Insurance companies will always attempt to use your medical bills against you, often for the propositions 1) that you overtreated; and 2) that they should not be responsible for the cost of diagnostic tests that turned out negative.
Neither concept makes much sense. Insurance companies are generally in no position to assess or govern your medical treatment. Nevertheless, they frequently do just that. Moreover, it is illogical that an insurance company would complain about negative diagnostic test results. Diagnostic tests are ordered by doctors for medical reasons.
If you do not follow-through with an ordered test, and your case proceeds to litigation, you can assume that an insurance defense attorney will raise this issue in the context of a mitigation of damages defense. Nevertheless, when you do follow-through appropriately and tests come out negative, expect an insurance company to complain. I often ask claims adjusters why they are complaining: would they prefer, for instance, that a CT scan or an MRI were positive?
Note, too, that the amount of medical bills in an injury case are generally the primary factor used by an insurance company to evaluate claim value.
Delay in Treatment
Insurance companies also like to point out delay in treatment for the proposition that you were not seriously injuried. Ideally, auto accident victims should go to the hospital (if necessary) on the day of the accident or as soon as possible thereafter. Similarly, you should begin chiropractric treatment or physical therapy as soon as possible after your accident. Long delays in seeking treatment can give rise to numerous defenses including but not limited to a claim of intervening injury. Further, long delays between treatments can give rise to a mitigation of damages defense as well as a claim of intervening injury.
As a simple rule: get treatment as soon as possible after an accident and stick with that treatment until you are released by your doctor.