The Nordic Cochrane Centre, Rigshospitalet, University of Copenhagen, Denmark.
BMJ. 2010 Mar 23;340:c1241. doi: 10.1136/bmj.c1241.
To determine whether the previously observed 25% reduction in breast cancer mortality in Copenhagen following the introduction of mammography screening was indeed due to screening, by using an additional screening region and five years additional follow-up.
We used Poisson regression analyses adjusted for changes in age distribution to compare the annual percentage change in breast cancer mortality in areas where screening was used with the change in areas where it was not used during 10 years before screening was introduced and for 10 years after screening was in practice (starting five years after introduction of screening).
Copenhagen, where mammography screening started in 1991, and Funen county, where screening was introduced in 1993. The rest of Denmark (about 80% of the population) served as an unscreened control group.
All Danish women recorded in the Cause of Death Register and Statistics Denmark for 1971-2006.
Annual percentage change in breast cancer mortality in regions offering mammography screening and those not offering screening.
In women who could benefit from screening (ages 55-74 years), we found a mortality decline of 1% per year in the screening areas (relative risk (RR) 0.99, 95% confidence interval (CI) 0.96 to 1.01) during the 10 year period when screening could have had an effect (1997-2006). In women of the same age in the non-screening areas, there was a decline of 2% in mortality per year (RR 0.98, 95% CI 0.97 to 0.99) in the same 10 year period. In women who were too young to benefit from screening (ages 35-55 years), breast cancer mortality during 1997-2006 declined 5% per year (RR 0.95, CI 0.92 to 0.98) in the screened areas and 6% per year (RR 0.94, CI 0.92 to 0.95) in the non-screened areas. For the older age groups (75-84 years), there was little change in breast cancer mortality over time in both screened and non-screened areas. Trends were less clear during the 10 year period before screening was introduced, with a possible increase in mortality in women aged less than 75 years in the non-screened regions.
We were unable to find an effect of the Danish screening programme on breast cancer mortality. The reductions in breast cancer mortality we observed in screening regions were similar or less than those in non-screened areas and in age groups too young to benefit from screening, and are more likely explained by changes in risk factors and improved treatment than by screening mammography.
通过在另一个筛查区域使用五年额外的随访，确定哥本哈根引入乳房 X 线照相筛查后乳腺癌死亡率降低 25%是否确实归因于筛查。
我们使用泊松回归分析调整年龄分布的变化，比较在引入筛查的区域中乳腺癌死亡率的年变化百分比与在引入筛查之前的 10 年和筛查实施后（在引入筛查五年后开始）的 10 年中未使用筛查的区域中的变化。
哥本哈根，乳房 X 线照相筛查于 1991 年开始；菲英郡，筛查于 1993 年开始。丹麦的其余地区（约占人口的 80%）作为未经筛查的对照组。
丹麦死因登记册和丹麦统计局记录的 1971 年至 2006 年所有丹麦妇女。
提供乳房 X 线照相筛查的地区和未提供筛查的地区乳腺癌死亡率的年变化百分比。
在可以从筛查中受益的女性（55-74 岁）中，我们发现筛查区域的死亡率每年下降 1%（相对风险（RR）0.99，95%置信区间（CI）0.96 至 1.01）在可以产生影响的 10 年期间（1997-2006 年）。在同一年龄的非筛查区域的女性中，同一 10 年内死亡率每年下降 2%（RR 0.98，95%CI 0.97 至 0.99）。在年龄太小而无法从筛查中受益的女性（35-55 岁）中，在筛查区域，1997-2006 年间乳腺癌死亡率每年下降 5%（RR 0.95，CI 0.92 至 0.98），在非筛查区域每年下降 6%（RR 0.94，CI 0.92 至 0.95）。对于年龄较大的年龄组（75-84 岁），在筛查和非筛查区域，乳腺癌死亡率随时间变化的变化不大。在引入筛查之前的 10 年期间，趋势不太明显，在非筛查区域，75 岁以下女性的死亡率可能会增加。
我们无法发现丹麦筛查计划对乳腺癌死亡率的影响。我们在筛查区域观察到的乳腺癌死亡率的降低与非筛查区域相似或更低，并且在年龄太小而无法从筛查中受益的年龄组中，更可能是由于危险因素的变化和治疗的改善，而不是乳房 X 线照相筛查。
Zotero 插件
