Age Under-Representation in Biologic Trials for Chronic Rhinosinusitis with Nasal Polyps: A Systematic Review

Introduction
Chronic rhinosinusitis with nasal polyps (CRSwNP) is ranked as the sixth most common chronic condition in older patients. The European Position Paper on Rhinosinusitis and Nasal Polyps estimates CRSwNP prevalence at 5% in adults aged ≥60, versus 1–4% in the general adult population.

Current conservative treatments primarily reduce symptoms and dampen inflammation rather than substantially manage the underlying pathology. Surgery for CRSwNP has a considerable post-operative recurrence rate, ranging from 12–51%.

Despite the clear epidemiological preponderance in older adults, this group remains comparatively under-represented in interventional trials evaluating biologic therapies for CRSwNP.

Methods
ClinicalTrials.gov, ISRCTN and Health Research Authority public research summaries were searched using pre-specified terms relating to CRSwNP. Records were included if they described UK-relevant interventional trials involving adults with CRSwNP. Records were deduplicated using registry identifiers and manually checked by title, intervention and study population. We extracted age eligibility, presence of an upper age cut-off, and publicly reported participant age and frailty-relevant characteristics where available.

Results
Ten relevant adult trial records were identified. All included adults aged at least 18 years. Three trials (30%) had explicit upper age cut-offs below 80 years: one at 70 years and two at 75 years. Seven trials (70%) had no explicit upper cut-off below 80 years. Publicly reported participant age data were identified for six trials. No accessible record identified use of a frailty measure (Clinical Frailty Scale), care-home residence, functional dependence, or the proportion of participants aged ≥75 or ≥80.

Conclusions
Explicit upper age cut-offs were relatively uncommon in UK CRSwNP biologic trials. However, given the disproportionate burden of CRSwNP in older adults, sparse reporting of frailty measures, care-home residence, and age distribution means that representativeness of this population cannot be confirmed. Trials should report recruited age distributions and frailty characteristics, not only broad eligibility criteria.