Determination of needed radiographic room capacity to serve an emergency department

This study describes a method for determining the number of radiographic rooms devoted to emergency radiology that would be required to keep mean patient waiting time at a desired level. A desired mean waiting time for patients must be determined. In our setting, a mean waiting time of 8 minutes resulted in few complaints. The waiting time then sets the required utilization rate of available capacity. Daily and hourly volume and variability in volume of examinations were measured over a 3-month period. This represents the demand. The needed number of rooms is determined by comparing demand with effective available capacity for different numbers of rooms. To maintain an 8-minute mean waiting time, 50% utilization of capacity is required. Mean demand on Sundays is 176 examinations. Five rooms are required, since this gives a 180-examination effective capacity. Using waiting time as the primary decision criterion for making capacity decisions in emergency radiology has several advantages: the method is easy to use, volume variability is taken into account, and the focus is on service to patients.     

Ancient,highly polymorphic human major histocompatibility complex DQA1 intron sequences

A 438 basepair intron 1 sequence adjacent to exon 2 in the human major histocompatibility complex DQA1 gene defined 16 allelic variants in 69 individuals from wide ethnic backgrounds. In contrast, the most variable coding region spanned by the 247 basepair exon 2 defined 11 allelic variants. Our phylogenetic human intron 1 tree derived by the Bootstrap algorithm reflects the same relative allelic relationships as the reported DQA1 exon 2 tree [Gyllensten and Erlich, Hum Immunol 36:1–10, 1989]. Thus 3′ DQA1 intron 1 and exon 2 have cosegregated since divergence of the human races. Comparison of human alleles to a Rhesus monkey DQA1 first intron sequence found only 10 nucleotide substitutions unique to Rhesus, with the other 428 positions (98%) found in at least one human allele. This high degree of homology reflects the evolutionary stability of intron sequences since these two species diverged over 20 million years ago. Because more intron 1 alleles exist than exon 2 alleles, these polymorphic introns can be used to improve tissue typing for transplantation, paternity testing, and forensics and to derive more complete phylogenetic trees. These results suggest that introns represent a previously underutilized polymorphic resource. © 1994 Wiley-Liss, Inc.     

Update: Ansa Cervicalis to Recurrent Laryngeal Nerve Anastomosis for Unilateral Laryngeal Paralysis

Twenty cases of unilateral laryngeal paralysis are reported. Satisfactory follow-up intervals and data (videostroboscopy and glottographic analysis) were available on 12 patients. The excellent to normal phonatory quality achieved in many of these patients indicates that the ansa cervicalis to recurrent laryngeal nerve anastomosis is the procedure of choice in selected patients with unilateral vocal cord paralysis. Excellent medialization of the paralyzed cord, as well as correction of arytenoid malposition and thyroarytenoid muscle atrophy appear to explain the technique's success, since the reinnervated cord neither abducts nor adducts. We feel that this technique is the procedure of choice in younger patients, or those who use their voices professionally, since the phonatory quality achieved is superior to Teflon® injection or Isshiki thyroplasty, and the technique is reversible.     

Revisiting the Relationship between Managed Care and Hospital Consolidation

Objective. This paper analyzes whether the rise in managed care during the 1990s caused the increase in hospital concentration.
Data Sources. We assemble data from the American Hospital Association, InterStudy and government censuses from 1990 to 2000.
Study Design. We employ linear regression analyses on long differenced data to estimate the impact of managed care penetration on hospital consolidation. Instrumental variable analogs of these regressions are also analyzed to control for potential endogeneity.
Data Collection. All data are from secondary sources merged at the level of the Health Care Services Area.
Principle Findings. In 1990, the mean population-weighted hospital Herfindahl–Hirschman index (HHI) in a Health Services Area was .19. By 2000, the HHI had risen to .26. Most of this increase in hospital concentration is due to hospital consolidation. Over the same time frame HMO penetration increased three fold. However, our regression analysis strongly implies that the rise of managed care did not cause the hospital consolidation wave. This finding is robust to a number of different specifications.     

Multiple steroid hormone levels in depressed patients and normal controls before and after exogenous ACTH

Forty depressed patients and 36 age- and sex-matched controls were given 250 μg ACTH_1–24 by bolus. Plasma steroid hormone levels were measured prior to and 60 min after ACTH administration. The depressed patients had significantly greater cortisol (F), 11-deoxycortisol (S), androstenedione (AD), and 17-hydroxyprogesterone (17-OHP) responses (delta; p<0.05) and a marginally greater 11β-hydroxyandrostenedione (11β-OHAD) response (delta; p=0.091) than the controls. There was no significant difference in the corticosterone (B) response between the two groups.

With the exception of 11β-OHAD, all the steroid hormones were significantly negatively correlated with age in the controls, but only S and AD marginally demonstrated this relationship in the depressed patients. F, S, AD, 17-OHP, and B, but not 11β-OHAD, were significantly positively correlated with each other in the controls, but only F was significantly correlated with AD in the depressed patients. These data suggest that the hypercortisolemia found in some depressed patients involves increased precursor and metabolite levels both at baseline and in response to exogenous ACTH, compared to controls. Furthermore, variability in these precursors is greater in depressed patients, and their relationship to age is lost. These findings are consistent with the hypothesis that adrenal products other than cortisol also could be related to affective symptoms.