Neonatologists can be said to have invented “Outcomes Research”, the systematic evaluation of patients after an acute-care event. It is a field of research which has now been extended from early infancy into the adult period and provided enormous insights into what happens to babies who are born very preterm. When the field was developing there were concerns about how our patients would fare when their brain development had been interrupted by preterm delivery, often accompanied by serious illness, and sometimes major complications, surgery, and brain injuries seen on CT scan or ultrasound. As a result much work has concentrated on neurological examinations and developmental screening tests, partly to evaluate and describe outcomes, but also to ensure that chlidren received any interventions they might need with minimal delay.
The major question that we need to ask now is: what outcomes are most important to parents? One serious problem with our outcome research had been the attempt to categorize infants into “normal” and “abnormal”. This has been driven by the appropriate concern that our NICUs should be aiming for not just improved survival, but for improved “intact survival”. That is a term that I have heard many times, but it requires some thought; what do we mean by intact? And who decides what is an acceptable outcome?
I have written many times on this blog about the problems that arise when we decide that a Bayley score at 18 to 24 months of age below 2 SD below the mean is an adverse outcome, whereas a score of 1.9 SD below the mean is a good outcome, even when the child has a serious behaviour disorder. This arbitrary and artificial dichotomising of the whole of child development skews the literature, and has impacts on how we care for babies.
What we measure matters also because we use the results of outcome studies in our counselling of parents regarding the institution and continuing of active NICU care. (Weiss EM, Kukora S, Barrington KJ. Use of composite NICU research outcomes for goals of care counselling creates ethical challenges. Acta Paediatr. 2021) Data which are collected in order to describe outcomes are then used to determine whether babies should be allowed to die without active intervention.
In this post I will not be concentrating much on how the artificial dichotomising of child development skews research design, even though that is a major problem. Because it is easier to design studies with a dichotomous composite, where death and “NDI” are given equal weight, and the answer to whether a treatment is better than another is supposed to them be yes or no, based on the impact on that composite outcome.
In everyday clinical practice we (as health care professionals) really want to know whether treatment A decreases death compared to treatment B, and if not, what are the relative impacts on developmental progress, pulmonary development, neurologic impairment, etc. But what do parents want to know? I think we can be sure that parents would want to know if one treatment compared to another affected mortality, but beyond that, what outcomes are really important to parents? What are their relative importance? What kind of adverse outcome would be enough to outweigh an improvement in survival?
Personally, I would be surprised if a group of parents cared whether their babies’ Bayley scores were more likely to be above or below 70.
A group of collaborators from my hospital have just published an article reporting a study (which is part of the Parent Voices Project) where parents were asked their opinions about the progress of their extremely preterm infants. Jaworski M, et al. Parental perspective on important health outcomes of extremely preterm infants. Arch Dis Child Fetal Neonatal Ed. 2021:fetalneonatal-2021-322711. This was a group of parents with 213 children aged from 18 months to 7 years of age, less than 29 weeks gestational age. Children are routinely followed until 36 months corrected age, and then some are discharged if they are doing well with normal developmental progress and the parents have no behavioural concerns, which means that the older children in the cohort tend to be those where there are some issues that need following. Overall there were 55% of parents who had some concerns about their infants developmental progress, including an 18% who had concerns about behavioural and emotional issues. Parents of the 53 infants identified as having “severe NDI” (defined as a motor, language, or cognitive composite score <70 on the Bayley3, or cerebral palsy with a GMFCS of 3,4, or 5, or needing amplification or being visually impaired in both eyes), were only slightly more likely to have concerns about the development of their infant than the 82 without “NDI”. Growth, feeding and respiratory concerns were similarly represented among the subgroups. Mothers and Fathers had similar concerns and there were no substantial differences by gestational age group.
Of the issues that matter to parents, the quotes suggest that it is really the child’s functioning that they worry about (‘I wish she would express herself more clearly’), whereas scores on standardised tests were never mentioned! Of course, if those scores help to identify infants who would benefit from intervention, then they may be of value to the individual. If they, overall, reflect the function of the group then they could be a reasonable way of summarizing outcomes. But behavioural/emotional development is very rarely mentioned in outcome studies, despite the major importance to many parents, nor are feeding and growth commonly reported.
This project says to me that we should systematically describe and report behavioural, emotional, feeding and growth outcomes in our follow-up studies, and in the follow-up of our RCTs in extremely preterm infants. Those things concern parents just as much as developmental delay, and have impacts on the families similar to other things that we describe routinely.
As a parent myself of an extremely preterm infant, perhaps I can allow myself, for this first post of the new year, to give my opinion of what outcomes matter. My daughter indeed had her standardized tests, administered by a friend and colleague in the McGill University follow up system (Dr Elise Couture). I was rather uninterested in the results of those tests, I don’t even remember if she “passed” or not. I knew she was progressing, was learning new skills, and had behavioural issues that were not out of the ordinary. She had feeding issues that were more disruptive than any problems with cognitive development, and when she got to school had some issues with her learning style, of an executive function type. With the dedication of her mother, in particular, she was able to progress through school, and is very soon to graduate from high school, at which she works extremely hard. For me the most important features of follow-up were to know whether there were any specific therapies that could help to make her life easier: Did she need physio? Would speech therapy help? How could we best assist her learning pattern? Her ENT problems and pulmonary development were also of major interest, and fortunately she didn’t have any major hearing or vision problems needing intervention, other than spectacles. I try to imagine what my attitude would have been if she had turned out to have a Bayley MDI (she did the version 2) score <70. I can’t imagine Annie or I would have treated her any differently, and the idea that having a low Bayley score would have been the same outcome as her being dead, I find offensive.
On the other hand, evaluating, and finding a way to summarize, the developmental progress of our patients is worthwhile, having a more robust development, more similar to babies born at term would be a good thing. A more detailed description of outcomes, including average scores and the spread of scores, on standardized screening tests, would give a more useful picture of the outcomes of our patients than just the proportion of babies below various thresholds. More information about what outcomes matter to parents should help us to design follow up programs that respond to their needs.