Patient error

Disadvantages of urine methods include incomplete collection owing to patient error and impaired excretion caused by renal disease. Concomitant measurement of urinary creatinine excretion allows assessment of the completeness of the collection. Salivary cortisol measurement is practical and convenient to assess cortisol secretion in ambulatory patients who can provide multiple specimens that can be stored in a freezer between clinic visits. Morning salivary cortisol concentration is decreased in adrenal insufficiency evening values are increased in Cushing s syndrome. ... 

Any decent model used to analyse a series of n-of-1 trials will allow for at least three sources of variation pure between-patient variability, within-patient variability and a random effect for patient-by-treatment interaction. Since a series of measurements are being obtained, however, it may be inappropriate to assume that within-patient errors are independent (or more formally that the correlations between measures are equal). If patients are subject to spells of illness for example, then two measurements taken during two administrations of the same drug are more likely to be similar if the administrations are close together rather than far apart. This phenomenon can be referred to as serial correlation and is potentially a problem for the analysis of n-of-1 trials. (It would also be a problem for multiperiod cross-overs, the standard analysis of which, however, ignores the even more serious problem of patient-by-treatment interaction.)... 

D Within-patient error The variability shown from treatments period to treatment period when the same patient is given the same treatment... 

IV-PCA systems are also prone to patient errors and system malfunctions. In some cases these issues occur at a frequency great enough to cause the US Food and Drug Administration (FDA) to take action by issuing a recall due to a design defect that caused some of the infusion pumps to disrupt analgesic therapy [ 11 ]. Furthermore, the complexity of the IV-PCA system may increase the risk of SREs, due to problems with the infusion pump, IV line, or other components of the system. 

These two examples hint at a few of the reasons for the importance of knowledge-based systems. A medical faciHty may handle hundreds of infectious disease cases a year. Speedy, accurate diagnosis of these cases, aided by a system such as Mycin, may help the medical faciHty handle more patients, more effectively. Likewise, configuring large computer systems composed of many components can be a time-consuming and error-prone task. 

If a tower does become flooded in the bottom section, a common operator error is to try to pump the level out too quickly. This can easily damage trays by imposing a downward acting differential pressure produced by a large weight of liquid on top of the tray and a vapor space immediately below the tray. To eliminate the flooding, it is better to lower feed rate and heat to the reboiler. It is important to be patient and avoid sudden changes. 

Epilepsy may be defined as a permanent, recurrent seizure disorder. Examples of the known causes of epilepsy include brain injury at birth, head injuries, and inborn errors of metabolism, hi some patients, the cause of epilepsy is never determined. 

Where did the error orcur (eg, hospital, outpatient or retail pharmacy, nursing home, patient s home) ... 

Was patient counseling provided Q No Q Yes If yes, before or after error was discovered ... 

There has been a push for direct data collection (DDC) as an alternative to remote data capture (RDC). In this approach most of the required clinical data are acquired directly from existing patient record systems such as MRI machines, ECG, EEG, TTM, laboratories, and other measurement equipment. This approach eliminates the need for paper transcription and reentry to another system. It promises error-free and resource-efficient data capture, which allows early locking of the database and therefore potentially earlier product launch [30]. 

A problem long appreciated in economic evaluations, but whose seriousness has perhaps been underestimated (Sturm et al, 1999), is that a sample size sufficient to power a clinical evaluation may be too small for an economic evaluation. This is mainly because the economic criterion variable (cost or cost-effectiveness) shows a tendency to be highly skewed. (One common source of such a skew is that a small proportion of people in a sample make high use of costly in-patient services.) This often means that a trade-off has to be made between a sample large enough for a fully powered economic evaluation, and an affordable research study. Questions also need to be asked about what constitutes a meaningful cost or cost-effectiveness difference, and whether the precision (type I error) of a cost test could be lower than with an effectiveness test (O Brien et al, 1994). 

It has been long believed that a lithium ion-selective electrode would render obsolete the flame photometer in the clinical laboratory. Lithium is administered to manic depressive psychiatric patients. Since the therapeutic range (0.5-1.5 mM) is quite close to the toxic range (>2 mM), it must be closely monitored. Most of the iono-phores propo d to date have not met the Li" /Na selectivity required for an interference-free assay. However, it has been reported that calibration in the presence of 140 mMNa permitted the analysis of Li in serum The errors observed are due to fluctuations in the Na concentrations in the sample. More selective ionophores would certainly improve the accuracy of this method. 

Inhibitors of AR have been demonstrated to prevent a wide variety of biochemical, functional and structural alterations in animal models of diabetes. Early studies demonstrated arrest of both early cataract development and nerve conduction velocity. At least 30 clinical trials of AR inhibitors have been published involving nearly 1000 patients in total. However, there is little impressive data of their efficacy up to now but, rather than undermine the hypothesis linking excess polyol pathway activity to diabetic complications, it may reflect methodological difficulties and trial design errors. 

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