Ernst 1989.
| Methods | Parallel‐group randomised controlled trial | |
| Participants |
Participants: 18 preterm infants Mean birth weight: 1185 grams in the control group and 1256 grams in the NNS group Mean gestational age: 29 weeks in the control group and 29 weeks in the NNS group Mean postnatal age: study began on day 1 Setting: Indiana University Medical Center, Indianapolis, IN, USA Inclusion criteria: infants were included if they were very low birth weight babies between 890‐1400 grams with an appropriate weight, length, and head circumference for their gestational age (27 to 30 weeks) Exclusion criteria: infants with seizures, CNS haemorrhage, requirement of surgery, fluid restrictions, prolonged mechanical ventilation, significant supplemental oxygen, discontinued feeding or formula that was different from the routinely used premature feeding formula |
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| Interventions |
Experimental group: NNS during and after gavage feeding. Pacifier given at the commencement of nasogastric tube feeding and remained in mouth post‐feeding. Total time of pacifier in mouth was 30 min. Movement of the pacifier or stroking of the infants' cheek was used to restimulate non‐nutritive sucking during the 30‐minute period. Control: gavage feeding with no pacifier. Infants in the control group were not allowed to suck on pacifiers between feeding times. Treatment phase of the study concluded when infants weighed approximately 1700 grams. At this point gavage feeding was discontinued and replaced by nipple feeding. Both groups: no pacifier between feedings. Intake was held constant in both groups. |
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| Outcomes | Anthropometric measures: weight, length, head and arm circumferences, skin folds (subscapular and triceps) obtained weekly. Gastrointestinal transit time: determined using carmine markers that were mixed with initial feeding on day 1 of the study and at weekly intervals. Transit time was determined upon the first appearance when the marker appeared in the stools for the first time. Other measures: description and frequency of stools and amount of aspirated gastric residue Blood samples were obtained individually from each infant on day 1 of the study by venepuncture, and by heel stick weekly for serum protein determinations. Energy expenditure: estimated where cumulative heart rate measurements were correlated with energy expenditure in premature infants. Infants were monitored for 4‐6 consecutive hours during the 72 hour fecal collections. Energy and fat excretions/energy expenditure: determined in a subgroup of 8 baby boys (4 control, 4 NNS). Measured at baseline, and 1 and 2 weeks post‐treatment from 72 hour fecal collections. A second carmine marker was administered to infant boys 72 hours after the first marker so that stool collections exactly corresponded to 72 hours of formula intake. The total caloric value was determined by bomb calorimetry. |
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| Notes | — | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Infants were "randomly assigned" to the intervention or treatment group based on sex and birth weight. No further information provided |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding (performance bias and detection bias) All outcomes | High risk | Blinding of intervention ‐ no Blinding of outcome assessors ‐ no |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Complete follow‐up ‐ yes |
| Selective reporting (reporting bias) | Unclear risk | Study protocol not obtained. |