index (in'deks?) (in'di-sez?) plural.indexes, indices [L. index, pointer]
1. The forefinger.
2. The ratio of the measurement of a given substance to that of a fixed standard.
addiction severity index
A structured assessment tool that evaluates the impact of addictive behavior on seven areas of living: alcohol use, drug use, employment, family relationships, illegal activities, physical health, and psychological health.
alveolar indexGnathic index.
ankle-brachial index Abbreviation: ABI
A measure of the adequacy of blood flow to the arteries of the legs. It is used to gauge the severity of peripheral vascular disease.
The index is obtained by measuring the systolic blood pressure in the upper and lower extremities after the patient has been lying on his or her back for about 5 min and then repeating the measurements after the patient walks for 5 min. There are several ways to obtain an ABI. The most accurate test results are obtained by measuring the blood pressure in both arms using a blood pressure cuff and Doppler ultrasound and recording the higher of these two pressures. The measurement is repeated in each leg, with measurement of blood pressures at both the posterior tibial and dorsalis pedis arteries. The pressure that should be recorded is the pressure found during the first return of a pulse to the cuffed limb. The blood pressure in each leg is divided by the blood pressure in the higher pressure of the two arms to obtain an ABI for each lower extremity. An ABI above 0.9 is normal, except when it exceeds 1.3 (an indicator of severe peripheral arterial obstruction). Severe obstruction is also indicated by an ABI of less than 0.5. Moderate peripheral arterial disease is suggested by an ABI of 0.8. A drop in the ABI after exercise also strongly suggests peripheral arterial disease. Patients with mild or moderately abnormal ABIs are usually treated with antiplatelet medications, an exercise regimen, and cholesterol-lowering drugs or diet. Those who smoke are encouraged to quit. Patients with severe disease may need angiography and, in some instances, arterial bypass surgery or stenting.
apnea-hypopnea index Abbreviation: AHI
The number of times in an hour when a sleeping person either stops breathing completely or has limited airflow. Each episode must last at least 10 sec. The AHI is one indicator of obstructive sleep apnea, although it is recognized as an imperfect diagnostic tool. An AHI of 30 or more events in an hour indicates severe sleep apnea; 15 to 29 events suggests moderate apnea; and 5 to 14 events indicates mild apnea.
Barthel index See: Barthel index
bispectral index Abbreviation: BIS
An electroencephalographic measure of the effect of sedative and hypnotic drugs on an anesthetized patient. It is used (along with clinical assessment of the patient) to determine the level of central nervous system depression. The index ranges from zero (completely unresponsive to stimulation) to 100 (awake and alert). At levels below 60, most patients are adequately sedated for surgery.
BODY MASS INDEX
body mass index Abbreviation: BMI
An index for estimating obesity. The BMI can be obtained by dividing weight in kilograms by height in meters squared, or according to the following formula: BMI = (Weight/2.205) / (Height/39.37)2 . In adults, a BMI greater than 30 kg/m2 indicates obesity; a BMI greater than 40 kg/m2 indicates morbid obesity; and a BMI less than 18.5 kg/m2 indicates a person is underweight. The lowest overall death rate is found in people with a BMI of 20 to 24.9 kg/m2. Synonym: Quetelet index See: illustration
burn scar index
A rating scale developed to assess hypertrophic burn scars and their rate of development or resolution. It is available at Burnsurgery.org. Synonym: Vancouver scar index; Vancouver scar scale
The cardiac output (expressed in liters per minute) divided by the body surface area (expressed in square meters).
The biparietal diameter of the skull divided by its occipitofrontal diameter, all multiplied by 100.
The ratio of greatest transverse diameter to the greatest anteroposterior diameter of the cranium.
The ratio of the toxicity of a drug, expressed as the maximum tolerated dose per kilogram of body weight to the minimal curative dose per kilogram of body weight. This index is used in judging the safety and effectiveness of drugs.
clinical risk index for babies Abbreviation: CRIB
An index of the severity of illness, used to estimate the likelihood of mortality in very low birth weight infants who are cared for in a neonatal intensive care unit.
An outmoded method of expressing the amount of hemoglobin present in each red cell.
Cumulative Index to Nursing and Allied Health Literature See: Cumulative Index to Nursing and Allied Health Literature
A system of numbers for indicating comparative size of the teeth.
The index of dental health and caries experience based on the number of decayed, missing, and filled (DMF) teeth or tooth surfaces.
dynamic gait index Abbreviation: DGI
A semiquantitative tool used to evaluate a patient's ability to modify gait by changing task demands, esp. in patients with dizziness and balance deficits. This test is used to identify patients, esp. older adults, who are predisposed to falling. Patients are graded on their ability to vary speed, turn their heads, turn their bodies, step over and around obstacles, climb stairs, turn while walking, pick objects up from the floor, and perform alternate step-ups on a stool.
A relative value indicating the quantity of ionizing radiation received by a digital radiographic image receptor. Although vendors currently use many kinds of exposure indices, e.g., Sensitivity Numbers, standardization is being developed by physicists' organizations.
The difference between the muscle power generated during peak exertion and the power that can be generated after repeated loading and unloading of the muscle.
Frenchay Activities Index
A formal interview for patients who have suffered a stroke to compare their functional abilities preceding and following the stroke. The patient describes how employment, meal preparation and clean up, gardening, shopping, and other activities of daily living have been altered by the stroke.
gas exchange index
One of several measurements of the efficiency of respiration, esp. of the extent of intrapulmonary shunting in respiratory failure. Among the commonly used gas exchange indices is the alveolar-arterial oxygen tension difference (a measurement derived from an analysis of the oxygen tension of an arterial blood gas compared with the atmospheric oxygen content).
A ratio used to describe the ability of a food to increase blood glucose levels as compared with consumption of either glucose or white bread as the standard. Foods with a low glycemic index result in a slower rise and lower maximum elevation of blood glucose levels than foods with a higher glycemic index. Consumption of low glycemic index foods can contribute to blood glucose regulation in patients with diabetes mellitus. Another use for the index is to identify the choice of food that will raise blood sugar levels after, e.g., endurance exercise.
A measure of the degree of projection of the upper jaw by finding the ratio of the distance from the nasion to the basion to that of the basion to the alveolar point and then multiplying by 100. Synonym: alveolar index
human development index
A measure of national quality of life used by the United Nations Development Program. It consists of three elements: life expectancy at birth, mean years and expected years of schooling, and the gross national income at purchasing power parity per capita.
Insall-Salvati index See: Insall-Salvati index
International Sensitivity Index Abbreviation: ISI
A laboratory standard for thromboplastins, the reagents used to determine the prothrombin time (PT). Because thromboplastin contents vary, PT results performed on the same sample of blood in different laboratories can be markedly different, even though the patient's actual level of anticoagulation is a constant. The ISI is used to calculate the international normalized ratio, a standardized measure of anticoagulation, thus enabling health care professionals working with different laboratories to compare results and adjust anticoagulant doses according to a single set of guidelines.
Karnofsky Index See: Karnofsky Index
The rate at which cells take up identifiable chemicals that they use in cell division. The index is a measure of the rate of the reproduction of the cells, as in fetal tissue development or the growth of cancers.
A test formerly used to determine hypersensitivity to foods, in which the white blood cell count is checked 90 min after the consumption of a suspected allergen. A precipitous decrease in the white blood cell count within 90 min after ingestion of the test food was thought to indicate that the food was incompatible with that person.
life satisfaction index Abbreviation: LSI
A self-reporting instrument to measure personal fulfillment or contentment, esp. with one's social relationships, occupation, maturation, or aging. A total of five rating scales are used.
McMurtryindex See: McMurtry index
A publication of the National Library of Medicine that lists biomedical and health sciences journal articles by title, subject, field, and country of publication. The major national and international medical and biological journals are indexed.
Mentzer Index See: Mentzer index
The number of mitoses seen in a biopsy specimen per square millimeter of tissue examined. Mitoses in tissue are indicative of malignancy. The higher the mitotic index, the more rapidly a tumor is dividing and the worse the prognosis.
The greatest width of the nasal aperture in relation to a line from the lower edge of the nasal aperture to the nasion.
notch width index
The width of the femoral intercondylar notch divided by the width of the femoral condyles.
A ratio of the number of bacteria that are ingested by leukocytes contained in the serum of a normal individual compared with the number ingested by leukocytes in the study patient's blood serum.
oral hygiene index Abbreviation: OHI
A popular indicator developed in 1960 to determine oral hygiene status in epidemiological studies. The index consists of an oral debris score and a calculus score. Six indicator teeth are examined for soft deposits and calculus. Numerical values are assigned to the six indicator teeth according to the extraneous deposits present. The scores are added and divided by the number of surfaces examined to calculate the average oral hygiene score.
Oswestry Disability Index Abbreviation: ODI
A questionnaire that requires a patient to rate the effect of back pain on 10 different activities, each having six levels of disability. The test was designed to assess patients with failed back surgery, but it is widely used for nonsurgical patients with other spinal conditions. Synonym: Oswestry disability score
oxygenation index Abbreviation: OI
A measure of the efficiency of oxygen exchange by the lungs. The index is used in critical care medicine to assess the severity of acute lung injury and to gauge the effectiveness of ventilator management strategies. Mathematically it is represented as the product of the fractional concentration of inspired oxygen and the mean airway pressure, divided by the arterial oxygen concentration.
Pearl index See: Pearl index
The ratio of pelvic conjugate and transverse diameters multiplied by 100.
periodontal (Ramfjord) index
An extensive consideration of the periodontal status of six teeth by evaluating gingival condition, depth of gingival sulcus or pocket, appearance of plaque or calculus, attrition, tooth motility, and extent of tooth contact.
The average number of bacteria ingested by each leukocyte after incubation of the leukocytes in a mixture of serum and bacterial culture.
physiological cost index Abbreviation: PCI
The metabolic expenditure per unit of distance traveled. It is expressed as the number of heartbeats per meter traveled and is calculated by subtracting the resting heart rate from the exercise heart rate divided by the distance traversed.
Pneumonia Severity Index, pneumonia severity index
A diagnostic scoring system for predicting the level of care a patient with pneumonia will require. It includes demographic factors (such as the patient's age, whether he or she resides in a nursing home); findings on physical examination (such as altered mental status, fever, tachycardia, and low blood pressure); laboratory data (including serum pH, glucose and sodium levels); and the presence of other illnesses (such as heart, lung, brain, liver, or kidney disease). Synonym: pneumonia PORT score.
The ratio of an individual's height to the cube root of his or her weight; used to determine body mass. See: body mass index
proliferative index Abbreviation: PI
The proportion of cells within a tumor specimen that are actively reproducing. In general, as the number of replicating cells in a tumor increases, the cancer behaves more aggressively and the prognosis for the patient worsens.
index of refraction
1. The ratio of the angle made by the incident ray with the perpendicular (angle of incidence) to that made by the emergent ray (angle of refraction).
2. The ratio of the speed of light in a vacuum to its speed in another medium. The refractive index of water is 1.33; that of the crystalline lens of the eye is 1.413. Synonym: refractive index
refractive indexIndex of refraction.
rapid shallow breathing index Abbreviation: f/TV; RSBI.
The ratio of the respiratory rate (f) and the tidal volume (TV) of a patient treated with mechanical ventilation while breathing on a T-piece (or at minimal levels of positive airway pressure or pressure support). Levels less than 105/min/L indicate that a patient may be able to be weaned successfully from the ventilator and breathe unassisted.
Reid index See: Reid index
respiratory index Abbreviation: RI
respiratory disturbance index
A measurement of the number of disordered breathing cycles during sleep. Sleep disordered breathing, which includes both apneas and hypopneas, results in daytime fatigue. It is also associated with an increased prevalence of cardiovascular disease.
The sacral breadth multiplied by 100 and divided by the sacral length.
The relative degree to which different foods of the same caloric value satisfy hunger.
In hematology, the amount of hemoglobin present in a known volume of blood compared with the normal amount.
Science Citations Index Abbreviation: SCI.
An electronic database of scientific journal articles published and referred to by other authors.
The Index is a proprietary product of the Thomson Corporation.
1. The systolic blood pressure divided by the heart rate.
2. The heart rate divided by the systolic blood pressure.
sulcus bleeding index Abbreviation: SBI.
A sensitive measure of gingival condition that involves probing of all sulci. The score is based on six defined criteria. It is calculated by counting the number of sulci with bleeding, dividing by the total number of sulci, and multiplying by 100.
sunscreen protective factor index
In preparations for protecting the skin from the sun (using sunscreens), the ratio of the amount of exposure needed to produce a minimal erythematous response with the sunscreen in place divided by the amount of exposure required to produce the same reaction without the sunscreen. This index assesses the ability of sunscreens to block (short-wavelength) ultraviolet B rays but does not measure the protective effect of sunscreens against (long-wavelength) ultraviolet A radiation. See: erythema dose
The maximum tolerated dose of a drug divided by the minimum curative dose.
The ratio of the thoracic anteroposterior diameter to the transverse diameter.
Vancouver scar indexBurn scar index.
ventilation index Abbreviation: VI.
A calculation used to determine the severity of respiratory illness (acute lung injury and/or respiratory distress syndrome) in critically ill patients. The VI is the partial pressure of arterial CO2
multiplied by the peak airway pressure multiplied by the rate of ventilation, all divided by 1000.
Symbolically, the ventilation index is calculated as follows: VI = [RR x (PIP - PEEP) × PaCo2]/1000.
2. In environmental science, a measure of air pollution based on the speed of the wind and the height of the column of air in which smoke or other pollutants mix.
The ratio of the number of births to the number of deaths in a population over a stated period of time.
Western Ontario McMaster Osteoarthritis Index See: Western Ontario McMaster Osteoarthritis Index
Medical Dictionary, © 2009 Farlex and Partners