			Home About us Contact

Study Power (study + power)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Managing people and performance: an evidence based framework applied to health service organizations

INTERNATIONAL JOURNAL OF MANAGEMENT REVIEWS, Issue 2 2004
Susan Michie
People and their performance are key to an organization's effectiveness. This review describes an evidence-based framework of the links between some key organizational influences and staff performance, health and well-being. This preliminary framework integrates management and psychological approaches, with the aim of assisting future explanation, prediction and organizational change. Health care is taken as the focus of this review, as there are concerns internationally about health care effectiveness. The framework considers empirical evidence for links between the following organizational levels: 1Context (organizational culture and inter-group relations; resources, including staffing; physical environment) 2People management (HRM practices and strategies; job design, workload and teamwork; employee involvement and control over work; leadership and support) 3Psychological consequences for employees (health and stress; satisfaction and commitment; knowledge, skills and motivation) 4Employee behaviour (absenteeism and turnover; task and contextual performance; errors and near misses) 5Organizational performance; patient care. This review contributes to an evidence base for policies and practices of people management and performance management. Its usefulness will depend on future empirical research, using appropriate research designs, sufficient study power and measures that are reliable and valid. [source]

Does intraarticular morphine improve pain control with femoral nerve block after anterior cruciate ligament reconstruction? (Vanderbilt University Medical Center, Nashville, TN) American Journal of Sports Medicine 2001;29:327,332.

PAIN PRACTICE, Issue 4 2001
Eric C. McCarthy
In a prospective, randomized, double-blinded manner, the authors of this study compared the effects of a preoperative intraarticular injection of morphine (5 mg) or a placebo, combined with a postoperative femoral nerve block, on postoperative pain. Sixty-two patients underwent an arthroscopically assisted anterior cruciate ligament reconstruction using patellar tendon autograft under general anesthesia. No statistical difference between the 2 groups was evident in terms of age, sex, weight, operative time, volume of bupivacaine received with the femoral nerve block, or tourniquet use or tourniquet time. A comparison of the visual analog pain scale scores revealed no statistical difference between the groups at any point after the operation. Both groups had a significant decrease in visual analog scale scores after the femoral nerve block. No significant difference in postoperative narcotic medication use was evident in the recovery room or at home. A post hoc analysis revealed that the study power reached 87% with a significance level of 5%. Conclude that the postoperative femoral nerve block was effective and intraarticular morphine provided no additional benefit. Comment by Alan David Kaye, M.D., Ph.D., and Erin Bayer, M.D. This prospective, randomized, double blinded study compared the effects of preoperative intraarticular injection of morphine or a placebo along with postoperative femoral "three-in-one" block on postoperative pain. 62 patients underwent arthroscopic ACL reconstruction under general anesthesia. After induction of anesthesia, patients were injected with either morphine 5 mg or placebo along with local anesthetics intraarticularly. Femoral nerve blocks were performed in the recovery room with a total of 3 mg/kg bupivacaine. The VAS of pain was assessed immediately postoperatively and at six time points afterward up to 24 hours. This study concluded that there were no statistical differences between the two groups comparing VAS. Also no significant difference was observed in postoperative narcotic use in the recovery room or at home. The study included antiemetics; however, the results did not include if the morphine group had a larger incidence of nausea or vomiting postoperatively. Finally, the authors suggest that there are no advantages to use of intraarticular morphine with a femoral nerve block post-operatively. A future study employing preoperative femoral nerve block with or without use of intraarticular morphine might be interesting to see on arthroscopic ACL repairs to obtain adequate analgesia as the authors suggested. [source]

Analyzing Incomplete Data Subject to a Threshold using Empirical Likelihood Methods: An Application to a Pneumonia Risk Study in an ICU Setting

BIOMETRICS, Issue 1 2010
Jihnhee Yu
Summary The initial detection of ventilator-associated pneumonia (VAP) for inpatients at an intensive care unit needs composite symptom evaluation using clinical criteria such as the clinical pulmonary infection score (CPIS). When CPIS is above a threshold value, bronchoalveolar lavage (BAL) is performed to confirm the diagnosis by counting actual bacterial pathogens. Thus, CPIS and BAL results are closely related and both are important indicators of pneumonia whereas BAL data are incomplete. To compare the pneumonia risks among treatment groups for such incomplete data, we derive a method that combines nonparametric empirical likelihood ratio techniques with classical testing for parametric models. This technique augments the study power by enabling us to use any observed data. The asymptotic property of the proposed method is investigated theoretically. Monte Carlo simulations confirm both the asymptotic results and good power properties of the proposed method. The method is applied to the actual data obtained in clinical practice settings and compares VAP risks among treatment groups. [source]

Advanced Statistics: Missing Data in Clinical Research,Part 1: An Introduction and Conceptual Framework

ACADEMIC EMERGENCY MEDICINE, Issue 7 2007
Jason S. Haukoos MD
Missing data are commonly encountered in clinical research. Unfortunately, they are often neglected or not properly handled during analytic procedures, and this may substantially bias the results of the study, reduce study power, and lead to invalid conclusions. In this two-part series, the authors will introduce key concepts regarding missing data in clinical research, provide a conceptual framework for how to approach missing data in this setting, describe typical mechanisms and patterns of censoring of data and their relationships to specific methods of handling incomplete data, and describe in detail several simple and more complex methods of handling such data. In part 1, the authors will describe relatively simple approaches to handling missing data, including complete-case analysis, available-case analysis, and several forms of single imputation, including mean imputation, regression imputation, hot and cold deck imputation, last observation carried forward, and worst case analysis. In part 2, the authors will describe in detail multiple imputation, a more sophisticated and valid method for handling missing data. [source]