In what circumstances will a court admit a statement made by a witness in a medical malpractice case?

In People v. Cowan, supra, 50 Cal.4th 401, the witness testified that he had told the truth regarding the statement in question "to the best of his ability," although he admitted that his memory had been " 'jumbled' and 'scrambled' because of" drug use. (Id. at p. 466.) We found this testimony sufficient to admit the prior statement. We explained that " 'whether an adequate foundation for admission' of a statement under Evidence Code section 1237 has been established turns on whether the declarant's 'testimony that [the] statement was true was reliable,' and the trial court who hears the declarant's testimony has 'the best opportunity' to assess its credibility." (Id. at p. 467.) We concluded that, "[u]nder the circumstances, we cannot say that the trial court abused its discretion in determining the statement was sufficiently reliable to be admitted under [Evidence Code] section 1237." (Ibid.)