OPINION
Richard Hebert and his wife, Janet Hebert, appeal from a district court judgment dismissing, for failure to serve the expert report required by chapter 74 of the civil practice and remedies code, a health care liability claim they asserted against Timothy Hopkins, M.D., and Shannon Clinic.1 The Heberts bring two issues, urging respectively that (1) the district court abused its discretion in concluding that they failed to serve an expert report complying with chapter 74; and (2) chapter 74’s expert-report requirement violates various constitutional protections. We will overrule these contentions and affirm the district court’s judgment.
BACKGROUND
The Heberts filed the underlying suit alleging that Dr. Hopkins, a neurosurgeon, committed professional negligence in performing spinal surgery on Richard Hebert at Shannon in September 2008 after Richard broke his neck in a fall. Specifically, they pled that Richard had presented with a fracture of the cervical 6(C6) vertebra that was “very unstable” due to a preexisting condition known as ankylosing spon-dylitis that had self-fused his spinal vertebrae on either side of the fracture; that the standard of care in such circumstances had required Hopkins to perform “an anterior and posterior fusion surgery” to ensure stability; that Hopkins had performed “an anterior fusion with plates and screws at C4-C7 but took no appropriate surgical measures to stabilize the fusion posteriorly;” and that the anterior-only fusion had subsequently “failed as one or more of the screws had pulled out causing the vertebral segments to move and compress the spinal cord at C4-C7,” rendering Richard a quadriparetic (i.e., paralyzed in all four limbs). The Heberts asserted that Shannon was vicariously liable for Hopkins’s negligence by virtue of Hopkins’s status as a “partner or member” of the clinic.
Within 120 days thereafter, in an attempt to comply with chapter 74’s expert-report requirement, the Heberts served a report from P. Merrill White, M.D., along with Dr. White’s curriculum vitae.2 Hop*889kins and Shannon timely objected to the sufficiency of Dr. White’s report, asserting that the report had failed to adequately set forth, and was “eonclusory” with respect to the underlying factual bases of, opinions regarding the applicable standard of care for Hebert in light of his underlying medical conditions, the manner in which Hopkins’s care had failed to meet that standard, or a causal linkage to the fusion failure and Richard’s injuries.3 By now, the 120-day period for serving an “expert report” had expired, so appellees also moved to dismiss the Heberts’ suit with prejudice and sought a mandatory award of attorney’s fees.4 Both sides submitted briefing on the merits of appellees’ objections. Following a hearing at which the parties presented argument, the district court sustained appellees’ objections but granted the Heberts a thirty-day extension to cure any deficiencies.5
Within the extension period, the He-berts served a supplemental report from White. Contending that White’s supplemental report had failed to cure the deficiencies in his original report, appellees again moved to dismiss the Heberts’ suit with prejudice.6 The Heberts filed a response joining issue regarding the sufficiency of the two reports and also asserting that chapter 74’s expert-report requirement violates various protections of the U.S. or Texas constitutions. Following a hearing, the district court granted appellees’ motion to dismiss. Subsequently, after hearing evidence, the district court awarded appellees attorney’s fees as required by chapter 74,7 and this order also served to make the court’s prior dismissal order final. The Heberts then timely perfected this appeal.
ANALYSIS
Sufficiency of expert reports
In their first issue, the Heberts urge that the district court abused its discretion in holding that Dr. White’s report, either in its original form or as supplemented, did not represent an objective good faith effort to comply with the statutory definition of an expert report.
The standards governing the contents of the expert report or reports required by chapter 74 are well established. Chapter 74 defines an “expert report” as “a fair summary of the expert’s opinion as of the date of the report regarding applicable standards of care, the manner in which the care rendered by the physician or health care provider failed to *890meet the standards, and the causal relationship between that failure and the injury, harm, or damages claimed.”8 “A court shall grant a motion challenging the adequacy of an expert report only if it appears to the court, after hearing, that the report does not represent an objective good faith effort to comply” with this definition of “expert report.”9 To constitute a “good faith effort,” as the Texas Supreme Court has explained, the report must include the expert’s opinion on “each of the three main elements: standard of care, breach, and causation,” and must provide enough information to fulfill two purposes with respect to each element: (1) it must inform the defendant of the specific conduct the plaintiff has called into question; and (2) it must provide a basis for the trial court to conclude that the claims have merit. See Jelinek v. Casas, 328 S.W.3d 526, 538-40 & n. 9 (Tex.2010); Bowie Mem’l Hosp. v. Wright, 79 S.W.3d 48, 52 (Tex.2002) (per curiam); American Transitional Care Ctrs. of Tex., Inc. v. Palacios, 46 S.W.3d 873, 878-79 (Tex.2001). Although these requirements do not require a plaintiff to marshal all of his or her proof or to present expert testimony in a form that would be admissible at trial, see Jelinek, 328 S.W.3d at 539-40 & n. 9, they do necessitate that “the expert must explain the basis for his statements to link his conclusions to the facts” and not merely state conclusions. Id. (quoting Wright, 79 S.W.3d at 52 (quoting Earle v. Ratliff, 998 S.W.2d 882, 890 (Tex.1999))); see also id. at 539-40 (observing, with respect to the causation element, “the expert must ... explain, to a reasonable degree, how and why the breach caused the injury based on the facts presented”). This is so, in the supreme court’s view, because “ ‘[a] report that merely states the expert’s conclusions about the standard or care, breach, and causation’ does not fulfill the two purposes of a good-faith effort.” Id. at 539 (quoting Palacios, 46 S.W.3d at 879); see also id. at 540 (expert “must include sufficient detail” regarding how breach caused plaintiffs injuries “to allow the trial court to determine if the claim has merit”).
Importantly, the only information relevant to determining whether an expert report complies with these requirements is that contained within “the four corners” of the report itself. Palacios, 46 S.W.3d at 878. Consequently, neither the trial court nor this Court may infer additional opinions or underlying facts to fill in gaps that the report itself leaves open. See Wright, 79 S.W.3d at 53; see also Austin Heart, P.A. v. Webb, 228 S.W.3d 276, 279 (Tex.App.-Austin 2007, no pet.) (this requirement “precludes a court from filling gaps in a report by drawing inferences or guessing as to what the expert likely meant or intended” (citing Wright, 79 S.W.3d at 53)).
Our standard of review is likewise limited. Chapter 74 imposes a mandatory duty on a trial court to grant a motion challenging the adequacy of an expert report “if it appears to the court” that the report does not meet the above-described requirements. See Tex. Civ. Prac. & Rem. Code Ann. § 74.351(1) (“A court shall grant a motion challenging the adequacy of an expert report only if it appears to the court ... that the report does not represent an objective good faith effort to comply with the definition of an expert report in Subsection (r)(6).”) (emphasis added). *891Conversely, the trial court is prohibited from granting such a motion unless such noncompliance “appears to the court.” Id. (“A court shall grant a motion challenging the adequacy of an expert report only if it appears to the court-”) (emphasis added). But the linchpin determination that controls which of these two alternative sets of mandatory duties applies — whether “it appears to the court” that the report does not comply with the requirements — has been committed to the trial court’s sound discretion by the Legislature. See Palacios, 46 S.W.3d at 877-78. Consequently, we review the trial court’s determination for abuse of that discretion. See Wright, 79 S.W.3d at 52 (citing Palacios, 46 S.W.3d at 878).
A trial court abuses its discretion when it acts in an arbitrary or unreasonable manner without reference to any guiding rules or principles. See id. (citing Downer v. Aquamarine Operators, Inc., 701 S.W.2d 238, 241-42 (Tex.1985)). “When reviewing matters committed to the trial court’s discretion, a court of appeals may not substitute its own judgment for the trial court’s judgment.” Id. (citing Flores v. Fourth Court of Appeals, 111 S.W.2d 38, 41 (Tex.1989)). We do not, in other words, examine the contents of Dr. White’s reports and make our own de novo determination as to whether he has provided sufficient information, with respect to his opinions regarding standard of care, breach, and causation, to (1) inform appel-lees of the specific conduct the Heberts have called into question; and (2) provide a basis for the district court to conclude that the claims have merit. See Jelinek, 328 S.W.3d at 538-40 & n. 9; Wright, 79 S.W.3d at 52; Palacios, 46 S.W.3d at 878-79. Instead, we determine only whether the district court acted arbitrarily, unreasonably, and without reference to guiding rules and principles in determining that the reports failed to provide that information. See Wright, 79 S.W.3d at 52; see also Jelinek, 328 S.W.3d at 542 (Jefferson, C.J., dissenting) (“The dividing line between a sufficient and an inadequate report is impossible to draw precisely. We have said, therefore, that the determination must be made in the first instance by the trial court, and review of that decision asks not how an appellate court would have resolved that issue, but instead whether the trial court abused its discretion.”) (citing Jernigan v. Langley, 195 S.W.3d 91, 93 (Tex.2006); Walker v. Gutierrez, 111 S.W.3d 56, 63 (Tex.2003)).
Applying this deferential abuse-of-discretion standard of review, we cannot conclude that the district court acted arbitrarily, unreasonably, and without guiding rules and principles in determining that Dr. White’s reports did not supply it sufficient information regarding his opinions concerning standard of care and breach, as they relate to the underlying facts, to enable it to determine whether the Heberts’ claims had merit.
In his initial report, White summarized medical records reflecting that Richard Hebert sought treatment at Shannon in the early morning hours of September 7, 2008, following a fall in which he injured his neck, and that Richard was placed under Hopkins’s care. According to White, CT scans and other evaluations revealed that Richard had suffered “a trace traumatic subarachnoid hemorrhage” (i.e., bleeding on the brain) and a “fracture through the superior vertebral body of C6 with a fracture extending through the posterior elements of C5-6.” The injury “was initially managed in a cervical collar which was changed to a Philadelphia collar and spinal precautions were ordered” within about five hours. That same evening, White indicated, Hopkins performed a surgical procedure in which the neurosurgeon *892fused Richard’s C5-C6 vertebrae and implanted “C4 through C7 anterior instrumentation” — a plate over or along the front of Richard’s spine, attached by-screws to his bone — to provide stability and support while the fracture healed. On the following day, White continued, the medical records indicated that Richard had showed signs of recovery progress and that “[c]ervical collar is discontinued per Dr. Hopkins’[s] order.” But four days later, during the afternoon of September 12, Richard had a decline in neurological function and subsequent CT scans “confirmed] failure of implant fixation at C6 and C7” and injury to the spinal cord. Although another neurosurgeon, Dr. Duarte, operated on Richard thereafter to remove the failed anterior instrumentation and implement a different type of fixation method, Richard ended up with “increased neurological deficit (quadriparesis).”
The medical récords, as summarized by White, additionally reflected that Richard had a history of “coronary artery disease treated with cardiac stints, Plavix, and aspirin; cerebrovascular accident [ (i.e., a stroke)] on two occasions with residual left hand paraesthesias [ (tingling or prickling sensations) ] treated with Plavix and aspirin; and hypertension,” as well as “an-kylosing spondylitis,” a degenerative condition of the spine that causes both brittleness of bones and self-fusion of vertebrae.
Although he did not indicate whether or how Richard’s other medical conditions impacted the standard of care, White emphasized his opinion that a patient with ankylosing spondylitis warranted special precautions when performing surgery to address spinal fracture:
In the surgical treatment of cervical spine fractures complicating ankylosing spondylitis, the prudent spine surgeon must recognize the unstable nature of these fractures. The instability is con-
tributed to by the long level arms cranial and caudal to the fracture site resulting from the multilevel autofusion and poor bone quality associated with anky-losing spondylitis. These two factors result in increased susceptibility to spine fractures as a result of relatively minor trauma, greater instability, and a greater likelihood of neurologic deficit resulting from a cervical fracture than found in patients with cervical spine fractures and otherwise normal spinal anatomy. The prudent spine surgeon should design a surgical plan of care allowing decompression of the spinal cord, reduction of the traumatic deformity, and immediate stabilization of the spinal column to protect the spinal cord and to facilitate mobilization and nursing care to the patient in the short term and healing of the spinal fusion in the longer term.
As for the standard of care regarding the specific means by which these objectives should be achieved, White initially suggested that anterior-only internal instrumentation was inconsistent with the standard of care and that some form of posterior internal instrumentation, either additionally or as an alternative to anterior instrumentation, would instead be preferable:
Over the recent years, the debate of the spinal community has been in which circumstances fusion with posterior only fixation or fusion with anterior and posterior fixation is appropriate. Anterior instrumentation only is predictably inadequate in a fracture pattern with gross anterior and posterior column instability such as Mr. Hebert’s. Adequate treatment of Mr. Herbert’s [sic] fracture requires anterior and posterior instrumentation in order to meet the standard of care.
In Mr. Herbert’s [sic] situation, the standard of care requires fixation stable *893enough to allow mobilization of the patient without loss of fixation resulting in increased neurological deficits. This goal is more likely to be achieved by multilevel posterior internal fixation in addition to at least single level anterior internal fixation with fusion at appropriate levels.
However, in the next sentence, within the same paragraph, White acknowledged that “clinical situations” could arise in which anterior-only instrumentation, coupled with “supplemental protection” other than posterior implementation, would be consistent with the standard of care:
If the clinical situation in which the surgeon finds himself and the patient allows only inadequate internal fixation, the surgeon is obligated to protect the patient supplementing the internal fixation with external bracing and/or activity limitations. The supplemental protection should continue until the patient can be returned to the operating room for additional internal fixation or the fracture becomes stable through healing.
Following these statements regarding standard of care, White turned to whether or how Hopkins breached an applicable standard. Consistent with the first portion of his explanation of the standard of care, White began by asserting that Hopkins breached the standard by utilizing “anterior only plate/screw fixation”:
Dr. Timothy Hopkins’fs] choice of anterior only plate/screw fixation fails to meet the applicable standard of care. Constrained anterior cervical plates function as tension band devices and require relative stability of the posterior elements. In extension these devices resist distraction of the anterior column. These devices do not effectively resist flexion forces and require stable posterior elements to limit deformity resulting from flexion forces. In the absence of adequate posterior stability, anterior plate/screw constructs typically fail in flexion by plate breakage or, as in this case, by screw pullout. Mr. Herbert’s [sic] fracture resulted in significant instability of both the anterior and posterior elements at the C5-6 level. Anterior only plate/screw fixation, in this setting, is predictably doomed to failure.
But in the next sentence, White seemed to allude to his previously expressed view that a surgeon could act within the standard of care by “supplementing” otherwise “inadequate internal fixation” with some form of “external bracing and/or activity limitations” as an alternative to posterior surgical fixation:
The prudent spine surgeon must recognize the limitations of the various internal fixation constructs available and if necessary must compensate for the predictable weaknesses by adequate external bracing and/or activity limitation.
Then White ended his discussion of breach with the following conclusion:
The standard of care for the surgical treatment of this fracture requires a multilevel posterior fixation and a fusion in conjunction with anterior fixation and fusion with or without supplemental external fixation as was ultimately performed by Dr. Duarte on September 12, 2008.
White then offered the following opinions as to causation, now referencing perceived inadequacies in internal and external fixation without elaborating as to the nature or identity of any of the latter category:
The failure to choose the internal and external fixation construct capable of providing stability to allow mobilization of the patient, prevent spinal displacement, and protect the spinal cord is the proximate cause of Mr. Herbert’s [sic] *894increased neurologic deficit (quadripare-sis). This occurred as a result of the constrained anterior plate/screw construct’s predictable inability to neutralize flexion forces resulting in screw pullout at C6 and C7 levels followed by displacement of the spinal column through the C5-6 fracture/allograft site with subsequent spinal cord injury and deterioration of neurologic function.
Among their objections to the sufficiency of White’s initial report, appellees urged that the report did not represent an objective good faith attempt to comply with chapter 74’s requirements — i.e., that it discussed the standard of care, breach, and causation with sufficient specificity to (1) inform them of the conduct called into question and (2) provide a basis for the district court to determine that the claims have merit — because it was internally inconsistent as to the standard of care that applied and did not address whether or not Hopkins complied with the standard of care through the use of the “external bracing and/or activity limitation” White had contemplated. And these asserted deficiencies, appellees further suggested, in turn undermined any factual bases underlying White’s assertions that the standard of care either required Hopkins’s use of anterior-only internal fixation or was breached by his choice not to use posterior interior fixation.
In arguing that the district court abused its discretion in sustaining appellees’ objections, the Heberts emphasize the portions of White’s initial report focusing on the relative merits of anterior versus posterior internal fixation. But the district court was within its discretion also to consider White’s recognition of an apparent exception, qualification, or limitation to his broader criticisms of anterior fixation: “the clinical situation in which the surgeon finds himself and the patient” may “allow! ] only inadequate internal fixation,” in which case the standard of care could be met by “supplementing the internal fixation with external bracing and/or activity limitations.” Along with White’s recognition of this aspect of the standard of care, the court also could have reasonably considered that White never elaborated on the nature or type of “clinical situation” that would “allow[] only inadequate internal fixation” or whether such a situation did or did not exist in regard to Richard, a patient who, as White acknowledged in his report, had a history of coronary artery disease, two strokes, and hypertension, not to mention bleeding on the brain from his fall. The court likewise could reasonably have viewed White’s references to “external bracing” or “activity limitations” as an alternative to further internal fixation as begging the question as to whether the unspecified “spinal precautions” Hopkins had ordered, the cervical collar Richard wore following surgery, or other “external bracing” or “activity limitations” Hopkins imposed had or had not satisfied the standard of care.
In short, we cannot conclude that the district court acted arbitrarily, unreasonably, or without regard to guiding principles in determining that White’s initial report fell short of describing the applicable standard or care or breach thereof, as applicable to the underlying facts, with sufficient specificity to provide the court a basis to determine that White’s claims have merit. See Jelinek, 328 S.W.3d at 538-40 & n. 9; Wright, 79 S.W.3d at 52; Palacios, 46 S.W.3d at 878-79. And in the face of such deficiencies regarding standard of care and breach, the district court would have acted within its discretion in determining that any assertions by White to the effect that anterior-only internal fixation breaches the standard of care or that only posterior internal fixation can suffice lack an underlying factual basis— *895i.e., are “conclusory” — and fail to satisfy chapter 74. See Wright, 79 S.W.3d at 52 (“the expert must explain the basis of his statements to link his conclusions to the facts” (quoting Earle, 998 S.W.2d at 890)).
The Heberts urge us to indulge a “fair reading” that White’s opinions regarding unspecified “clinical situations” refers to a surgeon who is attempting to perform a combined anterior and posterior procedure but gets interrupted by “surgical complications such as delays or blood loss,” and that no such complications arose here. The dissent similarly relies on inferences or implications that such “extraordinary circumstances” were not present. But the problem with these arguments is that White never actually says any of this in his initial report, and the established rule is that the report must stand or fall on the contents within its “four corners.” Palacios, 46 S.W.3d at 878. This requirement, again, “precludes a court from filling gaps in a report by drawing inferences or guessing as to what the expert likely meant or intended.” Austin Heart, P.A., 228 S.W.3d at 279 (citing Wright, 79 S.W.3d at 53).
Nor did the district court abuse its discretion in holding that such deficiencies were not cured by White’s supplemental report. In his supplement, although White reiterates and emphasizes at length his conclusions and assertions regarding anterior versus posterior fixation generally, nowhere does he address the deficiencies concerning the standard of care and breach that the district court could have perceived in his initial report.
We overrule the Heberts’ first issue.
Constitutional claims
In their second issue, the He-berts bring forward constitutional challenges to chapter 74’s expert-report requirement. While not appearing to quarrel with the general concept that the Legislature can validly impose some form of threshold report requirement for asserting health care liability claims or other types of civil claims, the He-berts complain about three basic features of chapter 74’s expert-report requirement: (1) the fixed deadline of 120 days to serve an expert report, subject to a single 30-day extension; (2) the requirements focusing judicial analysis of a report’s sufficiency solely on the “four corners” of the report and prohibiting courts from considering extrinsic evidence of a claim’s merits; and (3) the mandatory requirement that courts dismiss health care liability claims with prejudice for failing to serve an adequate expert report and also award attorney’s fees. The Heberts contend that these mechanisms unfairly “single out” health care liability claimants for unconstitutional “disparate treatment,” deprive courts of judicial discretion in violation of the separation-of-powers protections of the Texas Constitution, and deprive claimants of access to the courts in violation of due-process or open-courts protections.10
*896When reviewing the constitutionality of a statute, we begin with a presumption that it is constitutional. Herrera v. Seton Nw. Hosp., 212 S.W.3d 452, 460-61 (Tex.App.-Austin 2006, no pet.) (citing Walker, 111 S.W.3d at 66); see also Tex. Gov’t Code Ann. § 311.021(1) (West 2005). The wisdom or expediency of the law is the Legislature’s prerogative, not ours. Smith v. Davis, 426 S.W.2d 827, 831 (Tex.1968). We presume that the Legislature has not acted unreasonably or arbitrarily. Sax v. Votteler, 648 S.W.2d 661, 664 (Tex.1983) (quoting Davis, 426 S.W.2d at 831). The party challenging a statute’s constitutionality has the burden of proving that the statute fails to meet constitutional requirements. Walker, 111 S.W.3d at 66. A party must show that a statute is unconstitutional either on its face or as applied to that party. Texas Workers’ Comp. Comm’n v. Garcia, 893 S.W.2d 504, 518 n. 16 (Tex.1995); see also City of Corpus Christi v. Public Util. Comm’n, 51 S.W.3d 231, 240-41 (Tex.2001) (per curiam) (Owen, J., concurring). To sustain a facial challenge, the party must show that the statute, by its terms, always operates unconstitutionally. Garcia, 893 S.W.2d at 528 n. 16. To sustain an as-applied challenge, the party must show that the statute is unconstitutional when applied to that particular person or set of facts. Id.
We note at the outset that the Heberts face an uphill battle because every court that has considered similar challenges to chapter 74’s expert-report requirement, including this Court, has rejected them. See, e.g., Stockton v. Offenbach, 336 S.W.3d 610, 618 (Tex.2011) (denying open-courts challenge); Hightower v. Baylor Univ. Med. Ctr., 348 S.W.3d 512, 521-22 (Tex.App.-Dallas 2011, pet. denied) (rejecting special-law, vagueness, due-course-of-law, and separation-of-powers challenges); Broxterman v. Carson, 309 S.W.3d 154, 159 (Tex.App.-Dallas 2010, pet. denied) (rejecting due-process challenge); Gulf Coast Med. Ctr., LLC v. Temple, No. 13-09-00350-CV, 2010 WL 196972, at *6 (Tex.App.-Corpus Christi Jan.21, 2010, no pet.) (mem. op.) (rejecting due-process and due-course-of-law challenges); Bogar v. Esparza, 257 S.W.3d 354, 372-73 (Tex.App.-Austin 2008, no pet.) (same); Wilson-Everett v. Christus St. Joseph, 242 S.W.3d 799, 802-04 (Tex.App.-Houston [14th Dist.] 2007, pet. denied) (rejecting separation-of-powers challenge); Ledesma v. Shashoua, No. 03-05-00454-CV, 2007 WL 2214650, at *9 (Tex.App.-Austin Aug. 3, 2007, pet. denied) (mem. op.) (rejecting due-process and open-courts challenges); Thoyakulathu v. Brennan, 192 S.W.3d 849, 855-56 (Tex.App.-Texarkana 2006, no pet.) (due process does not require “exceptions [to the expert-report requirement] that would encompass any conceivable complication in order to pass constitutional muster”); Herrera, 212 S.W.3d at 461-62 (rejecting equal-protection, due-process, due-course-of-law, and open-courts challenges). Texas courts also uniformly rejected constitutional challenges to an expert-report requirement under chapter 74’s predecessor statute, article 45901 See, e.g., Strom v. Memorial Hermann Hosp. Sys., 110 S.W.3d 216, 227 (Tex.App.-Houston [1st Dist.] 2003, pet. denied) (rejecting due-process, equal-protection, and jury-trial challenges); Villa v. Hargrove, 110 S.W.3d 74, 81 (Tex.App.-San Antonio 2003, pet. denied) (rejecting due-process and equal-protection challenges); Walker, 111 S.W.3d at 66 (rejecting due-process challenge); Perry v. Stanley, 83 S.W.3d 819, *897825 (Tex.App.-Texarkana 2002, no pet.) (rejecting open-courts challenge); Mocega v. Urquhart, 79 S.W.3d 61, 64 (Tex.App.Houston [14th Dist.] 2002, pet. denied) (same); Gill v. Russo, 39 S.W.3d 717, 718-19 (Tex.App.-Houston [1st Dist.] 2001, pet. denied) (same); Knie v. Piskun, 23 S.W.3d 455, 467 (Tex.App.-Amarillo 2000, pet. denied) (rejecting equal-protection, due-process, open-courts and free-speech challenges); Schorp v. Baptist Mem’l Health Sys., 5 S.W.3d 727, 736-38 (Tex.App.-San Antonio 1999, no pet.) (rejecting due-process, open-courts, and jury-trial challenges).11
The Heberts acknowledge the constitutional validity of the expert-requirement in chapter 74’s predecessor statute, article 4590i, but attempt to distinguish it as “less draconian.” See Act of May 5, 1995, 74th Leg., R.S., ch. 140, § 1, sec. 13.01, 1995 Tex. Gen. Laws 985, 985-88, repealed and recodified as amended by Act of June 2, 2003, 78th Leg., R.S., ch. 204, § 10.01, sec. 74.351, 2003 Tex. Gen. Laws 847, 875-77 (amended 2005) (current version at Tex. Civ. Prac. & Rem.Code Ann. § 74.351). They emphasize differences in the deadlines article 4590i imposed for serving expert reports and the extent of discretion vested in trial courts to extend deadlines. Specifically, article 4590i allowed claimants to either serve an expert report within 90 days of filing suit or file a cost bond. See former art. 4590i, § 13.01(a). An expert report was required within 180 days of suit, though the court could grant a 30-day extension if the failure to serve was not intentional or the result of conscious indifference, but was the result of an accident or mistake. Id. § 13.01(d), (g).
The Heberts also assert that “4590i did not mandate what had to be included in the contents of the report,” and that “there was no requirements or authorization for the court to summarily dismiss the case based on the deficiencies in the language of the report.” They also contend that parties opposing an article 4590i expert report had to “satisfy summary judgment procedures to secure a dismissal with prejudice.” To the contrary, a court considering the sufficiency of an expert report under article 4590i, as under chapter 74, was limited to the “four corners” of the report. See Palacios, 46 S.W.3d at 878. Likewise, if a claimant failed to serve a report, or served a report that the trial court concluded did not represent a good faith effort to comply with the statutory definition of expert report, the trial court was required to dismiss the case with prejudice and award costs and attorney’s fees to the opposing party. See former art. 4590i, § 13.01(e), (l), (r)(6); see also Palacios, 46 S.W.3d at 877.
“Disparate treatment ”
The Heberts contend that chapter 74 irrationally singles them out for disparate treatment in violation of their rights to due process and equal protection. The due-course-of-law guarantee of the Texas Constitution provides: “No citizen of this State shall be deprived of liberty, property, privileges or immunities, or in any manner disenfranchised, except by due course of the law of the land.” Tex. Const, art. I, § 19. Similarly, the federal due-*898process clause provides: “No state shall make or enforce any law which shall abridge the privileges or immunities of the citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law;.... ” U.S. Const, amend. XIV, § 1. While the Texas Constitution is textually different in that it refers to “due course” rather than “due process,” Texas courts regard these terms as without substantive distinction unless and until a party demonstrates otherwise, and the Heberts suggest no reason to construe them differently here. See University of Tex. Med. Sch. at Houston v. Than, 901 S.W.2d 926, 929 (Tex.1995) (citing Mellinger v. City of Houston, 68 Tex. 37, 3 S.W. 249, 252-53 (1887)).
Under federal and state guarantees of due process, legislation that does not affect a fundamental right or interest is valid if it bears a rational relationship to a legitimate state interest. Rylander v. B & A Mktg. Co. ex rel. Atl. Richfield Co., 997 S.W.2d 326, 333-34 (Tex.App.-Austin 1999, no pet.) (citing Williamson v. Lee Optical, 348 U.S. 483, 491, 75 S.Ct. 461, 99 L.Ed. 563 (1955); Garcia, 893 S.W.2d at 525). Similarly, the constitutional guarantee of equal protection requires only that disparate treatment of different classifications be rationally related to a legitimate state purpose, unless the classification impinges on the exercise of a fundamental right or distinguishes between people on a “suspect” basis, such as race or national origin.12 The Heberts have not demonstrated that chapter 74 impinges on a fundamental or important right or a suspect class. By its terms, chapter 74 is facially neutral and applies to any party asserting a health care liability claim. Consequently, in addressing the Heberts’ due-process and equal-protection claims, we must determine whether chapter 74 bears a rational relationship to a legitimate state interest and whether the Legislature had a rational basis in differentiating between health care liability claimants and other litigants. “In so doing, we must uphold the law if we can conceive of any rational basis for the Legislature’s action.” Owens Corning v. Carter, 997 S.W.2d 560, 581 (Tex.1999).
In enacting chapter 74, the Legislature made a number of findings about the state of the health care system in Texas. See Act of June 2, 2003, 78th Leg., R.S., ch. 204, § 10.11, 2003 Tex. Gen. Laws 847, 884-85. Specifically, it found the frequency of claims and the amounts paid out by insurers in judgments and settlements had risen inordinately since 1995, which created a public problem in the availability and affordability of adequate medical professional liability insurance. Id. § 10.11(a)(1), (3), (4). This “crisis” increased costs to physicians, hospitals, patients, and the public. Id. § 10.11(a)(5), (7). As a result, the Legislature concluded the “adoption of certain modifications in the medical, insurance and legal systems” would “have a positive effect on the rates charged by insurers for medical professional liability insurance.” Id. § 10.11(a)(12). In enacting various measures, including chapter 74, the Legislature intended to reduce the frequency and severity of health care liability claims, decrease costs of claims, and en*899sure that awards were rationally related to costs, but “do so in a manner that will not unduly restrict a claimant’s rights any more than necessary to deal with the crisis.” Id. § 10.11(b)(1), (2), (B).
In Smalling v. Gardner, the Fourteenth Court of Appeals recognized that the “legislature has broad authority to create classifications for legislative purposes, so long as they have a reasonable basis and operate equally on all persons within the class.” 203 S.W.3d 354, 371 (Tex.App.-Houston [14th Dist.] 2005, pet. denied) (addressing special-law challenge to constitutionality of article 4590i).13 The expert report is required only for claims against healthcare providers for departures from accepted standards of medical or health care or safety. Id. Accordingly, the expert-report requirement applies equally to all physicians and health care providers and rationally relates to the interests of the State “in ensuring that medical practitioners were not ‘being placed in the situation of defending frivolous claims at a high cost’ to the health care system.” Id. (quoting Schorp, 5 S.W.3d at 737). Recently, the Dallas Court of Appeals adopted the Smalling analysis and applied it to chapter 74. See Hightower, 348 S.W.3d at 521.
While Smalling and Hightower dealt with special-law challenges, we previously rejected an equal-protection challenge to chapter 74’s predecessor for similar reasons. Fields v. Metroplex Hosp. Found., No. 03-04-00516-CV, 2006 WL 2089171, at *4 (TexApp.-Austin July 28, 2006, no pet.) (mem. op.) (“[T]he legislature determined that medical liability plaintiffs should be treated differently because of the negative effects of the numbers and cost of their lawsuits had on the provision of health care.”). In that case, the claimant failed to show article 4590i’s expert-report requirement was not rationally or substantially related to the government’s interest in reducing the aggregate costs of defending against frivolous costs and reducing the costs of insurance and medical care to all. Id.; see also Bogar, 257 S.W.3d at 373 (in addressing due-process challenge to chapter 74: “We disagree that it is irrational, in light of the legislature’s goal of curtailing frivolous health care liability claims, for it to require that appellees serve an expert report explaining why or how this outcome was actually caused by the conduct of [the defendant], as opposed to some other person or health care provider.”).
The Heberts challenge the Legislature’s rationale as “pre-textual, not supported by empirical data and refuted by surveys showing there aren’t excessive frivolous medical malpractice suits.” They reason that because the Legislature had previously acted to curb frivolous medical malpractice claims by enacting article 4590i, its subsequent enactment of chapter 74 reflects intent to “single out medical malpractice claimants for special and harsh treatment by making it so onerous to file and prosecute [a claim] that they or their counsel will not take the case, or once it is filed, to make it so difficult to prosecute the case that they or their counsel will just give up.” The Heberts likewise complain that chapter 74 strips them “of all the rights accorded to other litigants in the Texas Rules of Civil Procedure,” but does not place similar restrictions on “major corporations like insurance companies and banks suing for breach of contract, or on individual or corporate clients suing attor*900neys, accountants, bankers and brokers.” According to the Heberts, no compelling state interest or rational basis supports this “arbitrary” classification.
We find no merit in the He-berts’ argument that the Legislature, evaluating the impact of 4590i, could not have rationally concluded that a problem had nonetheless persisted in the cost and availability of health care due to the prevalence of medical-malpractice suits. To the extent the Heberts challenge the underlying policies of chapter 74, it is not our place to question the Legislature’s policy decisions when conducting a rational basis review. See Bell v. Low Income Women of Tex., 95 S.W.3d 253, 264 (Tex.2002) (“The restriction clearly serves [the act’s] purposes, and it is not for us to second-guess the Legislature’s policy choices.”). The Heberts fail to demonstrate that the Legislature lacked any rational basis in differentiating between health care liability claimants and other litigants. Accordingly, we reject the Heberts’ “disparate treatment” constitutional challenges.
Separation of powers
For similar reasons, the He-berts’ other constitutional challenges fail. They claim the Legislature has impermis-sibly interfered with the judicial branch through chapter 74. The Texas Constitution vests the judicial power of the State in the courts. Tex. Const, art. V, § 1. The separation-of-powers requirement prohibits one branch of government from exercising a power inherently belonging to another branch. Id. art. II, § 1; Wilson-Everett, 242 S.W.3d at 802 (citing General Servs. Comm’n v. Little-Tex Insulation Co., 39 S.W.3d 591, 600 (Tex.2001)). Only when the executive or legislative branch interferes with the functioning of the judicial process in a field constitutionally committed to the control of the courts does a constitutional problem arise. Wilson-Everett, 242 S.W.3d at 802.
Chapter 74’s expert report imposes a threshold procedural requirement aimed at filtering out meritless or premature lawsuits from proceeding until a claimant makes a good-faith effort to demonstrate that at least one expert believes that a breach of the applicable standard of care caused the claimed injury. Id. at 802-04 (rejecting argument that chapter 74 “inter-efere[d] with the judiciary’s constitutional power to decide when and how to render judgments” (citing Murphy v. Russell, 167 S.W.3d 835, 838 (Tex.2005) (per curiam); Walker, 111 S.W.3d at 66). Though the Heberts contend chapter 74 “prohibits the courts from using the rules of procedure and directs the courts in every respect,” in actuality, the courts retain the judicial power to determine whether a timely served report is adequate in this regard and to render a decision accordingly. See Tex. Civ. Prac. & Rem.Code Ann. § 74.351(Z), (r)(6); see also Carrick v. Summers, 294 S.W.3d 886, 891 (Tex.App.-Beaumont 2009, no pet.) (“[I]mposing a strict, non-discretionary time limit on serving the expert report does not restrict the trial court’s power to hear evidence, determine the facts of a case and the rights of the parties, apply the law to the facts and to enter a judgment appropriate to the case, any more than a statute of limitations does.”). The same is true of chapter 74’s requirement that courts award attorney’s fees upon dismissal. Hightower, 348 S.W.3d at 522 (rejecting separation-of-powers challenge based on attorneys’ fees provision because “court still retains its constitutional authority to determine the reasonable fees based on the law and the evidence presented by the parties”). The Heberts offer no persuasive authority to the contrary. Accordingly, we reject the *901Heberts’ separation-of-powers constitutional challenge.
Right of access
Finally, the Heberts argue chapter 74 violates their right of access to the courts and due course of law. The open-courts provision of the Texas Constitution guarantees litigants the right to redress their grievances. Tex. Const. art. I, § 13; LeCroy v. Hanlon, 713 S.W.2d 335, 341 (Tex.1986). It protects a person from having his or her right to sue cut off by a legislative act before the individual has been afforded a reasonable opportunity to discover the wrong and bring suit. Shah v. Moss, 67 S.W.3d 836, 842 (Tex.2001). It is premised on the rationale that the Legislature has no power to make a remedy by due course of law contingent upon an impossible condition. Hightower, 348 S.W.3d at 522 (citing Moreno v. Sterling Drug, Inc., 787 S.W.2d 348, 355 (Tex.1990)); see also Stockton, 336 S.W.3d at 618 (rejecting open-courts challenge based on chapter 74’s 120-day deadline). To prove that the statute violates the open-courts provision, the Heberts must show that: (1) a cognizable common law cause of action is being restricted, and (2) the restriction is unreasonable or arbitrary when balanced with the statute’s purpose and basis. Sax, 648 S.W.2d at 666.
A claimant bringing an as-applied open-courts challenge to chapter 74 must show that the expert-report requirements actually prevented him from bringing his claims. Herrera, 212 S.W.3d at 461; McGlothlin v. Cullington, 989 S.W.2d 449, 453 (Tex.App.-Austin 1999, pet. denied). The Heberts failed to prove how the provisions of chapter 74, as opposed to their own failure to provide an adequate report, prevented them from pursuing their claims. See Ledesma, 2007 WL 2214650, at *9 (rejecting open-courts challenge when plaintiff failed to serve sufficient reports); see also Stockton, 336 S.W.3d at 618-19 (rejecting as-applied open-courts challenge when plaintiff failed to exercise due diligence in serving expert report on defendant physician).
As discussed above, the He-berts have also failed to show chapter 74 is unreasonable or arbitrary when balanced with the statute’s purpose and basis. Health care liability claims require expert testimony at trial. See Smalling, 203 S.W.3d at 371. The expert-report requirement “‘does not violate the open-courts provision by requiring an expert report sooner rather than later in the litigation.’ ” Id. (addressing article 4590i (quoting Mocega, 79 S.W.3d at 64)); see also Gill, 39 S.W.3d at 718-19 (article 4590i expert-report requirement did not violate open-courts provision because plaintiff raising medical negligence claim required to prove claim by competent expert testimony to avoid summary judgment and/or prevail at trial); Bankhead v. Spence, 314 S.W.3d 464, 466 (Tex.App.-Waco 2010, pet. denied) (“This Court and others have determined that the expert-report requirement itself does not violate the open-courts guarantee because it ‘is rationally related to the purpose of the statute to discourage frivolous malpractice suits.’ ” (quoting Powell v. Clements, 220 S.W.3d 138, 140 (Tex.App.-Waco 2007, pet. denied))); Fields, 2006 WL 2089171, at *4 (holding report requirement not so onerous that it “effectively deprived the litigant of access to the court”).14
*902The Heberts have failed to demonstrate a constitutional defect in chapter 74’s expert-report requirement.15 Accordingly, we overrule their second issue.16
CONCLUSION
Having overruled the Heberts’ issues on appeal, we affirm the district court’s judgment.
*903Jones, C.J., dissent.