Randomised Controlled Trials for Informing Perinatal Care

Warming Prior to Heel Stick: Blood Sample Quality and Infant Comfort-A Randomized Controlled Trial

BACKGROUND

Capillary blood sampling (heel stick) in infants is commonly performed in neonatal care units. Before the procedure, warming the infant's heel is often a customary practice, but no consensus exists on the most effective heel-warming method.

PURPOSE

To compare the effects of routinely used warming methods (glove, gel pack, or blanket) applied prior to heel stick on blood sample quality and infant's comfort.

METHODS

This prospective, double-blind, randomized controlled trial conducted in the neonatal intensive care unit included infants (postmenstrual age of ≥28 + 0 weeks and ≤43 + 6 weeks) who were computer-randomized to 1 of 3 warming methods.The primary outcome was blood flow velocity at sampling. Secondary outcomes were hemolysis index, infant COMFORTneo score, and frequency of postprocedure skin injuries. In addition, irrespective of the warming method used, the correlation between heel skin temperature and postprocedure heel skin injury was analyzed.

RESULTS

A total of 176 heel warmings were successfully randomized, and 173 were analyzed. Despite a significant difference in obtained heel skin temperature after warming between the 3 warming methods ( P = .001), no difference in blood flow velocity ( P = .91), hemolysis index ( P = .99), or COMFORTneo score ( P = .76) was found. Baseline skin temperatures above 37.0°C were associated with higher incidences of skin injury, and skin temperatures after warming were significantly higher in skin-injured heels ( P = .038).

IMPLICATIONS FOR PRACTICE AND RESEARCH

All 3 warming methods had similar effects on blood sample quality and infant's comfort. However, excessive warming of the heel should be avoided to prevent skin injuries.

Probiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants

BACKGROUND

Intestinal dysbiosis may contribute to the pathogenesis of necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Dietary supplementation with probiotics to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of NEC and associated mortality and morbidity in very preterm or VLBW infants.

OBJECTIVES

To determine the effect of supplemental probiotics on the risk of NEC and associated mortality and morbidity in very preterm or very low birth weight infants.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Maternity and Infant Care database, and CINAHL from inception to July 2022. We searched clinical trials databases and conference proceedings, and examined the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing probiotics with placebo or no probiotics in very preterm infants (born before 32 weeks' gestation) and VLBW infants (weighing less than 1500 g at birth).

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated risk of bias of the trials, extracted data, and synthesised effect estimates using risk ratios (RRs), risk differences (RDs), and mean differences (MDs), with associated 95% confidence intervals (CIs). The primary outcomes were NEC and all-cause mortality; secondary outcome measures were late-onset invasive infection (more than 48 hours after birth), duration of hospitalisation from birth, and neurodevelopmental impairment. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 60 trials with 11,156 infants. Most trials were small (median sample size 145 infants). The main potential sources of bias were unclear reporting of methods for concealing allocation and masking caregivers or investigators in about half of the trials. The formulation of the probiotics varied across trials. The most common preparations contained Bifidobacterium spp., Lactobacillus spp., Saccharomyces spp., andStreptococcus spp., alone or in combination. Very preterm or very low birth weight infants Probiotics may reduce the risk of NEC (RR 0.54, 95% CI 0.46 to 0.65; I² = 17%; 57 trials, 10,918 infants; low certainty). The number needed to treat for an additional beneficial outcome (NNTB) was 33 (95% CI 25 to 50). Probiotics probably reduce mortality slightly (RR 0.77, 95% CI 0.66 to 0.90; I² = 0%; 54 trials, 10,484 infants; moderate certainty); the NNTB was 50 (95% CI 50 to 100). Probiotics probably have little or no effect on the risk of late-onset invasive infection (RR 0.89, 95% CI 0.82 to 0.97; I² = 22%; 49 trials, 9876 infants; moderate certainty). Probiotics may have little or no effect on neurodevelopmental impairment (RR 1.03, 95% CI 0.84 to 1.26; I² = 0%; 5 trials, 1518 infants; low certainty). Extremely preterm or extremely low birth weight infants Few data were available for extremely preterm or extremely low birth weight (ELBW) infants. In this population, probiotics may have little or no effect on NEC (RR 0.92, 95% CI 0.69 to 1.22, I² = 0%; 10 trials, 1836 infants; low certainty), all-cause mortality (RR 0.92, 95% CI 0.72 to 1.18; I² = 0%; 7 trials, 1723 infants; low certainty), or late-onset invasive infection (RR 0.93, 95% CI 0.78 to 1.09; I² = 0%; 7 trials, 1533 infants; low certainty). No trials provided data for measures of neurodevelopmental impairment in extremely preterm or ELBW infants.

AUTHORS' CONCLUSIONS

Given the low to moderate certainty of evidence for the effects of probiotic supplements on the risk of NEC and associated morbidity and mortality for very preterm or VLBW infants, and particularly for extremely preterm or ELBW infants, there is a need for further large, high-quality trials to provide evidence of sufficient validity and applicability to inform policy and practice.

Prebiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants

BACKGROUND

Dietary supplementation with prebiotic oligosaccharides to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of necrotising enterocolitis (NEC) and associated mortality and morbidity in very preterm or very low birth weight (VLBW) infants.

OBJECTIVES

To assess the benefits and harms of enteral supplementation with prebiotics (versus placebo or no treatment) for preventing NEC and associated morbidity and mortality in very preterm or VLBW infants.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Maternity and Infant Care database and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), from the earliest records to July 2022. We searched clinical trials databases and conference proceedings, and examined the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing prebiotics with placebo or no prebiotics in very preterm (< 32 weeks' gestation) or VLBW (< 1500 g) infants. The primary outcomes were NEC and all-cause mortality, and the secondary outcomes were late-onset invasive infection, duration of hospitalisation since birth, and neurodevelopmental impairment.

DATA COLLECTION AND ANALYSIS

Two review authors separately evaluated risk of bias of the trials, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference (MD), with associated 95% confidence intervals (CIs). The primary outcomes of interest were NEC and all-cause mortality; our secondary outcome measures were late-onset (> 48 hours after birth) invasive infection, duration of hospitalisation, and neurodevelopmental impairment. We used the GRADE approach to assess the level of certainty of the evidence.

MAIN RESULTS

We included seven trials in which a total of 705 infants participated. All the trials were small (mean sample size 100). Lack of clarity on methods to conceal allocation and mask caregivers or investigators were potential sources of bias in three of the trials. The studied prebiotics were fructo- and galacto-oligosaccharides, inulin, and lactulose, typically administered daily with enteral feeds during birth hospitalisation. Meta-analyses of data from seven trials (686 infants) suggest that prebiotics may result in little or no difference in NEC (RR 0.97, 95% CI 0.60 to 1.56; RD none fewer per 1000, 95% CI 50 fewer to 40 more; low-certainty evidence), all-cause mortality (RR 0.43, 95% CI 0.20 to 0.92; 40 per 1000 fewer, 95% CI 70 fewer to none fewer; low-certainty evidence), or late-onset invasive infection (RR 0.79, 95% CI 0.60 to 1.06; 50 per 1000 fewer, 95% CI 100 fewer to 10 more; low-certainty evidence) prior to hospital discharge. The certainty of this evidence is low because of concerns about the risk of bias in some trials and the imprecision of the effect size estimates. The data available from one trial provided only very low-certainty evidence about the effect of prebiotics on measures of neurodevelopmental impairment (Bayley Scales of Infant Development (BSID) Mental Development Index score < 85: RR 0.84, 95% CI 0.25 to 2.90; very low-certainty evidence; BSID Psychomotor Development Index score < 85: RR 0.24, 95% 0.03 to 2.00; very low-certainty evidence; cerebral palsy: RR 0.35, 95% CI 0.01 to 8.35; very low-certainty evidence).

AUTHORS' CONCLUSIONS

The available trial data provide low-certainty evidence about the effects of prebiotics on the risk of NEC, all-cause mortality before discharge, and invasive infection, and very low-certainty evidence about the effect on neurodevelopmental impairment for very preterm or VLBW infants. Our confidence in the effect estimates is limited; the true effects may be substantially different. Large, high-quality trials are needed to provide evidence of sufficient validity to inform policy and practice decisions.

Bubble devices versus other pressure sources for nasal continuous positive airway pressure in preterm infants

BACKGROUND

Several types of pressure sources, including underwater bubble devices, mechanical ventilators, and the Infant Flow Driver, are used for providing continuous positive airway pressure (CPAP) to preterm infants with respiratory distress. It is unclear whether the use of bubble CPAP versus other pressure sources is associated with lower rates of CPAP treatment failure, or mortality and other morbidity.  OBJECTIVES: To assess the benefits and harms of bubble CPAP versus other pressure sources (mechanical ventilators or Infant Flow Driver) for reducing treatment failure and associated morbidity and mortality in newborn preterm infants with or at risk of respiratory distress.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2023, Issue 1); MEDLINE (1946 to 6 January 2023), Embase (1974 to 6 January 2023), Maternity & Infant Care Database (1971 to 6 January 2023), and the Cumulative Index to Nursing and Allied Health Literature (1982 to 6 January 2023). We searched clinical trials databases and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials comparing bubble CPAP with other pressure sources (mechanical ventilators or Infant Flow Driver) for the delivery of nasal CPAP to preterm infants.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of the evidence for effects on treatment failure, all-cause mortality, neurodevelopmental impairment, pneumothorax, moderate-severe nasal trauma, and bronchopulmonary dysplasia.

MAIN RESULTS

We included 15 trials involving a total of 1437 infants. All trials were small (median number of participants 88). The methods used to generate the randomisation sequence and ensure allocation concealment were unclear in about half of the trial reports. Lack of measures to blind caregivers or investigators was a potential source of bias in all of the included trials. The trials took place during the past 25 years in care facilities internationally, predominantly in India (five trials) and Iran (four trials). The studied pressure sources were commercially available bubble CPAP devices versus a variety of mechanical ventilator (11 trials) or Infant Flow Driver (4 trials) devices.  Meta-analyses suggest that the use of bubble CPAP compared with mechanical ventilator or Infant Flow Driver CPAP may reduce the rate of treatment failure (RR 0.76, 95% confidence interval (CI) 0.60 to 0.95; (I² = 31%); RD -0.05, 95% CI -0.10 to -0.01; number needed to treat for an additional beneficial outcome 20, 95% CI 10 to 100; 13 trials, 1230 infants; low certainty evidence). The type of pressure source may not affect mortality prior to hospital discharge (RR 0.93, 95% CI 0.64 to 1.36 (I² = 0%); RD -0.01, 95% CI -0.04 to 0.02; 10 trials, 1189 infants; low certainty evidence). No data were available on neurodevelopmental impairment. Meta-analysis suggests that the pressure source may not affect the risk of pneumothorax (RR 0.73, 95% CI 0.40 to 1.34 (I² = 0%); RD -0.01, 95% CI -0.03 to 0.01; 14 trials, 1340 infants; low certainty evidence). Bubble CPAP likely increases the risk of moderate-severe nasal injury (RR 2.29, 95% CI 1.37 to 3.82 (I² = 17%); RD 0.07, 95% CI 0.03 to 0.11; number needed to treat for an additional harmful outcome 14, 95% CI 9 to 33; 8 trials, 753 infants; moderate certainty evidence). The pressure source may not affect the risk of bronchopulmonary dysplasia (RR 0.76, 95% CI 0.53 to 1.10 (I² = 0%); RD -0.04, 95% CI -0.09 to 0.01; 7 trials, 603 infants; low certainty evidence).  AUTHORS' CONCLUSIONS: Given the low level of certainty about the effects of bubble CPAP versus other pressure sources on the risk of treatment failure and most associated morbidity and mortality for preterm infants, further large, high-quality trials are needed to provide evidence of sufficient validity and applicability to inform context- and setting-relevant policy and practice.

Proportion of Infant Neurodevelopment Trials Reporting a Null Finding: A Systematic Review

CONTEXT

Discovering new interventions to improve neurodevelopmental outcomes is a priority; however, clinical trials are challenging and methodological issues may impact the interpretation of intervention efficacy.

OBJECTIVES

Characterize the proportion of infant neurodevelopment trials reporting a null finding and identify features that may contribute to a null result.

DATA SOURCES

The Cochrane library, Medline, Embase, and CINAHL databases.

STUDY SELECTION

Randomized controlled trials recruiting infants aged <6 months comparing any "infant-directed" intervention against standard care, placebo, or another intervention. Neurodevelopment assessed as the primary outcome between 12 months and 10 years of age using a defined list of tools.

DATA EXTRACTION

Two reviewers independently extracted data and assessed quality of included studies.

RESULTS

Of n = 1283 records screened, 21 studies (from 20 reports) were included. Of 18 superiority studies, >70% reported a null finding. Features were identified that may have contributed to the high proportion of null findings, including selection and timing of the primary outcome measure, anticipated effect size, sample size and power, and statistical analysis methodology and rigor.

LIMITATIONS

Publication bias against null studies means the proportion of null findings is likely underestimated. Studies assessing neurodevelopment as a secondary or within a composite outcome were excluded.

CONCLUSIONS

This review identified a high proportion of infant neurodevelopmental trials that produced a null finding and detected several methodological and design considerations which may have contributed. We make several recommendations for future trials, including more sophisticated approaches to trial design, outcome assessment, and analysis.

Masks versus prongs as interfaces for nasal continuous positive airway pressure in preterm infants

BACKGROUND

Nasal masks and nasal prongs are used as interfaces for providing continuous positive airway pressure (CPAP) for preterm infants with or at risk of respiratory distress, either as primary support after birth or as ongoing support after endotracheal extubation from mechanical ventilation. It is unclear which type of interface is associated with lower rates of CPAP treatment failure, nasal trauma, or mortality and other morbidity.

OBJECTIVES

To assess the benefits and harms of nasal masks versus nasal prongs for reducing CPAP treatment failure, nasal trauma, or mortality and other morbidity in newborn preterm infants with or at risk of respiratory distress.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was October 2021.

SELECTION CRITERIA

We included randomised controlled trials comparing masks versus prongs as interfaces for delivery of nasal CPAP in newborn preterm infants (less than 37 weeks' gestation) with or at risk of respiratory distress.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. treatment failure, 2. all-cause mortality, and 3. neurodevelopmental impairment. Our secondary outcomes were 4. pneumothorax, 5. moderate-severe nasal trauma, 6. bronchopulmonary dysplasia, 7. duration of CPAP use, 8. duration of oxygen supplementation, 9. duration of hospitalisation, 10. patent ductus arteriosus receiving medical or surgical treatment, 11. necrotising enterocolitis, 12. severe intraventricular haemorrhage, and 13. severe retinopathy of prematurity. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 12 trials with 1604 infants. All trials were small (median number of participants 118). The trials occurred after 2001 in care facilities internationally, predominantly in India (eight trials). Most participants were preterm infants of 26 to 34 weeks' gestation who received nasal CPAP as the primary form of respiratory support after birth. The studied interfaces included commonly used commercially available masks and prongs. Lack of measures to blind caregivers or investigators was a potential source of performance and detection bias in all the trials. Meta-analyses suggested that use of masks compared with prongs may reduce CPAP treatment failure (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 8 trials, 919 infants; low certainty). The type of interface may not affect mortality prior to hospital discharge (RR 0.83, 95% CI 0.56 to 1.22; 7 trials, 814 infants; low certainty). There are no data on neurodevelopmental impairment. Meta-analyses suggest that the choice of interface may result in little or no difference in the risk of pneumothorax (RR 0.93, 95% CI 0.45 to 1.93; 5 trials, 625 infants; low certainty). Use of masks rather than prongs may reduce the risk of moderate-severe nasal injury (RR 0.55, 95% CI 0.44 to 0.71; 10 trials, 1058 infants; low certainty). The evidence is very uncertain about the effect on bronchopulmonary dysplasia (RR 0.69, 95% CI 0.46 to 1.03; 7 trials, 843 infants; very low certainty).

AUTHORS' CONCLUSIONS

The available trial data provide low-certainty evidence that use of masks compared with prongs as the nasal CPAP interface may reduce treatment failure and nasal injury, and may have little or no effect on mortality or the risk of pneumothorax in newborn preterm infants with or at risk of respiratory distress. The effect on bronchopulmonary dysplasia is very uncertain. Large, high-quality trials would be needed to provide evidence of sufficient validity and applicability to inform policy and practice.

Synbiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants

BACKGROUND

Intestinal dysbiosis may contribute to the pathogenesis of necrotising enterocolitis (NEC) in very preterm or very low birth weight (VLBW) infants. Dietary supplementation with synbiotics (probiotic micro-organisms combined with prebiotic oligosaccharides) to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of NEC and associated mortality and morbidity.

OBJECTIVES

To assess the effect of enteral supplementation with synbiotics (versus placebo or no treatment, or versus probiotics or prebiotics alone) for preventing NEC and associated morbidity and mortality in very preterm or VLBW infants.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, the Maternity and Infant Care database and CINAHL, from earliest records to 17 June 2021. We searched clinical trials databases and conference proceedings, and examined the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing prophylactic synbiotics supplementation with placebo or no synbiotics in very preterm (< 32 weeks' gestation) or very low birth weight (< 1500 g) infants.

DATA COLLECTION AND ANALYSIS

Two review authors separately performed the screening and selection process,  evaluated risk of bias of the trials, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference, with associated 95% confidence intervals (CIs). We used the GRADE approach to assess the level of certainty for effects on NEC, all-cause mortality, late-onset invasive infection, and neurodevelopmental impairment.

MAIN RESULTS

We included six trials in which a total of 925 infants participated. Most trials were small (median sample size 200). Lack of clarity on methods used to conceal allocation and mask caregivers or investigators were potential sources of bias in four of the trials. The studied synbiotics preparations contained lactobacilli or bifidobacteria (or both) combined with fructo- or galacto-oligosaccharides (or both).  Meta-analyses suggested that synbiotics may reduce the risk of NEC (RR 0.18, 95% CI 0.09 to 0.40; RD 70 fewer per 1000, 95% CI 100 fewer to 40 fewer; number needed to treat for an additional beneficial outcome (NNTB) 14, 95% CI 10 to 25; six trials (907 infants); low certainty evidence); and all-cause mortality prior to hospital discharge (RR 0.53, 95% CI 0.33 to 0.85; RD 50 fewer per 1000, 95% CI 120 fewer to 100 fewer; NNTB 20, 95% CI 8 to 100; six trials (925 infants); low-certainty evidence). Synbiotics may have little or no effect on late-onset invasive infection, but the evidence is very uncertain (RR 0.84, 95% CI 0.58 to 1.21; RD 20 fewer per 1000, 95% CI 70 fewer to 30 more; five trials (707 infants); very low-certainty evidence). None of the trials assessed neurodevelopmental outcomes. In the absence of high levels of heterogeneity, we did not undertake any subgroup analysis (including the type of feeding).

AUTHORS' CONCLUSIONS

The available trial data provide only low-certainty evidence about the effects of synbiotics on the risk of NEC and associated morbidity and mortality for very preterm or very low birth weight infants. Our confidence in the effect estimates is limited; the true effects may be substantially different from these estimates. Large, high-quality trials would be needed to provide evidence of sufficient validity and applicability to inform policy and practice.

Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

Enteral feeding for very preterm or very low birth weight (VLBW) infants is often delayed for several days after birth due to concern that early introduction of feeding may not be tolerated and may increase the risk of necrotising enterocolitis. Concerns exist, however, that delaying enteral feeding may diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

OBJECTIVES

To determine the effects of delayed introduction of progressive enteral feeds on the risk of necrotising enterocolitis, mortality and other morbidities in very preterm or VLBW infants.

SEARCH METHODS

Search strategies were developed by an information specialist in consultation with the review authors. The following databases were searched in October 2021 without date or language restrictions: CENTRAL (2021, Issue 10), MEDLINE via OVID (1946 to October 2021), Embase via OVID (1974 to October 2021), Maternity and Infant Care via OVID (1971 to October 2021), CINAHL (1982 to October 2021). We also searched for eligible trials in clinical trials databases, conference proceedings, previous reviews, and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials that assessed the effects of delayed (four or more days after birth) versus earlier introduction of progressive enteral feeds on necrotising enterocolitis, mortality and other morbidities in very preterm or VLBW infants.

DATA COLLECTION AND ANALYSIS

Two review authors separately evaluated trial risk of bias, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence for effects on necrotising enterocolitis, mortality,  feed intolerance, and invasive infection.

MAIN RESULTS

We included 14 trials in which a total of 1551 infants participated. Potential sources of bias were lack of clarity on methods to generate random sequences and conceal allocation in half of the trials, and lack of masking of caregivers or investigators in all of the trials. Trials typically defined delayed introduction of progressive enteral feeds as later than four to seven days after birth and early introduction as four days or fewer after birth. Infants in six trials (accounting for about half of all of the participants) had intrauterine growth restriction or circulatory redistribution demonstrated by absent or reversed end-diastolic flow velocities in the fetal aorta or umbilical artery.  Meta-analyses showed that delayed introduction of progressive enteral feeds may not reduce the risk of necrotising enterocolitis (RR 0.81, 95% confidence interval (CI) 0.58 to 1.14; RD -0.02, 95% CI -0.04 to 0.01; 13 trials, 1507 infants; low-certainty evidence due risk of bias and imprecision) nor all-cause mortality before hospital discharge (RR 0.97, 95% CI 0.70 to 1.36; RD -0.00, 95% CI -0.03 to 0.03; 12 trials, 1399 infants; low-certainty evidence due risk of bias and imprecision). Delayed introduction of progressive enteral feeds may slightly reduce the risk of feed intolerance (RR 0.81, 95% CI 0.68 to 0.97; RD -0.09, 95% CI -0.17 to -0.02; number needed to treat for an additional beneficial outcome = 11, 95% CI 6 to 50; 6 trials, 581 infants; low-certainty evidence due to risk of bias and imprecision) and probably increases the risk of invasive infection (RR 1.44, 95% CI 1.15 to 1.80; RD 0.10, 95% CI 0.04 to 0.15; number needed to treat for a harmful outcome = 10, 95% CI 7 to 25; 7 trials, 872 infants; moderate-certainty evidence due to risk of bias).  AUTHORS' CONCLUSIONS: Delaying the introduction of progressive enteral feeds beyond four days after birth (compared with earlier introduction) may not reduce the risk of necrotising enterocolitis or death in very preterm or VLBW infants. Delayed introduction may slightly reduce feed intolerance, and probably increases the risk of invasive infection.

Evaluation of the Quality of Perinatal Trials: Making the GRADE

BACKGROUND

Assessing the quality of clinical research is a key evidence-based practice skill. Clinicians, guideline producers, policy makers, service commissioners, and families need to have a sense of the validity, applicability, and certainty of research evidence when determining how it should inform their decision-making and practice.

METHODS

We consider the various methodological and study design factors that contribute to the validity and applicability of clinical research findings. We describe the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methodology and discuss how this approach is used to assess and report certainty of evidence and strength of recommendations.

RESULTS

The randomized controlled trial (RCT) is the gold standard method for assessing interventions because randomization balances prognostic characteristics between comparison groups. The GRADE approach considers evidence from RCTs as high quality, but acknowledges that the quality and level of certainty of trial evidence may be "downgraded" based on consideration of threats across 5 domains: risk of bias in included trials, inconsistency between trials in outcome estimates, indirectness of the evidence, imprecision of estimates, and likelihood of publication bias.

CONCLUSIONS

Structured critical appraisal using GRADE methods to assess risk of bias and other threats to the internal and external validity of RCTs and systematic reviews and meta-analyses of their data facilitates transparency and consistency in using evidence to inform policy and practice.

Probiotics to prevent necrotising enterocolitis in very preterm or very low birth weight infants

BACKGROUND

Intestinal dysbiosis may contribute to the pathogenesis of necrotising enterocolitis (NEC) in very preterm or very low birth weight infants. Dietary supplementation with probiotics to modulate the intestinal microbiome has been proposed as a strategy to reduce the risk of NEC and associated mortality and morbidity.  OBJECTIVES: To determine the effect of supplemental probiotics on the risk of NEC and mortality and morbidity in very preterm or very low birth weight infants.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 2) in the Cochrane Library; MEDLINE Ovid (1946 to 17 Feb 2020), Embase Ovid (1974 to 17 Feb 2020), Maternity & Infant Care Database Ovid (1971 to 17 Feb 2020), the Cumulative Index to Nursing and Allied Health Literature (1982 to 18 Feb 2020). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing probiotic supplementation with placebo or no probiotics in very preterm or very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of evidence for effects on NEC, all-cause mortality, late-onset infection, and severe neurodevelopmental impairment.

MAIN RESULTS

We included 56 trials in which 10,812 infants participated. Most trials were small (median sample size 149). Lack of clarity on methods to conceal allocation and mask caregivers or investigators were the main potential sources of bias in about half of the trials. Trials varied by the formulation of the probiotics. The most commonly used preparations contained Bifidobacterium spp., Lactobacillus spp., Saccharomyces spp., and Streptococcus spp. alone or in combinations. Meta-analysis showed that probiotics may reduce the risk of NEC: RR 0.54, 95% CI 0.45 to 0.65 (54 trials, 10,604 infants; I² = 17%); RD -0.03, 95% CI -0.04 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) 33, 95% CI 25 to 50. Evidence was assessed as low certainty because of the limitations in trials design, and the presence of funnel plot asymmetry consistent with publication bias. Sensitivity meta-analysis of trials at low risk of bias showed a reduced risk of NEC: RR 0.70, 95% CI 0.55 to 0.89 (16 trials, 4597 infants; I² = 25%); RD -0.02, 95% CI -0.03 to -0.01; NNTB 50, 95% CI 33 to 100. Meta-analyses showed that probiotics probably reduce mortality (RR 0.76, 95% CI 0.65 to 0.89; (51 trials, 10,170 infants; I² = 0%); RD -0.02, 95% CI -0.02 to -0.01; NNTB 50, 95% CI 50 to 100), and late-onset invasive infection (RR 0.89, 95% CI 0.82 to 0.97; (47 trials, 9762 infants; I² = 19%); RD -0.02, 95% CI -0.03 to -0.01; NNTB 50, 95% CI 33 to 100). Evidence was assessed as moderate certainty for both these outcomes because of the limitations in trials design. Sensitivity meta-analyses of 16 trials (4597 infants) at low risk of bias did not show an effect on mortality or infection. Meta-analysis showed that probiotics may have little or no effect on severe neurodevelopmental impairment (RR 1.03, 95% CI 0.84 to 1.26 (five trials, 1518 infants; I² = 0%). The certainty on this evidence is low because of limitations in trials design and serious imprecision of effect estimate. Few data (from seven of the trials) were available for extremely preterm or extremely low birth weight infants. Meta-analyses did not show effects on NEC, death, or infection (low-certainty evidence).

AUTHORS' CONCLUSIONS

Given the low to moderate level of certainty about the effects of probiotic supplements on the risk of NEC and associated morbidity and mortality for very preterm or very low birth weight infants, and particularly for extremely preterm or extremely low birth weight infants, further, large, high-quality trials are needed to provide evidence of sufficient quality and applicability to inform policy and practice.

Core outcomes in neonatology: development of a core outcome set for neonatal research

BACKGROUND

Neonatal research evaluates many different outcomes using multiple measures. This can prevent synthesis of trial results in meta-analyses, and selected outcomes may not be relevant to former patients, parents and health professionals.

OBJECTIVE

To define a core outcome set (COS) for research involving infants receiving neonatal care in a high-income setting.

DESIGN

Outcomes reported in neonatal trials and qualitative studies were systematically reviewed. Stakeholders were recruited for a three-round international Delphi survey. A consensus meeting was held to confirm the final COS, based on the survey results.

PARTICIPANTS

Four hundred and fourteen former patients, parents, healthcare professionals and researchers took part in the eDelphi survey; 173 completed all three rounds. Sixteen stakeholders participated in the consensus meeting.

RESULTS

The literature reviews identified 104 outcomes; these were included in round 1. Participants proposed 10 additional outcomes; 114 outcomes were scored in rounds 2 and 3. Round 1 scores showed different stakeholder groups prioritised contrasting outcomes. Twelve outcomes were included in the final COS: survival, sepsis, necrotising enterocolitis, brain injury on imaging, general gross motor ability, general cognitive ability, quality of life, adverse events, visual impairment/blindness, hearing impairment/deafness, retinopathy of prematurity and chronic lung disease/bronchopulmonary dysplasia.

CONCLUSIONS AND RELEVANCE

A COS for clinical trials and other research studies involving infants receiving neonatal care in a high-income setting has been identified. This COS for neonatology will help standardise outcome selection in clinical trials and ensure these are relevant to those most affected by neonatal care.