eLetters

71 e-Letters

published between 2018 and 2021

  • Response to Comments on the analyses and the generalizability of findings from the Economic Evaluation of SIFT

    We thank the authors for the comments on the Economic Evaluation of SIFT (1) and we are grateful for the opportunity to respond to their comments.
    Taking each of the authors’ points in the order in which they are presented:
    1. In relation to the first point about the loss to follow up and the exclusion of such patients from the analysis, we point out that we used complete case analysis and accounted for the missing patients following best practice using a multiple imputation analysis which is provided in the supplementary materials. We state the following in the paper:

    “Mean total costs for all infants, adjusting for missing data using multiple imputation, are found in the online supplementary table S3. When the missing values were accounted for, faster feed increments remain more costly in comparison to slower feed increments but at a slightly higher level (£378 more) per infant, reflecting the high level of uncertainty in the difference in costs, especially with regard to the healthcare resource use after discharge estimated by the multiple imputation” (last paragraph of methods))

    2. In relation to the authors second concern, whilst death was slightly higher in the slower feeds arm during initial hospital stay there are two important points in response to this. First, we clarify that by definition economic analysis is not an exercise in accountancy where death is assumed to incur a zero cost, because economic evaluation focuses on costs and ou...

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  • Comments on the analyses and the generalizability of findings from the Economic Evaluation of SIFT

    I read with interest the economic evaluation of Speed of Increasing milk Feeds Trial (SIFT) in preterm infants presented by Tahir and colleagues.(1) While the clinical findings from the SIFT had shown short-term benefits such as lesser TPN days with faster feed increments, and was equivocal for the composite primary outcome of death and disability measured at 24 months, this analysis recommends against faster feed increments based on the cost-effectiveness analyses. The average total costs is shown to be marginally higher for subjects in this arm, with a mean difference of £267 (0.25%). I highlight below many issues that probably affect the conclusions, and the generalizability of the findings, of this economic evaluation.

    First, the trial enrolled 1394 and 1399 patients in the two study arms. However, the cost data of initial hospitalization is presented for 1224 and 1246 patients in these arms. It seems that 170 and 153 patients from the two trial arms were lost to follow-up after the initial hospitalization;(2) however, the data for these subjects should not be excluded while calculating the average initial hospitalization costs per subject.

    Second, more deaths during the initial hospitalization were reported in the slower increment arm and those probably lowered the average cost for this arm. It is well known that the hospitalization costs for very preterm infants that die during the neonatal period are substantially lower than those of the survivors....

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  • A reply to: “Parenteral nutrition for preterm infants: Correcting for arachidonic and docosahexaenoic acid may not suffice” by Bernard et al.

    A reply to:

    “Parenteral nutrition for preterm infants: Correcting for arachidonic and
    docosahexaenoic acid may not suffice” by Bernard et al. regarding the publication:
    Frazer LC, Martin CR. Parenteral lipid emulsions in the preterm infant: current issues
    and controversies. Arch Dis Child Fetal Neonatal Ed. 2021 Jan 29: fetalneonatal-
    2020-319108. doi: 10.1136/archdischild-2020-319108. Epub ahead of print. PMID:
    33514630.

    Lauren C. Frazer1,2, Camilia R. Martin2,3,4

    1Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA, USA
    2Department of Pediatrics, Harvard Medical School, Boston, MA, USA
    3Division of Translational Research, Beth Israel Deaconess Medical Center, Boston, MA, USA 4Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, MA, USA
    Correspondence: cmartin1@bidmc.harvard.edu

    Word Count: 216

    Keywords: arachidonic acid, docosahexaenoic acid, lipid emulsions, preterm infant

    Dear Editor,

    We would like to thank Bernhard and colleagues for their thoughtful letter “Parenteral nutrition for preterm infants: Correcting for arachidonic and docosahexaenoic acid may not suffice” written in response to our review. The authors of the letter raised important issues regarding the lack of data surrounding the optimal balance of arachidonic (ARA) and docosahexaenoic acid (DHA) that should be administered...

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  • The need for adequate methodology to study bronchopulmonary dysplasia using lung ultrasound

    In response to: "Early lung ultrasound affords little to the prediction of bronchopulmonary dysplasia".

    We read with great interest the article by Dr Woods et al (1) that adds evidence to recent, large multicenter studies on lung ultrasound (LUS) as a predictive tool for bronchopulmonary dysplasia (BPD) (2-4). These studies, performed on a total of more than 600 infants, stem from a validated scoring system whose signs represent a progressive decrease in lung aeration in standardized ultrasound views (5). Notably, this approach is also well established in adult critical care (6).
    The grading system adopted by Dr Woods and coworkers, has not been validated and its highest scores do not correspond to less air in the lung and therefore to a more severe pulmonary disease. Also, rather than the conventional sum of scores, Dr Woods et al. calculate a two-decimals mean score that may undermine the technique discrimination. None of these choices have ever been made for any other LUS scores, neither in neonates nor in older patients, despite ultrasound semiology and statistics needed to evaluate the predictive power are always the same (6). These factors may undermine the LUS prediction power for BPD.
    Moreover, the authors needed a full ROC procedure to perform a formal diagnostic accuracy analysis, but even then, its strength would have been questionable with only 7 out 96 infants suffering from moderate-to-severe BPD (7) as target condition. This smal...

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  • Visual assessment after HIE

    Dear authors, dear editors,

    Thanks for this excellent focus on visual abilities of infants following HIE.
    More than three decades ago, at a time when brain imaging of newborns with HIE was limited to ultrasound and CT scanning, we have published impairments of visual functions at an early age (Early Hum Dev 1989;20:267-279 and Neuropediatrics 1990;21:76-78) .
    We could do so using standardized, outpatient methods of visual assessment.
    Further use of this relatively simple tools could and should be part of assessments of infants with HIE, in particular when (diffusion weighted) MRI indicates involvement of visual tracts.

    With kind regards,

    Floris Groenendaal

  • Stillbirth rates should be carefully assessed, and women should not be blamed for adverse perinatal outcomes

    Stillbirths are tragic events with devastating consequences on women and couples: all efforts to better understand, manage and prevent their occurrence are welcome. Nevertheless, we have some concerns on what reported by De Curtis et al, who suggested an increase of stillbirth rate during the COVID-19 pandemic lockdown in Lazio, Italy.
    1. First, we do not believe that a crude comparison with the corresponding months of 2019 is a proper control. Stillbirths are rare events, with a variable incidence during the year and alternating phases of low incidence and clusters of cases. The assumption that in the period Mar-May 2020 their number in the Lazio region should have been the same as of Mar-May 2019 is unsubstantiated. Consistently, the incidence reported by the authors in Lazio for 2020 (3.23 ‰) is almost the same of what reported for the same region in 2019 yearly statistics (3.00 ‰) [1] in which stillbirth is defined as a loss after 180 days (25 wks + 5 days). Furthermore, when using the 22 wks definition, reported stillbirth rate for Italy is significantly higher (4.70 ‰) [2].
    2. Second, the authors suggest that the supposed increase could be due to reduced visits to hospitals due to the fear of contracting COVID-19. Unfortunately, this claim (that indeed blames women for the loss of their unborn child) is not at all supported by facts, as it wasn’t in the manuscript that the authors cite as a reference. Data from a sample of 2448 women who were pregnant or...

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  • First wave SARS-CoV-2 pandemic did not affect stillbirth prevalence.

    De Curtis et al reported some changes occurring in perinatal outcomes during lockdown in Lazio region, Italy. In particular, according to their data, preterm deliveries were reduced while stillbirth (SB) rate seems to be three-fold increased respect with the same period of 2019 (1).
    We collected the same outcomes in Emilia-Romagna (ER), a northern Italian region with 4.47 million residents. Gestational age at delivery has been obtained by Birth Certificates (CedAP) while SB occurrence was collected from the Surveillance system of SB. This system is active since 2014. It records and audits, in a multidisciplinary way, each single case reported by every birth center of the Region. SB was defined according to WHO as published elsewhere together with other details of the Audit process (2).
    In Emilia-Romagna, in the quarter March to May 2020, the one of the national lockdown, there were 22 SB (≥22+0 weeks) out of 6800 singletons births, for a rate of 3.24/1000. For the same quarter, in the previous 6 years, SB rate ranged from 2.86 (22/7687) in 2016 to 4.32 (31/7170) in 2019. According to one-way analysis of variance for 2014-2020 years, SB rate not changed significantly (p value >0.05 for each years of observation).
    It has to be highlighted that a small number of events allow to a great variations in the rates, in a phenomenon such as SB that has a very low prevalence. For this reason, a comparison of only two points as previously done (1) could lead artif...

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  • Increase of stillbirth and decrease of late preterm infants during the COVID-19 pandemic lockdown

    Ravaldi et al. in their letter raise two points of dispute. The first is linked to epidemiological data and the other to the fact that, according to them, a reduction in gynecological checks during pregnancy did not occur in the lockdown of spring 2020. I appreciate their engagement with the article but I disagree.

    On the first point (epidemiological data), the difference between the data presented by Ravaldi and those indicated by us is linked to the fact that they mistakenly refer to older years. Ravaldi’s 2019 stillbirth is taken from the Italian Statistical Yearbook 2019, which refers to the entire 2016. Our data, obtained from the CEDAP (hospital discharge database, which records perinatal information on all newborns), are instead those of Mar-May 2019 and Mar-May 2020 (3 months of lockdown).
    Furthermore, Ravaldi’s stillbirth data starting from 22 weeks were taken from the ISTAT Reproductive Health document published in 2018, which refers to 2015 data. The authors therefore cannot contest the difference in the results because they are using different data sources. A further analysis (to be published) on larger samples on all births in Lazio confirmed a significant difference between stillbirths in the period March-May 2020 compared to the same months in the years 2017-2019 (3.23 vs 1.83 per thousand, p value = 0.014) . The increase in stillbirths in the first half of 2020 was observed in numerous developed and developing countries as well as in Italy (1-...

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  • Constant or variable flow nCPAP devices.

    Dear Sir or Madam!
    Nasal CPAP is one of the most important therapies in neonatology. Accordingly, the manufacturers of such devices are very interested in gaining market share. Not all of their "sales arguments" correspond to clinical or physical reality. This is why studies comparing different devices are so extremely important.
    The authors claim to have compared three CPAP systems that are referred to as "variable-flow" devices. This refers to CPAP systems that generate their CPAP through one or more jets, corresponding to jet ventilation as it is known in laryngeal surgery. But does the Miniflow CPAP belong in this category? The Miniflow has one inspiratory and one expiratory tube and does not have a jet. Pressure is generated through the expiratory valve of a ventilator. Such CPAP devices are actually called "constant-flow" devices.
    Basically, the division into variable-flow and constant-flow devices is considered very confusing and, above all, physically questionable. However, the terms are very persistent. In any case, however, the statement of the study could be supplemented. It shows not only that there is no difference between variable flow devices, but equally no difference between variable and constant flow devices.
    Yours sincerely,
    Martin Wald

  • Blood pressure trials in preterm infants

    We read with interest results from the Hypotension in Preterm Infants (HIP) trial by Dempsey et al.1 Unfortunately this multicentre randomised controlled trial (RCT) could not provide robust conclusions. Enrolment was limited to 58 of the planned 830 infants, 7% of those screened, attributed to strict inclusion criteria and recruitment challenges. This along with high inotropic usage in the restrictive group limits study power and generalisation.
    Some clarification would be useful. The CONSORT diagram should label the two study arms, where imbalance in numbers not receiving the allocated intervention (6/29 vs 1/29) may warrant further analysis. The proportion with invasive lines seems low, exact reasons for exclusion/non-inclusion could be detailed, and maximum age at enrolment given.
    In our published RCT 2, three blood pressure (BP) intervention protocols were compared (BP below gestational age as in HIP, more active, or less active). This single centre pilot study randomised 60 infants <29 weeks, 45% of those screened and 100% of target recruitment, with invasive BP acquired every 10 seconds for a week. The HIP trial suggests their hypotension rate of 25% is low but without BP acquisition details, comparison is difficult. Their figure showing BP following dopamine or placebo requires data variability measures.
    In our study, we found higher BP was associated with lower EEG discontinuity.3 The HIP study4 did not stipulate commonly used end-organ p...

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