[Eddy]

A basal average of 0.7/hr would equal 16.8 daily, which roughly jives with your current Lantus regimen. IIUC, the 80% multiplier is safety margin to avoid a wicked round of hypos, should CSII give better absorption than your basal.

I'm not fond of large, sudden changes. It can be tricky enough to converge on the correct basal rate without major dose changes.

When I switched from 1x/day Lantus to 2x/day Levemir, I gradually decreased my Lantus while gradually increasing my Levemir. I made certain that my total basal was never more than a couple units (out of 35-ish) off. Granted, I was not switching from MDI to CSII, but the principle is the same.

e.g.:

Day 1 : decrease Lantus to 7U/dose; set basal to 0.075
Day 2 : decrease Lantus to 6U/dose; set basal to 0.150
Day 3 : decrease Lantus to 5U/dose; set basal to 0.225
Day 4 : decrease Lantus to 4U/dose; set basal to 0.300
Day 5 : decrease Lantus to 3U/dose; set basal to 0.375
Day 6 : decrease Lantus to 2U/dose; set basal to 0.450
Day 7 : decrease Lantus to 1U/dose; set basal to 0.525
Day 8 : no more Lantus; set basal to 0.600

Consider adjusting as needed, should the above basals be either too conservative or aggressive, but be suspicious of an apparent "need" for any huge deviations from what you might expect. Be sure to write down what you're doing each day! It's easy to lose track!

I like to correct my nighttime basal before messing with daytime. It's arguably easier (no food/bolus stuff), and rather important (long stretch of time).

Once your nighttime basal is sorted, examine your daytime correctional boluses. Average those out over your waking hours as a starting point for daytime tinkering.

FWIW: I'd planned to transition from Lantus to Levemir over three or four weeks. I became impatient, and did it over a week and a half.