Dataset Information

Baby-OSCAR: Outcome after Selective early treatment for Closure of patent ductus ARteriosus in preterm babies-a statistical analysis plan for short-term outcomes.

ABSTRACT:

Background

The Baby-OSCAR trial is a multi-centre, randomised, placebo-controlled parallel group trial of early treatment of large patent ductus arteriosus (PDA) with ibuprofen in extremely preterm infants. This paper describes the statistical analysis plan for the short-term health outcomes of the Baby-OSCAR trial.

Methods and design

This is a randomised controlled trial to determine if early-targeted treatment of a large PDA with parenteral ibuprofen in extremely preterm babies improves short and long-term health and economic outcomes. Infants born between 23⁺⁰ and 28⁺⁶ weeks of gestation, confirmed by echocardiography as having a large PDA (with a diameter of at least 1.5 mm and unrestricted pulsatile PDA flow pattern), with parental informed consent, were randomly allocated to receive either ibuprofen or placebo within 72 h of birth. The primary outcome is a composite of death by 36 weeks' postmenstrual age or moderate or severe bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age.

Results

Baseline demographic and clinical characteristics will be described by randomised group. The primary analysis will be on the modified intention to treat (ITT) population. Counts and percentages will be presented for binary and categorical variables, and mean and standard deviation or median and interquartile range will be presented for continuous variables. For binary outcomes, risk ratios and confidence intervals will be calculated using log binomial or Poisson regression with a robust variance estimator. Continuous outcomes will be analysed using linear regression models, or quantile regression models if skewed. Analyses will be adjusted for all minimisation factors where technically possible, and correlation between siblings from multiple births will be accounted for by nesting the clusters as a random effect. Both crude and adjusted effect estimates will be presented, with the primary inference based on the adjusted estimates. Ninety-five per cent confidence intervals will be used for all pre-specified outcome comparisons.

Conclusion

This paper describes the statistical analysis plan for short-term health outcomes of the trial, including the analysis principles, definitions of important outcomes, methods for primary analysis, pre-specified subgroup analysis, and secondary analysis. The plan was finalised prior to completion of short-term follow-up.

Trial registration

ISRCTN registry ISRCTN84264977 . Registered on 15 September 2010.

SUBMITTER: Bell JL

PROVIDER: S-EPMC8157743 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundThe question of whether to treat patent ductus arteriosus (PDA) early or wait until symptoms appear remains high on the research agenda for neonatal medicine. Around 7000 extremely preterm babies under 29 weeks' gestation are born in the UK every year. In 40% of cases the PDA will fail to close spontaneously, even by 4 months of age. Untreated PDA can be associated with several serious and life-threatening short and long-term complications. Reliable data to support clinical decisions about PDA treatment are needed to prevent serious complications in high risk babies, while minimising undue exposure of infants. With the availability of routine bedside echocardiography, babies with a large PDA can be diagnosed before they become symptomatic.MethodsThis is a multicentre, masked, randomised, placebo-controlled parallel group trial to determine if early-targeted treatment of a large PDA with parenteral ibuprofen in extremely preterm babies (23+ 0-28+ 6 weeks' gestation) improves short and long-term health and economic outcomes. With parental informed consent, extremely preterm babies (born between 23+ 0-28+ 6 weeks' gestation) admitted to tertiary neonatal units are screened using echocardiography. Babies with a large PDA on echocardiography, defined by diameter of at least 1.5 mm and unrestricted pulsatile PDA flow pattern, are randomly allocated to either ibuprofen or placebo within 72 h of birth. The primary endpoint is the composite outcome of death by 36 weeks' postmenstrual age or moderate or severe bronchopulmonary dysplasia (BPD) at 36 weeks postmenstrual age.DiscussionProphylactic pharmacological treatment of all preterm babies unnecessarily exposes them to potentially serious side effects of drug treatment, when their PDA may have closed spontaneously. However, delaying treatment until babies become symptomatic could result in loss of treatment benefit as irreversible damage may have already been done. Targeted, early pharmacological treatment of PDA in asymptomatic babies has the potential to overcome the disadvantages of both prophylactic (overtreatment) and symptomatic approaches (potentially too late). This could result in improvements in the clinically important short-term clinical (mortality and moderate or severe BPD at 36 weeks' postmenstrual age) and long-term health outcomes (moderate or severe neurodevelopment disability and respiratory morbidity) measured at 2 years corrected age.Trial registrationISRCTN84264977 . Date assigned: 15/09/2010.

Project description:BackgroundSymptomatic patent ductus arteriosus (PDA) is associated with mortality and morbidity in preterm infants. In these infants, prophylactic use of indomethacin, a non-selective cyclooxygenase inhibitor, has demonstrated short-term clinical benefits. The effect of indomethacin in preterm infants with a symptomatic PDA remains unexplored.ObjectivesTo determine the effectiveness and safety of indomethacin (given by any route) compared to placebo or no treatment in reducing mortality and morbidity in preterm infants with a symptomatic PDA.Search methodsWe used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 31 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-RCTs.Selection criteriaWe included RCTs and quasi-RCTs that compared indomethacin (any dose, any route) versus placebo or no treatment in preterm infants.Data collection and analysisWe used the standard methods of Cochrane Neonatal, with separate evaluation of trial quality and data extraction by at least two review authors. We used the GRADE approach to assess the certainty of evidence for the following outcomes: failure of PDA closure within one week of administration of the first dose of indomethacin; bronchopulmonary dysplasia (BPD) at 28 days' postnatal age and at 36 weeks' postmenstrual age; proportion of infants requiring surgical ligation or transcatheter occlusion; all-cause neonatal mortality; necrotizing enterocolitis (NEC) (≥ Bell stage 2); and mucocutaneous or gastrointestinal bleeding.Main resultsWe included 14 RCTs (880 preterm infants). Four out of the 14 included studies were judged to have high risk of bias in one or more domains. Indomethacin administration was associated with a large reduction in failure of PDA closure within one week of administration of the first dose (risk ratio (RR) 0.30, 95% confidence interval (CI) 0.23 to 0.38; risk difference (RD) -0.52, 95% CI -0.58 to -0.45; 10 studies, 654 infants; high-certainty evidence). There may be little to no difference in the incidence of BPD (BPD defined as supplemental oxygen need at 28 days' postnatal age: RR 1.45, 95% CI 0.60 to 3.51; 1 study, 55 infants; low-certainty evidence; BPD defined as supplemental oxygen need at 36 weeks' postmenstrual age: RR 0.80, 95% CI 0.41 to 1.55; 1 study, 92 infants; low-certainty evidence) and probably little to no difference in mortality (RR 0.78, 95% CI 0.46 to 1.33; 8 studies, 314 infants; moderate-certainty evidence) with use of indomethacin for symptomatic PDA. No differences were demonstrated in the need for surgical PDA ligation (RR 0.66, 95% CI 0.33 to 1.29; 7 studies, 275 infants; moderate-certainty evidence), in NEC (RR 1.27, 95% CI 0.36 to 4.55; 2 studies, 147 infants; low-certainty evidence), or in mucocutaneous or gastrointestinal bleeding (RR 0.33, 95% CI 0.01 to 7.58; 2 studies, 119 infants; low-certainty evidence) with use of indomethacin compared to placebo or no treatment. Certainty of evidence for BPD, surgical PDA ligation, NEC, and mucocutaneous or gastrointestinal bleeding was downgraded for very serious or serious imprecision.Authors' conclusionsHigh-certainty evidence shows that indomethacin is effective in closing a symptomatic PDA compared to placebo or no treatment in preterm infants. Evidence is insufficient regarding effects of indomethacin on other clinically relevant outcomes and medication-related adverse effects.