It's hard to say without more information. It's normal to see dead bees and some mites on the bottom this time of year but it really doesn't tell you much. Normally natural mite fall is measured over a specific period of time (24 hours, 48 hours). If you know know how many mites fell in a given period of time it would tell you more (and would even be better if you had a bit of history. ie. last month you counted 10 mites in 24 hours, before treatment it was 100 in 24 hours, etc.)

Without testing (natrual drop, sugar rolls, etc.) before and after treatment you can't really be sure the treatment worked. Apistan may have had little effect (there is widespread resistance to it) though the combination may have worked.

Unfortunately there is little you can do right now (unless you live in the south) as most of the reatments require warmer temperatures. I would plan on monitoring the mite fall and plan on treatment in the spring if necessary.

-Tim