Pilot Studies
Important Terminology
Pilot Study
A small scale study to look at process, protocol and feasability of study approach before conducting a larger scale study.
Clinical Study
A research study involving human volunteers (also called participants) that is intended to add to medical knowledge. There are two types of clinical studies: interventional studies (also called clinical trials) and observational studies.
Protocol
The written description of a clinical study. It includes the study's objectives, design, and methods. It may also include relevant scientific background and statistical information.
Principle Investigator (PI)
The person who is responsible for the scientific and technical direction of the entire clinical study.
Collaborator
An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Clinical Study Stage
The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
Primary Completion Date
The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "estimated" primary completion date is the date that the researchers think will be the primary completion date for the study.
Study Design
The investigative methods and strategies used in the clinical study.
Study Documents
Refers to the type of documents that the study sponsor or principal investigator may add to their study record. These include a study protocol, statistical analysis plan, and informed consent form.
Primary Outcome Measure
In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Placebo
An inactive substance or treatment that looks the same as, and is given in the same way as, an active drug or intervention/treatment being studied.
Eligibility Criteria
The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.
Enrollment
The number of participants in a clinical study. The "estimated" enrollment is the target number of participants that the researchers need for the study.
Group/Cohort
A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Adverse Event
An adverse event that is not a serious adverse event, meaning that it does not result in death, is not life-threatening, does not require inpatient hospitalization or extend a current hospital stay, does not result in an ongoing or significant incapacity or interfere substantially with normal life functions, and does not cause a congenital anomaly or birth defect; it also does not put the participant in danger and does not require medical or surgical intervention to prevent one of the results listed above.
Study Results
A study record that includes the summary results posted in the ClinicalTrials.gov results database. Summary results information includes participant flow, baseline characteristics, outcome measures, and adverse events (including serious adverse events).
US Food and Drug Administration (FDA)
An agency within the U.S. Department of Health and Human Services. The FDA is responsible for protecting the public health by making sure that human and veterinary drugs, vaccines and other biological products, medical devices, the Nation's food supply, cosmetics, dietary supplements, and products that give off radiation are safe, effective, and secure.
Recruitment Status
- Not yet recruiting: The study has not started recruiting participants.
- Recruiting: The study is currently recruiting participants.
- Enrolling by invitation: The study is selecting its participants from a population, or group of people, decided on by the researchers in advance. These studies are not open to everyone who meets the eligibility criteria but only to people in that particular population, who are specifically invited to participate.
- Active, not recruiting: The study is ongoing, and participants are receiving an intervention or being examined, but potential participants are not currently being recruited or enrolled.
- Suspended: The study has stopped early but may start again.
- Terminated: The study has stopped early and will not start again. Participants are no longer being examined or treated.
- Completed: The study has ended normally, and participants are no longer being examined or treated (that is, the last participant's last visit has occurred).
- Withdrawn: The study stopped early, before enrolling its first participant.
- Unknown: A study on ClinicalTrials.gov whose last known status was recruiting; not yet recruiting; or active, not recruiting but that has passed its completion date, and the status has not been last verified within the past 2 years.