Time-to-signal comparison for drug safety data-mining algorithms vs. traditional signaling criteria.

Data mining may improve identification of signals, but its incremental utility is in question. The objective of this study was to compare associations highlighted by data mining vs. those highlighted through the use of traditional decision rules. In the case of 29 drugs, we used US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) data to compare three data-mining algorithms (DMAs) with two traditional decision rules: (i) N >or= 3 reports for a designated medical event (DME) and (ii) any event comprising >2% of reports in relation to a drug. Data-mining methods produced 101-324 signals vs. 1,051 for the N >or= 3 rule but yielded a higher proportion of signals having publication support. For the 2% rule, the fraction of signals having publication support was similar to that associated with data mining. Data-mining signals lagged N >or= 3 signaling by 1.5-11.0 months. It may therefore be concluded that data mining identifies fewer signals than the "N >or= 3 DME" rule. The signals appear later with data mining but are more often supported by publications. In the case of the 2% rule, no such difference in publication support was observed.

Sensitivity and specificity of the BAX for screening/Listeria monocytogenes assay: internal validation and independent laboratory study.

In this study to certify the BAX for Screening/Listeria monocytogenes assay (DuPont Qualicon, Wilmington, DE), an internal evaluation was conducted on 16 food types that were simultaneously analyzed with the BAX system (BAX), and the ISO method for the detection of L. monocytogenes (ISO). No statistically significant difference in performance between the BAX and ISO methods was observed. Inclusivity/exclusivity testing showed that the BAX system was able to detect 97 of 97 (100%) of L. monocytogenes strains tested. None of 56 other Listeria species or non-Listeria tested gave a reproducible positive BAX result. Ruggedness testing demonstrated that performance of the assay was not affected by reasonable variability in the operating parameters. BAX was then submitted for independent laboratory validation. In this phase, BAX was compared with standard culture methods for the detection of L. monocytogenes in chicken (USDA-FSIS), crab meat (BAM), and milk (AOAC). This study validated product claims of sensitivity and specificity >98% in accordance with AOAC Performance Tested Method requirements.

Sensitivity and specificity of the test kit BAX for screening/E. coli O157:H7 in ground beef: independent laboratory study.

An independent laboratory study of the BAX for Screening/E. coli O157:H7 kit was conducted at the National Food Laboratory, Inc., Dublin, CA, to complete AOAC Performance Tested Method certification. The BAX system kit was compared with the BAM culture method and a modified BAM culture method for detection of E. coli O157:H7 in ground beef. The BAX system kit detected the target organism at levels approximately 10-fold lower than those that gave positive BAM results. This study validated product claims, and Performance Tested Method status was granted.

Axial bone density in rheumatoid arthritis: comparison of dual-energy projection radiography and dual-photon absorptiometry.

The usefulness of dual-energy projection radiography (DEPR) in the evaluation of rheumatoid arthritis was compared with that of dual-photon absorptiometry (DPA). Bone density measurements of the lumbar spine and the proximal femur were obtained with DPA in 75 patients (45 women and 30 men). For comparison, the bone density of the lumbar spine was measured with DEPR in a subset of 52 patients (33 women and 19 men). High correlation was documented between DEPR and DPA measurements of the lumbar spine. No significant relationship between bone density and age was observed, in contrast to the known relationship in healthy subjects regardless of sex, site of measurement, or measurement technique. Bone density values in the spine and the proximal femur were significantly reduced for both sexes as compared with matched normative data. Interlevel variation in lumbar vertebral density as measured with DEPR was not significantly different in patients with rheumatoid arthritis as compared with control subjects. Significant correlation between bone density determination and body weight, as well as duration of menopause, was noted, whereas duration of disease, functional status, and cumulative corticosteroid dose were not predictive. Rheumatoid arthritis did not appear to influence the relationship between DEPR and DPA measurements of the spine, and neither method nor site of measurement exhibited a consistent advantage in discriminating patients with rheumatoid arthritis from healthy control subjects.