PubMed · 1393319
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
A Martínez-Taboas, M Francia. 1992. Multiple personality disorder.. https://doi.org/10.1192/bjp.161.3.417
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We study prevalence-dependent diagnostic accuracy measures, specifically, positive and negative predictive values. These measures permit an assessment of the clinical utility of diagnostic tests across populations with different disease prevalences. In many cases, prevalence may not be known with certainty and the evaluation of the diagnostic tests must account for this uncertainty. A sensitivity analysis may be desired across a prevalence continuum defining low to high-risk populations. For this scenario, simultaneous inference about the predictive values across a range of prevalences is proposed. For situations where a non-point prior distribution on prevalence is specified, we suggest inferences based on averaging the accuracy measures with respect to the prior, leading to simple numerical summaries. The methods are illustrated in a meta-analysis of diagnostic tests for intravascular device-related bloodstream infection, where the prevalence may vary widely both within and across populations.
The last three decades have seen a dramatic rise in the implementation of screening programmes for cancer in industrialised countries. However, in contrast to screening for infectious diseases, most cancer screening programmes only have the potential to reduce mortality; they cannot lower the incidence of cancer in a population. In fact, most cancer screening programmes have been shown to increase the incidence of the disease as a consequence of over-diagnosis. A further dilemma of cancer screening programmes is that they do not distinguish between healthy people and those with disease. Rather, they identify a continuum of disease severity. Consequently, many healthy people who have abnormal screening tests are wrongly diagnosed. Indeed, studies have demonstrated that for each screening-prevented death from cancer, at least 200 false-positive results are given. Therefore, screening has the potential to be harmful as well as beneficial. The psychosocial consequences of false-positive screening results cannot be determined by diagnostic tests or by other technical means. Instead, patient reported outcome measures must be employed. To measure the outcomes of screening accurately and comprehensively patient reported outcome measures have to capture; the nature and extent of the psychosocial consequences and how these change over time. The outcome measures used must have high content validity and their psychometric properties should be determined prior to their use in the specific population. In particular it is important to establish unidimensionality, additivity and item ordering through the application of Item Response Theory.
UNLABELLED: We report a patient with human herpesvirus-6 (HHV-6) encephalitis diagnosed by diffusion-weighted magnetic resonance imaging (DW-MRI). A previously healthy 10-month-old girl developed acute encephalopathy. HHV-6 DNA was detected in her cerebrospinal fluid during the acute phase of the disease by polymerase chain reaction. The patient demonstrated cortical diffusion abnormalities in affected brain parenchyma, partially as the initial or most sensitive sign of encephalitis that could be detected not by conventional MRI but by DW-MRI. Serial imaging showed that the diffusion abnormality DW-MRI returned to normal after 45 days. CONCLUSION: DW-MRI may be a valuable tool for early detection and diagnosis of HHV-6 encephalitis and is more sensitive than conventional MRI to detect a subtle edematous change in the brain.