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a careful examination of a phenomenon; see also design.
cohort study prospective study.
cross-sectional study one employing a single point of data collection for each participant or system being studied. It is used for examining phenomena expected to remain static through the period of interest. It contrasts with a longitudinal s.
electrophysiological s's (EPS) studies from within the heart of its electrical activation and response to electrical stimuli and certain drugs. In general they include intravenous and/or intra-arterial placement of one or more electrode catheters at sites in the atria, ventricles, or coronary sinus, and sometimes the pulmonary artery or aorta. They record activity or stimulate the heart at various rates and cadences and are aids in the evaluation of electrophysiologic properties such as automaticity, conduction, and refractoriness. They also initiate and terminate tachycardias, map the sequence of activation, and aid in evaluation of patients for various forms of therapy and for the response to therapy. During these studies catheter ablation procedures, such as radio frequency ablation and electrical ablation, may be performed.
flow study uroflowmetry.
longitudinal study one in which participants, processes, or systems are studied over time, with data being collected at multiple intervals. The two main types are prospective studies and retrospective studies. It contrasts with a cross-sectional s.
pilot study a smaller version of a proposed research study, conducted to refine the methodology of the later one. It should be as similar to the proposed study as possible, using similar subjects, the same setting, and the same techniques of data collection and analysis.
prospective study an epidemiologic study in which the groups of individuals (cohorts) are selected on the bases of factors that are to be examined for possible effects on some outcome. For example, the effect of exposure to a specific risk factor on the eventual development of a particular disease can be studied. The cohorts are then followed over a period of time to determine the incidence rates of the outcomes being studied as they relate to the original factors in question. Called also cohort study.

The term prospective usually implies a cohort selected in the present and followed into the future, but this method can also be applied to existing longitudinal historical data, such as insurance or medical records. A cohort is identified and classified as to exposure to the risk factor at some date in the past and followed up to the present to determine incidence rates. This is called a historical prospective study, prospective study of past data, or retrospective cohort study.
retrospective study an epidemiologic study in which participating individuals are classified as either having some outcome (cases) or lacking it (controls); the outcome may be a specific disease, and the persons' histories are examined for specific factors that might be associated with that outcome. Cases and controls are often matched with respect to certain demographic or other variables but need not be. As compared to prospective studies, retrospective studies suffer from drawbacks: certain important statistics cannot be measured, and large biases may be introduced both in the selection of controls and in the recall of past exposure to risk factors. The advantage of the retrospective study is its small scale, usually short time for completion, and its applicability to rare diseases, which would require study of very large cohorts in prospective studies. See also prospective s.
urinary flow study uroflowmetry.
voiding pressure study simultaneous measurement of bladder contraction, urinary flow, and sphincter electromyogram.


Research, detailed examination, and analysis of an organism, object, or phenomenon.
[L. studium, study, inquiry]


n. pl. stud·ies
a. Attentive examination or analysis: The new drug is still under study.
b. A detailed examination, analysis, or experiment investigating a subject or phenomenon: conducted a study of children's reading habits.
c. A document or publication presenting the results of such an endeavor.
2. Medicine A diagnostic test.
v. stud·ied, stud·ying, stud·ies
a. To perform a study of; investigate: We need to study the problem further.
b. To read or look at carefully: studied the map; studied his expression.
c. To give careful thought to; contemplate: Let's study our next move.
2. Medicine To perform a diagnostic test on (a part of the body, for example).


(1) Clinical trial, see there.
(2) A series of related clinical trials.


The formal examination of a phenomenon or the relationship between two or more factors in the pathogenesis or management of a disease. See ABC study, Analysis, BEIR study, Biological Indicators of Exposure study, Blinded study, CAESAR AIDS study, Cache County study, Case study, Case-control study, Cheese Study, Clinical research, Clinical study, Cohort study, Combination study, Concorde study, Contract study, Cross-sectional study, Descriptive study, Disease and symptom prevalence study, Dose-ranging study, Double blinded study, Double contrast study, Double labeling study, Electrophysiologic study, Enteroclysis study, Epidemiologic study, Experimental study, Feasibility study, FRIC study, Harvard-Hsiao study, Health outcomes study, Intracardiac electrophysiologic study, LETS study, Level II study, Longitudinal study, Massachusetts Male Aging study, Mechanistic study, Mixing study, MONICA, National Polyp study, Nerve conduction study, Nun study, Nurses' Health study, Observational study, Parametric study, pH study, phase I/II/II/IV study, Pilot study, Platelet aggregation study, Port Pirie Cohort study, Prevalence study, Primary study, Prospective study, Quasi-experimental study, Red cell survival study, Replication study, Retrospective study, Rochester study, Safari study, Schecter study, Seven-yr study, Six Cities study, Sixty Plus study, SMART surveillance study, Synthetic/integrative study, Trial, Triple-blinded study, Tuskeegee study, Twin study, Understudy, Upper GI study, Viral study, Women's Health Initiative Observational Study.


Research, detailed examination, or analysis of an organism, object, or phenomenon.
[L. studium, study, inquiry]


A research project, a detailed examination or a procedure.
case study A method designed to give a detailed description of a single case (case report) or of more than one case (case series). It may be used to describe a rare condition, a new procedure and how cases with the same condition vary.
case-control study A longitudinal retrospective study in which two groups of individuals, the cases, people who have the disease, and the controls who do not have the disease are compared for specific characteristics that may be more commonly found in the diseased group (risk factors) than in the control group. This type of study may be affected by confounding factors (e.g. imprecise records, mismatch of the two groups).
cohort study A longitudinal study in which a group of subjects, called a cohort, is followed over a period of time. It can be either followed into the future (prospective study) or analysing past records (retrospective study). It is usually compared to another cohort, the controls, who do not possess the attribute being investigated.
cross -
over study An experimental design in which the effect of two or more treatments on a particular feature (e.g. a drug therapy) are given to each individual, one treatment after the other in random order.
cross -
sectional study A design in which the prevalence of a condition in a group of individuals is determined at a given point in time. See longitudinal study.
double -
blind study An experimental design in which neither the person receiving the treatment (or recording the results of a test) nor the person administering it, knows the identity of the treatment or test. See randomized controlled trial.
longitudinal study A design in which subjects are followed over a period of time with data collected at various intervals. Examples: prospective study, retrospective study. See cross study.
- sectional.
observational study 
A research method designed to draw inferences about the possible effect of exposure on an established outcome (e.g. a disease, a therapy) without the investigator's intervention. Examples: case-control study, cohort study, cross-sectional study.
prospective study A longitudinal study aimed at establishing an association between a specific risk factor (or therapy) and the development of a disease (or cure). Two groups of individuals (cohorts), one group exposed to a specific risk factor and the other not exposed, are examined over a period of time and the incidence rates of the outcome are compared between the two groups. It is a more powerful design than a retrospective study to determine an association. See randomized controlled trial.
retrospective study A longitudinal study aimed at establishing the presence of specific factors that are associated with a given outcome (e.g. a disease, a cure) by analysing the past records of patients with the outcome as compared to patients without the outcome. Example: case-control study.
single-blind study A method of testing in which the treatment assignment or procedure is unknown to the patient or subject. See placebo.
triple -
blind study An experimental design in which the subject, practitioner and the person administering the test do not know the identity of the treatment or test. See randomized controlled trial.


Research, detailed examination, and analysis of an organism, object, or phenomenon.
[L. studium, study, inquiry]


n the pursuance of education; analysis.
study cast,
study, graduate,
n the baccalaureate educational efforts pursued for credit toward an advanced degree in institutions of higher learning.
study model,
study, postgraduate,
n postdoctoral educational endeavors that may or may not earn credits for advanced degrees.
study, time,
n the technique of random sampling used for analysis of the time spent for rendering each phase of each of the various professional services performed by the dental professional.


a scholarly examination. Specific types of study are also detailed under blind, case-control, cohort, cross-sectional.

analytical study
one in which a phenomenon is described and an attempt made to analyze the effects of variables on the phenomenon.
descriptive study
one in which a phenomenon is described but no attempt is made to analyze the effects of variables on the phenomenon.
follow-up study
one carried out to find out whether there has been change in the situation since the initial study.
longitudinal study
one carried out over a period of time so that chronological time has an opportunity to exert an effect as a variable.
observational study
see descriptive study (above).
prospective study
one in which the data to be studied are yet to be generated, the events having not yet occurred.
retrospective study
one based on examination of existing data, on events that have already occurred.
simulation study
one in which the real circumstances are simulated, either in fact, or by means of a set of mathematical formulae each of which expresses the probability of each outcome in a series of consequential events that mirror the possible pathways in a real-life situation.

Patient discussion about study

Q. what is the Multimodal Treatment Study... I am very much interested in studying medicine. This interest was rooted in me bcoz of the social interest I have. So I want to know, what is the Multimodal Treatment Study of Children with ADHD?

A. Liam, I found some information here on the National Institute of Mental Health's site:

I hope it helps.

Q. Do I have to speak Chinese to study Chinese medicine? I’m thinking about studying Chinese medicine next year at a local college. Do I have to study Chinese before I start studying? Will it make any difference?

A. The main language of China is Mandarin. Hong Kong is Cantonese. Tawainese people speak (duh) Tawainese and Mandarin. Then you have like hundreds of other dialects from small provinces and island. I speak Mandarin which is the official language. A lot of Chinese People speak more than one dialect.

If I was you, I would go with Mandarin because it is becoming a standard in China. (Although Cantonese is very very popular in NYC, esp in Chinatown)

There are books at Barnes and Nobles that include audio lesson and video lessons, if you don't want to take a class, you can try that.

Q. Could someone please explain about the Fibromyalgia and sleep studies? My cousin who is 15 yrs old is suffering from sleep related problems. Should I suspect that he have fibromyalgia syndrome? Could someone please explain about the Fibromyalgia and sleep studies?

A. You could have given more details about your cousin’s sleep related problem. I could not say anything directly for your cousin as I don’t know about his actual problem. But generally saying, Individuals who have been diagnosed with fibromyalgia/who suspect they have fibromyalgia syndrome, sometimes submit themselves to sleep studies. Sleep studies can provide confirmation of a patient's sleep related problems by monitoring brain wave activity. By monitoring such neural activity, information can be gleaned regarding the quality and nature of sleep that a fibromyalgia patient experiences. Recent evidence indicates that fibromyalgia may be related to insufficient amounts of deep level delta wave sleep. Delta wave sleep is the level of sleep at which a person's body both recuperates and regenerates. Failure to reach or maintain deep level sleep may have something to do with the pain that is experienced by those who have fibromyalgia.

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