Clancy 1985.

Methods	Double‐blind, placebo‐controlled, prospective RCT over a 3‐month winter period in 1983
Participants	50 patients from Royal Newcastle Hospital with COPD not taking corticosteroids or immunosuppressants Mean age of all participants: 65.5
Interventions	NTHi vaccine and 2 placebo arms (enteric‐coated glucose tablets or 25 mg sodium tauroglycocholate). 3 courses of tablets were taken at 0, 28, 56 days. Each course was 2 tablets taken before breakfast on 3 consecutive days.
Outcomes	Number of lower respiratory infections Haemophilus influenzae isolation Salivary antibodies
Notes	Many participants were taking antibiotics and bronchodilator agents but were not taking steroids or immunosuppressants. Ciba‐Geigy (Australia) was cited for financial assistance in the Discussion. Trial was conducted at the Royal Newcastle Hospital.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation was completed independently by a "Dr Smith" who kept the trial code allocations privately; how randomisation was performed was not disclosed. Whilst Dr Smith is not one of the trial authors, the exact nature of their relationship with the study is unknown. Randomisation in 1 arm had a very uneven male‐to‐female ratio
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	For each participant with an acute upper and lower respiratory infection, an infection questionnaire was completed by doctors who were not involved with the study and had no knowledge of the participant's test group
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Infection questionnaire with an independent doctor with no knowledge of test group Sputum cultures collected to detect H influenzae involvement objectively Blood tests collected to assess salivary antibodies objectively
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants were accounted for. 2 participants out of the 50 originally enrolled died during the study
Selective reporting (reporting bias)	Low risk	Nil
Other bias	Low risk	Nil