癌死亡率统计数据的趋势似乎是评估乳腺 X 线筛查计划效果的一种简单方法。我们对欧洲基于人群的筛查此类研究进行了回顾，以评估其价值。
文献回顾确定了 17 篇论文，其中 12 篇提供了关于筛查影响的定量估计。由于比较和结果测量指标的差异，未计算出效果的汇总估计值。
比较包括筛查引入前后的乳腺癌死亡率、早期和晚期开始地区的趋势以及受筛和不受筛年龄组的趋势。那些计算筛查开始后每年百分比变化的研究发现，每年减少 1-9%（1%、2.3-2.8%和 9%，随访时间充足）。在比较引入筛查前后时间段死亡率的研究中，3 项单国研究均有充足的随访，估计死亡率降低幅度从 28%到 36%不等。人群死亡率研究的局限性包括无法排除在被邀请参加筛查前已被诊断患有乳腺癌的女性的死亡人数，这会稀释筛查的任何可观察到的影响，以及筛查在一个国家或地区的逐步实施。
尽管随着时间的推移分析人群乳腺癌死亡率可以作为检查筛查引入后变化的第一步，但这种方法对于评估筛查效果的价值有限。需要其他方法和个体数据来正确量化效果。
