Insulin profiles are inconsistent with manufacturer data and do not respect the low level setting for duration of insulin action time

[ana0]

I recently switched to Novorapid in pump (from Apidra in pen) and have set up xdrip to use multiple insulin profiles in the first days of treatment. I have also continued to enter boluses in xdrip. Both my pump and xdrip have a duration of insulin action set at 4 hours. But I've noticed a few inconsistencies

• xdrip shows a much lower amount of insulin on board then the pump. Looking into the code, I see the Novorapid profile is set for max duration of 3 hours (here), but the manufacturer data sheet says "The maximum effect is exerted between 1 and 3 hours after the injection, and the duration of action is 3 to 5 hours" (here) - so I'm curious how the 3 hour max duration was arrived at?
• in my low level predictive simulation settings, I have my insulin duration of action set as 4 hours (same as my pump) but this appears to not be used/not taken into account when entering a specific insulin. This seems likely to be unclear to users (it definitely was to me)
• the duration of action for Apidra and Fiasp is much longer, 5 hours - this is a fine number in and of itself, but when you take into account that Novorapid is set at 3 hours, it becomes inconsistent with published comparisons (for example this one, under Pharmacological Properties then Pharmacokinetic Properties)

I really like having a reliable calculation for insulin on board in xdrip and use it to make choices about activity levels, snacking, etc. I realize I can enter any type of insulin I want, or not use the multiple types/profiles, so there are work arounds - but I think the way this is currently set up is confusing, and likely leading to unreliable insulin on board numbers for some users

[Navid200]

I don't use the xDrip's predictive simulation and don't enter carb or insulin. I am saying that upfront so that it is clear I have no experience with the function.
But, I am working on addressing the requests that I can.

I have suggested in the past that we change the insulin setup such that the user would have only 3 insulin types. But, they all would be custom. So, the user would get the option of setting them exactly as each works for them. I say this because my understanding is that what you see published from a manufacturer is only based on statistics gathered from different users in a trial period. But, each insulin affects each person differently. So, the manufacturer publishes the average that is the closest to the most users. But, there is no way to expect a profile would exactly represent how the insulin affects you.

If we allow each user to customize their insulin profiles, we will provide the ability to each user to have the impact of insulin represented perfectly for them.

The problem with that is that if someone makes a mistake, it could lead to a disaster! So, that suggestion has pros and cons and it may never go through.

In the meantime, if someone opens a submission to improve any existing insulins to better match what is published by the manufacturer, I'm sure it will be reviewed and I hope it will be approved. Although, I cannot guarantee that last part.

As this is really outside my experience zone, there is no way I myself would open a submission for this.
But, I am going to tag someone who may if they have time and interest.

@TheConen

[ana0]

Thanks for getting back! The current set up is also causing problems for users. I've taken several correction boluses in the last few days that turned out to be ill-advised, because I still had insulin on board that was not showing in xdrip

I'd be happy to make a quick correction to the Novorapid profile, considering I've spent some time reading about it recently, provided there is community blessing

I personally like the idea of fully customizable presets, but also agree it would add a lot of complexity and need to be thought through as a feature. But in terms of making the current functionality more clear to users (that the low level duration of insulin setting doesn't override the insulin presets) smaller changes could be something like 1) some simple text that says this 2) (more opinionated) disabling the duration of insulin action input when the multiple insulin types option is turned on

[Navid200]

If you open a submission, I promise it will be reviewed. I cannot promise it will be approved. But, the first step is to have it reviewed.

A problem with this to keep in mind is the impact on users. When a change is made to xDrip, depending on exactly what the change may be, it could have serious results affecting users. Let me say in a very crude way this: If users have already got used to a wrong profile and have got used to it as is, if we change it, they may get confused!
So, I am just stating that so that you are aware what questions may come up during the review.

You will need to show that the error is significant and that it is not just a matter of opinion between different sources. I mean it will not help if there are different contradictory sources.
A question that could come up is why was this profile set the way it is to begin with? Is there possibly another reference that claims that our current profile is actually correct?

I won't be the one reviewing. I'm just proving info hoping to help.

It may also help if you look at previous PRs related to insulin profiles.

[ana0]

Got it, yes if a PR is the preferred place to discuss this, I can open it up there. I will also look through the commit history related to these presets