(Medicare National Coverage Determinations Manual)

190.22 - Thyroid Testing  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110  Thyroid function studies are used to de lineate the presence of absence of hormonal abnormalities of the thyroid and pituitary glands.  These abnormalities may be either primary or secondary and often but not always accompany clinically defined signs and symptoms indicative of thyroid dysfunction.  Laboratory evaluation of thyroid function has become more scientifically defined.  Tests can be done with increased specificity, thereby reducing the number of tests needed to diagnose and follow treatment of most thyroid disease.  Measurements of serum sensitive thyroid- stimulating hormone (TSH) levels, complemented by determination of thyroid hormone levels [free thyroxine (fT -4) or total thyroxine (T4) with Triiodothyronine (T3) uptake] are used for diagnosis and follow -up of patients with thyroid di sorders.   Additional tests may be necessary to evaluate certain complex diagnostic problems or on hospitalized patients, where many circumstances can skew tests results.  When a test for total thyroxine (total T4 or T4 radioimmunoassay) or T3 uptake is per formed, calculation of the free thyroxine index (FTI) is useful to correct for abnormal results for either total T4 or T3 uptake due to protein binding effects.  Indications   Thyroid function tests are used to define hyper function, euthyroidism, or hypofunction of thyroid disease.  Thyroid testing may be reasonable and necessary to:    Distinguish between primary and secondary hypothyroidism    Confirm or rule our primary hypothyr oidism    Monitor thyroid hormone levels (for example, patients with goiter, thyroid nodules, or thyroid cancer)    Monitor dug therapy in patients with primary hypothyroidism    Confirm or rule out primary hyperthyroidism    Monitor therapy in patients with hyper thyroidism   Thyroid function testing may be medically necessary in patients with disease or neoplasm of the thyroid and other endocrine glands.  Thyroid function testing may also be medically necessary in patients with metabolic disorders; malnutrition; hy perlipidemia; certain types of anemia; psychosis and non- psychotic personality disorders; unexplained depression; ophthalmologic disorders; various cardiac arrhythmias; disorders of menstruation; skin conditions; myalgias; and a wide array of signs and sym ptoms, including alterations in consciousness; malaise; hypothermia; symptoms of the nervous and musculoskeletal system; skin and integumentary system; nutrition and metabolism; cardiovascular; and gastrointestinal system.   It may be medically necessary to  do follow -up thyroid testing in patients with a personal history of malignant neoplasm of the endocrine system and in patients on long- term thyroid drug therapy.   Limitations   Testing may be covered up to two times a year in clinically stable patients; mo re frequent testing may be reasonable and necessary for patients whose thyroid therapy has been altered or in whom symptoms or signs of hyperthyroidism of hypothyroidism are noted.   190.23 - Lipid Testing  (Rev. 28, Issued: 02- 11-05, Effective:  01 -01-05, Implementation:  03- 11-05)  Lipoproteins are a class of heterogeneous particles of varying sizes and densities containing lipid and protein.  These lipoproteins include cholesterol esters and free cholester ol, triglycerides, phospholipids and A, C, and E apoproteins.  Total cholesterol comprises all the cholesterol found in various lipoproteins.  Factors that affect blood cholesterol levels include age, sex, body weight, diet, alcohol and tobacco use, exerci se, genetic factors, family history, medications, menopausal status, the use of hormone replacement therapy, and chronic disorders such as hypothyroidism, obstructive liver disease, pancreatic disease (including diabetes), and kidney disease.   In many indi viduals, an elevated blood cholesterol level constitutes an increased risk of developing coronary artery disease.  Blood levels of total cholesterol and various fractions of cholesterol, especially low density lipoprotein cholesterol (LDL -C) and high densi ty lipoprotein cholesterol (HDL -C), are useful in assessing and monitoring treatment for that risk in patients with cardiovascular and related diseases.  Blood levels of the above cholesterol components including triglyceride have been separated into desir able, borderline and high- risk categories by the National Heart, Lung, and Blood Institute in their report in 1993.  These categories form a useful basis for evaluation and treatment of patients with hyperlipidemia.  Therapy to reduce these risk parameters  includes diet, exercise and medications, and fat weight loss, which is particularly powerful when combined with diet and exercise.   Indications   The medical community recognizes lipid testing as appropriate for evaluating atherosclerotic cardiovascular di sease.  Conditions in which lipid testing may be indicated include:    Assessment of patients with atherosclerotic cardiovascular disease    Evaluation of primary dyslipidemia    Any form of atherosclerotic disease, or any disease leading to the formation of atherosclerotic disease    Diagnostic evaluation of diseases associated with altered lipid metabolism, such as: nephrotic syndrome, pancreatitis, hepatic disease, and hypo and hyperthyroidism    Secondary dyslipidemia, including diabetes mellitus, disorders of gastrointestinal absorpt ion, chronic renal failure    Signs or symptoms of dyslipidemias, such as skin lesions    As follow -up to the initial screen for coronary heart disease (total cholesterol + HDL cholesterol) when total cholesterol is determined to be high (>240 mg/dL), or borde rline-high (200 -140 mg/dL) plus two or more coronary heart disease risk factors, or an HDL cholesterol, <35 mg/dL.  To monitor the progress of patients on anti -lipid dietary management and pharmacologic therapy for the treatment of elevated blood lipid dis orders, total cholesterol, HDL cholesterol and LDL cholesterol may be used.  Triglycerides may be obtained if the lipid fraction is also elevated or if the patient is put on drugs (for example, thiazide diuretics, beta blockers, estrogens, glucocorticoids, and tamoxifen) which may raise the triglyceride level.   When monitoring long- term anti- lipid dietary or pharmacologic therapy and when following patients with borderline high total or LDL cholesterol levels, it may be reasonable to perform the lipid panel  annually.  A lipid panel at a yearly interval will usually be adequate while measurement of the serum total cholesterol or a measured LDL should suffice for interim visits if the patient does not have hypertriglyceridemia.  Any one component of the panel or a measured LDL may be reasonable and necessary up to six times the first year for monitoring dietary or pharmacologic therapy.  More frequent total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride testing may be indicated for marked elevat ions or for changes to anti -lipid therapy due to inadequate initial patient response to dietary or pharmacologic therapy.  The LDL cholesterol or total cholesterol may be measured three times yearly after treatment goals have been achieved.   Electrophoreti c or other quantitation of lipoproteins may be indicated if the patient has a primary disorder of lipoid metabolism.   Effective January 1, 2005, the Medicare law expanded coverage to cardiovascular screening services.  Several of the procedures included in this NCD may be covered for screening purposes subject to specified frequencies.  See 42 CFR 410.17 and section 100, chapter 18, of the Claims Processing Manual, for a full description of this benefit.   Limitations   Lipid panel and hepatic panel testing m ay be used for patients with severe psoriasis which has not responded to conventional therapy and for which the retinoid etretinate has been prescribed and who have developed hyperlipidemia or hepatic toxicity.  Specific examples include erythrodermia and generalized pustular type and psoriasis associated with arthritis.   Routine screening and prophylactic testing for lipid disorder are not covered by Medicare.  While lipid screening may be medically appropriate, Medicare by statute does not pay for it.  Li pid testing in asymptomatic individuals is considered to be screening regardless of the presence of other risk factors such as family history, tobacco use, etc.   Once a diagnosis is established, one or several specific tests are usually adequate for monitoring the course of the disease.  Less specific diagnoses (for example, other chest pain) alone do not support medical necessity of these tests.  When monitoring long- term anti- lipid dietary of pharmacologic therapy and when following patients with borderline high total or LDL cholesterol levels, it is reasonable to perform the lipid panel annually.  A lipid panel at a yearly interval will usually be adequate while measurement of the serum total cholesterol or a measured LDL should suffice for interim visits if the patient does not have hypertriglyceridemia.   Any one component of the panel or a measured LDL may be medically necessary up to six times the first year for monitoring dietary or pharmacologic therapy.  More frequent total cholesterol, HDL cho lesterol, LDL cholesterol and triglyceride testing may be indicated for marked elevations or for changes to anti -lipid therapy due to inadequate initial patient response to dietary or pharmacologic therapy.  The LDL cholesterol or total cholesterol may be measured three times yearly after treatment goals have been achieved.   If no dietary or pharmacologic therapy is advised, monitoring is not necessary.  When evaluating non- specific chronic abnormalities of the liver (for example, elevations of transaminase, alkaline phosphatase, abnormal imaging studies, etc.), a lipid panel would generally not be indicated more than twice per year.   190.24 - Digoxin Therapeutic Drug Assay  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110  A digoxin therapeutic drug assay is useful for diagnosis and prevention of digoxin toxicity and/or prevention for under dosage of digoxin.  Indications   Digoxin levels may be performed to monitor drugs levels of individuals receiving digoxin therapy because the margin of safety between side effects and toxicity is narrow or because the blood level may not be high enough to achieve the desired clinical effect.   Clinical indications may include individuals on digoxin:    With symptoms, signs or electrocardiogram (ECG) suggestive of digoxin toxicity   Taking medications that influence absorption, bioavailability, distribution, and/or elimination of digoxin    With impaired renal, hepatic, gastrointestinal, or thyroid function   With pH and/or electrolyte abnormalities    With unstable cardiovascular status, including myocarditis    Requiring monitoring of patient compliance   Clinical indication may include individuals:   Suspected of accidental or intended overdose    Who have an accep table cardiac diagnosis and for whom an accurate history of use of digoxin is unobtainable   The value of obtaining regular serum digoxin levels is uncertain, but it may be reasonable to check levels once yearly after a steady state is achieved.  In additio n, it may be reasonable to check the level if:    Heart failure status worsens    Renal function deteriorates    Additional medications are added that could affect the digoxin level    Signs or symptoms of toxicity develop  Steady state will be reached in approximately 1 week in patients with normal renal function, although 2- 3 weeks may be needed in patients with renal impairment.  After changes in dosages or the addition of a medication that could affect the digoxin level, it is reasonable to check the di goxin level one week after the change or addition.  Based on the clinical situation, in cases of digoxin toxicity, testing may need to be done more than once a week.   Digoxin is indicated for the treatment of patients with heart failure due to systolic dysfunction and for reduction of the ventricular response in patients with atrial fibrillation of flutter.  Digoxin may also be indicated for the treatment of other supraventricular arrhythmias, particularly in the presence of heart failure.   Limitations   This test is not appropriate for patients on digitoxin or treated with digoxin FAB (fragment antigen binding) antibody.  190.25 - Alpha-fetoprotein  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110  Alpha -fetoprotein (AFP) is  a polysaccharide found in some carcinomas.  It is effective as a biochemical marker for monitoring the response of certain malignancies to therapy.   Indications   The AFP is useful for the diagnosis of hepatocellular carcinoma in high- risk patients (such a s alcoholic cirrhosis, cirrhosis of viral etiology, hemochromatosis, and alpha 1-antitrypsin deficiency) and in separating patients with benign hepatocellular neoplasms or metastases from those with hepatocellular carcinoma and, as a non -specific tumor associated antigen, serves in marking germ cell neoplasms of the testis, ovary, retroperitoneum, and mediastinum.   190.26 - Carcinoembryonic Antigen  (Rev. 17, Issued: 07- 02-04) (Effective/Implementation: Not Applicable) PM AB -02-110