What I do if there is any question of a possible decline is I call quite a few carriers in advance and do what I call an anonymous prescreen. I go over the general health status with an underwriting rep, and they will usually tell me what the likely outcome is going to be BEFORE even applying.
Blue Cross recently changed their underwriting guidelines, and they no longer exclude conditions from coverage, so, if you have too many "rateable" conditions, they will sometimes just decline. It really all depends on current health status.
Here are a few gotchas: If anyone has recently been diagnosed with elevated BP or Cholesterol, it's an automatic decline untill you have been stabilized on fewer than 2 meds for at least 6 months or controlled with diet and exercise within 6 months. If you have three or more "rate-able" conditions, conditions for which you could be up-rated, the likely outcome with BCBS will be a decline.
A body mass index of >30 combined with elevated Blood Pressure or cholesterol will lead to a decline with BCBS, regardless of whether or not the condition is controlled.
Any kind of health condition for which there isn't a clear outcome or treatment plan usually leads to a decline until a doctor either gives a clean bill of health or a definitive treatment plan. This is because the insurance carriers don't like any kind of uncertainty as to whether a surgery or expensive treatment could be lurking in the near future. Examples include back/neck injuries, suspicious moles, cysts or lumps that have not been examined, etc.
Any kind of history of cancer during the past 5-10 years, history of drug or alcohol abuse (even if currently clean) or history of attempted suicide will lead to a decline.