If you withold information that could be grounds to deny coverage
This is why there has been a big debate in European countries about whether genetic testing and medical IT is compatible with private insurance systems at all.
Private insurance relies on being able to exclude people who would not be profitable. In order to do this they need access to what they call 'assymetrical information' which is information that you may have on your relatives and their diseases or your own diseases that you may not have told them.
That is one of the things the huge MIB database is for. As lifespans increase they are counting on being able to access more kinds of insurance about people (and their ancestors) so that employers and insurers can make informed decisions on who to hire or who to insure. They ask all those questions so that they can disqualify people in the future if they have lied.
They feel that the continued viability of commercial insurance depends on this and much more that is in the pipeline and they are pushing very hard for dramatic expansions of what is called 'medical IT'. The main element of this is extensive use of database technologies to allow standardized care. This may help in some situations and hurt in others.
Alternatively, they may use telepresence to allow doctors to be separated from their patients geographically, for example, your doctor may be overseas and 'see' you via a high speed Internet connection.
This is so that their businesses can remain as profitable as they have been. Right now almost 1/3 of every healthcare dollar spent in the US goes to pay insurance companies 'administrative costs'.
That does not mean that computers will be deciding what kind of care people will receive, yet, but its not many years away.
They see their hands as tied due to the demographics and cost of medical care.
Medical care does not easily commoditize like other business have, and it canot be shipped offshore (although some self-insured companies are now having their employees go overseas, for example, to India, for elective surgery)
"The magic of the marketplace"