PubMed Health⌕ Search

Biomedical subjects

D Showalter

Publications and source records attributed to D Showalter.

5 recordsLinked to original sources
PubMed1999

Interrater reliability levels of multiple clinical examiners in the evaluation of a schizophrenic patient: quality of life, level of functioning, and neuropsychological symptomatology.

Sir Ronald Fisher used a single-subject design to derive the concepts of appropriate research design, randomization, sensitivity, and tests of statistical significance. The seminal work of Broca demonstrated that valid and generalizable findings can and have emerged from studies of a single patient in neuropsychology. In order to assess the reliability and/or validity of any clinical phenomena that derive from single subject research, it becomes necessary to apply appropriate biostatistical methodology. The authors develop just such an approach and apply it successfully to the evaluation of the functioning, quality of life, and neuropsychological symptomatology of a single schizophrenic patient.

Activities of Daily Living↗
PubMed1997

A computer program for assessing interexaminer agreement when multiple ratings are made on a single subject.

This report describes a computer program for applying a new statistical method for determining levels of agreement, or reliability, when multiple examiners evaluate a single subject. The statistics that are performed include the following: an overall level of agreement, expressed as a percentage, that takes into account all possible levels of partial agreement; the same statistical approach for deriving a separate level of agreement of every examiner with every other examiner; and tests of the extent to which a giver examiner's rating (say a symptom score of three on a five-category ordinal rating scale) deviates from the group or overall average rating. These deviation scores are interpreted as standard Z statistics. Finally, both statistical and clinical criteria are provided to evaluate levels of interexaminer agreement.

Diagnosis, Computer-Assisted↗
PubMed1997

A new method for assessing interexaminer agreement when multiple ratings are made on a single subject: applications to the assessment of neuropsychiatric symtomatology.

A new method is introduced for assessing levels of interexaminer agreement when multiple ratings are made on a single subject, with an application in psychiatric research. It is designed to provide an overall level of interexaminer agreement and separate indices of agreement for each examiner. These indices are based on biostatistical and clinical criteria to determine whether the ratings of any given examiner are appreciably higher or lower than the group average, or a consensus diagnosis. A number of examples, from ongoing psychiatric research, are provided to illustrate conditions favoring the application of the new methodology. Finally, the necessary software for performing the analyses is available to clinical investigators with interest in this area of assessment.

Diagnosis, Computer-Assisted↗
PubMed1989

Cryopreserved venous homografts as vascular conduits in canine carotid arteries.

In this study we evaluated the histologic condition, prostacyclin production, and compliance of morphologically intact cryopreserved venous homografts (CVH) and autografts 3, 6, and 9 months after arterial implantation. Eighteen external jugular veins were cryopreserved and implanted into the carotid arteries of mongrel dogs. All grafts were patent at the time of excision. Electron microscopy documented a disrupted endothelium in the homografts at 3 months that was intact at 9 months. The cellular infiltrate, suggestive of rejection, in the 3-month homografts resolved by 9 months. Prostacyclin production at 3 months was 8.7 +/- 3.2 pg/ml/cm2 compared with 24.1 +/- 9.6 pg/ml/cm2 (p less than 0.025) in the adjacent carotid artery. The prostacyclin production in the 6-month homografts was 21.7 +/- 12.4 pg/ml/cm2, not significantly different from the adjacent carotid artery. The return of prostacyclin paralleled the return of an intact endothelium. Compliance of fresh vein was diminished by cryopreservation, from 1.57 +/- 0.39% radial change/mm Hg (10(-2] to 0.79 +/- 0.21% radial change/mg Hg (10(-2] (p less than 0.02). The compliance of CVH at 3 months (1.7 +/- 1.0) and at 6 months (1.1 +/- 0.42) was not significantly different from cryopreserved veins. These data showed that CVH remained patent in dogs for 9 months, without loss of compliance for 6 months, and developed a morphologically intact and functional endothelium that paralleled the resolution of the inflammatory infiltrate.

Animals↗