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Robitaille A.,University of Victoria | Orpana H.,University of Ottawa | McIntosh C.N.,Statistical Consultants Ltd
Canadian Journal on Aging | Year: 2012

In this study we examined the longitudinal relationships between five dimensions of social support and psychological distress to determine whether (1) social support was related to subsequent psychological distress levels; or (2) if distress levels were related to subsequent social support levels; or (3) if distress and support had a reciprocal (bi-directional) relationship across time. Using bivariate autoregressive cross-lagged models, we analysed data from 2,564 older adults. We found support for the reciprocal relationship between affectionate support and distress. Higher psychological distress was related to subsequently higher levels of positive social interaction, and significantly related to subsequently higher emotional/informational support. No significant relationship was found between tangible and structural support and psychological distress. This study demonstrates that different types of support are associated in correspondingly different ways with psychological distress, and that psychological distress may be important in predicting levels of social support two years later. © 2012 Canadian Association on Gerontology. Source

Sun G.,Celgene | Quan H.,Sanofi S.A. | Kringle R.,Statistical Consultants Ltd | Meng Z.,Sanofi S.A.
Journal of Biopharmaceutical Statistics | Year: 2012

The ICH E14 guidance recommends the use of a time-matched baseline, while others recommend alternative baseline definitions including a day-averaged baseline. In this article we consider six models adjusting for baselines. We derive the explicit covariances and compare their power under various conditions. Simulation results are provided. We conclude that type I error rates are controlled. However, one model outperforms the others on statistical power under certain conditions. In general, the analysis of covariance (ANCOVA) model using a day-averaged baseline is preferred. If the time-matched baseline has to be used as per requests from regulatory agencies, the analysis by time point using ANCOVA model should be recommended. Copyright © Taylor & Francis Group, LLC. Source

Schuster M.G.,University of Pennsylvania | Meibohm A.,Statistical Consultants Ltd | Lloyd L.,Philadelphia Medical Center | Strom B.,University of Pennsylvania
Journal of Infection | Year: 2013

To investigate the risk factors and outcomes associated with Candida krusei bloodstream. Methods: We performed a case control study of patients with C. krusei bloodstream infection at the University of Pennsylvania from 1982 to 2010. Controls were without candidemia, and matched to cases on duration of hospitalization and underlying disease. Results: We enrolled 34 cases and 114 matched controls. Most subjects (62%) had hematologic malignancies. In the multivariate model, including a priori the duration of fluconazole use (OR 1.06; 95% CI 1.00, 1.11) and days of neutropenia (OR 1.01; 95% CI 0.98, 1.13), risk factors associated with C. krusei bloodstream infection were splenectomy (OR 11.66; 95% CI 1.04, 130.64), and exposure to antimicrobials with anaerobic activity (OR 5.74; 95% CI 1.76, 18.67). Outcomes of infected patients were poor. Only 32% of case patients survived to hospital discharge, compared to 89% of controls. For 48% death was attributed to C. krusei infection. Conclusions: C. krusei bloodstream infection occurs most commonly in neutropenic patients with hematologic malignancy. The association with prior fluconazole exposure is less marked than previously described. Splenectomy and the receipt of antimicrobials with anaerobic activity are significant risk factors. The outcome of infected patients remains poor, despite appropriate antifungal therapy. © 2012. Source

Kadam R.V.,Statistical Consultants Ltd | Field J.B.,University of Adelaide
Journal of Anaesthesiology Clinical Pharmacology | Year: 2011

Introduction: Transversus abdominis plane (TAP) block is a new regional analgesic technique for postoperative pain in abdominal surgery. Its efficacy is not clear, and thus it needs to be explored for its regular utilisation on prolonged period. The objective was to study the continuous local anaesthetic infusion effect on postoperative analgesia. Continuous use of TAP block as an analgesic technique has not been evaluated prospectively in clinical trials. This study evaluates the efficacy of ultrasoundguided TAP block in comparison with PCA fentanyl in major abdominal surgery. Materials and Methods: There were 20 patients in the study, allocated to TAP and control groups. The parameters measured were pain scores on a numerical rating scale (NRS) of 0-10 at various time intervals and the amount of fentanyl used as rescue analgesia. Patient satisfaction scores were recorded in the TAP block group and along with any complications related to the block. Results: The postoperative median pain scores on coughing on day one were 6.0 for control group and 2.0 for the TAP group (P = 0.02); on day two, the equivalent scores were 7.0 and 2.0 (P = 0.01). The fentanyl requirement at one hour was 203 μ for the control group and 78 μg for the TAP group (P = 0.03); at day one, the control and TAP requirements were 1237 μg and 664 μg respectively (P = 0.01). Three TAP patients rated their satisfaction as 'excellent', four as 'satisfied, and two as 'poor'. Conclusion: TAP block is a promising technique for postoperative analgesia in major abdominal surgeries. Our study demonstrated lower pain scores in the TAP group with reduced fentanyl requirement. Further, a large scale study is needed to establish the efficacy of TAP block in this setting. Source

Williamson E.D.,UK Defence Science and Technology Laboratory | Duchars M.G.,Genie Bio Logic Frederick | Kohberger R.,Statistical Consultants Ltd
Expert Review of Vaccines | Year: 2010

The identification of immune correlates of protection is becoming increasingly important in order to derive a quantitative assessment of the benefit conferred by vaccination in clinical trials. The use of immune correlates of protection as an indirect measure of clinical efficacy is essential to achieve regulatory approval for vaccines for which clinical efficacy cannot be tested directly, for example, biodefence vaccines. The correlates apply to the specific vaccine formulation being developed; in general, if a statistically significant correlation is found between a measurable immunological readout and survival in authentic animal models of human infection, the same immunological readout can be defined and applied as a surrogate marker of protection in clinical studies. The surrogate markers of protection can then be used to predict the protective efficacy of a candidate vaccine in humans. This review summarizes some of the immune correlates data reported for biodefence vaccines as well as some of the analytical approaches that can be applied in order to predict clinical efficacy. © 2010 Expert Reviews Ltd. Source

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