OPINION
MICHAEL MASSENGALE, Justice.This is a mandamus proceeding arising from a pretrial discovery dispute.* The underlying suit involves a defamation claim asserted by the plaintiff and real party in interest, Dr. Bruce Halbridge, against defendant and relator Dr. Kenneth Higby. Dr. Halbridge’s claim is based upon statements allegedly made by Dr. Higby in an ethics complaint submitted to the grievance committee of the American College of Obstetricians and Gynecologists (ACOG).
Dr. Higby was deposed concerning his communications with the ACOG grievance committee, and he declined to answer certain questions, asserting a medical peer review communications privilege. See Tex. OoC.Code Ann. § 160.007(e) (Vernon 2004). Dr. Halbridge moved to compel Dr. Hig-*742b/s responses, and the trial court granted the motion to compel.
Generally, the scope of discovery is within the trial court’s discretion. In re Colonial Pipeline Co., 968 S.W.2d 938, 941 (Tex.1998) (orig.proceeding); In re BP Prods. N. Am. Inc., 263 S.W.3d 106, 111 (Tex.App.-Houston [1st Dist.] 2006, orig. proceeding). Mandamus relief is available only to correct a “clear abuse of discretion” when there is no adequate remedy by appeal. Walker v. Packer, 827 S.W.2d 833, 839 (Tex.1992) (orig.proceeding). The heavy burden of establishing a clear abuse of discretion is on the party resisting discovery. In re CSX Corp., 124 S.W.3d 149, 151 (Tex.2003) (orig.proceeding) (citing Canadian Helicopters Ltd. v. Wittig, 876 S.W.2d 304, 305 (Tex.1994) (orig.proceeding)). A clear abuse of discretion occurs when a trial court “reaches a decision so arbitrary and unreasonable as to amount to a clear and prejudicial error of law.” Walker, 827 S.W.2d at 839 (citing Johnson v. Fourth Court of Appeals, 700 S.W.2d 916, 917 (Tex.1985) (orig.proceeding)). Even if the reviewing court would have decided the issue differently, it cannot disturb the trial court’s decision unless the decision is shown to be arbitrary and unreasonable. Walker, 827 S.W.2d at 840. Mandamus is proper when a trial court improperly denies a claim of medical peer review privilege. See, e.g., Mem’l Hosp.The Woodlands v. McCown, 927 S.W.2d 1, 12 (Tex.1996) (orig.proceeding).
As the party seeking to avoid discovery, Dr. Higby bore the burden to assert and prove that the medical peer review communications privilege applies. In re E.I. DuPont de Nemours & Co., 136 S.W.3d 218, 223 (Tex.2004) (orig.proceeding); In re BP Prods., 263 S.W.3d at 112. In order to make a prima facie demonstration of privilege at the hearing on Dr. Halbridge’s motion to compel, Dr. Higby was required to “present any evidence necessary to support the ... privilege either by testimony at the hearing or by affidavits served on opposing parties at least seven days before the hearing.” Tex.R. Civ. P. 199.6.
The source of the privilege asserted by Dr. Higby is Occupations Code section 160.007(e):
Unless disclosure is required or authorized by law, a record or determination of or a communication to a medical peer review committee is not subject to subpoena or discovery and is not admissible as evidence in any civil judicial or administrative proceeding without waiver of the privilege of confidentiality executed in writing by the committee. The evidentiary privileges created by this subtitle may be invoked by a person or organization in a civil judicial or administrative proceeding unless the person or organization secures a waiver of the privilege executed in writing by the chair, vice chair, or secretary of the affected medical peer review committee.
Tex. Occ.Code § 160.007(e) (emphasis supplied). To enforce his claim of privilege under this statute, Dr. Higby had to prove that the ACOG grievance committee was a “medical peer review committee.” Id. To prove that, he had to prove that ACOG was a “health care entity,” and that it “operates under written bylaws approved by the policy-making body or the governing board of the health care entity and is authorized to evaluate the quality of medical and health care services or the competence of physicians.” Id. § 151.002(a)(8) (Vernon Supp.2009) (defining “medical peer review committee” for purposes of Medical Practice Act, Tex. Occ.Code Ann. §§ 151.001-165.160 (Vernon 2004 & Supp. 2009)). To prove that ACOG was a “health care entity,” he had to prove that ACOG or its grievance committee followed “a formal peer review process to further *743quality medical care or health care.” Id. § 151.002(a)(5)(C) (Vernon Supp.2009) (defining “health care entity” for purposes of Medical Practice Act).
Dr. Higby bore the burden of proving the application of the privilege in the trial court, and in this mandamus proceeding he bears the burden of demonstrating a clear abuse of discretion by the trial court. Nevertheless, the mandamus record before us contains no proof of any of the predicate facts that would establish whether a privilege applies. Dr. Higby’s response to the motion to compel was not verified. No testimony was presented at the hearing on the motion to compel. See Tex.R. Civ. P. 199.6. Dr. Higby did submit a one-page affidavit, which stated, in its entirety:
My name is Kenneth Higby, M.D. I am an obstetrician/gynecologist practicing in San Antonio, Texas. I have been licensed to practice medicine in Texas since 1991. This affidavit is based on my personal knowledge and is true and correct.
All of the statements made by me to the ACOG Grievance Committee, either in writing or orally, were based on my good faith belief in the truth of those statements. My statements were substantiated by the documents produced and prepared in the Lange case.
As a practicing obstetrician and gynecologist in Texas, I have an interest in upholding the standards of medical care in my profession.
As a fellow of the American College of Obstetricians and Gynecologists, I have a duty to report questionable behavior by another physician. I am bound by the ACOG Code of Ethics, which states “all physicians are required to respond to evidence of questionable conduct or unethical behavior by other physicians through appropriate procedures established by the relevant organization.”
My statements were made only to the members of the Grievance Committee who have an interest in regulating the fellows of the ACOG.
(Emphasis in original.) This affidavit does not address any of the facts necessary to establish whether the ACOG grievance committee was a “medical peer review committee,” as explained above. Also attached to the response to the motion to compel was a copy of ACOG’s Code of Professional Ethics, but no affidavit was provided to prove the substance of the Code, and in any case the Code did not prove that the ACOG grievance committee was a “medical peer review committee.”
The only other documents referenced by Dr. Higby’s mandamus petition in support of his contention that the ACOG grievance committee was a “medical peer review committee” are the exhibits to his motion for summary judgment, which was orally withdrawn at the hearing on Dr. Hal-bridge’s motion to compel. Even if we were to assume that in granting the motion to compel the trial court considered the exhibits to a withdrawn motion for summary judgment, which included additional information about ACOG’s mission and its grievance committee (but no copy of any written bylaws), the matters reflected in these documents were not proved by an affidavit or testimony of any person with knowledge. See Tex.R. Civ. P. 199.6.
By contrast, in Memorial Hospital-The Woodlands v. McCown, 927 S.W.2d 1 (Tex.1996), the Supreme Court relied upon a mandamus record which included affidavits of medical staff coordinators with personal knowledge who provided evidence of the structures of hospital credentialing committees at issue, including the bylaws under which such committees had been *744formed. Id. at 11. In addition to establishing the facts necessary to demonstrate eligibility for a communications privilege, the affidavits also established predicate facts to demonstrate the specific application of the privilege to the documents at issue. Id. at 12. No such evidentiary record has been provided to us in support of this petition.
An appellate court may not deal with disputed areas of fact in an original mandamus proceeding. West v. Solito, 563 S.W.2d 240, 245 (Tex.1978). Faced with a record devoid of the necessary proof to establish whether a privilege applies, we cannot conclude that the trial court clearly abused its discretion by granting the motion to compel. We express no opinion on whether the ACOG grievance committee served as a “medical peer review committee” for the purposes of Occupations Code section 160.007(e). See, e.g., VanDevender v. Woods, 222 S.W.3d 430, 433 (Tex.2007) (noting “the cardinal principle of judicial restraint — if it is not necessary to decide more, it is necessary not to decide more” (quoting PDK Labs., Inc. v. U.S. Drug Enforcement Admin., 362 F.3d 786, 799 (D.C.Cir.2004) (Roberts, J., concurring))).
We deny the petition for writ of mandamus, and we vacate this Court’s order of June 16, 2009, which stayed the trial court’s order granting Dr. Halbridge’s motion to compel.
Justice KEYES, concurring.
The underlying case is Bruce L. Halbridge, M.D. v. Kenneth Higby, M.D., No. 08-DCV-166064, in the 268th District Court of Fort Bend County, Texas, the Hon. Brady G. Elliott, presiding.