Mirmiran 2003.
| 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) ‐ yes. All data were scored by an experienced infant sleep researcher, who was masked to experimental condition of the infant | |
| Participants | Preterm infants admitted to the NICU Setting: single‐centre, Lucile Packard Children's Hospital at Stanford, Palo Alto, CA, USA Study period: not stated |
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| Interventions | CL group: 19 infants, mean (SD) PMA 30.7 weeks (1.3 weeks), birth weight range 962‐1817 g, were allocated to the 'cycled' group and were cared for in a day‐night lighted room. Their incubator/bassinet was covered from 19:00 hours to 7:00 hours with a nearly opaque blanket, except during feeding or other interventions provided by parents and caregivers. The blanket was removed from 7:00 hours to 19:00 hours, at which time room lighting was turned up to standard lighting levels (approximately 300 lux) to produce a regular light‐dark cycled condition. Number of days of intervention was mean (SD) 35 days (25 days) DL group: 21 infants, mean (SD) PMA 29.8 weeks (1.7 weeks), birth weight range 751‐2280 g, were allocated to DL group and were cared for in a dimly lit room (< 20 lux) 24 hours a day. Their incubator/bassinet was covered with a nearly opaque blanket, except during feeding or other interventions provided by parents and caregivers. Number of days of intervention was mean (SD) 39 days (17 days) No attempt was made to modify the light‐dark cycle at home |
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| Outcomes | Weight at 35 weeks' and 4 months' PMA. Body temperature was recorded continuously for up to 3 days at 36 weeks' PMA, as well as at home at 1 and 3 months' CA, using a digital ambulatory recorder. Sleep was recorded at the same times using 24‐hour time‐lapse video recordings in conjunction with rectal temperature recordings. This provided non‐invasive monitoring of sleep. Infrared and low light level cameras allowed for recording of the infant even during dark periods. Results for body temperature amplitude, active sleep time during the 12 hours of night‐time and quiet sleep during the 12 hours of night‐time were presented in graph form only, and data could not be entered into Review Manager (RevMan 2014) | |
| Notes | PAS abstract of the same study from 2001 indicates that 19 infants were assigned to the CL group and 20 to the DL group | |
| 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 to one of two groups" |
| Blinding (performance bias and detection bias) All outcomes | High risk | Study could not be blinded |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Study authors successfully recorded 19 infants in the CL group and 21 in the DL group. Study authors do not state how many infants were enrolled. See note above about different numbers of participants enrolled in the trial as reported in an abstract in 2001 |
| 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 |