G330 The preview trial – a prospective, randomised, double-blind, placebo controlled trial assessing oral prednisolone in pre-school aged children with viral associated wheeze

Background Pre-school aged children experience frequent episodes of wheeze that follow a different clinical course to asthma in adolescents and adults. The beneficial role of corticosteroid administration in reducing the need for hospitalisation in asthma episodes in adults has been demonstrated, however the evidence supporting corticosteroid use in pre-school aged children with acute wheeze exacerbations is less robust. Aim To assess the efficacy of oral prednisolone in pre-school-aged children presenting to a paediatric emergency department (PED) with viral associated wheeze. Methods A superiority analysis of the randomised, double-blind placebo controlled trial, comparing the effect of a 3 day course of daily oral prednisolone (1 mg/kg/day) with placebo on the primary outcome of length of hospital stay in children (aged 24 to 72 months) presenting to a tertiary PED with VAW. Results Between June 2012 and June 2015 we randomised 624 eligible patients with 605 (300 placebo and 305 prednisolone) being available for full analysis. The ‘ready for discharge’ length of stay (LOS) was significantly reduced in the prednisolone group (median [interquartile range] 370 min [121, 709]) compared to placebo (median [interquartile range] 540 min (124, 971)); the unadjusted ratio of geometric means for LOS was 0·79 (95% CI; 0·64, 0·97; p=0·0227, n=605). The prednisolone group had significantly reduced risk, relative to placebo group, of the LOS exceeding either 7 or 12 hours, adjusted RR 0·82 (95% CI; 0·.69,0·96; p=0·0166) and 0·67 (95% CI; 0·51,0·86; p=0·0018) respectively. Subgroup analysis demonstrated efficacy (reduced continuous LOS, and reduced risk of LOS exceeding either 7 or 12 hours) for prednisolone among patients with more severe exacerbations. The absolute reduction (difference) in the percentage of patients with a LOS exceeding 12 hours (13.7%) represents a number needed to treat of approximately 8 patients to prevent the LOS of 1 patient exceeding 12 hours. Conclusion Oral prednisolone demonstrated a clear benefit over placebo at reducing the LOS in children presenting to a PED with viral associated wheeze; with the greatest efficacy observed among patients with more severe features of wheeze.