Trust, but verify. The accuracy of references in four anesthesia journals.

To determine the accuracy of bibliographic citation in the anesthesia literature, we reviewed all 1988 volumes of ANESTHESIOLOGY, Anesthesia and Analgesia, British Journal of Anaesthesia, and Canadian Journal of Anaesthesia and sequentially numbered all references appearing in that year (n = 22,748). One hundred references from each of the four journals were randomly selected. After citations to nonjournal articles (i.e., books or book chapters) were excluded, the remaining 348 citations were analyzed in detail. Six standard bibliographic elements--authors' names, article title, journal title, volume number, page numbers, and year--were examined in each selected reference. Primary sources were reviewed, unless our institution did not own the source or could not obtain it through interlibrary loan, in which case standard indexes, abstracting services, and computerized databases were consulted. Each element was checked for accuracy, and references were classified as either correct or incorrect. A reference was correct if each element of the citation was identical to its source. Of the examined references, more than half (50.3%) contained an error in at least one element. The elements most likely to be inaccurate were, in descending order, article title, author, page numbers, journal title, volume number, and year. No significant differences (P = 0.283) existed in the error rates of the four journals; the percentage of citations containing at least one error ranged from 44% (Anesthesia and Analgesia) to 56% (British Journal of Anaesthesia). The citation error rate of anesthesia journals is similar to that reported in other specialties, where error rates ranging from 38% to 54% have been documented.     

Cost-effectiveness of inpatient substance abuse treatment.

OBJECTIVE: To identify the characteristics of cost-effective inpatient substance abuse treatment programs. DATA SOURCES/STUDY SETTING: A survey of program directors and cost and discharge data for study of 38,863 patients treated in 98 Veterans Affairs treatment programs. STUDY DESIGN: We used random-effects regression to find the effect of program and patient characteristics on cost and readmission rates. A treatment was defined as successful if the patient was not readmitted for psychiatric or substance abuse care within six months. PRINCIPAL FINDINGS: Treatment was more expensive when the program was smaller, or had a longer intended length of stay (LOS) or a higher ratio of staff to patients. Readmission was less likely when the program was smaller or had longer intended LOS; the staff to patient ratio had no significant effect. The average treatment cost $3,754 with a 75.0% chance of being effective, a cost-effectiveness ratio of $5,007 per treatment success. A 28-day treatment program was $860 more costly and 3.3% more effective than a 21-day program, an incremental cost-effectiveness of $26,450 per treatment success. Patient characteristics did not affect readmission rates in the same way they affected costs. Patients with a history of prior treatment were more likely to be readmitted but their subsequent stays were less costly. CONCLUSIONS: A 21-day limit on intended LOS would increase the cost-effectiveness of treatment programs. Consolidation of small programs would reduce cost, but would also reduce access to treatment. Reduction of the staff to patient ratio would increase the cost-effectiveness of the most intensively staffed programs.     

Testing the effectiveness of the exercise plus program in older women post-hip fracture

Background: Exercise is an important strategy with potential to improve recovery in older adults following a hip fracture.Purpose: The purpose of this study was to test the impact of a self-efficacy based intervention, the Exercise Plus Program, and the different components of the intervention, on self-efficacy, outcome expectations, and exercise behavior among older women post-hip fracture.Methods: Participants were randomized to one of four groups: exercise plus, exercise only, plus only (i.e., motivation), or routine care. Data collection was done at baseline (within 22 days of fracture), 2, 6, and 12 months post-hip fracture.Results: A total of 209 women were recruited with an average age of 81.0 years (SD=6.9). The majority was White (97.1%), was widowed (57.2%), and had a high school education (66.7%). Generalized Estimating Equations were used to perform repeated measures analyses. No differences in trajectories of recovery were observed for self-efficacy or outcome expectations. A statistically significant difference in the overall trajectory of time in exercise was seen (p<.001), with more time spent exercising in all three treatment groups.Conclusions: The study demonstrated that it was possible to engage these women in a home-based exercise program and that the plus only, exercise only, and the exercise plus groups all increased exercise. Support for this project was provided by National Institute on Aging grants R37 AG09901, R01-AG18668, R01 AG17082, and the Claude D. Pepper Older Americans Independence Center P60-AG12583.     

Loss of T-type Calcium Current in Sensory Neurons of Rats with Neuropathic Pain

Background: Pathophysiology in the primary sensory neuron may contribute to chronic neuropathic pain. Ca channels play a central role in neuronal processes, and sensory neurons are rich in low-voltage-activated calcium channels (LVACCs). However, the physiologic function of these channels is unknown. Their possible role in rebound burst firing makes them a candidate for increased excitability after neuropathic injury.

Methods: This study uses pharmacological methods to isolate LVACC in cells from the dorsal root ganglia of neuropathic and sham-operated rats, including the blockade of high-voltage-activated Ca channels with fluoride and selective toxins. LVACCs were examined with conventional whole cell patch clamp electrophysiology techniques.

Results: After chronic constriction injury of the peripheral axon, LVACC was significantly reduced compared to sham rats as shown by a 60% reduction in peak current density and an 80% reduction in total calcium influx. A depolarizing shift in the voltage dependence of activation and an increase in the rate of deactivation and inactivation appear to cause this reduction of LVACC. Either Ni2+ or mibefradil, blockers of LVACC, applied in the bath to normal dorsal root ganglion cells during current clamp significantly and reversibly increased excitability.     

骨骼肌的生物力学

骨骼肌能产生力和运动,肌肉的收缩与运动的激发完美协调。本文回顾骨骼肌的生物力学特点,描述力的产生和力通过肌细胞的传递。首先描述正常的肌肉结构特征和不同的肌肉结构形式,随后讨论肌肉的功能及其结构对功能的影响,分析收缩蛋白与中间肌丝在力从细胞内肌小节传递到细胞外基质过程中的相互作用。     

Comparison of Methodologies for Calculating Quality Measures Based on Administrative Data versus Clinical Data from an Electronic Health Record System: Implications for Performance Measures

New reimbursement policies and pay-for-performance programs to reward providers for producing better outcomes are proliferating. Although electronic health record (EHR) systems could provide essential clinical data upon which to base quality measures, most metrics in use were derived from administrative claims data. We compared commonly used quality measures calculated from administrative data to those derived from clinical data in an EHR based on a random sample of 125 charts of Medicare patients with diabetes. Using standard definitions based on administrative data (which require two visits with an encounter diagnosis of diabetes during the measurement period), only 75% of diabetics determined by manually reviewing the EHR (the gold standard) were identified. In contrast, 97% of diabetics were identified using coded information in the EHR.The discrepancies in identified patients resulted in statistically significant differences in the quality measures for frequency of HbA1c testing, control of blood pressure, frequency of testing for urine protein, and frequency of eye exams for diabetic patients. New development of standardized quality measures should shift from claims-based measures to clinically based measures that can be derived from coded information in an EHR. Using data from EHRs will also leverage their clinical content without adding burden to the care process.     

Role of endothelin in the exercise intolerance of chronic heart failure

In conclusion, plasma levels of the endothelialderived vasoconstrictor endothelin-1 (but not those of other neurohormonal vasoconstrictor factors), measured during exercise correlated closely with objective variables of exercise capacity in patients with heart failure. These findings suggest that endothelin-1 may contribute to exercise intolerance in patients with heart failure, perhaps by limiting the ability of the peripheral vasculature to dilate during exercise.