No award shall be made in any action or arbitration for damages for injury occurring as the result of health care which is provided after June 25, 1976, unless the plaintiff establishes one or more of the following propositions:
Unless otherwise provided in this chapter, the plaintiff shall have the burden of proving each fact essential to an award by a preponderance of the evidence.
RCW 7.70.030
Severability-1975-'76 2nd ex.s. c 56: See note following RCW 4.16.350.