A systematic review of the proportion of adolescents recruited to RCTs of asthma treatments for adults and adolescents

Abstract

Background: To guide adolescent asthma management, evidence from RCTs of treatment efficacy and safety is needed for this age group. The EMA recommends adolescents are included in adult asthma RCTs.

Aims and objectives: To evaluate in published RCTs of pharmaceutical asthma therapies that recruit both adolescents and adults:

1. The proportion of adolescents recruited

2. Whether therapies studied are subsequently licenced for adolescents and/or adults

Methods: Multiple databases were systematically searched for RCTs of asthma therapies recruiting adolescents and adults published between 2015-20. Three authors assessed reporting of: proportion of adolescents, age of youngest participant, and conclusions drawn regarding use of each therapy in adolescence. NICE guidelines were reviewed to assess whether therapies were approved to treat asthma in adolescents and/or adults.

Results: 58 RCTs were identified. In 34(59%) of these, proportion of adolescents recruited was not reported. In 37(64%), age of youngest participant was not reported. Of the 24(41%) trials where proportion of adolescents was reported, this ranged between 1-49%(median 6%). Only 6(10%) trials reported adolescent sub-group data. 22 different therapies were studied, of which NICE approved 12 for use in adolescents and adults and a further 6 in adults only.

Conclusions: In published asthma RCTs, it is frequently unclear whether adolescents have been recruited. Furthermore, when reported, the proportion is often minimal. Consequently, caution is needed when using data from some RCTs to support management decisions in adolescents with asthma.