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A standardization approach to compare treatment safety and effectiveness outcomes between clinical trials and real-world populations in psoriasis

Lookup NU author(s): Dr Philip Hampton



This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).


© 2019 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.Background: Patients recruited in randomized controlled trials (RCTs) for biologic therapies in psoriasis are not fully representative of the real-world psoriasis population. Objectives: Firstly, to investigate whether patient characteristics are associated with being included in a psoriasis RCT. Secondly, to estimate the differences in the incidence of severe adverse events (SAEs) and the response rate between RCT and real-world populations of patients on biologic therapies for psoriasis using a standardization method. Methods: Data from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR) were appended to individual participant-level data from two RCTs assessing ustekinumab in patients with psoriasis. Baseline variables were assessed for association of being in an RCT using a multivariable logistic regression model. Propensity score weights were derived to reweigh the registry population so that variables had the distribution of the trial population. We measured the C-statistic of the model with trial status as the dependent variable, and the risk differences in the incidence rate of SAEs in the first year and Psoriasis Area and Severity Index (PASI) after 6 months in the BADBIR cohort before and after weighting. Results: In total 6790 registry and 2021 RCT participants were included. The multivariable logistic regression model had a C-statistic of 0.82 [95% confidence interval (CI) 0.81–0.83]. The risk differences for the incidence rate of SAEs and the proportion of patients with PASI < 1.5 were 9.27 (95% CI −3.91–22.5) per 1000 person-years and 0.95 (95% CI −1.98–4.15), respectively. Conclusions: Our results suggest that RCTs of biologic therapies in patients with psoriasis are not fully representative of the real-world population, but this lack of external validity does not account for the efficacy–effectiveness gap.

Publication metadata

Author(s): Yiu ZZN, Mason KJ, Barker JNWN, Hampton PJ, McElhone K, Smith CH, Warren RB, Griffiths CEM, Lunt M, Burden AD

Publication type: Article

Publication status: Published

Journal: British Journal of Dermatology

Year: 2019

Volume: 181

Issue: 6

Pages: 1265-1271

Print publication date: 01/12/2019

Online publication date: 01/03/2019

Acceptance date: 28/02/2019

Date deposited: 23/07/2019

ISSN (print): 0007-0963

ISSN (electronic): 1365-2133

Publisher: Wiley-Blackwell


DOI: 10.1111/bjd.17849

PubMed id: 30822358


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