Coleman M P, Babb P, Sloggett A, Quinn M, De Stavola B
Cancer and Public Health Unit, London School of Hygiene and Tropical Medicine, London, England, UK.
Cancer. 2001 Jan 1;91(1 Suppl):208-16. doi: 10.1002/1097-0142(20010101)91:1+<208::aid-cncr6>3.0.co;2-e.
Cancer survival often has been reported as lower for the poor than the rich, but, to the authors' knowledge, systematic national estimates of deprivation gradients in survival over long periods of time have not been available.
The authors estimated national population-based survival rates for almost 3 million people who were diagnosed with 1 of 58 types of cancers (47 in adults, 11 in children) in England and Wales during the 20-year period 1971-1990 and followed through December 31, 1995. Cancer patients were assigned by their address at diagnosis to 1 of 5 categories (quintiles of the national distribution) of material deprivation by using a standard index derived from census data on unemployment, car ownership, household overcrowding, and social class that was available for all 109,000 census tracts in Great Britain. The authors used relative survival rates: the ratio of observed survival among the cancer patients to the survival that would have been expected if they had had the same background mortality as the general population. Background mortality differed widely among socioeconomic categories, and the authors constructed life tables from raw national mortality data by gender, single year of age, calendar period of death, and socioeconomic category to adjust for it. The authors used variance-weighted least squares regression to estimate both time trends in age standardized survival and socioeconomic gradients in survival. The number of avoidable deaths was estimated from the observed mortality excess compared with the expected mortality in each group of patients.
Survival rose steadily for most cancers over 25 years to 1995 in England and Wales, but inequalities in survival between patients living in rich and poor areas were geographically widespread and persistent over this period of time. These patterns existed for 44 of 47 adult cancers examined but not for 11 childhood cancers. These inequalities in survival represented more than 2500 deaths that would have been avoided each year if all cancer patients had had the same chance of surviving up to 5 years after diagnosis as patients in the most affluent group.
The largest national cancer survival study has provided strong evidence of systematic disadvantage in outcome among patients who lived in poorer districts compared with those who lived in wealthier districts.
癌症生存率的报告通常显示，穷人低于富人。但据作者所知，长期以来尚未有全国性的关于生存剥夺梯度的系统性估计。
作者估计了1971年至1990年这20年间在英格兰和威尔士被诊断患有58种癌症（47种成人癌症，11种儿童癌症）之一的近300万人基于全国人口的生存率，并随访至1995年12月31日。通过使用从关于失业、汽车拥有量、家庭拥挤程度和社会阶层的人口普查数据得出的标准指数，将癌症患者根据其诊断时的住址分配到物质剥夺的5个类别（全国分布的五等分）之一，该指数适用于大不列颠所有109,000个人口普查区。作者使用相对生存率：癌症患者的观察生存率与如果他们具有与一般人群相同的背景死亡率时预期的生存率之比。背景死亡率在社会经济类别之间差异很大，作者根据原始的全国死亡率数据按性别、单一年龄、死亡日历期和社会经济类别构建生命表以进行调整。作者使用方差加权最小二乘回归来估计年龄标准化生存率的时间趋势和生存率的社会经济梯度。根据观察到的死亡率超过每组患者预期死亡率的情况估计可避免死亡的数量。
到1995年，在英格兰和威尔士，大多数癌症的生存率在25年中稳步上升，但在此期间，贫富地区患者之间的生存不平等在地理上广泛存在且持续存在。在所检查的47种成人癌症中有44种存在这些模式，但11种儿童癌症不存在。这些生存不平等意味着，如果所有癌症患者在诊断后存活至5年的机会与最富裕组的患者相同，那么每年将可避免超过2500例死亡。
这项最大规模的全国性癌症生存研究有力地证明，与生活在较富裕地区的患者相比，生活在较贫困地区的患者在治疗结果方面存在系统性劣势。
