Mann 1986.

Methods	Single‐centre, randomised, controlled trial I. Blinding of randomisation ‐ cannot determine II. Blinding of intervention ‐ no III. Complete follow‐up ‐ yes IV. Blinding of outcome measurement(s) ‐ no
Participants	41 preterm infants with PMA 27‐35 weeks, postnatal age on study entry 1‐63 days Setting: single centre in Nottingham, England Study period: August‐December 1984
Interventions	Day and night nursery group: 20 infants with mean PMA (SD) 32.0 weeks (2.0 weeks) (range 28‐35 weeks), mean birth weight (SD) 1620 g (350 g) (range 1130‐2370 g) Control nursery group: 21 infants with mean PMA (SD) 31.6 weeks (1.9 weeks), mean birth weight (SD) 1640 g (390 g) (range 1020‐2430 g) Infants spent at least 10 days in 1 of the 2 nurseries Night and day nursery was identical in size and in number and distribution of windows as control nursery. During the daytime, the environment was identical in the 2 nurseries, but at 19:00 hours, windows in the night and day nursery were covered by dark, lined curtains, lights were turned off and the only illumination was provided by a low‐intensity night light. The radio was turned off, and staff and visitors were urged to make as little noise as possible. Low light and noise intensity were maintained until 7:00 hours. The control nursery contained 6 cots, measured 23 × 13 feet (7 × 4 m), had a large exterior window and smaller internal windows without curtains and was lit by bright fluorescent strip lights that remained permanently on. No attempt was made to reduce noise from the radio, staff, parents or other visitors at any time
Outcomes	Number of hours spent awake in 24 hours; number of hours spent feeding in 24 hours; and weight on discharge, at expected date of birth, at 6 weeks' CA and at 12 weeks' (3 months') CA. Mean time spent asleep, awake or feeding was calculated from 48 hours of recordings
Notes	All outcome results were presented in graphic form only and could not be entered into Review Manager (RevMan 2014)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided
Allocation concealment (selection bias)	Unclear risk	"...randomly assigned"
Blinding (performance bias and detection bias) All outcomes	High risk	Study could not be blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported for all infants enrolled
Selective reporting (reporting bias)	Unclear risk	Study was not registered in a trials registry; therefore, we were unable to ascertain whether deviations from the protocol had occurred
Other bias	Low risk	Appeared free of other bias