Monday 12 March 2012

iBGStar Review - blood glucose meter for iPhone / iPod Touch

I was delighted to be invited in January 2012 to be one of the first people in the UK to use and review the iBGStar - a blood glucose meter by Sanofi Aventis designed to work with an iPhone or iPod Touch. The agency that sent me the meter and asked me to provide feedback prior to the UK launch and swore me to secrecy until today, when it becomes available for purchase in Boots. I was provided with an iBGStar and a supply of strips free of charge, and I've not been paid to write this review or say anything, good, bad or otherwise - what follows is just my opinion after a few weeks' use. To save my fingers I'll lazily just be saying iPhone from now on. If you've got an iPod Touch you'll need to do a little mental inline editing.

I should start by saying that I reeeeeally wanted to like this meter right from the outset. The designer in me has long had a love for that fine fruit-based technology company. I've been logging all my BG results on Apple products for years and the idea of a meter which plugs straight into an iPhone or iPod Touch has immediate appeal.

First impressions
The first thing you notice is that it is absolutely tiny! There's also a pleasing 'Apple' influence to the general design. The shiny curved edges on the front, the smooth nicely shaped matt-finished reverse side and, perhaps nicest of all, the fact that the on-off 'button' is seamlessly built into the front fascia of the device. The designers have also bothered to build-in a nicer-than-expected screen on the front of the meter which displays results and a small animated prompt during BG tests which means that it is perfectly possible to carry out a test whether the meter is connected to your iPhone or not (handy if, for example your phone ran out of charge when you were out for the day). First impressions? Even before I'd got a strip out of the pot - this is going to be amazing.

How small is small?
By my reckoning it's about 55mm by 24mm (including the dock connector). Everything about this meter is smaller. The strips are smaller, the pot they come in is smaller. The supplied finger pricker (more about that later) is small too. The supplied black zip-up case is perhaps 50%-60% the size of a standard Roche Accu-Chek one and maybe 70% the size of the case for the Contour-Link meter that works with 'Artoo' my pump. If you took the strips, fingerpricker and iBGStar loose in a coat pocket they would take up very little room. The iBGStar aligns well with the width of my iPhone4 and is just slightly narrower than my 1st Gen iPod Touch. Of course you don't keep it connected to your mobile device the whole time, and with another nice touch they provide a small cap to cover the dock connector which doubles as a little clip to secure the meter and stop it getting lost in the bottom of a pocket or bag if you take it 'loose'. The advantage of this tininess, of course, is that it makes it much less hassle to take your meter with you. And you don't have to worry about all the careful logging etc when you are on the run, unless you want to. The iBGStar can be used perfectly well on its own and will remember and allow you to refer back through several readings on the device itself (it stores 300). When you have a bit more time you can sync with your iPhone and add any insulin doses/carbs/notes to keep your records up to date. If you were having a period of lazy no-logging the 'unplugged' iBGStar helpfully displays an average figure when first turned on allowing you to keep a general eye on things. To get the most of the meter though, you'd want to download and use the iBGStar App.

The iBGStar App
Downloadable free of charge from the App store, compatible with iPhone, iPod Touch and iPad. Requires iOS3 or later. I haven't tested any iCloud-based shenanigans for people with multiple devices, so I cannot confirm or deny whether the iBGStar App would allow you to use several devices concurrently. Having taken a while to find a logging app that suited me I was a little worried that the iBGStar app might be a bit clunky, but was pleasantly surprised. Data entry is slick and easy and individual records consist of tabbed 'cards' which can be flicked through on the home screen. Easy enough to add and edit things like insulin dose and carbs eaten, while a series of 'notes' can be added from a prepopulated menu of food/exercise/dose/meds/general. There are some pretty sensible entries already there 'ate fatty food', 'light exercise' and so on, but you can edit and amend any of the pre-defined choices to make the app work for you. You can also add any extra ones that you might find helpful. There are some other sweet personalisation touches too. For example you can choose the 'background theme' to the home screen from six choices (cityscape, beach, forest...) and as you flick through the result cards watch the sun rise, set and the stars come out depending on the time that the BG reading was taken. I liked the zoomable 'scatter graph' in the data analysis section too, which colour-codes readings above and below the target range you specify. You can also view averages, numbers of tests and even Standard Deviation (how raggedly spread out or tightly packed your results are) over 7, 14, 30, 90 days or a custom range. Critically it is also very easy to email-out the results data, including all notes, carbs and doses for printing and waving in front of your Doctor or DSN. The only tiny quibbles I had with the app were that it did not allow fully pump-friendly dose recording (Artoo does meal doses to two decimal places, the iBGStar App only allows one) and the 'logbook' view is a bit limited showing BG results only - with the 'expanded view' being particularly useless and simply showing the same BG data a bit more spaced out rather than revealing data for doses, carbs etc.

Taking a test
The supplied finger pricker is er... a bit flimsy. It's servicable enough and at least has a variable depth setting, but lacks the smooth solid action of my Accu-Chek MultiClix and has a slightly worrying, plasticky, 'cracker novelty' feel to it. It stayed in the box. The sample size is a modest 0.5 microlitres, strips don't need coding and results take around 6 seconds. One slightly surprising irritation was that the strips felt like they were the 'wrong way round' in the pot. Unlike any other meter I've had the 'sample' end of the strips for the iBGStar are not the end that you grab hold of, so each time you get a strip out you need to turn it around before pushing it into the meter. The strips themselves are also a fairly uniform black so it's not always immediately obvious which end is which. There is a tiny notch in the 'meter' end, but in low light and for overnight tests this was a full 'lights-on' meter. I also found it slightly tricky to apply the sample in that the finger-to-strip alignment seemed to need to be a bit more precise, and the strips themselves a little less 'slurpy' than other meters I've used. If you use the meter plugged into your iPhone and with the iBGStar app running you get a little swooshy animation on the phone screen after the 'apply sample' prompts. I preferred to use the meter separately and then plug it in to sync data and log meal and/or other details. The iBGStar has a rechargeable battery and is supplied with a mains charger or can be charged via computer USB port. I have a fairly intensive testing schedule but a full charge still lasted my me a good two or three weeks. Helpfully the iBGStar begins to show remaining charge as a percentage once you have dipped below 50%.

Accuracy
So far, so good. If I were finishing the review here it would be a straight 4.5 stars. Unfortunately though I have a nagging worry. Quite by chance, when I was asked to review the iBGStar I had recently switched from an Accu-Chek Expert to a ContourLink (the latter sends results to Artoo via bluetooth). When I switched between those two meters, out of interest I did a couple of tests between the two. Now I had three meters on the go, and strips for all of them, so I did a few random tests across them all. Now at this point I must absolutely stress that these tests are in no way 'properly' scientific. The sample size is one - me. I do not have access to any lab results for any of the blood samples so I can never know which of the meters, if any, was ever giving a truly accurate result. All meters are permitted to have a 20% variation from a lab result (there's a whole blog post right there) so any result could be a bit high on one, a bit low on another. All I can say is that I got a larger-than-average drop of blood, stuck a strip into all three meters, tested and compared the results. To begin with it was all hunky-dory. But then I noticed a test where the iBGStar read quite a bit higher than the Contour. A few more tests followed and by and large the Contour and Expert were closer together, the iBGStar almost always higher. And the higher the level, the more extreme the variation. As a pattern I actually liked that predictability. I know people who find their correction doses less and less effective as their BG rises. A meter that reads a little higher at higher levels could be ideal - set the correction factor appropriately and you would automatically get a more effective correction when you needed it. Sadly though I soon found the results that broke the pattern. Results with larger differences at lower levels, and results will almost no difference at higher levels. I mentioned this in my 'feedback' to the agency who had sent me the iBGStar and had fantastic customer service experience from Sanofi Aventis who sent me a new meter along with some control solution and asked for the old one back so that they could have a look at it. I've not heard whether they found anything, but the results with the new meter (which passed the control solution test) are very similar to the first.

Once I had the replacement I spent a couple of days cross-testing the three meters just to double check before I mentioned this experience here. There were 22 tests taken over a 2 day period including before and after meals, before and after exercise and overnight. For what little they are worth here's what I found when I looked at the results:

  • In general terms the iBGStar read the highest averaging 8.9mmol/L (160mg/dl) and the Contour the lowest averaging 7.7mmol/L (139). The Expert averaged 8.0mmol/L (144).
  • The average difference between the iBGStar and the Contour was +1.29mmol/L (+23mg/dl)
  • The average difference between the Expert and the Contour was +0.35mmol/L (+6mg/dl)
  • Notwithstanding the official 20% 'acceptable' variation, I consider +/-0.5mmol/L (9mg/dl) to be a better indication for my own purposes of whether or not readings are 'more or less the same'
  • Only 18% of results between the IBGStar and Contour were within 0.5mmol/L
  • Between the Contour and Expert a much more respectable 73% came within 0.5mmol/L (with more than a quarter of results coming within 0.2)
  • As soon as differences between meters reach +/-1.5mmol/L (27mg/dl) it begins to make a difference of almost half a unit on an insulin dose or correction for me. An extra 0.5u when I don't need it could even risk dropping me into a low level hypo
  • Over the 2 days 37% of readings on the iBGStar were 1.5mmol/L or more higher than the Contour
  • There were no readings that showed that much variation between the Contour and Expert. None.
  • The single worst difference was 10.5mmol/L (189) on the Contour vs 15.8mmol/L (284) on the iBGStar - a difference of 5.3mmol/L (95), that's more than 50% of the reading - the Expert read 11.2 (202).

Again I must stress that these are just my own not-very-scientific results. I have no idea which results, if any, were the 'real' ones, but the variation in the iBGStar and the lack of variation between Contour and Expert cast a shadow of doubt over the iBGStar for me. It may just be something to do with my blood chemistry and the iBGStar's strips - I have no idea. I may be the only person in the UK who would find this variation.

Conclusion
I really like this meter. It's small, nicely designed. The app is great, very easy to use and ticks almost all the boxes for me. I successfully used it on its own for a week and a half, even after I had noticed its tendency to read a little high. I simply reduced my 'usual' correction factor to take into account the possibility that the meter might think I'm higher than others I have used before. At the end of the day BG meters for use at home are only ever going to give you a general guide as to your levels. If you read the small print in the handbooks they never pretend to do anything else. Back in the real world though, I do need my meter to perform as consistently as possible. If it's going to have a quirk, that's fine - but it has to be a reliable quirk. My life 'playing at being a pancreas' is full of enough variables without adding another into the mix. I'm sure the iBGStar will work well for many people - unfortunately I'm not one of them.

Final score: 3/5

UPDATE: Sanofi checked the first meter and gave this response.

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