Oral prednisolone for acute lower respiratory tract infection in clinically unrecognised asthma: an exploratory analysis of the Oral Steroids for Acute Cough (OSAC) randomised trial

Background: Acute lower respiratory tract infection (ALRTI) is often treated in primary care with antibiotics. The recent ‘OSAC’ RCT showed corticosteroids were not an effective alternative in nonasthmatic adults with ALRTI.

Aim: To investigate if corticosteroids are beneficial for ALRTI in patients with unrecognised asthma.

Design and Setting: Exploratory analysis of the primary care OSAC trial.

Methods: Sub-group analysis in patients responding yes to the International Primary Care Airways Group (IPCAG) question: did you have wheeze and/or at least two of nocturnal cough/chest tightness/dyspnoea in the past year. Sensitivity analysis in those answering yes to wheeze and at least two of the nocturnal symptoms.

Primary outcomes: duration of cough (0 to 28 days, minimum clinically important difference (MCID) of 3.79 days) and mean symptoms’ severity score (0 to 6; MCID
1.66 units).

Results: Forty (10%) patients were included in the main analysis: mean age 49 (SD, 17.9) years, 52% male. Median cough duration was 3 days in both prednisolone (interquartile range [IQR], 2-6 days) and placebo (IQR, 1-6 days) groups (adjusted hazard ratio (HR), 1.10; 95% CI, 0.47-2.54; P=0.83), equating to 0.24 days longer (95% CI 1.23 days shorter to 2.88 days longer). Mean symptom severity difference was -0.14 (95% CI -0.78, 0.49, P=0.65) comparing prednisolone with placebo. Similar findings were found in the sensitivity analysis.

Conclusion: We found no evidence to support the use of corticosteroids for ALRTI in patients with clinically unrecognised asthma. Clinicians should not the IPCAG questions to target oral corticosteroid treatment in patients with ALRTI.