Glossary of Terms | La Dept. of Health

Glossary of Terms

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Acute Lymphocytic Leukemia: Acute lymphocytic leukemia (ALL), also called acute lymphoblastic leukemia, is a type of cancer that starts from the lymphoid cells in the bone marrow and then spreads to the blood. From there it can go into the lymph nodes, spleen, liver, central nervous system, and other organs. “Acute” means that the leukemia can progress quickly, and if not treated, would probably be fatal in a few months.

Acute Myeloid Leukemia: Acute myeloid leukemia (AML) is a cancer that starts in the cells that are supposed to mature into different types of blood cells. AML starts in the bone marrow, but in most cases it moves quickly into the blood. From there it can go to the lymph nodes, spleen, liver, central nervous system, and other organs. “Acute” means that the leukemia can progress quickly, and if not treated, would probably be fatal in a few months.

Acute Myocardial Infarction: Acute Myocardial Infarction, more commonly known as a heart attack, is a medical condition that occurs when the blood supply to part of the heart is interrupted. The resulting blood or oxygen shortage causes damage and potential death of heart tissue.

Admission Date: The date of admission to a hospital.

Age Adjusted Rate: A rate that is statistically modified to eliminate the effect of different age distributions in the different populations. The rate accounts for the possibility that there may be many people in one age group and few people in another age group. A crude rate does not make this adjustment.

Age Group: Data that represent people grouped together based on age. For example, an age group of people age 35 or older may represent people at higher risk for heart attacks.

Ambient Air: Air that is outside, not inside of a building.

Ancephaly
A rare type of neural tube defect in which a baby is born without parts of the brain and skull. The neural tube is a narrow channel that folds and closes during the third and fourth weeks of pregnancy to form brain and skull, spinal cord, and back bones. Anencephaly occurs when the upper part of the neural tube that forms the brain and skull does not close all the way. This results in the baby’s brain not being fully formed or often not being covered by bone or skin when the baby is born.

Asbestosis: A serious, progressive, long-term disease of the lung that results from scar tissue caused by inhaling asbestos fibers that irritate and inflame lung tissues. The scarring may cause difficulty breathing. Asbestosis progresses slowly, and typically appears 10 - 20 years after the initial exposure. The disease can vary from no symptoms to disabling and potentially fatal.

Asthma: A disease that affects the lungs, causing repeated episodes of wheezing, breathlessness, chest tightness, and nighttime or early-morning coughing.

Average Annual Incidence Rate: The number of new cases of a disease or condition diagnosed over a period of time, generally multiple years, divided by an approximation of the person-years of observation during the time periods and age-adjusted to a standard population. Examples include the average annual incidence rate of certain cancers as reported the Louisiana Tumor Registry.
Average Daily Admission: The average number of people with a specified health issue, such as an asthma attack or heart attack, visiting an emergency department or admitted to a hospital, each day of a given month or year.

Average Daily Number: The average number of people with a specified health issues, such as an asthma attack or heart attack, each day of a given month or year.

Birth Weight: The weight of a newborn baby obtained after birth.

Bladder Cancer: Cancer that forms in tissues of the bladder, the organ that stores urine.

Body Mass Index (BMI): BMI is a unit represented as a person’s weight in kilograms divided by the square of their height in meters. An adult is considered obese if that individual has a BMI greater than or equal to 30. Although BMI is only a relative measure, it can be used to screen for weight categories that may lead to health problems. It is not a diagnostic of body fat, nor does it convey the health of an individual.

Brain and CNS Cancer: A type of cancer that occurs in the brain or central nervous system (CNS).

Cancer: A group of diseases in which cells in the body grow uncontrollably. There are more than 100 different types of cancer. Cancers are often named for the part of the body where it starts, although it can also spread to other parts of the body.

Carbon Monoxide (CO): An odorless, colorless gas that can cause sudden illness and death. CO is found in combustion fumes, such as those produced by cars and trucks, small gasoline engines, stoves, lanterns, burning charcoal and wood, gas ranges, and heating systems.

Carbon Monoxide Poisoning: Illness that results from exposure to carbon monoxide. The most common symptoms are headache, dizziness, weakness, nausea, vomiting, chest pain,and confusion. Carbon monoxide poisoning can sometimes result in death.

Carcinogen: A substance or agent that may cause or increase the risk of cancer.

Carpal Tunnel Syndrome: Carpal Tunnel Syndrome results when the nerve that runs from the forearm to the palm of the hand through the carpal tunnel becomes pressed or squeezed at the wrist. Symptoms usually start gradually, with numbness, tingling, weakness, and sometimes pain in the hand and wrist.

Centers for Disease Control and Prevention (CDC): The CDC, a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting public health activities in the United States.

Chemical Contaminants: Chemicals in the environment that cause harm or discomfort to humans or other living organisms or that damage the environment.

Childhood Cancer: Cancers occurring before age 15 or cancers occurring before age 20.

Chronic Lymphocytic Leukemia: Chronic lymphocytic leukemia (CLL) is a type of cancer that starts in the white blood cells, known as lymphocytes, in the bone marrow and then moves to the blood. Leukemia cells tend to build up in the body over time. In many cases people have no symptoms for at least a few years. Compared to other types of leukemia, CLL usually grows slowly.

Cleft Lip - With and Without Cleft Palate: Cleft lip is an opening in the upper lip that occurs when a baby’s lip does not form properly during pregnancy. The opening can be a small slit in the lip or it can be a large opening that goes through the lip into the nose. A cleft lip can be on one or both sides of the lip or in the middle of the lip. Children with cleft lip can also have cleft palate. This happens when the roof of the mouth, or palate, does not join together completely during pregnancy.

Cleft Palate - Without Cleft Lip: A cleft palate is an opening in the roof of the mouth, called the palate. A cleft palate does not join together completely during pregnancy. For some babies, both the front and back parts of the palate are open. For other babies, only part of the palate is open.

Colorectal Cancer: Colorectal cancer is cancer that starts in the colon or rectum. According to the Louisiana Tumor Registry, colorectal cancer is one of the most frequently diagnosed cancers in Louisiana. Though in the last two decades, incidence and mortality rates of colorectal cancer have decreased due to screening tests and changes in risk factors.

Confidence Interval: A measure of precision of an estimated statistic such as a calculated rate of disease incidence or prevalence. The smaller the confidence interval, the closer the calculated statistic or value is likely to be to the true value being estimated. Larger confidence intervals generally indicate less confidence that the calculated statistic or value is close to the true value being estimated. A confidence interval is bounded by the lower confidence limit (LCL) and Upper Confidence Limit (UCL).

Count: The number of cases of events.

Crude Rate: The number of cases or events divided by the total number of people in the population of interest.

Data Considerations: Specific information related to the quality or completeness of the data that must be considered in order to understand and interpret it correctly.

Discharge Date: The date of discharge from a hospital. Discharge occurs when a person is released from and leaves the hospital.

Down Syndrome (Trisomy 21)
Down syndrome, also known medically as Trisomy 21, is a condition in which a baby is born with an extra chromosome. Chromosomes are small, threadlike structures found in the nucleus of cells that carry genetic information in the form of genes. Normally, a baby is born with 23 pairs (46 total) chromosomes. Babies born with Down syndrome have an extra copy of chromosome 21. This extra copy or piece changes how the baby’s body and brain develop, which causes mental and physical challenges. No one knows for sure why Down syndrome occurs, but one factor that increases the risk for having a baby with Down syndrome is a mother’s age. Women who are 35 years or older when they become pregnant are more likely to have a pregnancy affected by Down syndrome.

Duplicate Record: More than one record for the same person with the same hospital admission data (i.e., all columns have the same information).

Emergency Department Visits: Occurs when people are admitted to the emergency room of a hospital due to a serious illness or health condition.

Environmental Health: The branch of public health that is concerned with understanding how the environment affects human health. The environment is the air we breathe, our water, our surroundings, and our food; it is the chemical, physical, and biological toxins that have contact with us every day. Understanding how we interact with the environment and how the environment may affect our health is complicated.

Environmental Public Health Tracking: Environmental public health tracking is the ongoing, systematic collection, integration, analysis, interpretation, and dissemination of data from environmental hazard monitoring, and from human exposure and health effects surveillance.

Epidemiology: The study of the distribution and determinants of health-related states or events in a population; the study of the occurrence and causes of health effects in humans.

Esophageal Cancer: Cancer that occurs in the esophagus, the hollow, muscular tube that connects the throat to the stomach.

Exposure: Contact with a substance by swallowing or breathing or by direct contact such as through the skin or eyes. Exposure may be short term, intermediate duration, or long term.

Female Breast Cancer: Cancer that occurs in the breast of females. Breast cancer cells usually form a tumor that can often be seen on an x-ray or felt as a lump. The tumor is malignant if the cells can grow into surrounding tissues or spread (metastasize) to distant areas of the body. According to the Louisiana Tumor Registry, breast cancer is one of the most frequently diagnosed cancers in Louisiana.

Fertility: The ability of a female to conceive a child.

Fertility Rate: The number of births per 1,000 women of childbearing or reproductive age.

Fish Consumption Advisory: A state-issued warning that cautions people about eating contaminated fish caught in local waters.

Fixed Facility Releases: Release of a toxic substance from an industrial plant or facility that might reasonably be expected to cause adverse human health outcomes.

Gastroschisis

Gastroschisis is a birth defect of the abdominal wall that causes a portion of the intestine to protrude outside of the baby’s body through an opening beside the belly button. The opening can be small or large. Sometimes other organs, such as the stomach and liver, also protrude outside of the baby’s body. Gastroschisis occurs early during pregnancy when the muscles that make up the baby’s abdominal wall do not form correctly.

Geocode: The process of identifying the geographic coordinates of a location. This process is used so data and information can be shown on a map. Typically, geocoding is used to convert mailing addresses to a latitude and longitude.

Gestational Age: A term used during pregnancy to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman’s last menstrual cycle to the current date of the pregnancy. A normal pregnancy ranges from 38 to 42 weeks.

Heart Attack: Also known as acute myocardial infarction, a heart attack is a medical condition that occurs when the blood supply to a part of the heart is interrupted. The resulting blood or oxygen shortage causes damage and potential death of heart tissue.

Heat Index: The heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature. The human body feels warmer in humid conditions and cooler in arid conditions. As the air temperature and relative humidity increases, the heat index also increases.

Heat Stress: A heat-related illness caused by your body’s inability to properly cool down. Heat stress can result in heat stroke, heat exhaustion, heat cramps, heat syncope, or heat rash.

Hospital transfers: A patient discharged from one facility and readmitted to a second facility on the same day.

Hospitalizations: Condition of being placed or treated as a patient in a hospital as an inpatient. Treatment as an out-patient is not considered hospitalization. For the hospitalization to be considered inpatient, the patient must stay in the hospital at least one night or more.

Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome is a type of congenital heart defect that affects normal blood flow through the heart. It occurs when the left side of the baby’s heart does not form correctly.

Hypospadias

Hypospadias is a birth defect in boys where the opening of the urethra is not located at the tip of the penis. In boys with hypospadias, the urethra forms abnormally during weeks 8-14 of pregnancy. The abnormal opening can form anywhere from just below the end of the penis to the scrotum.

Incidence Rate: The number of new cases of a given disease that develops in a population over a given period of time.

Indicator: For Tracking, an indicator is a characteristic that will be assessed to provide information about a population's health status, environment, or other related factor. Indicators and their associated measures enable the Tracking Network to effectively monitor trend and better understand the connection between the environment and health.

Infant Mortality: The death of an infant in the first year of life.

Infant Mortality Rate: The number of infant deaths, one year of age or younger, per 1,000 live births in a year.

Kidney Cancer: Also, known as renal cancer, kidney cancer is a cancer that starts in the kidneys. According to the Louisiana Tumor Registry, kidney cancer is one of the most frequently diagnosed cancers in Louisiana.

Laryngeal Cancer: Laryngeal cancer starts in the lower part of the throat known as the larynx.

Leukemia: Cancer of the white blood cells.

Liver and Intrahepatic Cancer: Cancer that starts in the liver or the small bile ducts within the liver.

Low Birth Weight: A baby is considered to be of low birth weight when its weight is less than 5.5 lbs, or 2500 grams, at birth. For Tracking, low birth weight is measured among singleton births only.

Lung Cancer: Cancer that forms in tissues of the lung, usually in the cells lining air passages. The two main types are small cell lung cancer and non-small cell lung cancer, diagnosed based on how the cells look under a microscope. According to the Louisiana Tumor Registry, lung cancer is one of the most frequently diagnosed cancers in Louisiana.

Male/Female Sex Ratio: The ratio of males to females at birth among term single births.

Malignant: Cancerous, invasive, or uncontrolled growth of a tumor.

Maternal Age: Age of mother.

Measure: A summary characteristic or statistic, such as a number, percentage, or rate. One or more measure may be available for each indicator.

Melanoma of the Skin: Melanoma is a cancer that usually starts in a certain type of skin cell called melanocytes. A major causes of Melanoma is exposure to harmful Ultraviolet (UV) radiation. Most UV radiation comes from the sun, but some can come from man-made sources such as tanning beds.

Mesothelioma: Mesothelioma is a rare form of cancer, which is almost always caused by exposure to asbestos that happens when harmful, or malignant, cells develop in the protective lining that covers most of the body’s internal organs. The most common sites for mesothelioma are in the chest or belly, where cells become abnormal in response to asbestos fibers that have embedded in the outer lining of the lungs or chest cavity, the lining of the abdominal cavity, or the sac that surrounds the heart.

Metadata: Metadata are "data about data". Metadata describe the content, quality, and context of a dataset and provide links to additional information such as quality assurance documents and data dictionaries. The Tracking Network contains metadata records for datasets used to create the Tracking Indicators and for datasets maintained by national, state, and local environmental health partners.

Micrograms per Liter (ug/L)*: See Parts Per Billion.

Milligrams per Liter (mg/L)*: See Parts Per Million.

Morbidity: Morbidity is the occurrence of a disease, illness, injury, or disability that alters health and quality of life.

Mortality: Death.

Musculoskeletal disorders: Injuries or disorders of the muscles, nerves, tendons, joints, cartilage, and supporting structures of the upper and lower limbs, neck, and lower back that are caused, precipitated or exacerbated by sudden exertion or prolonged exposure to physical factors such as repetition, force, vibrations, or awkward posture. Musculoskeletal Disorders do not include those conditions such as fractures, contusions, abrasions, and lacerations resulting from sudden physical contact of the body with external objects.

Myocardial Infarction: See Heart Attack.

National Ambient Air Quality Standards (NAAQS): Under the Clean Air Act, the U.S. EPA established standard limits for six air pollutants to protect public health and the environment. Those air pollutants are carbon monoxide, lead, nitrogen dioxide, particulate matter of 10 microns or less (PM10), particulate matter of 2.5 microns of less (PM2.5), ozone, and sulfur dioxide.

NAICS: The North American Industry Classification System is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy.

Nationally Consistent Data and Measures (NCDM): Standards developed by for the National Environmental Health Tracking Program to ensure compatibility and comparability of data and measures useful for understanding the impact of our environment on our health across the U.S. When states and cities use the same standardized measures for data analysis, trends and important findings are more easily seen.

Neonatal Mortality: An infant death which occurs in the first 27 days of life.

No Events: Data that is reported as true zero (0) for the number of cases. When there are no events, there are zero cases. This is different from missing data (No Record), suppressed data, or unreliable data.

No Record: Also expressed as No Data, No Record reflects missing data or data that has not been submitted to the health agency. This is different from No Events.
Non-Hodgkin Lymphoma: Non-Hodgkin lymphoma is sometimes called Non-Hodgkin’s lymphoma, NHL, or just lymphoma. It is a cancer that starts in cells called lymphocytes, which are part of the body’s immune system. Lymphocytes are in the lymph nodes and other lymphoid tissue, such as the spleen and bone marrow.

Number: The count of cases or events.

Obesity: Obesity is a range of weight that is greater than what is generally considered healthy for a given height. The term also identifies a range of weight that has been shown to increase the likelihood of certain diseases and other health problems. For adults, obesity ranges are determined by using weight and height to calculate a number called “body mass index” (BMI). Obesity is defined for adults as a BMI of 30 or higher.

Oral Cavity and Pharynx Cancer: Cancers that occur in the mouth and throat. This includes the lips and the inside lining of the lips.

Occupational Safety and Health Administration (OSHA): OSHA is the Federal agency responsible for the enforcement of occupational safety and health standards. OSHA helps to protect the health and safety of workers and ensure associated regulations are being followed in the workplace.

Ozone (O3): An oxygen compound that occurs in two layers of the atmosphere. In the stratosphere, ozone protects the earth from harmful ultraviolet rays. At ground-level, ozone is an air pollutant that can be harmful to human health and the environment. It is the principal component of "smog" and is produced from the action of sunlight on air contaminants from combustion sources including automobile exhausts. Ozone levels are most likely to be elevated on hot, sunny afternoons.

Pancreatic Cancer: Pancreatic cancer occurs when cells in the pancreas start to grow uncontrollably. The pancreas is an organ located behind the stomach that is a vital part of the digestive system and a critical controller of blood sugar levels.

Particulate Matter (PM): Also known as Particle Pollution, PM is a mixture of extremely small particles and liquid droplets in the air. PM is made up of a number of components, including acids, such as nitrates and sulfates, organic chemicals, metals, and soil or dust particles. Outdoors, PM come primarily from motor vehicle exhaust, power plants, wild fires, manufacturing processes, and the reaction of gases in the atmosphere. Indoor sources include tobacco smoke, cooking, fireplaces, and candles. PM10 refers to particles that are 10 micrometers in diameter or less. PM2.5 refers to particles that are 2.5 micrometers in diameter or less.

Parts per Billion (PPB): A measure of chemical concentration in a solution. Calculated as the mass of a chemical or contaminant per billion unit volume of water. Parts per billion can be expressed as its equivalent micrograms per liter (ug/L). 1 PPB = 0.001 PPM

Parts Per Million (PPM): A measure of chemical concentration in a solution. Calculated as the mass of chemical or contaminate per million unit volume of water. Parts per million can be expressed as its equivalent milligrams per liter (mg/L). 1 PPM = 1,000 PPB

Perinatal Mortality: A fetal death of 28 weeks gestation or more and an infant death in the first 6 days of life.

Person-Time

Person-time is an estimate of the actual time-at-risk – in years, months or days – during which a particular population was exposed to a certain risk factor. It is calculated as the sum of the difference in ages of each participant from when they were first exposed to the risk factor to when the exposure ended.

For example, if person #1 started smoking at age 40, and died in 2018 at age 50, then by 2018, s/he was exposed to (50 – 40) 10 person-years, or 3650 person-days, of cigarette smoking as a risk factor for cancer. If person #2 started smoking at age 20, and continues to smoke at age 52 in 2018, then s/he has been exposed to the risk factor for 32 person-years, or 11,680 person-days, during the same time. A third person (#3) in our population started smoking at age 30, but quit in 2000 by the time s/he was 35. Then by 2018, person #3 has been exposed to only 5 person-years (1825 person-days) to smoking as a risk factor. If our entire population consisted of only persons #1, #2 and #3, then the total person-time for the population is (10 + 32 + 5) 47 person-years, or 17,155 person-days.

Pesticide Exposure: Damage or illness that results from inhaling, absorbing, touching, or swallowing a pesticide.

PM2.5: Particulate matter that is less than 2.5 microns wide, or about 30 times smaller than human hair. Outside, they come primarily from motor vehicle exhaust, power plants, wild fires, manufacturing processes, and the reaction of gases in the atmosphere. Indoor sources include tobacco smoke, cooking, fireplaces, and candles.

Pneumoconiosis: A group of lung diseases caused by inhaling certain dusts and the lung tissue’s reaction to the dust. These diseases primarily include asbestosis, silicosis, and coal workers’ pneumoconiosis.

Postcensal Population Estimates: Population estimates produced for the intermittent years after the decennial census that is conducted every ten years when only the beginning population is known.

Postneonatal Mortality: A death which occurs between 28 days and a year of life.

Prematurity: Occurs when an infant is born before completing 37 weeks of gestation.

Preterm Birth: Preterm birth is the birth of an infant at least three weeks before the due date (less than 37 weeks gestation). For Tracking, preterm births are measured among singleton births only.

Prevalence: Sometimes referred to as prevalence rate, the number of people in a population who have a disease or illness at a given point in time or a specific a period of time.

Rate: A measure of the frequency with which an event occurs in a defined population.

Relative Standard Error (RSE): When only a few cases of a disease or condition occur in a selected geography, and a rate is calculated based on small numbers, the resulting rate may not accurately reflect the true burden of disease for the population. To account for this, a relative standard error calculation may be applied. In LDH Tracking for example, an RSE greater than 30% is flagged as an unstable or unreliable rate, proportion, or percentage. In general, rates generated from a sample count of 12 or more will begin to approach an RSE of 30 or less, and will be more stable or reliable.

Reliability: See Stability.

Silicosis: A disabling and often fatal lung disease caused by breathing dust that has very small pieces of crystalline silica in it. Crystalline silica is found in concrete, masonry, sandstone, rock, paint, and other abrasives. The cutting, breaking, crushing, drilling, grinding, or abrasive blasting of these materials may produce fine silica dust. Breathing this dust causes damage to the lungs that can progress to respiratory failure and death.

Singleton Birth: Pregnancy resulting in the birth of one child, not twins or triplets.

Sociodemographics: A combination of social and demographic factors. The LDH Tracking portal includes measures related to age, education, employment, family and social support, gender, income, language, race/ethnicity, rural and total population.

Spina Bifida (without Anencephaly)

Spina bifida is a neural tube defect that can happen anywhere along the spine when the neural tube does not close all the way. It may be, but is not always apparent at birth. In Spina Bifida without Anencephaly, the backbone that protects the spinal cord does not form and close as it should, which results in damage to the spinal cord and nerves.

Spline Graph: A spline graph displays a series of data points connected with a curved line. Spline graphs can assist in viewing and comparing various geographies over time in order to visualize data changes and possible trends. Its intended use on the LDH Tracking Portal is for general approximation only.

Stability: Rates, proportions, and percentages are checked for their stability, so that trends over time and between geographic areas or persons can be evaluated with reasonable confidence. Unstable or unreliable rates, proportions, or percentages can arise from small number of cases or events or from small populations.

Suppression: A method of protecting health data confidentiality when small numbers are reported. Suppression rules, which vary by data source, generally restrict the extent to which health data can be shared publically. Primary and secondary suppression techniques are used to prevent someone's personal health information from being discoverable by the general public. On the LDH Tracking portal, numbers and rates that are suppressed are displayed as asterisks (*).

Surveillance: A dynamic process in which data on the occurrence and distribution of health or disease in a population are collected, collated, analyzed, and disseminated.

Term Birth: Birth at or later than 37 completed weeks of gestation.

Tetralogy of Fallot

Tetralogy of Fallot is a type of congenital heart defect affecting normal blood flow through the heart that occurs when a baby’s heart does not form correctly. Tetralogy of Fallot is a combination of as many as four defects: a hole in the wall between the two lower chambers of the heart; a narrowing of the pulmonary valve and main pulmonary artery; an enlarged aortic valve that opens from both ventricles; or the muscular wall of the lower right chamber of the heart is thicker than normal.

Thyroid Cancer: Cancer that forms in the thyroid gland, a butterfly-shaped organ at the base of the throat that makes hormones that help control heart rate, blood pressure, body temperature, and weight.

Total Fertility Rate: The number of births per 1,000 women of reproductive age.

Toxics Release Inventory (TRI): A U.S. EPA program that tracks the management of certain toxic chemicals that may pose a threat to human health and the environment. U.S. facilities in different industry sectors must report annually how much of each chemical is released into the environment and/or managed through recycling, energy recovery, and treatment. A release of a chemical means that it was emitted to the air or water, or place in some type of land disposal.

Toxicology: The study of harmful effects of substances on humans.

Transport Releases: Release of a toxic substance that might reasonably be expected to cause human health outcomes from a transport vehicle, such as a semi-trailer truck or a train. A release of a chemical means that it was emitted to the air or water, or place in some type of land disposal.

Transposition of the Great Arteries (vessels)

Transposition of the Great Arteries is a congenital heart defect that occurs when the two main arteries that carry blood out of the heart - the aorta and the pulmonary artery - are switched in position.

Unreliable: See Stability.

Unstable: Data do not meet standards of reliability or precision. See Stability.

Upper and Lower Limb Deficiencies

Upper limb deficiencies occur when a part of, or the entire, arm of a fetus fails to form completely during pregnancy. Lower limb deficiencies occur when a part of, or the entire leg, of a fetus fails to form completely during pregnancy. These defects are also referred to as “limb reduction” because a limb is reduced from its normal size or is missing.

Very Low Birth Weight: A baby is considered to be of low birth weight when its weight is less than 3.3 lbs, or 1500 grams, at birth. For LDH Tracking, low birth weight is measured among singleton births only.

Very Preterm Birth: Very preterm birth is the birth of an infant at least 8 weeks before the due date (less than 32 weeks gestation). For Tracking, very preterm births are measured among singleton births only.

Workers' Compensation: Systems that provide benefits such as partial medical care and income protection to employees who are injured or become ill from their job.

Accessibility