Continuous glucose monitoring (CGM) is proving popular with families and young people with diabetes but is yet to deliver significant improvement in HbA1c or hypoglycaemia episodes despite all the government investment.
A survey of 55 patients and family members from the Royal North Shore Hospital’s paediatric diabetes and transition clinics found both parent and child fear of hypoglycaemia reduced significantly in the three months after CGM uptake.
High expectations before CGM were largely met with high satisfaction scores on follow-up. Participants also rated the usability of CGM highly despite some technical issues.
They indicated they were likely to continue using CGM although some concern was noted regarding the prospect of no financial subsidy beyond age 21.
The study found mean HbA1c moved in the right direction with CGM, from 8.7% to 8.3%, but the improvement was not significant. Instead there was a small but significant increase in total daily insulin dose from 0.74 to 0.81 units/kg/day.
There was no significant difference in ketosis or severe hypoglycaemic episodes over the short follow-up interval.
Coauthor of the study and paediatric endocrinologist Dr Shihab Hameed told the limbic it was likely that glycaemic control would improve over time.
“Use of CGM allowed patients and families to deliver more insulin which therefore will result in better glycaemic control, with HbA1c already trending down in this small cohort.”
Impact on staffing
But the CGM roll out came at a significant cost to the diabetes service.
The study estimated the time staff spent providing group education for CGM, reviewing sensor data, in lengthier consultations with family and additional administration to be about 7.7 hours per patient per year.
“We anticipated an increase in staffing requirements and that was borne out. When insulin pump consumables became subsidised on the NDSS, there was a large increase in insulin pump uptake across Australia and similarly with the CGM roll out for people under 21 we anticipated a large increase that was also borne out. It was useful to document the increase workload associated with that,” Dr Hameed said.
He advised colleagues that increased hours from the diabetes education teams should be factored into departmental plans.
“Initial CGM education involves looking at the CGM results and adjustments. One area that needs to be studied going forward is the advanced CGM features such as the trends and how to respond to that.”
Professor Fergus Cameron from the Royal Children’s Hospital Melbourne told the limbic the lack of a significant difference in HbA1c or hypoglycaemic episodes was not surprising.
“It’s not surprising when you look at the published medical literature – the outcomes of CGM usage are really variable.”
“There is some data from Perth again showing CGM made no difference to clinical outcomes but reduced parental anxiety so if there are any benefits they seem to be realised by the parents rather than the children.”
“There are people who would say we should weigh quality of life issues equally with more traditional clinical outcomes but the QOL outcomes are all parental not in the children.”
Opportunity cost of CGM
The findings raise the question of whether the Federal Government’s $54 million could have been better spent elsewhere especially when the funds only paid for devices, not education or other resources.
“So there was an opportunity cost – resources dragged away from other things that arguably could have been more effective in improving clinical outcomes,” Professor Cameron said.
He added that others – as reported here in the limbic – have also voiced concerns about the implementation of new technology over staffing and the impact on outcomes.
“And people’s resources are incredibly stretched. There is another article in the Journal of Paediatrics and Child Health showing just how under-resourced paediatric endocrinology care is here compared to the rest of the world.”
On the flip side, he said there was some merit in the argument that CGM was inevitable.
“The proponents of CGM would say CGM is an inevitable technology which we have to have to come to terms with because we are moving to closed loop insulin systems and half of that closed loop system is a CGM.”
He said better targeting of CGM to patients who would use the systems most effectively might be helpful.
“There are a number of demographic and behaviour variables that will predict who is going to use these systems effectively and then you can be targeting but that is not the way it [the CGM program] has been set up.”