An interesting question without a good answer is my initial reaction. But why do I say this? Well, if we take the NICE guidance at face value, it says the following about Continuous Subcutaneous Insulin Infusion (pump therapy):
In summary, there is little evidence from the RCTs of a significant difference between CSII and MDI therapy in terms of a decrease in HbA1c levels or in the rate of severe hypoglycaemic episodes in people with diabetes mellitus. Observational studies show a much greater improvement (decrease) in HbA1c levels with CSII therapy, as well as statistically significant decreases in the rate of severe hypoglycaemia episodes. There is no clear evidence of any greater benefit of CSII over MDI therapy in pregnancy.
Or in other words, when observational studies of pump users are undertaken, observational bias dictates that because they are being watched they get better results.
For CGM systems, NICE has to say the following:
The model showed that testing 8 or 10 times a day are the optimal strategies as they improved outcomes (reducing HbA1c level) at an acceptable cost compared to testing less frequently. The CGM strategy was never cost effective compared to SMBG 10 times even when its cost was decreased by 30% and the decrease in HbA1c was assumed to be calculated against SMBG 10. This is because of the high ongoing cost of CGM which is never offset by its effectiveness.
And a helpful table to show what happens:
Which basically says that finger pricking 10x a day is more effective than CGM, however…
Hypoglycaemic event rates were not obtained from our clinical data as they showed counter-intuitive results (the higher the frequency of SMBG testing, the higher the hypoglycaemic events); this was explained by the bias inherent in cross-sectional studies where patients who are more at risk of hypoglycaemic events are more likely to test more frequently (there is an inverse relationship between cause and effect).
Now this is interesting. It basically says that the discomfort of finger pricking ten times a day results in better Hba1C results than CGM and more hypos, but fails to recognise that the majority of users don’t finger prick ten times a day because it is uncomfortable and not always that straightforward to do so and that the likelihood is that the number of hypos on CGM is likely to be lower due to the ability to identify them before it happens. A slight flaw in the model in my view.
Hba1Cs are taken as the measurement standard as there is strong evidence that reduced levels result in fewer diabetic complications.
Additionally, for those who lack hypo awareness:
In this SA, the baseline rate of hypoglycaemic events was 6 times higher (660 per 100-patient years) than in the base case analysis in a general population, while the hypoglycaemic events rate in the CGM strategy was decreased up to 0 while it was kept constant (660 per 100-patient years) in the comparator.
So the sum of these two points is that CGM shows a noticeable reduction in Hba1C, but is not considered cost effective according to NICE’s own data and that the RCTs for pumps don’t show a valid case for Hba1C reduction and yet CCGs can fund these for people who are hypo unaware or have other lifestyle problems or high Hba1Cs.
And we haven’t looked at cost…
Here’s a selection of private costs for pumps:
Roche – Accuchek Insight
Pump Kit + Meter: £2,495
Quarterly Consumables: £370
Annual Consumables Cost:£1,480
Total First Year Cost: £3,975
Medtronic – Minimed 640G
Pump kit: £2995
Monthly Consumables: £97.90
Annual Consumables Cost:£1,174.80
Total First Year Cost: £4,169.80
Note that Enlite CGM Sensors can also be purchased at a cost of £525 for 10 or £275 for 5.
Ypsomed – Omnipod
PDM Handset: £420
Monthly Consumables: £251.50
Annual Consumables Cost:£3,018
Total First Year Cost: £3,438
Note that it would be possible to replace the PDM by buying yourself a new one when the new, Dexcom integrated version becomes available some time in 2016.
Animas – Vibe
Pump Kit: £2,800
Monthly Consumables: £137
Annual Consumables Cost: £1,647.95
Total First Year Cost: £4,447.95
So, the average cost of a pump, for which there is no evidence that Hba1Cs are reduced, is in the order of £4,000.
But what about CGMs? The following are the private costs of CGMs:
Dexcom G4 (available through Advanced Therapeutics):
Start-up Kit (including Receiver, Transmitter, cables, case): £1075
Sensor Pack (4 sensors): £250
Replacement Transmitter: £325
Lifetime of sensor: Est. 2 weeks
Lifetime of Transmitter: Est 12-14 months
First year cost assuming 1 sensor lasts for two weeks: £2825
Second year cost (including replacement transmitter): £2075
Total Two Year cost: £4900
Abbott Freestyle Libre:
Start up kit: £138
Sensors: £48 per sensor
Replacement reader (if you lose/break the original): £48
Lifetime of Sensor: 14 days
First year cost: £1290
Second year cost: £1248
Total Two year cost: £2538
Abbott Freestyle Navigator CGM:
System Kit (includes transmitter, receiver, skins and cables): £950
Sensors (6 sensors): £288 – if purchased in bulk, 18 per time, 10% discount applies
Replacement Transmitter: £400
Lifetime of transmitter: 1 year
Lifetime of sensor: 5 days
First year cost (assuming sensors bought on monthly basis): £4694
First year cost if able to afford bulk buying: £4060
Second year cost: £3856
Second year cost if able to afford bulk buying: £3510
Total Two year cost (assuming no bulk discounts): £8550
Discounting the Navigator, which is spuriously expensive, the cost of CGM or FGM for two years is around the same as that of a pump for one year, and remember that the pump has not demonstrated any reduction in Hba1C in RCTs, whereas the NICE evidence suggests that the CGM has. We can also see that in those lacking hypo awareness, there is a clear improvement (and associated removal of cost for hospital admissions or ambulance call outs as a result). It is therefore fair to deduce that the number of hypo incidents amongst hypo aware people using CGM would also be reduced.
So what do I take away from this? Simply put, CGM is cheaper than a pump and shows a meaningful reduction in Hba1C but can’t easily be obtained through the NHS. A pump however, shows no real benefits and is much easier to obtain. NICE has this entirely the wrong way around…
*All quotes in italics in this post plus the table are taken from the NICE Update to the Diabetes Guidelines Appendices: https://www.nice.org.uk/guidance/GID-CGWAVER122/documents/type-1-diabetes-update-appendices-h-u2