Observer error Health Dictionary

See “Type I error”.... alpha (i) error

See “Type II error”.... beta (i) error

An error or omission in the medical care provided to an individual. Medical errors can occur in diagnosis, treatment, preventive monitoring or in the failure of a piece of medical equipment or another component of the medical system. Often, but not always, medical errors result in adverse events such as injury or death. See also “malpractice”; and “incidence monitoring and reporting”.... medical error

The tendency for the estimated magnitude of a parameter (e.g. based upon the average of a sample of observations of a treatment or intervention effect) to deviate randomly from the true magnitude of that parameter. Random variation is independent of the effects of systematic biases. In general, the larger the sample size, the lower the random variation of the estimate of a parameter. As random variation decreases, precision increases.... random variation / random error

In statistics, the standard error is defined as the standard deviation of an estimate. That is, multiple measurements of a given value will generally group around the mean (or average) value in a normal distribution. The shape of this distribution is known as the standard error.... standard error

An error that is not the result of an individual’s actions, but the predictable outcome of a series of actions and factors that comprise a diagnostic or treatment process.... systems error

Also known as “false positive” or “alpha (?) error”. An incorrect judgment or conclusion that occurs when an association is found between variables where, in fact, no association exists. In an experiment, for example, if the experimental procedure does not really have any effect, chance or random error may cause the researcher to conclude that the experimental procedure did have an effect. The error of rejecting a true null hypothesis.... type i error

Also known as “false negative” or “beta (?) error”. An incorrect judgement or conclusion that occurs when no association is found between variables where an association does, in fact, exist. In a medical screening, for example, a negative test result may occur by chance in a subject who possesses the attribute for which the test is conducted. The error of failing to reject a false null hypothesis.... type ii error

Inherited defects of body chemistry. Inborn errors of metabolism are caused by single gene defects, which lead to abnormal functioning of an enzyme.

Some of these gene defects are harmless, but others are severe enough to result in death or physical or mental handicap. Examples include Tay–Sachs disease, phenylketonuria, Hurler’s syndrome, and Lesch–Nyhan syndrome. Collectively, inborn errors of metabolism affect around 1 child in 5,000.

Symptoms are usually present at or soon after birth. They may include unexplained illness or failure to thrive, developmental delay, floppiness, persistent vomiting, or seizures.

Routine tests are performed on newborn babies for some genetic disorders, such as phenylketonuria.

Treatment is not needed for some inborn errors of metabolism. For others, avoidance of a specific environmental factor may be sufficient. In some cases, the missing enzyme or the protein that it produces can be manufactured using genetic engineering techniques, or a vitamin supplement can help compensate for the defective enzyme. If the enzyme is made in blood cells, a bone marrow transplant may provide a cure.

People with a child or a close relative who is affected may benefit from genetic counselling before planning a pregnancy.... metabolism, inborn errors of

n. (in research) incorrectly rejecting a null hypothesis when it is true (type I error) or failing to reject a null hypothesis when it is false (type II error). See significance.... error

any one of a group of inherited conditions in which there is a disturbance in either the structure, synthesis, function, or transport of protein molecules. There are over 1500 inborn errors of metabolism; examples are *phenylketonuria, *homocystinuria, and *hypogammaglobulinaemia.... inborn error of metabolism

(in statistical surveys) see validity.... interobserver error

(in statistical surveys) see validity.... intraobserver error

an abnormality of the eye resulting in a blurred image on the retina as a result of abnormal focusing, which can be corrected by glasses, contact lenses, or *refractive surgery. Refractive errors include *myopia, *hypermetropia, and *astigmatism.... refractive error