One recent publication initially looked very interesting from the title, Vesoulis ZA, et al. Empirical estimation of the normative blood pressure in infants <28 weeks gestation using a massive data approach. J Perinatol. 2015. Unfortunately the authors interpretation of ‘massive data’ is to collect huge numbers of samples of blood pressure numbers from a very small number of babies. They initially included 62 infants in the study, but then excluded 17 owing to inotrope use, 6 due to high-grade intraventricular hemorrhage, and 4 because they died. Leaving 35 babies.
The authors seem inordinately proud of the fact that they had 11.9 million data points, but those data points are so numerous because they collected data every 2 seconds.
Just think if they had collected at 2 kHz instead they would have had 40 billion data points!! Maybe they would only have needed 10 babies, then they would still have had a billion data points.
Obviously collecting BP data from a very small number of babies is likely to mean that you won’t have the power to see any effects on BP of gestational age; eliminating all the babies who were treated with inotropes is likely to worsen this effect, as the babies with the lower blood pressures will be eliminated, so you are likely to be left among the most immature babies only those who had higher than average BP. Therefore it is not surprising that the authors state that GA and birth weight were not associated with BP.
Let’s get this straight, because a massive data approach, that is, analyzing BP data collected electronically from large numbers of babies, could actually be helpful. But it is the number of babies that is important, not how often you read the BP from the monitor.