Results of three analytical approaches on long-term efficacy of etanercept for psoriasis in daily practice

J Am Acad Dermatol. 2013 Jan;68(1):57-63. doi: 10.1016/j.jaad.2012.05.040. Epub 2012 Jul 28.


Background: 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.

Objective: To describe the long-term efficacy of etanercept for psoriasis in daily practice using 3 analytical approaches.

Methods: 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).

Results: 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.

Limitations: 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.

Conclusions: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Etanercept
  • Female
  • Follow-Up Studies
  • Humans
  • Immunoglobulin G / therapeutic use*
  • Intention to Treat Analysis
  • Male
  • Middle Aged
  • Patient Dropouts / statistics & numerical data
  • Prospective Studies
  • Psoriasis / drug therapy*
  • Receptors, Tumor Necrosis Factor / therapeutic use*
  • Registries
  • Severity of Illness Index
  • Statistics as Topic / methods*
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Anti-Inflammatory Agents, Non-Steroidal
  • Immunoglobulin G
  • Receptors, Tumor Necrosis Factor
  • Etanercept