Noise spec of AD8222, AD 8224, AD8426

Hi

I really find the instrumentation amplifier, AD8222, AD8224, AD8426 with differential output really useful. But I have a question regardign the noise spec when using these in differential output mode. With the term noise spec I am referring to terms Voltage noise, Current noise, Bias current, voltage offset etc. If I am using in the differential mode, do I need  to add twice the total noise for a noise budget?

"The differential configuration of the AD8222 has the same excellent dc precision specifications as the single-ended output configuration"

I found this description on AD8222 data sheet and a similar note on AD8224 datasheet too. I am not seeing anything related to this in AD8426. Is there any difference? And I would like to get more information than this on this topic (more than a sentence) about these amplifiers?

Regards

niranjan