I'm currently using the Freestyle Libre but am looking into Dexcom so I can use the alarms. Can anyone tell me what the difference is between the G4 and G5?
I see that the G5 works out as more expensive but does it have extra features or better accuracy to make it worthwhile?
Is G5 supposed to be a replacement for the G4? i.e. will the G4 eventually not be supported / available?
Any advice much appreciated
Having now used Dexcom G4 with xDrip, Libre, Dexcom G5 and Medtronic Enlites, I think I'm in a reasonable position to comment here.
For me, The Dexcom G5 and the Medtronic Enlites with Guardian 2 (Updated) transmitter (which appeared in the summer of 2016) are by far and away the most accurate. I achieved numbers that were typically within 9% of my blood glucose tests using those, although the Dexcom G5 remains in line more often. even if you are 12 hours late calibrating. The Enlites needed to be calibrated every 12 hours or the 640G stopped using the data.
For me the Libre and Dexcom G4 were similarly out from the blood tests, hitting the heady heights on average of around 12%.
There is some research showing that if you are going to bolus from the data, being less than 10% out is generally okay. As a result, the FDA and EMA have signed off bolusing from G5, which isn't something that's been done with any other CGM or CGR system.
It's reasonable to assume that access to G4 will start to become restricted sometime soon, simply because the G6 is in the offing and Dexcom have already announced that there is to be a reduction in size of the G5 transmitter (by 50%). With the G6 slated for launch in 2017 in the US, I'd anticipate that it will shortly only be possible to get G4 supplies through the pump suppliers that use G4.
In terms of longevity of the sensors, the best I've managed is 29 days on a G4, before the data got truly messy. On average I was getting about 21 days. G5, due to the algorithm difference in the transmitter, I find the data quality drops off and I get a lot of poor readings/loss of sensor errors at around 14-16 days.
The best I got out of the Enlites was a 12-day run, but typically I got 8-10 days.
All of them get less accurate as time goes by. The other thing to mention is that if you use xDrip on an Android phone, you can use G5 with it (but not all phones work) and people have got 5 months out of a transmitter. My G5 transmitter comes to the end of life on the official app this week so I'll be testing that out shortly.