Randomized trial questions superiority of insulin pumps over injections in children
medwireNews: Insulin pumps and multiple daily injections (MDI) deliver similar glycemic control and safety profiles when allocated alongside education and support at the point of type 1 diabetes diagnosis, say researchers.
Insulin pumps were considerably more expensive, however, making them not cost effective in this context, the team reports in The BMJ.
Study co-author John Gregory (Cardiff University, UK) told medwireNews that previous evidence for pumps being more effective than injections was “mostly of a fairly anecdotal nature” and the team suspected this could be influenced by patient treatment preference and the extensive education they receive when they switch from MDI to pumps.
“I’ve certainly had experience in recruiting for trials and finding that one of the major drivers for people wanting to be recruited is the perception that it will get them access to the treatment,” said Gregory. “It suggests that these individuals are very highly motivated and likely to derive benefit if they’re lucky enough to be randomized to the intervention arm.”
The investigators tried to minimize the influence of both factors by recruiting children at the point of diagnosis, when all families require extensive education and support and may have not yet developed strong treatment preferences. Nonetheless, a majority still expressed a preference for pumps, with 92% of parents/carers assigned to the pump group saying they had received their preferred allocation, compared with just 28% of those assigned to the MDI group.
Nevertheless, the team found the between-group differences in glycated hemoglobin (HbA1c) level to be “small and unimportant” after 1 year of treatment, at 60.9 versus 58.5 mmol/mol (7.7 vs 7.5%) in the 143 pump users versus the 142 MDI users, for an adjusted mean difference of 2.4 mmol/mol. This was despite people assigned to the pump group using significantly more insulin, at an adjusted average excess of 0.1 units/kg per day.
However, Gregory stressed that “we’re not saying that the findings after a year mean there is no benefit of changing to a pump in a highly motivated individual who’s already got several years of diabetes knowledge and experience under their belt when they change over. We have to be careful that people don’t over-interpret the findings.”
He said: “I guess what we were more interested in was what was the sort of advice that I should be giving to a family in clinic who are fairly ambivalent about whether or not they should go onto a pump […]
“I think most of us attempt to provide clinical care along a model that the families wish to work towards, and so when a family comes knocking at my door saying ‘we want to go on a pump’ you’d be daft not to try and support them to do that, because you know that if they’re highly motivated to follow a particular pattern of treatment they are more likely to do well.”
But for families with no strong preference, Gregory says the trial findings support physicians in telling them that they should do as well with MDI as with pumps if they engage in the diabetes education, and that the decision to move to a pump is something “that we can think about once you’ve got used to diabetes and you’ve developed a sense of how you want to manage the situation.”
The numbers of severe hypoglycemia and diabetic ketoacidosis events were low and not significantly different between the pump and MDI treatment groups (six vs two and two vs none, respectively).
The participants were aged a median of 9.8 years at the time of recruitment, and 47.8% were female. Of note, only around 50% of trial participants achieved the HbA1c target of 58 mmol/mol (7.5%), and only 15–20% achieved the more stringent target of 48 mmol/mol (6.5%).
Gregory observed that this is a possible weakness of the study, saying that the UK healthcare system currently does not “perform terribly well compared with some other European countries, and it may be that in these countries you would see different and better outcomes” for insulin pumps versus MDI.
To which he added that healthcare professionals in the UK have more experience with pumps outside of the clinical trial setting than they did when the trial was initiated, meaning they may now get better outcomes with pumps.
But Gregory stressed again the importance of distinguishing the benefits of the technology from the benefits of the accompanying intensive education, particularly given evidence that lower-income families are less likely to be given insulin pumps.
Education and support can be easily delivered to all families, he said, whereas “if there is in fact a benefit from technical aspects of the pump then we need to rethink the availability of this not inexpensive technology across the whole population we care for in pediatric diabetes services.”
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