Evans 1971.

Methods	Single centre cluster‐allocation trial. Blinding of randomisation: No. Allocation was by alternating 2 or 3 month periods (5 separate gowning periods totaling 11 months and 4 separate non‐gowning periods totaling 10 months). One month was excluded from the study Blinding of intervention: No Blinding of outcome assessment: Unknown Completeness of follow‐up: unknown
Participants	604 preterm infants admitted to the premature nursery. Inclusions: Infants nursed in incubators Exclusions: Infants who were severely ill (no definition provided).
Interventions	No gown: Visitors and attendants did not cover their outer clothing and nor did they wash their hands before entering the room. Nurses wore the white uniforms used to travel to the hospital. Those handling newborn infants through ports did not wear gowns but scrubbed for 3 minutes with an antiseptic soap. When infants were removed from an isolette, or when a hood was opened, all persons in the room wore a gown. Gown: Attendants and visitors removed their outer jackets, washed their hands for 3 minutes and donned a gown before entering the room. Nurses changed into scrub gowns at the beginning of their shift. Both anterior nares and the umbilicus were swabbed 4 to 5 mornings weekly until the infant was transferred from an incubator to an open crib.
Outcomes	1) Death 2) Systemic infection (pneumonia, meningitis, sepsis) 3) Localised infection (pyodermia, conjunctivitis and diarrhoea) 4) Colonisation of the nares and umbilicus were reported at 7 time points from day 1 to 21 but were tabulated by day of life acquired and by species. No overall prevalence by group was reported.
Notes	This trial was analysed as if allocation was by individual. The study was interrupted in September, during a non‐gowning period, because of transfer of the nursery to a new building. It was unclear how all infections were diagnosed. Pathology results were available for systemic infections but not for localised infections.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Single centre cluster‐allocation trial. Allocation was by alternating 2 or 3 month periods (5 separate gowning periods totaling 11 months and 4 separate non‐gowning periods totaling 10 months). One month was excluded from the study
Allocation concealment?	High risk	Blinding of randomisation: No
Blinding? All outcomes	Unclear risk	Blinding of intervention: No Blinding of outcome assessment: Unknown
Incomplete outcome data addressed? All outcomes	Unclear risk	Completeness of follow‐up: unknown