O’Driscoll 1993.

Methods	Design: randomised, double‐blind trial Duration: corticosteroid treatment continued for 10‐17 days depending on allocation; follow‐up continued until 4‐6 weeks after discharge Setting: treatment initiated on inpatient basis and completed at home; trial carried out in the UK
Participants	Population: 39 adults with an acute exacerbation of asthma were randomised to a tapering (n = 18 completed) or non‐tapering (n = 17 completed) course of prednisolone Age: 16‐55 years; mean age (range) in tapering group was 28 (18‐55) years and in non‐tapering group 37 (20‐53) years Inclusion criteria: 16‐55 years of age presenting with an acute asthma attack with PEFR < 65% predicted, admission under care of designated chest physician, ability to give informed consent and maintain PEFR diary for 28 days, use of inhaled corticosteroid (400‐2000 mcg daily) on discharge Exclusion criteria: major medical illnesses (especially pneumonia, heart failure, bronchiectasis and lung cancer), COPD, long‐term use of oral steroids, nebulisation at home, unable to comply with trial protocol, receiving IV hydrocortisone for > 2 days, requiring mechanical ventilation, had taken part in the trial during preceding 2 months Percentage withdrawn: 4 participants (10.3%) withdrawn overall but number from each group not reported Allowed medication: all other asthma treatments allowed at the discretion of the participant's personal physician, provided they were allowed under trial criteria. All participants received short‐acting beta‐2‐agonists and inhaled corticosteroids Disallowed medication: not reported
Interventions	Prednisolone taper group: 40 mg prednisolone once daily for 10 days, then tapering by 5 mg/d for 7 days (total dose 540 mg prednisolone equivalent) Prednisolone non‐taper group: 40 mg prednisolone once daily for 10 days, followed by placebo taper (total dose 400 mg prednisolone equivalent)
Outcomes	PEFR, asthma symptoms on a numerical scale (1‐5)
Notes	Type of publication: peer‐reviewed Funding: placebo tablets provided by Pfizer UK Ltd
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Prescriptions were sealed in a plain brown envelope and shuffled into a random order
Allocation concealment (selection bias)	Low risk	Prescriptions were sealed in a plain brown envelope and shuffled into a random order.. whenever an eligible patient entered the trial, one of the investigators would open the next envelope and dispatch the enclosed coded prescription to the pharmacy
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants received oral prednisolone for the active tapering arm or identical placebo tablets
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Only the pharmacist was unblinded to allocation and prepared study medications according to the coded prescription; however, it is not clear whether outcome assessments were performed blinded throughout the trial
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 4 of 39 participants were enrolled and randomised but did not complete the trial. Two were lost to follow‐up and 2 were withdrawn for protocol violation and incorrect enrolment (PEFR did not meet inclusion criteria)
Selective reporting (reporting bias)	High risk	Many diary outcomes are not reported numerically so cannot be included in the meta‐analysis. Data displayed graphically in many cases with no variance. Not clear whether study was prospectively registered
Other bias	Low risk	None noted