A medical provider may be liable for lack of informed consent.  The test of informed consent has four elements:

1)  That the health care provider failed to inform the patient of a material fact or facts relating to the treatment;

2)  That the patient consented to the treatment without being aware of or fully informed of such material fact or facts;

3)  That a reasonably prudent patient under similar circumstances would not have consented to the treatment if informed of such material fact or facts;

4)  That the treatment in question proximately caused injury to the patient.[1]

Washington courts apply an objective reasonable patient standard, not a subjective test of whether the claimant or some patients would have considered the risk material.

The determination of materiality is a two-step process: (1) the scientific nature of the risk must be ascertained (the nature of the harm and the probability of its occurrence), and (2) the trier of fact must then decide whether that probability is a risk which a reasonable patient would consider in deciding on treatment.[2]

The first step of the test requires expert testimony.[3]

If a patient signs a consent form there is a rebuttable presumption that there was informed consent.  Lack of a written consent form is not admissible to prove lack of informed consent.[4]

[2] Smith v. Shannon, 100 Wn.2d at 33; Ruffer v. St. Frances Cabrini Hosp., 56 Wn. App. 625, 631, 784 P.2d 1288, review denied, 114 Wn.2d 1023 (1990).

[3] Shannon, 100 Wn.2d at 33.

[4] RCW 7.70.060.