Reporting of concomitant and rescue topical therapies in atopic dermatitis randomised controlled trials evaluating a systemic treatment: a scoping review.

Abstract

Background: Randomised controlled trials (RCTs) evaluating new systemic treatments for atopic dermatitis (AD) have increased dramatically over the last decade. These trials often incorporate topical therapies either as permitted concomitant or rescue treatments. Differential use of these topicals post-randomisation introduces potential bias as they may nullify or exaggerate treatment responses.

Objectives: To determine the proportion of RCTs that clearly report the allowance or prohibition of concomitant and rescue topical treatments. Secondary outcomes involved examining the reporting of specific key parameters for these topicals.

Methods: We included AD systemic medication RCTs included in the living systematic review of Drucker et al (updated in March 2023, available at the time of this review). Inclusion criteria were published RCTs evaluating systemic immunomodulatory treatments in AD. Only anti-inflammatory topical therapies were included therapies in this review; emollients were not considered.

Results: We screened 83 AD trials and included 67 RCTs, published between 1991 and 2023. The majority adequately reported the allowance or prohibition of concomitant topical treatments (95.5%, N=64/67), but this clarity was less prevalent regarding rescue topicals (73.1%, N=49/67). All trials permitting concomitant therapies consistently reported the type, though details on potency (88.6%, N=31/35), duration (54.3%, N=19/35), application frequency (34.3%, N=12/35), and quantity (5.7%, N=2/35) were less frequently reported. Similarly, trials allowing rescue treatments often specified the type (91.2%, N=31/34) but provided limited information on potency (52.9%, N=18/34), duration (8.8%, N=3/34), application frequency (5.9%, N=2/34), and quantity (0%, N=0/34). Notably, only 23.5% (N=8/34) clearly reported the criteria for using rescue topical treatments, with the phrase "at investigator's discretion" being used in most cases (61.8%, N=21/34). In the multivariable logistic regression analysis including impact factor, journal's policy on adhering to CONSORT guidelines, publication year, funding, number of patients randomised and blinding status, only the publication year (≥ 2020) was associated with having better reporting for rescue topical treatments (aOR 9.55, 95% CI 1.76-39.8).

Conclusions: While most AD clinical trials of systemic treatments report concomitant topical treatments, reporting practices for rescue topicals were less consistent and inadequate. A standardized approach to reporting topical therapy in AD trials is needed to enhance transparency and interpretability.