Lutz J-M, Pury P, Fioretta G, Raymond L
Association Suisse des Registres des Tumeurs, Switzerland.
Eur J Cancer Prev. 2004 Feb;13(1):77-81. doi: 10.1097/00008469-200402000-00012.
Official cancer mortality in Switzerland decreased by about 16% over the 9-year period 1990-1998 and this trend has often been used to suggest that secondary prevention by screening for breast cancer could be useless. However, the clear downshift observed between 1994 and 1995 for some cancers, such as female breast and prostate, and the simultaneous change in ICD classification used by the Federal Office for Statistics in 1995 (ICD-8 to ICD-10) could be related, suggesting an impact of coding process on the observed trend. For every death occurred between 1980 and 1999, the death certificates have been retrieved, the cause of death has been recoded and site-specific mortality rates have been calculated again for each year during this period. As suggested, the trend appears to be overestimated: in order to be comparable with current rates, the mortality observed before 1995 should be lowered by about 7% for men and 5% for women. The error may be partially due to attributing the cause of death to co-morbidity factors not normally (and nowadays) defined as the underlying cause. Logically, the impact of such a miscoding is more important among older people and for cancer sites with long survival. For instance, the correction should be around 15% for female breast, 12% for prostate and up to 40% for testicular cancer.
1990年至1998年的9年间，瑞士官方统计的癌症死亡率下降了约16%，这一趋势常被用来表明通过筛查乳腺癌进行二级预防可能毫无用处。然而，1994年至1995年期间，某些癌症（如女性乳腺癌和前列腺癌）明显下降，以及联邦统计局在1995年同时更改了国际疾病分类（从ICD - 8到ICD - 10），这两者可能存在关联，表明编码过程对观察到的趋势有影响。对于1980年至1999年期间发生的每一例死亡，都检索了死亡证明，重新编码了死亡原因，并在此期间每年再次计算特定部位的死亡率。结果表明，这一趋势似乎被高估了：为了与当前死亡率可比，1995年之前观察到的死亡率对于男性应降低约7%，对于女性应降低约5%。这种误差可能部分归因于将死亡原因归为通常（以及现在）不被定义为根本原因的合并症因素。从逻辑上讲，这种错误编码在老年人以及生存期较长的癌症部位中的影响更为重要。例如，女性乳腺癌的校正幅度应为15%左右，前列腺癌为12%，睾丸癌高达40%。
