Multiple Sclerosis Performance Test: validation of self-administered neuroperformance modules.

BACKGROUND AND PURPOSE: The purpose was to determine the test-retest reliability, practice effects, convergent validity and sensitivity to multiple sclerosis (MS) disability of neuroperformance subtests from the patient self-administered Multiple Sclerosis Performance Test (MSPT) designed to assess low contrast vision (Contrast Sensitivity Test, CST), upper extremity motor function (Manual Dexterity Test, MDT) and lower extremity motor function (Walking Speed Test, WST) and to introduce the concept of regression-based norms to aid clinical interpretation of performance scores using the MSPT cognition test (Processing Speed Test, PST) as an example. METHODS: Substudy 1 assessed test-retest reliability, practice effects and convergent validity of the CST, MDT and WST in 30 MS patients and 30 healthy controls. Substudy 2 examined sensitivity to MS disability in over 600 MS patients as part of their routine clinic assessment. Substudy 3 compared performance on the PST in research volunteers and clinical samples. RESULTS: The CST, MDT and WST were shown to be reliable, valid and sensitive to MS outcomes. Performance was comparable to technician-administered testing. PST performance was poorer in the clinical sample compared with the research volunteer sample. CONCLUSIONS: The self-administered MSPT neuroperformance modules produce reliable, objective metrics that can be used in clinical practice and support outcomes research. Published studies which require patient voluntary consent may underestimate the rate of cognitive dysfunction observed in a clinical setting.

Analysis of the psychometric properties of the Multiple Sclerosis Impact Scale-29 (MSIS-29) in relapsing-remitting multiple sclerosis using classical and modern test theory.

BACKGROUND: Investigations using classical test theory support the psychometric properties of the original version of the Multiple Sclerosis Impact Scale (MSIS-29v1), a disease-specific measure of multiple sclerosis (MS) impact (physical and psychological subscales). Later, assessments of the MSIS-29v1 in an MS community-based sample using Rasch analysis led to revisions of the instrument's response options (MSIS-29v2). OBJECTIVE: The objective of this paper is to evaluate the psychometric properties of the MSIS-29v1 in a clinical trial cohort of relapsing-remitting MS patients (RRMS). METHODS: Data from 600 patients with RRMS enrolled in the SELECT clinical trial were used. Assessments were performed at baseline and at Weeks 12, 24, and 52. In addition to traditional psychometric analyses, Item Response Theory (IRT) and Rasch analysis were used to evaluate the measurement properties of the MSIS-29v1. RESULTS: Both MSIS-29v1 subscales demonstrated strong reliability, construct validity, and responsiveness. The IRT and Rasch analysis showed overall support for response category threshold ordering, person-item fit, and item fit for both subscales. CONCLUSIONS: Both MSIS-29v1 subscales demonstrated robust measurement properties using classical, IRT, and Rasch techniques. Unlike previous research using a community-based sample, the MSIS-29v1 was found to be psychometrically sound to assess physical and psychological impairments in a clinical trial sample of patients with RRMS.

Intraclass correlation for measures from a middle school nutrition intervention study: estimates, correlates, and applications.

This article presents the first estimates of school-level intraclass correlation for dietary measures based on data from the Teens Eating for Energy and Nutrition at School study. This study involves 3,878 seventh graders from 16 middle schools from Minneapolis-St. Paul, Minnesota. The sample was 66.8% White, 11.2% Black, and 7.0% Asian; 48.8% of the sample was female. Typical fruit and vegetable intake was assessed with a modified version of the Behavior Risk Factor Surveillance System questionnaire. Twenty-four-hour dietary recalls were conducted by nutritionists using the Minnesota Nutrition Data System. Mixed-model regression methods were used to estimate variance components for school and residual error, both before and after adjustment for demographic factors. School-level intraclass correlations were large enough, if ignored, to substantially inflate the Type I error rate in an analysis of treatment effects. The authors show how to use the estimates to determine sample size requirements for future studies.

GPT.EXE: a powerful tool for the visualization and analysis of general processing tree models.

This paper introduces GPT.EXE, a computer program for designing and implementing general processing tree (GPT) models. First, designing and building GPT models using this program is discussed. The second major emphasis is a description of various statistical procedures that can be carried out with GPT.EXE. There is also a brief section on the on-line documentation of this program. Throughout the text, pictures of windows from the program are displayed to help explain the procedures being described by the text.

Teicoplanin--home therapy for prosthetic joint infections.

Infection with methicillin-resistant organisms is increasingly common among implanted orthopaedic devices. The organisms involved are often multiresistant to other commonly used antibiotics. Rifampicin resistance is less common at isolation but may develop during treatment unless combination therapy with another drug is employed. However, tolerance of combinations is poor, particularly among elderly patients. These patients may require at least 6 weeks of antibiotic therapy, and where there is no suitable oral therapy, this has meant prolonged hospitalization solely for administration of parenteral antibiotics. Recently we have started treating such patients with teicoplanin, 6 mg/kg once daily, by intravenous bolus injection. The injections are administered by relatives at home and the patients attend the ward twice weekly for inspection and changing of the intravenous cannula. The potential for home administration of parenteral teicoplanin gives this drug a major advantage over other parenteral drugs for the treatment of prosthetic joint infections.

Transport of cholesterol autoxidation products in rabbit lipoproteins.

Radiolabeled pure [4-14C]cholesterol was kept at 60 degrees C under air to autoxidize for 5 weeks, after which approximately 12% cholesterol oxidation products were formed. The mixture, suspended in gelatin, was given to rabbits by gastric gavage. Rabbits were killed 4, 24, and 48 h after treatment. Cholesterol and its autoxidation products were separated by thin-layer chromatography into 5 fractions and radioactivities of each fraction were measured. Percentages of each fraction of cholesterol oxidation products and cholesterol in the original mixture before administration and in the rabbit sera after administration were similar, suggesting that the rates of absorption of cholesterol oxidation products are not significantly different from that of cholesterol. Lipoproteins were fractionated by ultracentrifugation into VLDL, LDL and HDL. Radioactivities of each fraction in lipoproteins separated by thin layer chromatography showed that fractions containing cholestane-3 beta,5 alpha,6 beta-triol, 7 alpha- and 7 beta-hydroxycholesterol and 7-ketocholesterol were more selectively transported in VLDL, whereas most of the 25-hydroxycholesterol was present in LDL. HDL contained only minute amounts of cholesterol oxidation products.