Department of Dermatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
J Am Acad Dermatol. 2013 Jan;68(1):57-63. doi: 10.1016/j.jaad.2012.05.040. Epub 2012 Jul 28.
A problem encountered when analyzing long-term efficacy is that the number of patients in follow-up decreases with time for different reasons. The method used to account for missing observations for the therapy under analysis has a great influence on the inference of efficacy.
To describe the long-term efficacy of etanercept for psoriasis in daily practice using 3 analytical approaches.
Prospective data from a cohort of patients with psoriasis treated with etanercept for at least 24 weeks were analyzed using 3 analytical approaches: as treated analysis, intention-to-treat analysis (ITT) with last observation carried forward (LOCF) and intention-to-treat analysis with modified nonresponder imputation (modified NRI).
One hundred thirty-one patients were treated with etanercept during 134 treatment episodes with a mean treatment duration of 2.7 years. The maximum follow-up was 6.0 years. The methodological approach chosen had a great influence. Psoriasis Area and Severity Index (PASI) 75 response rates varied from 60% in the as-treated approach to 34% in LOCF and to 29% in modified NRI at week 264.
All analytical methods applied have limitations. Other outcome measures could be used to overcome the bias introduced by each method of analysis, such as drug survival.
The methodological approach chosen to analyze long-term efficacy data has a great influence on the inferences that may be drawn regarding the degree of efficacy. Therefore we support the use of different methods to present long-term efficacy data.
在分析长期疗效时，会遇到一个问题，即由于各种原因，随访患者的数量会随时间减少。用于分析所研究治疗方法中缺失观察值的方法对疗效推断有很大影响。
使用 3 种分析方法描述依那西普治疗银屑病的长期疗效。
对至少接受 24 周依那西普治疗的银屑病患者队列的前瞻性数据进行分析，使用 3 种分析方法：按方案分析、意向治疗分析（ITT）伴末次观察结转（LOCF）和意向治疗分析伴改良无应答者插补（改良 NRI）。
131 例患者接受依那西普治疗，共 134 个治疗周期，平均治疗持续时间为 2.7 年。最长随访时间为 6.0 年。所选方法学途径有很大影响。银屑病面积和严重程度指数（PASI）75 应答率在按方案分析中为 60%，在 LOCF 中为 34%，在改良 NRI 中为 29%，均在第 264 周。
所有应用的分析方法都有局限性。可以使用其他疗效指标来克服每种分析方法引入的偏倚，例如药物生存。
用于分析长期疗效数据的方法学途径对可能得出的疗效程度的推断有很大影响。因此，我们支持使用不同方法来呈现长期疗效数据。
