Mahadevia Parthiv J, Fleisher Lee A, Frick Kevin D, Eng John, Goodman Steven N, Powe Neil R
Robert Wood Johnson Clinical Scholars Program, Johns Hopkins School of Medicine, Baltimore, Md, USA.
JAMA. 2003 Jan 15;289(3):313-22. doi: 10.1001/jama.289.3.313.
Encouraged by direct-to-consumer marketing, smokers and their physicians are contemplating lung cancer screening with a promising but unproven imaging procedure, helical computed tomography (CT).
To estimate the potential benefits, harms, and cost-effectiveness of lung cancer screening with helical CT in various efficacy scenarios.
DESIGN, SETTING, AND POPULATION: Using a computer-simulated model, we compared annual helical CT screening to no screening for hypothetical cohorts of 100 000 current, quitting, and former heavy smokers, aged 60 years, of whom 55% were men. We simulated efficacy by changing the clinical stage distribution of lung cancers so that the screened group would have fewer advanced-stage cancers and more localized-stage cancers than the nonscreened group (ie, a stage shift). Our model incorporated known biases in screening programs such as lead time, length, and overdiagnosis bias.
We measured the benefits of screening by comparing the absolute and relative difference in lung cancer-specific deaths. We measured harms by the number of false-positive invasive tests or surgeries per 100 000 and incremental cost-effectiveness in US dollars per quality-adjusted life-year (QALY) gained.
Over a 20-year period, assuming a 50% stage shift, the current heavy smoker cohort had 553 fewer lung cancer deaths (13% lung cancer-specific mortality reduction) and 1186 false-positive invasive procedures per 100 000 persons. The incremental cost-effectiveness for current smokers was $116 300 per QALY gained. For quitting and former smokers, the incremental cost-effectiveness was $558 600 and $2 322 700 per QALY gained, respectively. Other than the degree of stage shift, the most influential parameters were adherence to screening, degree of length or overdiagnosis bias in the first year of screening, quality of life of persons with screen-detected localized lung cancers, cost of helical CT, and anxiety about indeterminate nodule diagnoses. In 1-way sensitivity analyses, none of these parameters was sufficient to make screening highly cost-effective for any of the cohorts. In multiway sensitivity analyses, a program screening current smokers was $42 500 per QALY gained if extremely favorable estimates were used for all of the influential parameters simultaneously.
Even if efficacy is eventually proven, screening must overcome multiple additional barriers to be highly cost-effective. Given the current uncertainty of benefits, the harms from invasive testing, and the high costs associated with screening, direct-to-consumer marketing of helical CT is not advisable.
在直接面向消费者的营销推动下，吸烟者及其医生正在考虑采用一种前景良好但未经证实的成像检查方法——螺旋计算机断层扫描（CT）进行肺癌筛查。
评估在各种疗效情景下，螺旋CT肺癌筛查的潜在益处、危害及成本效益。
设计、设置和人群：我们使用计算机模拟模型，将每年的螺旋CT筛查与对10万名年龄为60岁的当前、正在戒烟和既往重度吸烟者的假设队列不进行筛查进行比较，其中55%为男性。我们通过改变肺癌的临床分期分布来模拟疗效，以使筛查组的晚期癌症比未筛查组少，局部阶段癌症比未筛查组多（即分期转移）。我们的模型纳入了筛查项目中已知的偏倚，如领先时间、病程和过度诊断偏倚。
我们通过比较肺癌特异性死亡的绝对差异和相对差异来衡量筛查的益处。我们通过每10万人中假阳性侵入性检查或手术的数量以及每获得一个质量调整生命年（QALY）的增量成本效益（以美元计）来衡量危害。
在20年期间，假设分期转移率为50%，当前重度吸烟者队列的肺癌死亡人数减少553例（肺癌特异性死亡率降低13%），每10万人中有1186例假阳性侵入性检查。当前吸烟者的增量成本效益为每获得一个QALY 116,300美元。对于正在戒烟者和既往吸烟者，增量成本效益分别为每获得一个QALY 558,600美元和2,322,700美元。除分期转移程度外，最具影响力的参数是对筛查的依从性、筛查第一年的病程或过度诊断偏倚程度、筛查发现的局部肺癌患者的生活质量、螺旋CT的成本以及对不确定结节诊断的焦虑。在单因素敏感性分析中，这些参数中没有一个足以使筛查对任何队列具有高度成本效益。在多因素敏感性分析中，如果对所有有影响力的参数同时使用极其有利的估计值，对当前吸烟者进行筛查的项目每获得一个QALY的成本为42,500美元。
即使最终证明了疗效，筛查要具有高度成本效益还必须克服多个额外障碍。鉴于目前益处的不确定性、侵入性检查的危害以及与筛查相关的高成本，螺旋CT直接面向消费者的营销是不可取的。
