Chapter 5 - Clinical Laboratory Procedures

Chiropractors are primary health care providers responsible for the assessment of their patients and diagnosis of their presenting complaints, thereby providing the basis for appropriate care. Laboratory diagnosis, for which chiropractors are trained, plays a valuable role. However, present legislation in Canada restricts direct access of chiropractors to clinical laboratories in most provinces. To circumvent this limitation Canadian chiropractors, unlike their colleagues in the United States, must often refer patients to their medical doctors. This process is unsatisfactory both in terms of cost and quality of care.

It may be argued that since legislation in various provinces currently prohibits the use of laboratory testing as a diagnostic adjunct for chiropractors, recommendations for specific laboratory tests serve no practical purpose. However, education in laboratory diagnosis is a mandatory component of the curriculum in accredited chiropractic colleges and of licensing board examinations in Canada and the USA. In addition the right to order and/or perform laboratory tests is likely to once more be an integral part of chiropractic practice in Canada in the near future because of changes in technology and the law.

In these circumstances the profession should have a set of guidelines in place that clearly defines the parameters within which clinical laboratory testing should be practised. These guidelines also deal with certain laboratory tests which are currently accessible to chiropractors but controversial in nature.

This chapter, with minor modifications, has been adopted from the proceedings of the Mercy Centre Consensus Conference (Haldeman et al. 1992). The list of tests which forms the basis for the guidelines does not constitute a comprehensive compilation of all clinical laboratory investigations. Rather it represents tests that are most commonly utilized in chiropractic practice where law permits.

Literature for well-established standard procedures is listed in the references, but detailed test descriptions are not possible in the space available. The bulk of this information appears in the Section VI recommendations. It has been divided for the purposes of clinical relevance into four sections:

A. General recommendations regarding use of laboratory procedures in chiropractic practice.
B. Detailed guidelines for ordering commonly used tests.
C. Investigational laboratory procedures.
D. Inappropriate laboratory procedures.

The Reference Section (Section VIII) is organized by topic to allow the reader to access relevant material upon which this chapter is based.

Lastly, this chapter contains an appendix that lists useful examples of clinical laboratory guidelines for the investigation of spinal disorders and common visceral pain disorders. Examples of focused organ/health problem profiles are also presented.

For definitions see the Glossary at the end of this publication.
Accuracy

Case Finding

False-Negative Result

False-Negative Rate (FNR)

False-positive rate

False Positive Rate (FPR)

False-Positive Result

"Gold-Standard' Test

Likelihood radio for a positive test result

Likelihood ratio

Negative ratio for a negative test-result

Negative test-result

Odds

Positive test-result

Post-test probability

Precision

Predictive value negative

Predictive value position

Pretest probability

Prevalence

Probability

Screening

Sensitivity

Specificity

True-negative rate

True-negative result

True-positive rate

A. General Recommendations

1. Skill and Training
2. The role of Clinical Laboratory Procedures in Chiropractic Practice
3. Laboratory Selection
4. Office Laboratories
5. Proper Patient Preparation
6. Specimen Collection and Preservation
7. The Need for Laboratory Testing
8. Laboratory Test Selection in Diagnosis
9. Laboratory Test Selection in Screening
10. Laboratory Test Selection in Patient Management
11. Interpretation of Laboratory Reference Values
12. Integration of Clinical Laboratory Data with Other Examination Findings
13. Communication of Laboratory Procedures to the Patient
14. Recording Laboratory Procedures
15. Consultation on Laboratory Procedures
16. Use of Focused Organ/Health Problem-Oriented Test Profiles
17. Use of Investigational Laboratory Tests
18. Novel Application of Established Laboratory Procedures in Chiropractic Practice

1. Routine Urinalysis
2. Complete Blood Count
3. Erythrocyte Sedimentation Rate
4. Biochemical Profiles
5. Plasma Glucose
6. Serum Urea Nitrogen and Creatinine
7. Serum Calcium
8. Serum Inorganic Phosphorus
9. Serum Total Protein and Albumin
10. Serum Cholesterol
11. Serum Alkaline Phosphatase
12. Serum Prostatic Acid Phosphatase
13. Serum Prostate-Specific Antigen
14. Serum Aspartate Aminotransferase
15. Serum Creatine Kinase
16. Thyroid Function
17. Serum Uric Acid
18. Rheumatoid Factor
19. Anti-Nuclear Antibody
20. HLA-B27
21. C-Reactive Protein
22. Serum Potassium
23. Serum Sodium
24. Serum Iron and Total Iron-Binding Capacity
25. Serum Ferritin
26. Fecal Occult Blood

1. Analysis of Trace Minerals in Hair

2. Live Cell Analysis

3. Biochemical Biopsy

4. Determination of "Optimal" Reference Values

D. Inappropriate Clinical Laboratory Procedures

1. Cytotoxic Testing for Food Allergies

2. Reams Testing and Interpretation of Urine

E. Appendix

This chapter has been adopted from the Proceedings of the Mercy Centre Consensus Conference (Haldeman et al. 1992). The literature search utilized the MEDLINE database on CD-ROM from 1980 to February, 1993 for articles using the medical subject heading terms relevant to guidelines for the selection and interpretation of laboratory tests. In addition, the CHIROLARS database was searched for articles related to the use of laboratory diagnosis in chiropractic practice. A manual search of the Chiropractic Research Archives Collection was also accomplished. From these sources bibliographies were compiled which contained both journal articles and textbooks.

Materials were selected for inclusion if they contained information on the usefulness of clinical laboratory tests in patient care. Included was information on the principles of test selection and interpretation of procedures commonly used in chiropractic practice. Priority was given to well-designed studies published in peer-reviewed journals. Second priority was given to review articles and textbooks.

Role of Laboratory Diagnosis

The role of clinical laboratory diagnosis in chiropractic has evolved since the inception of the profession to where currently, laboratory diagnosis courses are taught at all accredited chiropractic colleges. In addition, the majority of jurisdictions in North America allow some form of access to laboratory tests (Lamm, 1989).

The chiropractic practitioner, as a portal of entry health care provider, has the responsibility to perform an appropriate clinical examination for the purpose of assessing a patient's current health status and identifying if the patient is a proper subject for chiropractic care. The clinical laboratory can, at times, provide useful information when the findings from the clinical examination are insufficient to answer the questions at hand. The decision to order a test is made on the assumption that the results will appreciably reduce the uncertainty surrounding a given clinical question and significantly change the pre-test probability that a disorder is present.

Use of Laboratory Tests

Laboratory procedures can be used as screening devices to identify "at risk" patients who may be prone to an illness that can be prevented or diminished by early detection and care. For example, routine measurement of cholesterol can be useful in determining which patients should start on preventive management for atherosclerotic cardiovascular disease. The problem with screening, though, is the number of false-positive results it produces. As the prevalence of a disorder in a population falls, the percentage of false-positive results rises dramatically, so there are five to ten false-positive results for every true-positive one. In order to deal with this situation, many attempts have been made to develop guidelines for selection of appropriate patients and tests for early detection (Eddy, 1991).

A second reason for using clinical laboratory tests is to provide assistance in establishing diagnostic hypotheses. The laboratory may be particularly helpful in sorting out whether a patient's clinical complaints are due to a functional or organic disorder.

To rule out a disorder, very sensitive tests are most effective in reducing the probability of that disorder. Very specific tests are most effective in raising the probability of the presence of a disorder and thus are useful for ruling in diagnoses. Such tests when abnormal can confirm the presence of a disorder (Sox, 1988).

The intelligent selection of an appropriate laboratory test depends on choosing the proper test for the purpose intended. The purpose of the test is affected by the practitioner's estimate of the pretest likelihood that a disorder is present based on an assessment of the available clinical information. The use of a test to exclude or confirm a diagnosis should indicate that the practitioner's best estimate after a careful evaluation of the patient's problem is that the diagnosis in question is either relatively unlikely or probable, respectively. When these principles are followed, the conclusions reached from laboratory test results are likely to be correct and lead to appropriate action (Panzer 1991).

Laboratory tests are used for patient management which includes monitoring patient's response to care, the need for care, and determination of prognosis. Compared with tests for screening and diagnosis, tests used for monitoring are more likely to have abnormal results, show a change from previous test values, cause a change in patient care, and be followed up with repeat testing. Determining the optimal frequency for monitoring patients with repeat tests or procedures cannot be based solely on the presence of the disorder but requires the application of principles of normal physiology, knowledge of the tests or procedures used to monitor the disorder, and awareness of factors other than the disorder that may influence the test result.

Laboratory Test Characteristics

Each laboratory test or procedure possesses a set of characteristics that reflects the information expected in patients with and without the disorder in question. These test characteristics provide clinicians with answers to two fundamental questions: 1) If the disorder is present, what is the likelihood that the test result will be abnormal (positive)? and, 2) if the disorder is not present, what is the likelihood that the result will be normal (negative)? The answer to the first question defines the sensitivity of the test and the answer to the latter defines its specificity.

An ideal test is one for which there is no overlap in the range of results among patients with and without the disorder in question. Few tests are ideal. Usually there is an overlap of results among patients with or without a specific disorder. Each point along the distribution of results that overlap defines a set of operating characteristics for the test. As the point used to define an abnormal result (cutoff point) is moved in the direction of patients with the disorder, the sensitivity decreases. As it is moved in the direction of patients without the disorder, the reverse is true. Some tests may be used both to exclude or to confirm a disorder by altering the criteria for a positive test according to the purpose of the test.

Knowledge of test characteristics is important in deciding which test to select for a given purpose. The process of confirming a disorder requires a test whose specificity is high. When two or more tests are available for this purpose, the one with the highest specificity is ordinarily preferred. When a test is used either for the purpose of screening or to exclude a diagnostic possibility it must be sensitive. When two or more such tests are available, that with the highest sensitivity is ordinarily preferred. Multiple tests are most helpful when: 1) all are normal, thus tending to exclude the disorder; and 2) when all are abnormal, thus tending to confirm the presence of the disorder. Multiple tests are least helpful when one is positive and the others are normal. If two or more tests are highly sensitive and the primary purpose of the test is to exclude a disorder, the gain in sensitivity obtained by ordering more than one test may be offset by the increase in false-positive results.

Reference Ranges for Tests

The limits of normal for most analytical tests are determined by measurements done on a large number of subjects and defined as the range encompassed by two standard deviations from the mean value. There are several limitations inherent in this conventional definition. First, the definition excludes approximately 2.5 percent of the subjects whose values lie at the extremes of the distribution curve, rendering them abnormal but presumably not ill. Second, for most measurable biological substances, the distribution curve of test results is skewed rather than symmetric and the method used to express the reference range does not precisely define the central 95 percent of subjects. Third, the reference population used to calculate the limits is not necessarily free of illness. It is assumed that with a large enough sample, the impact of subjects with disease will be diluted. This assumption has been shown to be invalid for many chemistry determinations. The result is often the reporting of reference limits that are too broad. Fourth, few laboratories adjust the reference range for the many factors that may influence the test results other than disease; these include age, sex, weight, diet, time of day, activity, and position of the subject when the specimen is drawn. Last, and most important, the uniform method used to define the reference range does not recognize the many purposes that the test may serve. This range will differ according to whether the clinician is concerned with confirming a condition or excluding one. Although this traditional approach suffers from the above limitations, alternative approaches which create narrower reference ranges should follow acceptable methods in determining those ranges.

Laboratory Test Interpretation

To ensure proper interpretation of the results of laboratory tests, it is important to consider a prior estimate of the likelihood of the presence of a disorder suspected to be present from the history and clinical examination. This is referred to as a pretest probability or prevalence. When the pretest probability is high, a positive result tends to confirm the presence of a disorder, but an unexpected negative result is not particularly helpful in ruling the condition out. When the pretest probability is low, a normal result tends to exclude the condition, but an unexpectedly positive result is not particularly helpful in confirming the disorder.

If the sensitivity, specificity, and prevalence of the condition are known, then one may easily calculate the effect of the test result on the probability of a correct diagnosis. This is referred to as predictive value or post-test probability (Gottfried and Wagar, 1983).

Commonly Utilized Laboratory Procedures

This chapter contains information on commonly utilized laboratory tests. These tests were selected based upon an informal survey of test utilization by a representative sample of doctors of chiropractic. Each test is described as it relates to its usefulness in screening, diagnosis and patient management. A critical review of the literature on the utility of each test was performed to provide a basis for guideline recommendations.

Rating System 1 assessment criteria are used in this chapter. For an explanation of this system (see p. ...).

Suggested Strength of Recommendation Ratings

Type A: Strong positive recommendation. Based on Class I evidence or overwhelming Class II evidence when circumstances preclude randomized clinical trials.

Type B: Positive recommendation based on Class II evidence.

Type C: Positive recommendation based on strong consensus of Class III evidence.

Type D: Negative recommendation based on inconclusive or conflicting Class II evidence.

Type E: Negative recommendation based on evidence of ineffectiveness or lack of efficacy based on Class I or Class II evidence.

This chapter attempts to provide a conceptual model for the appropriate use of clinical laboratory tests in chiropractic practice.

Although at present there is no Canadian jurisdiction which allows access to the clinical laboratory by chiropractors, these guidelines will stand to emphasize the profession's conviction that the clinical laboratory is often a crucial component of a primary health care provider's armamentarium in the clinical decision making process. However, the true effectiveness of these guidelines will not be known until they are implemented in practice and produce a positive impact on patient care. In the meantime, the recommendations outlined in this chapter must be revised and updated periodically.

The role of Clinical Laboratory Tests in Chiropractic Practice

Adams AH. Determining the usefulness of diagnostic procedures and tests. Chiropractic Technique 1990; 2(3):90-93.

Gottfried EL, Gerard SK. Selection and interpretation of laboratory tests and diagnostic procedures. In: Samily AH, Douglas RG, Barondess JA (eds). Textbook of Diagnostic medicine. Philadelphia: Lea & Febiger, 1987:19-38.

Haldeman S, Chapman-Smith D, Peterson (Jr.) DM (eds). Guidelines for chiropractic quality assurance and practice parameters. Proceedings of Mercy Centre Consensus Conference Jan.25-30, 1992. Gaithersburg; Aspen Publications, 1993.

Jaquet P: The importance of laboratory methods in chiropractic diagnosis. Annals of the Swiss Chiropractors Association. 1971; Vol. V.

Lamm L. Chiropractic scope of practice. Am J Chiro Med 1989; 2(4):155-159.

Vear HJ. Scope of chiropractic practice. In: Vear HJ, ed. Chiropractic standards of practice and quality of care. Gaithersburg: Aspen Publication, 1992:49-67.

Wertman BG, et al. Why do physicians order laboratory tests? A study of laboratory test request and use patterns. JAMA 1980; 243:2080-2082.

Principles of Appropriate Laboratory Test Selection and Use

Baer D, et al. Regulation of physician's office laboratories. Medical Laboratory Observer 1988; Sept:26-32.

Black ER, et al. Characteristics of diagnostic tests and principles for their use in quantitative decision making. In: Panzer RJ, Black ER, Griner PF(eds). Diagnostic Strategies for Common Medical Problems. Philadelphia: American College of Physicians, 1991:1-21.

Griner PF, et al. Selection and interpretation of diagnostic tests and procedures. Principles and Applications. Ann Intern Med 1981;94:553-600.

Kassirer JP. Our stubborn quest for diagnostic certainty. A cause of excessive testing. N Engl J Med 1989; 320(22):1489-1491.

Sox HC, Jr. Probability theory in the use of diagnostic tests. In: Sox HC, ed. Common Diagnostic Tests, Use and Interpretation. Philadelphia: American College of Physicians, 1987:1-17.

Tetrault G: Sensitivity and specificity of clinical tests. Am J Clin Pathol 1991; 96:556.

Woolf SH, Kamerow DB: Testing for uncommon conditions. The heroic search for positive test results. Arch Intern Med 1990; 150:2451-58.

Principles of Laboratory Test Interpretation

Gottfried EL, Wagar, EA. Laboratory testing: a practical guide. Disease-A-Month 1983; 29(11):1.

Panzer RJ, et al. Interpretation of diagnostic tests and strategies for their use in quantative decision making. In: Panzer RJ, Black ER, Griner PF, eds, Diagnostic strategies for common medical problems. Philadelphia: American College of Physicians 1991; 17-28.

Skenzel LP. How physicians use laboratory tests. JAMA 1978; 239:1077-1080.

Speicher CE, Smith JW. Interpretation of strategies. In: Speicher CE, Smith JW eds. Choosing effective laboratory tests. Philadelphia: WB Saunders Co., 1983:37-46.

Statland BE, Winkel P. Selected pre-analytical sources of variation. In: Grasbeck Z, Alstrom T, eds. Reference values in laboratory medicine. The current state of the art. New York: John Wiley and Sons, 1981:127-141.

Guidelines for Ordering Commonly Utilized Laboratory Tests

Routine Urinalysis

Free AH, Free HM. Urinalysis: its proper role in the physician's office. Clinics in Laboratory Medicine 1986; 6(2):253-266.

Keil DP, Moskowitz MA. The urinalysis: a critical appraisal. Medical Clinics of North America 1987; 71(4):607-624.

Pels RJ, et al. Dipstick urinalysis screening of asymptomatic adults for urinary tract disorders, II. bacteriuria. JAMA 1989; 262(9):1221-1224.

Sheets D, Lyman JL. Urinalysis. Emergency Medicine Clinics of North America 1986; 4(2):263-280.

Woolhander S, et al. Dipstick urinalysis screening of asymptomatic adults for urinary tract disorders I. hematuria and proteinuria. JAMA 1989; 262(9):1215-1219.

Complete Blood Count (CBC)

Frye EB, Hubbell FA, Akin BV, Rucker L. Usefulness of routine admission complete blood counts on a general medical service. J Gen Intern Med 1987; 2:373-376.

Rich EC, Crowson TW, Connelly DP. Effectiveness of differential leukocyte count in case finding in the ambulatory care setting. JAMA 1983; 249:633-636.

Ruttiman S, Clemencon D, DuBach U. Usefulness of complete blood counts as a case-finding tool in medical outpatients. Ann Intern Med 1992; 116:44-50.

Shapiro MF, Greenfield S. The complete blood count and leukocyte differential count. An approach to their rational application. Ann Intern Med 1987; 106:65-74.

Erythrocyte Sedimentation Rate (ESR)

Bedell SE, Bush BT. Erythrocyte sedimentation rate from folklore to facts. Amer J Med 1985; 78:1001-1009.

Cunha BA. Interpreting the ESR: an advanced course. Diagnosis 1983; Feb. 62-69.

Lewis SM. Erythrocyte sedimentation rate and plasma viscosity. Association of Clinical Pathologists. London: Broadsheet, 1980; 94.

Sox HC. The erythrocyte sedimentation rate. Guidelines for rational use. Ann Intern Med 1986; 103:515-523.

Biochemical Profiles

Cebul RD, Beck JR. Biochemical profiles: application in ambulatory screening and preadmission testing of adults. Ann Intern Med 1987; 106:403-413.

Hubbell FA, Frye EB, Akin BV, Rucker L. Routine admission laboratory testing for general medical patients. Med Care 1988; 26:619-630.

Sackett DL. The usefulness of laboratory tests in health screening programs. Clin Chem 1973; 19:366-372.

Witte DL, Angstadt DS, Schweitzer JK. Chemistry profiles in wellness programs: test selection and participant outcomes. Clin Chem 1988; 34:1447-1450.

Plasma Glucose

National Diabetes Data Group. Classification and diagnosis of diabetes mellitus and other categories of glucose intolerance. Diabetes 1979; 28:1039-1057.

Service FI, O'Brien PC, Rizza RA. Measurements of glucose control. Diabetes Care 1987; 10:225-237.

Singer DE, et al. Screening for diabetes mellitus. Ann Intern Med 1988; 109:639-649.

Singer DE, et al. Tests of glycemia in diabetes mellitus. Ann Intern Med 1989; 110:125-187.

Serum Urea Nitrogen and Creatinine

Baum N, Dichoso CC, Carlton CR, Jr. Blood urea nitrogen and serum creatinine; Physiology and interpretations. Urology 1975; 5:583.

Beck LH, Kassirer JP. Serum electrolytes, serum osmolality, blood urea nitrogen. In: Sox HC, ed. Common diagnostic tests: use and interpretation. 2nd ed. Philadelphia: American College of Physicians, 1990; 367-389.

Checchio MD, Como AJ. Electrolytes, BUN creatinine: Who's at risk? Ann Rev Med 1988; 39:465-490.

Serum Calcium

Juan D. Hypocalcemia: Differential diagnosis and mechanisms. Arch inter Med 1979; 139:1167-1171.

Lafferty FW. Primary hyperparathyroidism: Changing clinical spectrum, prevalence of hypertension, and discriminant analysis of laboratory tets. Arch Intern Med 1981; 141:1761-1766.

Mundy G. Calcium homeostasis: Hypercalcemia and Hypocalcemia, 2nd ed. London: Martin Dunitz Ltd, 1990.

Wong ET, Freier EF. The differential diagnosis of hypercalcemia: An algorithm for more effective use of laboratory tests. JAMA 1982; 247:75-80.

Serum Inorganic Phosphorus

Knochel JP. The clinical status of hypophosphatemia: An update. N Engl J Med 1985; 313:47.

Yu GC, Lee DB. Clinical disorders of phosphorus metabolism. West J Med 1987; 147:569-576.

Serum Total Protein and Albumin

Whicher JT, Spencer C. When is serum albumin worth measuring? Ann Clin Biochem 1987; 24:572-580.

Whicher JT, et al. The laboratory investigation of paraproteinanemia. Ann Clin Biochem 1987; 24:119-32.

Serum Cholesterol

Garber AM, Sox HC, Littenberg B. Screening asymptomatic adults for cardiac risk factors: the serum cholesterol level. Ann Intern Med 1989; 110:622-639.

Krahn M, et al. Comparison of an aggressive (U.S.) and a less aggressive (Canadian) policy for cholesterol screening and treatment. Ann Intern Med 1991; 115:248-255.

Report of the national cholesterol education program expert panel on the detection, evaluation, and treatment of high blood cholesterol in adults. Arch Intern Med 1988; 148:36-39.

Schucker B, Bradford RH. Screening for High Blood Cholesterol. Clinics Laboratory Medicine 1989; 9(1):29-36.

Serum Prostatic Acid Phosphatase

Carson JL, et al. Diagnostic accuracy of four assays of prostatic acid phosphatase. JAMA 1985; 253:665-669.

Heller JE. Prostatic acid phosphatase: its current clinical status. J Urol 1987; 137:1091-1093.

U.S. preventative services task force. Screening for prostate cancer. In: Guide to Clinical Preventative Services. Baltimore: Williams & Wilkins; 1989:63.

Watson RA, Tang DB. The predictive value of prostatic acid phosphatase as a screening test for prostatic cancer. N Engl J Med 1980; 303-387.

Serum Prostate-Specific Antigen (PSA)

Brawer MK. Laboratory studies for the detection of carcinoma of the prostate. Urologic Clinics N Amer 1990; 17(4):759-768.

Catalona WJ, et al. Measurement of prostate specific antigen in serum as a screening test for prostate cancer. N Engl J Med 1991; 324:1156-1161.

Chadwick DJ, et al. Pilot study of screening for prostate cancer in general practice. Lancet 1991; 338:613-616.

Fiorelli RL, et al. Early detection of Stage A prostate carcinoma: combined use of prostate-specific antigen and transrectal ultra-sonography. JAOA 1991; 91(9):863-870.

Labrie F, et al. Serum prostate specific antigen as pre-screening test for prostate cancer. J Urology 1992; 147:846-851.

Serum Asparatate AminoTransferase (AST)

Chopra G, Griffin PH. Laboratory tests and diagnostic procedures in evaluation of liver disease. Am J Med 1985; 79(8):221-230.

Clermont RJ, Chalmers TC. The transaminase tests in liver disease. Medicine 1967; 46:199-207.

Kools AM, Bloomer JR. Abnormal liver function tests, how to assess their importance in asymptomatic patients. Postgraduate Medicine 1987; 81(6):45-51.

Serum Creatin Kinase (CK)

Lee TH, Goldman L. Serum enzyme assays in the diagnosis of acute myocardial infarction. In: Sox HC, ed. Common diagnostic tests, use and interpretation, 2nd ed. Philadelphia: American College of Physicians, 1990; 35-66.

Klatt EC, Wasef ES, Wong ET. Creatinine kinase in a biochemical test panel. The high cost of a seemingly inexpensive test. Amer J Clin Path 1982; 77(3): 289-284.

Lott JA, Wolf PL. Clinical enzymology, a case-oriented approach. New York: Field, Rich and Associates, Inc, 1986.

Thyroid Function Tests

DeLos Santos ET, Mazzaferri EL. Thyroid function tests. Guidelines for interpretation in common clinical disorders. Postgraduate Medicine 1989; 85(5):333-352.

Feldkamp CS, McKenna MI. Contemporary approach to thyroid disease-emphasizing use of high-sensitivity thyrotropin assays. Henry Ford Hosp Med J 1991; 39(1):25-29.

Helfand M, Crapo LM. Screening for thyroid disease. Ann Intern Med 1990; 112(11):840-849.

Surks MI, et al. American thyroid association guidelines for use of laboratory tests in thyroid disorders. JAMA 1990; 263(11):1529-1532.

Serum Uric Acid

Wallace SL, et al. Preliminary criteria for the classification of the acute arthritis of primary gout. Arthritis Rheum 1977; 20:895-900.

Rheumatoid Factor

Lichtenstein MJ, Pincus T. How useful are combinations of blood tests in "rheumatic panels" in diagnosis of rheumatic diseases? J Gen Intern Med 1988; 3:435-442.

Shmerling RH, Delbanco TL. The rheumatoid factor: An analysis of clinical utility. Amer J Med 1991; 91:528-534.

Wolfe F, Cathey MA, Roberts FK. The latex test revisited. Rheumatoid factor testing in 8,287 rheumatic disease patients. Arthritis Rheum 1991; 34:951-960.

Anti-Nuclear Antibody (ANA) Test

Fritzler MJ. Antinuclear antibodies in the investigation of rheumatic diseases. Bull Dis 1985; 35:1-10.

Sulcebe G, Morcka K. Diagnostic and prognostic significance of different antinuclear antibodies in more than 1000 consecutive Albanian patients with rheumatic diseases. Clin Exptl Rheumatol 1992; 10(3):255-261.

White RH, Robbins DL. Clinical significance and interpretation of antinuclear antibodies. West J Med 1987; 147:210-213.

HLA-B27

Baron M, Zendek I. HLA-B27 testing in ankylosing spondylitis: An analysis of the pretesting assumptions. J Rheumatol 1989; 16:631-636.

Hawkins BR, et al. Use of the B27 test in the diagnosis of ankylosing spondylitis: A statistical evaluation. Arthritis Rheum 1981; 24(5):743-746.

Khan MA, Khan MK. Diagnostic value of HLA-B27 testing in ankylosing spondylitis and Reiter's syndrome. Ann Intern Med 1982; 96:70-76.

C-Reactive Protein

Kushner I. C-reactive protein and the acute phase response. Adv Int Med 1992; 37:313-336.

Kushner I, Volanakis JE, Gewurz H. C-reactive protein and the plasma response to tissue injury. Annals New York Academy Sciences 1982; 389.

Marchand A, Van Lente F. How the laboratory can monitor acute inflammation. Diagnostic Medicine 1984; Nov/Dec:57-66.

Norris MK. Evaluating C-reactive protein levels. Nursing 1992; 22(5):119.

Okamura J, et al. Potential clinical application of C-reactive protein. J Clin Lab Analysis 1990; 4:231-235.

Serum Potassium

Beck LH, Kassirer J. Serum electrolytes, serum osmolality, blood urea nitrogen, and serum creatinine. In: Sox HC, ed. Common diagnostic tests, use and interpretation, 2nd ed. Philadelphia: American College of Physicians, 1990: 367-389.

Martin M, Hamilton R, West MF. Potassium. Emerg Med Clinics N America 1986; 4(1):131-144.

Narina RG, et al. Diagnostic strategies in disorders of fluid, electrolyte and acid-base homeostasis. Am J Med. 1982; 72:496-520.

Serum Sodium

Beck LH, Kassirer J. Serum electrolytes, serum osmolality, blood urea nitrogen, and serum creatinine. In: Sox HC, ed. Common diagnostic tests, use and interpretation, 2nd ed, Philadelphia: American College of Physicians, 1990: 367-389.

Janz T. Sodium. Emerg Med Clin N Amer 1986; 4(1): 115-130.

Narina RG, et al. Diagnostic strategies in disorders of fluid, electrolyte and acid-base homeostasis. Am J Med 1982; 72:496-520.

Serum Iron and Total Iron Binding Capacity

Cavill J, Jacobs A, Worwood M. Diagnostic methods for iron status. Ann Clin Biochem 1986; 23:168-171.

Fairbanks VF. Laboratory testing for iron status. Hospital Practice 1991; 26 (3 Suppl):168-171.

Psaty BM, et al. The value of serum iron studies as a test for iron-deficiency anemia in a country hospital. J Gen Intern Med 1987; 2:160-167.

Serum Ferritin

Fairbanks VF. Laboratory testing for iron status. Hospital Practice 1991; 26 (Suppl 3):17-24.

Patterson C, et al. Iron deficiency anemia in the elderly: The diagnostic process. Can Med Assoc J 1991; 144(4):435-440.

Fecal Occult Blood Test

Brandeau MI, Eddy D. The workup of the asymptomatic patient with a positive fecal occult blood test. Medical Decision Making 1987; 7(1):32-46.

Eddy D. Screening for colorectal cancer. Ann Intern Med 1990; 113:373-384.

Knight K, Fielding J, Battista R. Occult blood testing for colorectal cancer. JAMA 1989; 261(4):586-593.

Hair Analysis

Katz SA, Katz RB. Use of hair analysis for evaluating mercury intoxication of the human body: a review. J Applied Toxicol 1992; 12(2):79-84.

Klevay LM, et al. Hair analysis in clinical and experimental medicine. Am J Clin Nutr 1987; 46:233-236.

Taylor A. Usefulness of measurement of trace elements in hair. Ann. Clin Biochem 1986; 23:364-378.

Live Cell Analysis

Lowell JA. Live cell analysis: High-tech hokum. Nutrition Forum 1986; 3(11):81-85.

Biochemical Biopsy

Fernandes JJ. Realistic expectations of laboratory testing. JAOA 1991; 91(12):1223-1228.

Furda A. Biochemical biopsy. East Lansing: Privately published, 1978.

Gottfried EL, Wagar ED. Laboratory testing: A practical guide. Disease-A-Month 1983; 29(11):1-41.

Black ER, et al. Characteristics of diagnostic tests and principles for their use in quantitative decision making. In: Panzer RJ, Black ER, Grinler PF, eds. Diagnostic strategies for common medical problems. Philadelphia: American College of Physicians 1991:1-16.

Optimal Laboratory Values

Grasbeck R, Alstrom I. Reference Values in Laboratory Medicine. New York: John Wiley and Sons, 1981.

Cytotoxic Testing for Food Allergies

Sawyer CE, Adams AH. The cytotoxic leukocyte test. Amer Chiropractic Assoc J 1987; 21(2):59-61.

Appendix References

Guidelines for Clinical Laboratory Investigation and Laboratory Protocols for Spinal Disorders

Deyo R. Early Diagnostic Evaluaton of Low-back Pain. J Gen Intern Med 1986; 1:328-338.

Deyo R, Diehl A. Cancer as a cause of back pain: frequency, clinical presentation, diagnostic strategies. J Gen Intern Med 1988; 3:230-238.

Waddell G. An approach to backache. Br J Hosp Med 1982; Sept:187-219.

Focused Organ/Health Problem Profiles

Henry JB, Howanitz PJ. Organ panels and the relationship of the laboratory to the physician. In: Jones RJ, Palulonis RM, eds. Laboratory tests in medical practice. Chicago: Amer Med Assoc, 1980: 25-45.

A. General

5.1 The role of laboratory procedures in chiropractic practice

The appropriate use of clinical laboratory procedures in chiropractic practice is for diagnosis, screening, and patient management.

Comment: clinical laboratory tests are used by the practitioner to (1) aid in the diagnostic process; (2) to screen for early recognition of preventable health problems; and (3) monitor patient progress and outcomes. It is inappropriate to utilize clinical laboratory procedures for other purposes (e.g., for defensive testing or economic gain).

Rating: established
Evidence: Class III
Consensus level: 1

5.2 The need for laboratory testing

Laboratory procedures may be appropriate when the information available from the history, clinical examination, and previous evaluation is considered insufficient to address the clinical questions at hand.

Comment: the decision to order, perform or refer for a given test or procedure is made on the assumption that the results will appreciably reduce the uncertainty surrounding a given clinical question and significantly change the pre-test probability that the disorder is present.

Rating: Established

Evidence: Class I, II, III

Consensus level: 1

5.3 Laboratory selection

It is recommended that the practitioner who uses the services of a clinical laboratory should be aware of the laboratory's scope of services, recognition (licensure and accreditation), and reputation.

Rating: Established

Evidence: Class III

Consensus level: 1

5.4 Office laboratories

The practitioner who performs office laboratory procedures should carry out testing in a manner which meets government (provincial) regulations, and is consistent with quality laboratory practice.

Comment: provincial regulations define the scope of testing, qualification of laboratory personnel, and the need and extent of quality assurance and proficiency testing.

Rating: Established
Evidence: Class III
Consensus level: 1

5.5 Proper patient preparation

The practitioner should make sure the patient is adequately prepared for laboratory testing, and understands any special instructions he/she must follow to provide an adequate specimen necessary to generate valid laboratory results.

Rating: Established
Evidence: Class III
Consensus level: 1

5.6 Specimen collection and preservation

The practitioner should assure that in-office laboratory specimens are appropriately collected and preserved.

Rating: Established
Evidence: Class III
Consensus level: 1

5.7 Laboratory test selection in diagnosis

The practitioner should select a laboratory test(s) appropriate for the purpose of ruling out a specific condition(s) or confirming a strong clinical suspicion by considering the sensitivity and specificity of the test(s) and estimating the likelihood of the condition(s) (pre-tested probability) based on his or her assessment of the available clinical information.

Rating: Promising
Evidence: Class I, II, III
Consensus level: 1

5.8 Laboratory test selection in screening

The use of laboratory tests for screening purposes should include selection of a highly sensitive laboratory test(s), the appropriate application of the test(s) to health problem(s) which are common, have significant morbidity/ mortality and are preventable and/or amenable to effective care.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.9 Laboratory test selection in patient management (monitoring)

The reproducibility (precision) of the test is the most important characteristic when selecting laboratory tests for monitoring.

Comment: The optimal frequency for monitoring patients cannot be predicted solely on the basis of knowledge of the disorder or the effectiveness of chiropractic care. It requires the application of normal physiology, knowledge of the natural history of the underlying disorder, tests or procedures used to monitor the disorder and awareness of factors other than the disorder that may influence the test results.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.10 Interpretation of laboratory reference values

The practitioner should have an understanding of "normality" as it applies to conventional laboratory reference values in order to appropriately interpret laboratory results.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.11 Integration of clinical laboratory data with other examination ... findings

Clinical laboratory data should be integrated with results from other examinations as part of the clinical decision-making process when assessing or monitoring the patient's clinical status.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.12 Communication of laboratory procedures and results to the patient

The practitioner should effectively discuss with the patient the purposes, possible complications and clinical significance of the results of laboratory studies conducted or ordered.

Rating: Established
Evidence: Class III
Consensus level: 1

5.13 Recording laboratory results

Clinical laboratory results should be recorded in the patient case record.

Rating: Established
Evidence: Class III
Consensus level: 1

5.14 Consultation on laboratory procedures

The practitioner should seek assistance when uncertain about appropriate test selection, patient preparation, and/or interpretation of laboratory results.

Rating: Established
Evidence: Class III
Consensus level: 1

5.15 Use of focused organ/health problem oriented test profiles

The use of profiles which focus on an organ system and/or health problem in a symptomatic patient can be considered a cost-effective and efficient procedure for generating appropriate laboratory data to help confirm or rule out a diagnosis or clinical impression.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.16 Use of clinical laboratory tests considered investigational

Laboratory tests which are considered to be investigational should be used in clinical settings only when part of an acceptable research protocol which is supervised by the staff of a recognized research institution.

Comment: research protocols for the evaluation of investigational clinical laboratory tests should take into consideration the actual need for the tests, the inherent properties of the tests, the population characteristics to which the tests are applied, the existence of gold standard tests, the required study population size, and the tests' discrimination abilities relative to sensitivity, specificity and predictive value (Adams, 1990). Research protocols should be approved by an institutional review board.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

5.17 The novel application of established laboratory procedures in chiropractic practice

Novel application of established laboratory procedures should not be used in chiropractic practice as a substitute for conventional application of laboratory procedures in the clinical decision-making process.

Comment: novel applications of established tests should be evaluated by appropriate research methods. If used in a patient care setting, informed consent is necessary.

Rating: Established
Evidence: Class I, II, III
Consensus level: 1

B. Guidelines for ordering commonly utilized laboratory procedures

5.18 Guidelines for ordering a urinalysis

5.19 Guidelines for ordering a complete blood count (CBC)

5.20 Guidelines for ordering the erythrocyte sedimentation rate (ESR) test

5.21 Guidelines for ordering biochemical profiles

5.22 Guidelines for ordering a serum or plasma glucose test

5.23 Guidelines for ordering serum urea nitrogen and creatinine test

5.24 Guidelines for ordering a serum calcium test

5.25 Guidelines for ordering a serum inorganic phosphorus test

5.26 Guidelines for ordering serum total protein and albumin tests

5.27 Guidelines for ordering a serum cholesterol test

5.28 Guidelines for ordering a serum alkaline phosphatase test

5.29 Guidelines for ordering serum prostatic acid phosphatase test

5.30 Guidelines for ordering serum prostate-specific antigen (PSA) test

5.31 Guidelines for ordering a serum aspartate aminotransferase (AST) test

Note: this test was formerly known as glutamicoxaloacetic transaminase (SGOT).

5.32 Guidelines for ordering serum creatine kinase (CK)

Note: this test was formerly known as creatine phosphokinase (CPK).

5.33 Guidelines for ordering thyroid function tests

5.34 Guidelines for ordering a serum uric acid test

5.35 Guidelines for ordering a rheumatoid factor test

5.36 Guidelines for ordering the anti-nuclear antibody test (ANA)

5.37 Guidelines for ordering the HLA-B27 test

5.38 Guidelines for ordering the C-reactive protein (CRP) test

5.39 Guidelines for ordering a serum potassium test

5.40 Guidelines for ordering a serum sodium test

5.41 Guidelines for ordering a serum iron and total iron binding capacity (TIBC) tests.

5.42 Guidelines for ordering a serum ferritin test

5.43 Guidelines for ordering a fecal occult blood test

C. Investigational clinical laboratory procedures

5.44 Analysis of trace minerals in hair

5.45 Live cell analysis

5.46 Biochemical biopsy: (Multiple Test Analysis Including Protein Electrophoresis and Isoenzyme Fractionation with Predictive Interpretation of Results).

Biochemical biopsy utilizes a comprehensive approach to laboratory testing where a multitest biochemical test profile is ordered along with isoenzyme fractionation of common enzymes and a serum protein electrophoresis. It may also include other serum protein analyses and complete blood count. The rationale behind the use of this approach is detection of early pathologies in the subclinical phase.

5.47 Determination of "Optimal" Reference Values for Laboratory Tests without Following Acceptable Procedures for the Establishment of Reference Ranges.

D. Inappropriate clinical laboratory procedures

5.48 Cytotoxic testing for food allergies.

A. Useful Guidelines for Clinical Laboratory Investigation of Spinal Disorders
1. Positive Health History for:
Previous malignancy
Striking weight loss
Persistent pain, more than 50 years old
Use of Corticosteroids

2. Positive Clinical Examination for:
Systemic signs (i.e., fever)

3. Radiographic findings suggestive of pathology
4. Failure to improve with conservative care (See Chapter 9, Frequency and Duration of Care)

B. Laboratory Procedures Which May Be Useful for Spinal Disorders

C. Examples of Focused Organ/Health Problem Profiles

Utilization of these procedures requires clinical judgement and appropriateness.

Multisystem Involvement with Vague and Unexplained Physical Changes