Glossary of Clinical Research Terms
3-DIMENSIONAL: see COMPUTED TOMOGRAPHY
ABSORB/ABSORPTION: The passage of substances into or across tissues, such as the passage of food and water from the intestines into the bloodstream. Because of a lack of digestive enzymes, some foods eaten by people with CF may not be well absorbed and used by the body (see DIGESTIVE SYSTEM, ENZYMES, PANCREAS, INTESTINE and MALABSORPTION).
ADVERSE REACTION: Unwanted side effect resulting from a drug or mixture of drugs. It may appear quickly or over time (see SIDE EFFECTS).
AIRWAYS: Tubes that bring outside air into the lungs. The lungs have many airways of varied sizes. The largest is the trachea between the throat and the lungs. It branches into smaller airways in the lungs called bronchi. These divide into still smaller branches called bronchioles. These turn into alveoli, the very smallest airways.
APPROVED DRUG: In the United States, only drugs approved by the Food and Drug Administration (FDA) can be sold. The approval process involves several steps, including pre-clinical laboratory and animal studies, clinical trials for safety and effectiveness, filing a New Drug Application by the drug manufacturer, FDA review and approval of the application (see FOOD AND DRUG ADMINISTRATION).
ARM: Any of the treatment groups in a randomized trial. Most randomized trials have two arms, but some have three or more (see RANDOMIZED TRIAL).
AUTOSOMAL RECESSIVE: A genetic trait or disorder that appears only when a person inherits a pair of chromosomes, each of which has the gene for the trait. One chromosome of the pair comes from the father and the other from the mother. Autosomal recessive disorders occur only if each parent is either a carrier of the trait or has the trait. CF is an autosomal recessive disease (see CARRIER and GENE).
BACTERIA: Tiny one-celled creatures that are often the cause of infections. People with CF are prone to bacterial lung infections (often caused by the bacteria Staphylococcus aureus and Pseudomonas aeruginosa). Some bacteria normally found in the body are helpful. For example, Escherichia coli live in the intestines and help with digestion (see ANTIBIOTIC, INTESTINE, PSEUDOMONAS AERUGINOSA and STAPHYLOCOCCUS AUREUS).
BIOFILM: A substance that sticks to wet surfaces. Biofilms can form on solid or liquid surfaces as well as on soft tissue in living organisms. They are usually difficult to dissolve. In CF, a biofilm, or protective coating, is formed by Pseudomonas aeruginosa bacteria and prevents drugs from killing the bacteria.
BMI (Body Mass Index): A measurement comparing fat to muscle in the human body. Weight in kilograms is divided by height in meters to figure out the degree of nutritional health, such as determining malnutrition or obesity.
BURKHOLDERIA CEPACIA COMPLEX: Bacteria that can live in the lungs of people with CF and cause infection. This bacterium is resistant to antibiotics and easily spread between people with CF, and can cause life-threatening lung infections.
CADAVERIC: Having to do with a dead body (a cadaver).
CARRIER: A person having a single gene for a genetic trait or disorder like CF. Carriers show no signs of the disease. In CF, each parent of a child with CF either has CF or is a CF carrier (see GENE and HEREDITARY).
CHROMOSOME: The thread-like material that carriers genes, the units of heredity. Chromosomes are in the nucleus of every living cell. Every person should have 23 pairs of chromosomes in each cell.
CLINICAL STUDY: A type of research—also called observational research—in which participants are observed. While these studies do not use drugs or treatments, they are very important for developing new ideas about how diseases or progression of disease could be prevented or treated.
CLINICAL TRIAL: A type of research—also called interventional research—that follows certain government guidelines for testing the effect of drugs on people. Researchers observe how the drug affects the body under highly controlled conditions and whether the treatment is helpful.
COMPASSIONATE USE: When experimental drugs are provided to people before final FDA approval. Typically used only with individuals who may receive benefit but have no other treatment options and cannot enroll in a clinical trial.
COMPUTED TOMOGRAPHY (CT scan): A three-dimensional image or picture of the body showing three measurements, such as height, width and depth. Created by a computer from a series of cross-sectional pictures.
CONFIDENTIALITY: The FDA and medical ethics require that the identities and medical information of all clinical trial participants be kept confidential. When a person joins a clinical trial, they must agree to share their medical records with researchers. The Principal Investigator must guarantee these records remain confidential (see FDA and PRINCIPAL INVESTIGATOR).
CONTROL GROUP: In many clinical trials, one group of patients receives the experimental drug or treatment, while the control group receives either a standard treatment or placebo (see PLACEBO and STANDARD TREATMENT).
DATA SAFETY MONITORING BOARD (DSMB): An independent committee of clinical research experts and community representatives that reviews ongoing information from a clinical trial. The committee’s job is to watch for safety issues and ensure participants are not exposed to unnecessary risk. The DSMB can recommend that a trial be stopped.
DIGESTION: The process of breaking down the food we eat and absorbing its nutrients into the body for energy (see ABSORPTION).
DIGESTIVE SYSTEM: The organs that take in, digest and get rid of food. Includes the mouth, salivary glands, pharynx (throat), esophagus, stomach, intestines, liver, pancreas, colon, rectum and anus. In CF, thick mucus blocks some passages in the digestive system, like that between the pancreas and intestines.
DOUBLE BLIND TRIAL: A clinical trial in which neither the participants nor the staff knows which patients are receiving the experimental drug and which are receiving a placebo or standard therapy. Double blind trials are thought to be more objective because expectations of the physician and the participants don’t affect the outcomes (see BLIND TRIAL, SINGLE BLIND TRIAL and PLACEBO).
DRUG-DRUG INTERACTION: Changes in the effect of a drug when taken with another drug. The effect may be an increase or a decrease in the action of either drug, or it may be an adverse effect normally not associated with either drug (see ADVERSE REACTION).
DSMB: See DATA SAFETY MONITORING BOARD.
DUCT: A tube or passageway for secretions. Ducts are found in organs, such as the pancreas, organ systems and exocrine glands. In CF, thick mucus can block these ducts (see SECRETION).
ELIGIBILITY CRITERIA: Reasons for selection of participants to be excluded from a clinical trial (see INCLUSION/EXCLUSION CRITERIA).
ENZYMES: Proteins that help make and increase certain chemical processes in the body, like the breaking down of foods in digestion. Because people with CF have mucus that often blocks the passageways (or ducts) through which digestive enzymes from the pancreas flow, they may need enzyme replacements to digest food (see ABSORPTION, DIGESTIVE SYSTEM, MUCUS and PANCREAS).
EXCLUSION/INCLUSION CRITERIA: Standards used to decide whether a person may or may not enroll in a clinical trial. Criteria are based on such factors as age, gender, disease, previous treatment history, and other medical conditions. These criteria are not used to keep people out of clinical trials, but rather to identify the right participants and keep them safe in a trial.
EXPANDED ACCESS: Refers to any of the FDA procedures for distributing experimental drugs to patients who are no longer benefiting from currently available treatments and unable to participate in ongoing clinical trials (see COMPASSIONATE USE, PARALLEL TRACK and TREATMENT IND).
EXPERIMENTAL DRUG: A drug not licensed by the FDA for use in humans (see OFF-LABEL USE).
FDA: See FOOD AND DRUG ADMINISTRATION.
FOOD AND DRUG ADMINISTRATION (FDA): The agency of the U.S. Department of Health and Human Services (DHHS) responsible for monitoring the safety and effectiveness of all drugs, biologics, vaccines and medical devices, including those used in the diagnosis, treatment and prevention of CF and other diseases (see http://www.fda.gov/).
GASTROESOPHAGEAL REFLUX DISEASE (GERD): a condition in which food or liquid travels backwards from the stomach to the esophagus (the tube from the mouth to the stomach). This action can irritate the esophagus, causing heartburn and other symptoms.
GENE: The main unit of heredity. Each chromosome carries hundreds of genes. Genes decide body traits like eye and hair color, height, facial features and many health problems. CF is caused by an alteration of a gene. A child inherits CF when two CF genes are received, one from each parent (see AUTOSOMAL RECESSIVE, CARRIER and HEREDITARY).
GENETIC: Hereditary or inherited. Material that is passed on from parents to children (see GENE).
GOOD CLINICAL PRACTICE (GCP): The standard for clinical trial design, conduct, performance, monitoring, auditing, recording, analyzing and reporting. GCP ensures that reported results will be credible and accurate, and that the rights, integrity and confidentiality of patients are protected.
HIGH-RESOLUTION COMPUTER TOMOGRAPHY (CT scan): A three-dimensional image or picture of the body. Created by a computer from a series of cross-sectional pictures with edge-defining qualities to sharpen the image, sometimes with a closer view of a smaller area. A close-up CT scan. Used often to create images of a person’s lungs (see COMPUTED TOMOGRAPHY).
IND: See INVESTIGATIONAL NEW DRUG.
IRB: See INSTITUTIONAL REVIEW BOARD.
INCLUSION/EXCLUSION CRITERIA: Standards used to decide whether a person may or may not enroll in a clinical trial. Criteria are based on such factors as age, gender, disease, previous treatment history, and other medical conditions. These criteria are not used to keep people out of clinical trials, but rather to identify the right participants and keep them safe in a trial.
INFORMED CONSENT: The process of learning about a clinical study or trial before deciding whether to join. Doctors and nurses involved in the trial fully explain the study and answer any questions. The goal is to have people participate who are informed about the study or trial.
INFORMED CONSENT DOCUMENT: A document that describes the rights of clinical research participants and details about the study or trial. It includes the study’s purpose, length, required procedures, and staff contact information. It also explains any risks and potential benefits. The patient should ask the study staff any questions before signing.
INSTITUTIONAL REVIEW BOARD (IRB): Committee of research and disease experts, and community advocates working to ensure that a clinical trial is fair and ethical, and that the rights of all participants are protected. All clinical trials in the United States must be approved by an IRB before they can begin. This group approves the initial research and reviews the research as it progresses to help protect the rights and safety of participants. The IRB also must approve all materials prepared for participants, including the informed consent document, promotional posters, flyers, brochures, Web sites, and other items.
INTESTINE: Tube in the digestive system that connects the stomach to the anus. The long, narrow, upper part is the small intestine. The short, wide, lower part is the large intestine. Also called the bowel.
LUNG CLEARANCE INDEX (LCI): The result (a number) obtained from a multiple breath washout test. A higher number reflects more airway obstruction and a low number a healthier lung. A patient with more obstruction will take longer to clear the gas mixture from their lung and the result is a higher number or index (see MULTIPLE BREATH WASHOUT).
MALABSORPTION: Poor uptake of nutrients from food for use by the body. In CF, mucus may plug ducts of digestive organs and block the secretion of enzymes and hormones. This makes many nutrients unavailable for use in body maintenance and growth (see ABSORPTION, DIGESTION, DIGESTIVE SYSTEM, DUCT, ENZYME, FAILURE TO THRIVE, HORMONE, MUCUS, ORGAN, PANCREAS and SECRETION).
MULTIPLE BREATH WASHOUT: A test of lung function technique that measures the amount of obstruction or blockage in the airways. For this test, which can be used in people of all ages, the patient inhales a special gas mixture during normal relaxed breathing. The time that it takes for gas to wash out of the lung is measured and used to calculate the lung clearance index (LCI) (see LUNG CLEARANCE INDEX).
NSAIDS: Non Steroidal Anti-Inflammatory Drugs, such as ibuprofen and aspirin (see ANTI-INFLAMMATORY AGENT).
NATIONAL INSTITUTES OF HEALTH (NIH): The agency of the U.S. Department of Health and Human Services (DHHS) responsible for health and medical research. NIH conducts research in its own laboratories and funds billions of dollars in research at other facilities, including universities, in the United States and abroad.
NEW DRUG APPLICATION (NDA): An application for a new drug submitted to the FDA to review and approve an experimental drug. The application is submitted after the completion of clinical trials and before a drug can be available to the general public.
OFF-LABEL USE: When a drug is prescribed for conditions other than those approved by the FDA.
OPEN-LABEL TRIAL: A clinical trial where all parties, including physicians and participants, know if they are using an investigational drug. Also when all participants get to receive the investigational drug once its safety and effectiveness have been established and before the FDA approves it.
ORAL GLUCOSE TOLERANCE TEST (OGTT): This test is used to diagnose not just diabetes and CFRD but also the varied types of abnormal glucose tolerance in CF. You must first fast (nothing to eat or drink) for 12 hours. Then, blood is drawn to measure your “baseline” or “fasting” glucose level. You are then asked to drink glucose. Your blood sugar is measured again 2 hours later. Often, blood sugar is measured at 1, 2, and 3 hours later.
ORGAN: A part of the body that performs a specific function or group of functions. Some common organs are the heart, lungs, and brain. A group of related organs is an organ system, such as the digestive system.
ORPHAN DRUGS: An FDA category of medications used to treat rare diseases and conditions which affect fewer than 200,000 people. Orphan drug status gives a drug manufacturer a greater financial incentive to develop and provide such drugs. CF is an orphan disease.
OXIDANT: A substance that oxidizes another substance.
PFTs: See PULMONARY FUNCTION TESTS.
PANCREAS: A long organ with glands found behind the stomach. The pancreas secretes enzymes through ducts into the intestine to break down food. In CF, mucus may obstruct the pancreatic ducts, preventing digestion. Another part of the pancreas has endocrine tissue, which makes a hormone called insulin. Insulin controls storage and use of sugar (see ENZYMES and MUCUS).
PHASE 1 TRIALS: First step in drug development to test a drug’s safety and to find out how the human body reacts to the drug. The purpose of Phase 1 trials is to discover the side effects of increased doses and collect early evidence of drug effectiveness. Healthy volunteers or people who do not have the disease or condition being studied, are often included.
PHASE 3 TRIALS: Usually the last type of clinical trial before a drug is approved by the FDA. Intended to gather more information about 1) the general risk-benefit of the drug, and 2) how to administer the drug (see RISK-BENEFIT).
PROTOCOL: A detailed plan for a clinical trial. It describes what types of people may participate in the trial; the schedule of tests, procedures, medications and dosages; and the length of the study.
PULMONARY FUNCTION TESTS (PFTs): Tests to check lung function. Along with the patient’s history and physical exam, PFTs help doctors diagnose a health problem, and decide what therapy to prescribe. They can be used with children five years and older. PFTs measure air flow and lung volumes.
RANDOMIZATION: Commonly used to assign clinical trial participants to a treatment arm, based on chance (see ARM).
RANDOMIZED TRIAL: Participants are assigned by chance to one of two or more treatment arms of a clinical trial (see ARM).
REPRODUCIBLE: To make a counterpart, image, or copy. To produce again or anew. To re-create. In clinical research, it refers to the ability of one study to recreate the results of a different study, thereby showing that the results are valid.
RESEARCH COORDINATOR: A staff person chosen by the principal investigator to assist him/her in conducting the clinical trial (see PRINCIPAL INVESTIGATOR).
SAFETY: The condition or state of being safe. In clinical trials, this refers to an absence of harmful side effects resulting from use of the product and may be assessed by special tests and procedures, psychiatric evaluation, and/or physical examination of participants.
SCREENING: Identifying a potential clinical trial participant by finding out if the person meets the eligibility criteria (see ELIGIBILITY CRITERIA).
SECRETION: A product of a gland, like sweat or saliva (see GLAND).
SIDE EFFECTS: Any unexpected results from taking an investigational drug or treatment (see ADVERSE REACTION).
SPIROMETER: A device that measures air flow and lung volumes (see PULMONARY FUNCTION TESTS).
SPUTUM CULTURE: A test to see what germs may be growing in the sputum (see SPUTUM).
STANDARD OF CARE: Treatment or medical management based on state-of-the-art health care (see STANDARD TREATMENT).
STUDY ENDPOINT: Results from a clinical trial used to judge the effectiveness of a drug treatment (see OUTCOME).SUB-STUDY: A smaller study that is part of a larger study.
THERAPEUTIC: Refers to a substance that has a healing effect on a specific condition.
TREATMENT IND: IND stands for Investigational New Drug, and is part of the FDA’s approval process to market a new prescription drug. This process makes promising investigational drugs available to patients outside of clinical trials early in the drug development process, before the FDA approves it as a new drug.
UNDUE OR UNNECESSARY RISK: IRBs review clinical trial protocols to ensure participants are not required to do anything that would be harmful to their health (see INSTITUTIONAL REVIEW BOARDS).
• An Introduction to Cystic Fibrosis For Patients and Families, 5th Edition; 2003, Cystic Fibrosis Foundation