Could Maryland chiropractors legally order blood tests and urinalysis, or was that considered practicing medicine without a license?

Plain-English summary

The Board of Medical Examiners asked whether blood tests and urinalysis fell within the legal scope of chiropractic practice, which Maryland law defined as "diagnosing and locating" misaligned or displaced vertebrae without drugs or surgery. The concern was that these lab tests do not themselves directly show a vertebral misalignment; instead, chiropractors used them to rule out organic diseases that might explain a patient's symptoms instead of, or alongside, a spinal problem.

The Attorney General concluded, while calling it a close question, that chiropractors could use blood tests and urinalysis as part of their diagnostic process. The opinion read the statute's reference to "diagnosing... misaligned or displaced vertebrae" broadly enough to include ruling out other causes of a patient's symptoms, not just techniques that directly visualize a misalignment. It also pointed to the licensing exam's long-standing requirement that chiropractors demonstrate competence in bacteriology, histology, and pathology, subjects useful only for interpreting lab results, as evidence the legislature expected chiropractors to use those tests, plus decades of Board practice treating lab diagnosis as a normal part of chiropractic training and discipline.

Currency note

This opinion was issued in 1986. Subsequent statutory amendments, court decisions, or later AG opinions may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here.

Common questions

Did Maryland chiropractors in 1986 need a doctor's involvement to order a blood test or urinalysis on a patient?
The opinion did not address referral requirements for ordering the tests themselves; it addressed whether using blood tests and urinalysis as part of chiropractic diagnosis was within the statutory scope of chiropractic practice, and concluded that it was.

Why would ruling out an organic disease even count as part of "diagnosing misaligned or displaced vertebrae," if the test doesn't show anything about the spine?
The Attorney General reasoned that determining whether a patient's symptoms stem from a vertebral problem can properly include a process of eliminating other possible causes, not only techniques like x-rays or palpation that directly show a misalignment.

Were chiropractors ever required to send a patient to a physician instead of treating them?
Yes, according to the opinion's discussion of the Board of Chiropractic Examiners' position that chiropractors had a duty to refer patients to a physician when a condition was not amenable to chiropractic treatment, and that lab tests helped fulfill that referral duty.

Background and statutory framework

Maryland's Chiropractic Practice Act, originally enacted in 1920 and now Title 3 of the Health Occupations Article, defined "practice chiropractic" as a drugless system of health care based on locating and adjusting misaligned or displaced vertebrae, expressly excluding drugs, surgery, osteopathy, obstetrics, or "any other branch of medicine." HO §3-101(f). The opinion traced the statute's legislative history from a 1920 restriction-based approach through a 1929 definitional rewrite that separately identified "diagnosis" as part of chiropractic practice, a definition the legislature intended to carry forward without expansion or limitation when it was recodified in 1981.

The opinion built its conclusion on several strands: the statutory licensing exam had required competence in bacteriology since 1920 and added histology, pathology, and roentgenology in 1941, subjects meaningful only if chiropractors were expected to interpret lab results; the Board of Chiropractic Examiners had for decades required chiropractic schools to teach laboratory diagnostic techniques and tested for that skill on the licensing exam; and state health regulations authorized medical laboratories to release results to chiropractors alongside physicians and dentists. The opinion also reasoned that reading the statute to bar chiropractors from lab-based diagnosis could delay identification of serious organic conditions, a policy consideration it found consistent with a broader reading of the diagnostic authority the legislature granted.

Citations

Statutes:

• HO §3-101(f), and subsections (1) through (4) (statutory definition of the practice of chiropractic)
• HO §14-101(k) (broad definition of the practice of medicine, contrasted with chiropractic)
• HO §3-304, §3-304(d)(4)(i), §3-304(d)(4)(ii), and §3-304(d)(1) (chiropractic licensing examination subject requirements)
• HO §3-302(c)(2) and §3-402 (chiropractic school approval requirements)
• HO §3-308(d)(2) (continuing education requirements)
• Chapter 666, Laws of Maryland 1920 (original Chiropractic Practice Act)
• Chapter 534, Laws of Maryland 1929 (definitional rewrite of chiropractic practice)
• Chapter 704, Laws of Maryland 1949 (diet and hygiene provision, now HO §3-101(f)(4))
• Chapter 8, Laws of Maryland 1981 (recodification of the Health Occupations Article)
• Chapter 501, Laws of Maryland 1941 (added histology/pathology/roentgenology to licensing exam)
• Chapter 268, Laws of Maryland 1953 (Board-approved school requirement)
• Chapter 378, Laws of Maryland 1981 (statutory mandate for exam evaluation criteria)
• Chapter 105, Laws of Maryland 1973 (continuing education authority)
• COMAR 10.10.01.07D (medical laboratory results may be released to chiropractors)

Cases:

• Public Service Comm'n v. Baltimore Gas & Electric Co., 60 Md. App. 495, 508 (1984)
• Aitchison v. State, 204 Md. 538, 546 (1954)
• State v. Sinclair & Sinwellan Corp., 274 Md. 646, 658 (1975)
• State v. One Hundred and Fifty-Eight Gaming Devices, 304 Md. 404, 429 n. 12 (1985)
• People v. Bovee, 285 N.W.2d 53, 59 (Mich. App. 1979)
• Robinson v. State, 18 Md. App. 678, 692 (1973)
• Northland Insurance Co. v. Walls, 291 Md. 604, 611 (1981)
• Woodmont Country Club v. Montgomery County, 61 Md. App. 229, 236 (1985)
• Department of State Planning v. Mayor & Council of Hagerstown, 288 Md. 9, 14 (1980)
• Board of Examiners in Optometry v. Spitz, 300 Md. 466, 480 (1984)
• Jackson Marine Sales, Inc. v. State Dep't of Assessments & Taxation, 32 Md. App. 213, 217, cert. denied, 278 Md. 725 (1976)
• Salazar v. Ehmann, 505 P.2d 387, 389 (Colo. App. 1972)

Source

• Landing page: https://oag.maryland.gov/resources-info/Pages/attorney-general%E2%80%99s-opinions.aspx
• Original PDF: https://oag.maryland.gov/resources-info/Documents/pdfs/Opinions/1986/Volume71_1986.pdf

Original opinion text

Best-effort transcription from a scanned PDF. Minor errors may remain, the linked PDF is authoritative.

Health Occupations—Chiropractors—Blood Testing and Urinalysis Are Within Scope of Practice of Chiropractic.

August 1, 1986

Arthur T. Keefe, Jr., M.D.
Secretary, Board of Medical Examiners of Maryland

The Board of Medical Examiners has requested our opinion on whether the use of certain laboratory diagnostic techniques, specifically, blood tests and urinalysis, is within the scope of the practice of chiropractic, as defined by §3-101(f) of the Health Occupations Article ("HO" Article).

While the question is a close one, for the reasons given below, we conclude that the use of those laboratory procedures is within the scope of the practice of chiropractic.1

I
Statutory Definition of Practice of Chiropractic

The starting point of our analysis is, of course, the language of the statutory "scope of practice" provision applicable to chiropractors. See Public Service Comm'n v. Baltimore Gas & Electric Co., 60 Md. App. 495, 508 (1984). HO §3-101(f) defines the practice of chiropractic as follows:

"(1) 'Practice chiropractic' means to use a drugless system of health care based on the principle that interference with the transmission of nerve impulses may cause disease.

(2) 'Practice chiropractic' includes the diagnosing and locating of misaligned or displaced vertebrae and, through the manual manipulation and adjustment of the spine and other skeletal structures, treating disorders of the human body.

(3) Except as otherwise provided in this title, 'practice chiropractic' does not include the use of drugs or surgery, or the practice of osteopathy, obstetrics, or any other branch of medicine.

(4) The definition of 'practice chiropractic' does not prohibit a chiropractor from selecting diet and hygiene measures for an individual."

Thus, chiropractic is a limited form of health care. Cf. HO §14-101(k) (broadly defining practice of medicine). Accordingly, chiropractors are restricted in their practice to only those actions encompassed by the statutory definition. See 15 Opinions of the Attorney General 63, 65 (1930) (in absence of authorization under prior law, chiropractors could not prescribe diets). If chiropractors are not statutorily authorized to make use of laboratory procedures in "diagnosing... misaligned or displaced vertebrae," a chiropractor's attempt to do so would constitute unlawful practice of medicine.

It has been suggested that the definitional reference to "diagnos[is] of misaligned or displaced vertebrae" restricts chiropractors to using only those diagnostic techniques that will affirmatively and directly show the existence of such misalignments or displacements. X-rays and purely physical diagnostic techniques such as palpation will affirmatively show the existence and location of any misalignment or displacement. Laboratory analyses of blood and urine samples, however, will not. Rather, they are used by chiropractors to eliminate the possibility that a patient's symptoms are caused by an organic disorder not treatable by chiropractic. Accordingly, it has been suggested that the use of those laboratory procedures falls outside the scope of "diagnosing ... misaligned or displaced vertebrae."

However, in our view, HO §3-101(f)(2) need not and should not be read so restrictively. One legitimate way of determining whether a patient suffers from misaligned or displaced vertebrae is to eliminate other potential causes of the patient's symptoms.2 Accordingly, we think that "diagnosing... misaligned or displaced vertebrae" may be accomplished both by the use of diagnostic procedures that will affirmatively show the presence or absence of misalignment and by the use of less direct, process-of-elimination methods of diagnosis.

Of course, chiropractors are prohibited by HO §3-101(f)(3) from making use of any diagnostic procedure that involves the use of drugs or surgery.3 It has been suggested that HO §3-101(f)(3) also prohibits chiropractors from using the procedures at issue here, by prohibiting "the practice of osteopathy, obstetrics, or any other branch of medicine." We do not think that provision has such an effect, however.

Diagnosis certainly is a part of the practice of medicine in general. HO §14-101(k). See Aitchison v. State, 204 Md. 538, 546 (1954). However, the general phrase "any other branch of medicine" in HO §3-101(f)(3) follows a specific enumeration of particular medical specialties. In such a case, "the general words in the statute will usually be construed to include only those things of the same class or general nature as those specifically antecedently mentioned." State v. Sinclair & Sinwellan Corp., 274 Md. 646, 658 (1975). See also State v. One Hundred and Fifty-Eight Gaming Devices, 304 Md. 404, 429 n. 12 (1985). Diagnostic techniques do not in themselves constitute a comparable "branch of medicine", that is, diagnosis is not itself a medical treatment specialty similar to osteopathy or obstetrics.

Thus, HO §3-101(f)(3) as a whole should be read as prohibiting chiropractors from (i) using drugs or surgery for either diagnostic or treatment purposes and (ii) treating their patients by any of the methods used in any medical specialty, except those clearly permitted. E.g., HO §3-101(f)(4). It does not prohibit chiropractors from employing a diagnostic technique involving laboratory tests but not the use of drugs or surgery.

II
Background and Legislative History of Scope of Practice Provisions

A. Background of Enactment

In construing a statute, the background of its adoption, the circumstances existing at the time, may properly be considered in resolving any uncertainty as to its meaning. Northland Insurance Co. v. Walls, 291 Md. 604, 611 (1981).

The Chiropractic Practice Act, now codified as Title 3 of the Health Occupations Article, was originally enacted as Chapter 666 of the Laws of Maryland 1920. That Act did not expressly define the practice of chiropractic. Instead, it limited the scope of chiropractic by providing that chiropractors "may adjust by hand any articulations of the spinal column, but shall not prescribe [medication], practice major or minor surgery, obstetrics, nor any other branch of medicine, nor practice osteopathy." Chapter 666, Laws of Maryland 1920, sec. 6(c).

At that time, there was disagreement within the profession itself as to the proper scope of the practice of chiropractic. One school of thought held, on the ground that all diseases and disorders are caused by misalignment or displacement of vertebrae, that diagnosis is neither a necessary nor a proper part of the practice of chiropractic. Beideman, "Seeking the Rational Alternative: The National College of Chiropractic from 1906 to 1982," 3 Chiropractic History 17, 17-18 (1983). The other school held that diagnosis is fully as necessary and as proper in the practice of chiropractic as in the practice of medicine. Id. Accordingly, adherents of the second school of thought made use of appropriate diagnostic procedures except those involving the use of drugs or surgery.

Chiropractors in Maryland were predominantly adherents of that second school of chiropractic thought. Memorandum from D. Brent Owens, D.C., President, Board of Chiropractic Examiners, to Harry J. Matz, Assistant Attorney General (March 10, 1985). If the General Assembly had disapproved chiropractors' use of diagnostic procedures, the Chiropractic Practice Act, enacted "to authorize and regulate the practice of Chiropractic", would likely have included a clear prohibition against the practice. Instead, however, the Act reflected Maryland chiropractors' orientation toward diagnostic techniques, for example, in the Act's requirement that applicants for licensure as chiropractors demonstrate competence in subjects related to general diagnosis. Chapter 666, Laws of Maryland 1920, sec. 6(b). Hence, the General Assembly, in adopting the Act, apparently contemplated and approved the use by chiropractors in Maryland of commonly practiced drugless and nonsurgical diagnostic techniques.

B. Legislative History

The legislative history of HO §3-101(f) likewise, in our view, reflects an intention to authorize chiropractors to employ appropriate techniques in diagnosing vertebral misalignments.

Chapter 534 of the Laws of Maryland 1929 "substitut[ed] a definition of Chiropractic in place of the limitations imposed on persons practicing Chiropractic" by the 1920 Act. Under the 1929 Act, the practice of chiropractic was defined in part as "diagnosis, the location of misaligned or displaced vertebrae of the human spinal column, the procedure preparatory to and the adjustment by hand of such misaligned or displaced vertebrae." Chapter 534, Laws of Maryland 1929 (amending then Article 43, §384(c)).

Thus, in that original definition, diagnosis was identified as an element of the practice of chiropractic separate from the locating of a diagnosed misalignment or displacement, thereby reflecting the theory and practice of chiropractors in Maryland. Therefore, that definition should be read, in accordance with the ordinary signification of its terms, as authorizing chiropractors to perform appropriate nonsurgical and drugless diagnosis, in order to determine whether their patients suffer from conditions treatable by chiropractic. See Woodmont Country Club v. Montgomery County, 61 Md. App. 229, 236 (1985) (statutory language should be given its ordinary meaning, considered in light of statute's objectives).

That aspect of the original definition remained unchanged until its recodification, as part of a general revision and recodification of State law concerning the various health occupations, by Chapter 8 of the Laws of Maryland 1981.4 The Revisor's Note to HO §3-101(f) stated that "[t]he revised definition is not intended to expand, limit, or prohibit practices authorized under the former definition of 'practice of chiropractic.'" That definition was enacted as proposed by the revisor. Chapter 8, Laws of Maryland 1981, sec. 2 at 96-97. Thus, the present definition is unquestionably intended to be construed in the same way as the original definition.5

III
Other Relevant Statutory Provisions

A. Introduction

The language of any particular statutory provision must be construed in context and in relation to all other provisions of the statute. Department of State Planning v. Mayor & Council of Hagerstown, 288 Md. 9, 14 (1980). The relevant provisions of Title 3 of the Health Occupations Article bolster our view that the General Assembly did not intend to entirely prohibit chiropractors from using laboratory diagnostic tests.

B. Licensing Examination Requirements

HO §3-304 requires all applicants for licensure as chiropractors to pass a qualifying examination and sets minimum requirements for the content of that examination. The preclinical subjects covered on the examination must include at least bacteriology, histology, and pathology. HO §3-304(d)(4)(i). Those studies teach material that is necessary to an understanding of the results of laboratory tests, but is by no means necessary to the competent use of physical diagnostic techniques.6

In addition, the clinical studies that must be tested on the licensing examination include symptomatology, as well as physical diagnosis and roentgenology. HO §3-304(d)(4)(ii). That is, prospective chiropractors must demonstrate competence not only in their performance and evaluation of physical diagnosis and x-rays but also in their evaluation of symptoms in general. Were chiropractors restricted to ascertaining whether their patients suffer from misaligned or displaced vertebrae through x-rays and physical examinations alone, there would surely be no need for such a requirement. Indeed, in that case, HO §3-304(d)(4)(ii) would require chiropractors to demonstrate competence in a skill that they were prohibited from using. We think that the General Assembly could not have intended such a result. See Woodmont Country Club v. Montgomery County, 61 Md. App. 229, 236 (1985) (statutory construction that leads to unreasonable or illogical results is to be avoided).

C. History of Examination Requirements

Nor are these examination requirements by any means recent innovations. From its original enactment, the Chiropractic Practice Act required a licensing examination that included at least the subjects of symptomatology and bacteriology. Chapter 666, Laws of Maryland 1920, sec. 6(b). In 1941, histology and pathology were added to the list of subjects that must be included in the preclinical portion of the licensing examination, and roentgenology was added to the clinical portion. Chapter 501, Laws of Maryland 1941 (amending then Article 43, §446(b)).

The 1941 enactment also substituted the more standard terms "neurology" and "physical diagnosis" for "nerve tracing" and "physical examination" in the designations of the clinical subjects of the examination. By those additions and amendments to the minimum licensing requirements, the General Assembly clearly recognized that chiropractic had moved away from a "one cause, one cure" theory of disease and toward the mainstream of health care. R.C. Schafer, D.C., Chiropractic Health Care 62, 69-70 (3d ed. 1978). Moreover, in thus upgrading the licensing requirements to reflect that progress in the profession, the General Assembly acknowledged that chiropractors appropriately make use of certain of the same diagnostic techniques used by physicians, i.e., blood and urine analyses.

IV
Administrative Interpretations and Policy Considerations

A. Introduction

The interpretation given to a statute by those affected by it, and relied on by the public generally, is entitled to considerable weight in construing the statute. Board of Examiners in Optometry v. Spitz, 300 Md. 466, 480 (1984). On the present issue, it is apparent that chiropractors, their patients, and the public at large have long taken the view that laboratory analyses are an appropriate part of chiropractic diagnosis.

B. Educational Requirements

As already noted, chiropractic practice in Maryland has from its beginnings included the use of diagnostic techniques. See Part II A above. Accordingly, the Board of Chiropractic Examiners has long required that chiropractors licensed in Maryland be trained in the use of such techniques, including blood and urine analyses.

Since at least the early 1950's, the Board has required schools of chiropractic to train their students in laboratory diagnostic techniques. Board of Chiropractic Examiners, "Essentials for the Approval of Chiropractic Schools" at 12, 17 (December 17, 1953).7 The uniform standards for accreditation of chiropractic schools promulgated by the national Council on Chiropractic Education likewise require the schools to provide training in the use of laboratory diagnostic tests. Council on Chiropractic Education, "Educational Standards for Chiropractic Colleges" at III-7, III-23 (February, 1984). The Board now relies largely on those standards in determining whether to approve particular schools. See Revisor's Note, HO §3-402.

Further, the Board's criteria for evaluating performance on the licensing examination require prospective chiropractors to "demonstrate the ability to use standard methods of diagnostic procedures common to all healing arts," including blood and urine tests. Board of Chiropractic Examiners, Evaluation Criteria for Clinical Portion of Examination, Part VI (December 17, 1981). Notably, those criteria were promulgated in accordance with a statutory mandate. See Chapter 378, Laws of Maryland 1981 (enacting HO §3-304(d)(1)). In the years since the Board's adoption of those criteria, the General Assembly has taken no action to nullify the requirement of proficiency in laboratory diagnosis. Such legislative inaction is indicative that the requirement carries out the legislative intent regarding chiropractors' qualifications. Jackson Marine Sales, Inc. v. State Dep't of Assessments & Taxation, 32 Md. App. 213, 217, cert. denied, 278 Md. 725 (1976).

C. Practice Requirements

The General Assembly has likewise acquiesced in regulations that identify laboratory diagnostic techniques as appropriate subjects of required continuing education for chiropractors. In 1973, the Board was granted statutory authority to establish continuing education requirements for the annual renewal of chiropractors' licenses. Chapter 105, Laws of Maryland 1973. Those requirements "shall reflect current educational methods and chiropractic techniques." HO §3-308(d)(2). The regulations adopted under that authority include clinical laboratory diagnosis among the course subjects that satisfy the requirement, thereby clearly identifying such diagnostic techniques as part of "current ... chiropractic techniques." See Board of Chiropractic Examiners, "Policy and Procedures: Continuing Chiropractic Education." That identification, never repudiated by the General Assembly, evidences the legislative view of laboratory diagnosis as an appropriate part of the practice of chiropractic.8

Further, the Board has indicated that it will discipline chiropractors for failure to use laboratory diagnosis when laboratory tests are indicated. See Board of Chiropractic Examiners, "Position/Policy Paper on Diagnosis, Treatment and Referral." See also American Chiropractic Association, Chiropractic: State of the Art 1984 at 6-7 (1984) (quoting Council on Chiropractic Education statements adopted January 1978 and June 1979). In the Board's view, such tests are necessary to the complete fulfillment of a chiropractor's duty to refer patients to medical practitioners whenever a patient's condition is not amenable to treatment by chiropractic. Memorandum from Board of Chiropractic Examiners to Thomas J. Kwiatkowski, Jr., at 4 (June 23, 1983). See also Salazar v. Ehmann, 505 P.2d 387, 389 (Colo. App. 1972) (chiropractor has duty to refer patient to physician when chiropractor knows or reasonably should know that medical, rather than chiropractic, care is indicated).

D. Other Administrative Interpretation

The evidence regarding the scope of chiropractic that is provided by the administrative practices of the Board is bolstered by another administrative interpretation, in a different context.

Specifically, the Secretary of Health and Mental Hygiene, in regulations governing medical laboratories, has authorized laboratories to provide examination results to "a licensed practitioner of medicine, dentistry, podiatry, or other person authorized to engage in the practice of healing." COMAR 10.10.01.07D. Thus, medical laboratories are authorized to, and do, provide services to chiropractors. Such a practice is additional evidence that the use of laboratory tests is within the scope of the practice of chiropractic. Cf. Board of Examiners in Optometry v. Spitz, 300 Md. 466, 481 (1984) (ophthalmologists' practice of referring patients to opticians for contact lens fitting indicates opticians are authorized to perform such fittings).

E. Policy Considerations

For many patients, a chiropractor is the "portal of entry" health care provider, that is, the health care provider to whom the patient turns first. Those patients certainly expect the chiropractor to determine, by appropriate means of diagnosis, whether referral to a physician is needed.

If such a patient suffers from an organic disorder, the chiropractor's inability to perform or order laboratory tests may seriously delay a needed referral to a physician. In the case of a life-threatening disorder discoverable only by means of those tests, the consequences of such a delay could be grave. The alternative, presumably, would be for a chiropractor to refer patients to a physician for laboratory tests whenever the chiropractor has any reason to suspect the patient might suffer from such an organic disorder. In that case, the cost of health care would be significantly, and, perhaps, needlessly, increased. It is reasonable to conclude that the General Assembly, because of these possible effects, chose to define the scope of chiropractic practice to include the use of laboratory procedures.

V
Conclusion

In summary, it is our opinion that chiropractors may use blood tests and urinalysis as part of their diagnoses to determine whether their patients suffer from conditions amenable to chiropractic treatment. While the question is a close one, we believe that the statutory provisions governing chiropractors, read as a whole and in light of the long-standing practice of chiropractors, evidence a legislative intent to authorize chiropractors to use those diagnostic techniques.

Stephen H. Sachs
Attorney General
C.J. Messerschmidt
Assistant Attorney General

Jack Schwartz
Chief Counsel
Opinions and Advice

1 This opinion should not be understood to address the statutory authority for any laboratory procedure other than blood tests and urinalysis, the subject of your inquiry and the procedures traditionally used by chiropractors. See Part II A below.

2 Back pain, the complaint chiropractors most commonly see, may be caused by various organic disorders, as well as by misaligned vertebrae. Letter from D. Brent Owens, D.C., Vice-President, Board of Chiropractic Examiners, to Arthur T. Keefe, Jr., M.D., Secretary, Board of Medical Examiners, at 2 (December 17, 1982). Chiropractic treatment is inefficacious to remedy those disorders and, in some cases, may be contraindicated. Id.

3 A Michigan appellate court has held that taking a blood sample, because it involves piercing the skin with a needle, is prohibited by a statute prohibiting chiropractors from performing "incisive surgical procedures [or] an invasive procedure requiring instrumentation." People v. Bovee, 285 N.W.2d 53, 59 (Mich. App. 1979). That statutory language broadly prohibits all procedures involving intrusion into the body, whether or not those procedures constitute surgery. HO §3-101(f)(3), in contrast, prohibits "the use of ... surgery," but does not clearly prohibit all intrusive procedures. Taking blood samples is an intrusive procedure. See Robinson v. State, 18 Md. App. 678, 692 (1973). It is by no means, however, "surgery" as that term is generally understood.

4 Other aspects of the definition were amended in the interim. For example, Chapter 704 of the Laws of Maryland 1949 enacted a provision clarifying the right of chiropractors to "select[] food materials necessary for the nourishment of the body and measures of cleanliness incident to the care of the human body." That provision is now codified at HO §3-101(f)(4).

5 Even were that not so, we think that the change in phrasing is not so material as to evidence a legislative intent to modify the law. See In re Special Investigation No. 236, 295 Md. 573, 576-77 (1983).

6 We recognize that the statutory list of required examination subjects does not include certain other subjects relevant to laboratory analysis, for example, nephrology and urology. In our view, however, that omission merely reflects the fact that chiropractic is a more limited form of health care practice than medicine. The diagnosis that a chiropractor performs is not, therefore, a general medical diagnosis, but a diagnosis designed to ascertain whether a patient's symptoms are caused by misaligned or displaced vertebrae or by some organic disorder.

7 The Board was first granted authority to "recognize" schools that provided the statutorily required minimum chiropractic training by Chapter 501 of the Laws of Maryland 1941. Graduation from a Board-approved school was explicitly made a statutory prerequisite to licensure by Chapter 268 of the Laws of Maryland 1953. That requirement is now codified at HO §3-302(c)(2), and the minimum standards for Board approval of chiropractic schools are codified at HO §3-402.

8 This is so, in our view, notwithstanding that the Board does not specifically require chiropractors to take continuing education courses in laboratory diagnosis. While any particular chiropractor may choose other courses, the regular inclusion of laboratory diagnosis among the Board's course offerings is nonetheless indicative that such diagnostic techniques are regarded as an appropriate part of chiropractic.