Predicting length of stay in an acute psychiatric hospital

OBJECTIVE: Multivariate statistical methods were used to identify patient-related variables that predicted length of stay in a single psychiatric facility. The study investigated whether these variables remained stable over time and could be used to provide individual physicians with data on length of stay adjusted for differences in clinical caseloads and to detect trends in the physicians' practice patterns. METHODS: Data on all patients discharged over two six-month periods were collected at an acute psychiatric inpatient facility. Stepwise multiple regression analyses were conducted on the two datasets. RESULTS: The results from both analyses revealed that five variables significantly predicted length of stay and were stable over time. They were a primary diagnosis of schizophrenia, the number of previous admissions, a primary diagnosis of a mood disorder, age, and a secondary diagnosis of an alcohol- or other drug-related disorder. For some physicians, the mean length of stay of their patients differed significantly from the length predicted by the regression model--generally, it was shorter. CONCLUSIONS: The results demonstrate that patient-related predictors of length of stay in a single psychiatric hospital can be identified using relatively simple statistical procedures and can be consistent across a large dataset and over time.     

Photobleaching with phloxine B sensitizer to reduce food matrix interference for detection of Escherichia coli serotype O157:H7 in fresh spinach by flow cytometry

A flow cytometric method (RAPID-B™) with detection sensitivity of one viable cell of Escherichia coli serotype O157:H7 in fresh spinach (Spinacia oleracea) was developed and evaluated. The major impediment to achieving this performance was mistaking autofluorescing spinach particles for tagged target cells. Following a 5 h non-selective enrichment, artificially inoculated samples were photobleached, using phloxine B as a photosensitizer. Samples were centrifuged at high speed to concentrate target cells, then gradient centrifuged to separate them from matrix debris. In external laboratory experiments, RAPID-B and the reference method both correctly detected E. coli O157:H7 at inoculations of ca. 15 cells. In a follow-up study, after 4 cell inoculations of positives and 6 h enrichment, RAPID-B correctly identified 92% of 25 samples. The RAPID-B method limit of detection (LOD) was one cell in 25 g. It proved superior to the reference method (which incorporated real time-PCR, selective enrichment, and culture plating elements) in accuracy and speed.     

Total organic halogens (TOX) analysis in ether solutions

A new procedure to determine TOX (total organic halogens) recovered in ether extracts was developed as a modification of the EPA standard method for TOX analysis in aqueous solutions. A volume of sample was injected directly into the carbon in the pyrolysis furnace sample boat. Good recoveries (80–100%) were found for all the model compound solutions, except for the n-chloroalkanes. In this case, the molecules are long chain aliphatics and were not easily pyrolysed in the furnace. A linear correlation was found between the percentage recovery of these aliphatic compounds and the number of carbons in the molecule. The precision of the method was found to be 2–3% for TOX in the 10³–10⁵ ng injected range.     

A very large antenna for the 1.8 MHz band

This article describes a large 1.8 MHz antenna system that generates significantly more forward gain than that produced by commonly-used phased-vertical arrays. It provides coverage of all four azimuthal quadrants, along with a choice of four elevation angles, which may be selected at the turn of a switch