flow study

Also found in: Dictionary, Thesaurus, Legal, Encyclopedia.


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.

flow study

References in periodicals archive ?
The treatment effects from the irrigation-induced overland flow study are summarised in Table 3.
Clearly, sampling irrigation water behind the wetting front or ponding water prior to sampling, as occurs with many flumes and weirs (Grant 1992) and occurred in the rainfall-induced overland flow study, may result in the underestimation of P exports.
001), but the difference between the 2 fertilisers was the reverse of the rainfall-induced overland flow study.
In the irrigation-induced overland flow study, P exports are also likely to have reflected P mobilisation.
In the case described here, the family waited 10 hours to hear from the physician the results of the blood flow study and the news of the patient's death.
We thank Mr Keith Goodings for his supervision of the field rainfall simulation and overland flow study, and Mrs Irene Jacobsen for laboratory analyses.
Those issues include adopting a traffic flow study that will determine the traffic flow within the City, passing an ordinance that will increase the residential water tap fees by 39% and reviewing a $2,552 Capital Impact Fee that may effect all new development both commercial and residential.
Central City Officials are confident that the new Central City Parkway, scheduled to be completed this November, will boost and promote growth, although several residents, businesses and developments question the City's most recent actions pertaining to the traffic flow study, water tap increase and Capital Impact Fee.
There is expected to be several individuals representing local businesses, residents, property owners and proposed new developments and many plan on speaking regarding both issues especially since it is the public hearing for the water tap increase and they are planning on adopting the traffic flow study.
The researchers used Electron Beam Angiography (EBA) with 3-D reconstruction for direct visualization of coronary stents implanted following balloon angioplasty, in combination with a blood flow study by EBT for quantitative measurements.
The results of this blood flow study are very encouraging and demonstrate a potentially new therapeutic approach to treat FSAD.
One of the first projects under the new contract involves a groundwater flow study at the US Coast Guard ISD South Weymouth (MA) Buoy Depot.