I've never used expired CoaguChek XS strips. I don't know if the expiration dates were made to maintain test quality, or more as a method for ensuring continuous sales of strips. I really don't know. I'm not sure that, at $2 - $2.50 a strip (when you can get 'fresh' strips for about twice the cost), it's worth taking the risk. (That said, if I used an XS and couldn't afford non-expired strips, I may give them a try. If I had current strips, and could order the expired strips, I might do parallel tests and see if the results match).
Someone on this forum said that InRatio strips are good for a year after the printed expiration date. I was able to get some that had expired, and the results seemed to still be accurate.
When buying expired strips, even though they aren't supposed to require refrigeration -- I suspect that the strips STILL need to be kept out of extreme heat. If the strips were stored in a hot car or truck, or in a trunk or glove box, or even subjected to some really hot summer days, the reagents could, possibly, degrade.
I don't know if the CoaguChek XS would even accept expired strips - the code chip may have some kind of date code, and the only way the meter would allow you to use the strips is to change the date on the meter. The InRatio doesn't seem to have the capability of knowing when a strip is expired. You may just have to trust quality control on the strip (but that, too, could possibly be degraded over time).
When I used the ProTime meter, the strips required refrigeration and weren't supposed to be kept out of the refrigerator for more than a few days. A date code was printed on the cuvette (their word for strip), and it the meter detected an expiration date, it wouldn't accept the cuvette. I was able to get around the problem by resetting the date on the meter, and the cuvettes seemed to work accurately.
But - in answer to your question about the CoaguChek XS -- I really don't know. Even if the meter allowed you to use expired strips, is your life worth the $2-2.50 that you save? (And, again, if you can buy just a few strips, and test them against strips that are current, maybe the risk is minimal or non-existent)
