In an action to recover damages under AS 09.55.530 - 09.55.560, no advance payment made by the defendant health care provider or the professional liability insurer of the defendant to or on behalf of the plaintiff is admissible as evidence or may be construed as an admission of liability for injuries or damages suffered by the plaintiff; however, a final award in favor of the plaintiff shall be reduced to the extent of any advance payment. The advance payment shall inure to the exclusive benefit of the defendant or the insurer making the payment.