Coley C M, Barry M J, Fleming C, Fahs M C, Mulley A G
Massachusetts General Hospital, Boston, USA.
Ann Intern Med. 1997 Mar 15;126(6):468-79. doi: 10.7326/0003-4819-126-6-199703150-00010.
To evaluate the potential benefits, harms, and economic consequences of digital rectal examination and measurement of prostate-specific antigen (PSA) for the early detection of prostate cancer.
Relevant studies were identified from a MEDLINE search (1966 to 1995), reviews, bibliographies of retrieved articles, author files, and abstracts.
Probabilities for individual clinical outcomes were derived from various sources, including the largest screening study of community volunteers to data, analyses of Medicare claims, and recently published meta-analyses of the outcomes of alternative treatment strategies. Cost estimates were based on the 1992 Medicare fee schedule.
A cost-effectiveness model for one-time digital rectal examination and PSA measurement was constructed to examine the possible outcomes.
If a favorable set of assumptions is used, one-time digital rectal examination and PSA measurement may increase average life expectancy by approximately 2 weeks at a reasonable marginal cost for men who are between 50 and 69 years of age. Considerable iatrogenic illness would occur. If less favorable assumptions are used, the estimated net benefit would decrease and cost-effectiveness ratios would dramatically increase. Even if favorable assumptions are used, the model suggests that screening adds only a few days to the average life expectancy of men who are older than 69 years of age. If the assumptions are less favorable, older men are harmed.
The model suggests that screening may be reasonable in younger men if optimistic assumptions consistent with existing observational data are made. The lack of direct evidence showing a net benefit of screening for prostate cancer seems to mandate more clinician-patient discussion for this procedure than for many other routine tests.
评估直肠指检和前列腺特异性抗原（PSA）检测用于早期发现前列腺癌的潜在益处、危害及经济后果。
通过检索MEDLINE（1966年至1995年）、综述、检索文章的参考文献、作者档案及摘要确定相关研究。
个体临床结局的概率来自多种来源，包括对社区志愿者的最大规模筛查研究数据、医疗保险理赔分析以及近期发表的替代治疗策略结局的荟萃分析。成本估计基于1992年医疗保险费用表。
构建一次性直肠指检和PSA检测的成本效益模型以检验可能的结果。
如果采用一组有利的假设，对于50至69岁的男性，一次性直肠指检和PSA检测可能以合理的边际成本使平均预期寿命延长约2周。但会出现相当多的医源性疾病。如果采用不太有利假设，估计的净效益会降低，成本效益比会大幅增加。即使采用有利假设，该模型表明筛查对69岁以上男性的平均预期寿命仅增加几天。如果假设不太有利，老年男性会受到伤害。
该模型表明，如果做出与现有观察数据一致的乐观假设，在年轻男性中进行筛查可能是合理的。缺乏直接证据表明前列腺癌筛查有净效益，这似乎要求对此程序进行比许多其他常规检查更多的医患讨论。
