Factors associated with primary hip arthroplasty after hip fracture.

OBJECTIVES: To determine patient, clinical, and hospital factors associated with receiving total hip arthroplasty (THA) and hemiarthroplasty (HA) in the United States. STUDY DESIGN: Retrospective, cross-sectional study. METHODS: Hospital discharge records with a principal diagnosis of hip fracture and primary hip arthroplasty or no surgery were identified from the 2009 Nationwide Inpatient Sample data set of the Healthcare Cost and Utilization Project. Patient (age, sex, race, income, payer), clinical (comorbidities, severity, fracture type), hospital (region, location, teaching status, bed size, ownership), and outcome (receipt of THA or HA) variables were extracted and weighted for the analyses. Univariate and multivariate analysis were conducted and significance was set at P < .05. RESULTS: A total of 92,861, 15,489, and 9863 discharges occurred for HA, no surgery, and THA, respectively. Compared with no surgery, THA or HA was significantly more likely in patients who were aged > 50 years, white, and female; had > $39,000 income; lived in a medium-metro or noncore county; had comorbidities (anemia, hypertension); and had intracapsular fracture. THA or HA was significantly more likely in urban, privately owned hospitals with > 249 beds. Compared with no surgery, THA was significantly more likely in nonteaching hospitals, the Northeast region, and in private insurance or self-pay patients with moderate to severe fractures; HA was more likely in teaching hospitals, in the South and West, and in Medicare patients with minor fractures. CONCLUSIONS: Similarities and differences in patient, clinical, and hospital factors associated with surgical treatments of hip fracture warrant the attention of providers and payers.

Effects of acetylcholine mustard analogs on schistosome and vertebrate neuromuscular preparations.

Two acetylcholine mustard analogs were synthesized for studies of the structural requirements for drugs having selective neurotoxic effects in schistosomes. Drugs investigated in the present study include methyl- and butyl-2-acetoxyethyl-2'-chloroethylamine (MeM and BuM). In worm activity monitor experiments, both MeM and BuM irreversibly paralyzed Schistosoma mansoni after 1-hr exposure followed by 19 hr in drug-free medium. The concentrations required for parasite paralysis were similar to effective concentrations of known antischistosomal drugs. An immediate effect of both compounds was blockage of carbachol-induced paralysis, suggesting that they may bind at schistosome cholinergic sites. Furthermore, fluorescent labeling of schistosomes with dansyl choline was reduced by both compounds. In vertebrate studies, while MeM was a potent agonist at both muscarinic and nicotinic receptors, BuM had only a slight effect. MeM and BuM had no major irreversible cholinergic effect in vertebrate tissues. BuM, therefore, has distinctly different pharmacological actions in schistosomes and in vertebrates.