A Simple Locally Efficient Estimator For Relative Risk In Case-Cohort Studies

A case-cohort study is a two-phase study where at the first phase a representative sample, referred to as the study cohort, is selected from the target population. At the second phase, a subsample is selected from the cohort based on the case status. All cases are included in the subsample whereas only a random sample of controls is included. The endpoint of interest in such studies is usually the failure time. Several methods have been proposed to estimate the relative risk or hazard ratio from a case-cohort study. These methods almost always disregard the covariate information that is not included in the sampled study sub-cohort, and therefore, results in the loss of efficiency. While there have been attempts to derive the most efficient estimators, the resulting estimators were challenging from the data analysis point of view. We propose a locally efficient estimator (LEE) by restricting the estimator to a class of regular asymptotically linear estimators. The properties of this estimator are investigated through simulation and application to the Wilm's tumor study. The public health relevance of this dissertation is the use of innovative methodology to reduce cost associated with research

Neoadjuvant chemotherapy is associated with a high rate of perioperative blood transfusion at the time of interval cytoreductive surgery

Abstract Background The oncologic safety of allogeneic blood transfusion in ovarian cancer patients is unknow. We sought to determine the prevalence and oncologic safety of perioperative allogeneic blood transfusion during interval cytoreduction surgery among women receiving neoadjuvant chemotherapy for ovarian cancer. Methods We utilized retrospective chart review to identify a cohort of patients undergoing interval cytoreduction at a large academic tertiary referral center. We compared outcomes in patients who were exposed to perioperative blood transfusion compared with patients who were not exposed. Our primary endpoint was progression free survival; our secondary endpoint was overall survival. Baseline clinical characteristics were collected for patients in each group. Results Sixty-six women were included in the final cohort of women undergoing interval cytoreductive surgery after NACT. A total of 51 women (77%) were exposed to allogeneic perioperative pRBC transfusion. Fifteen women (23%) were not exposed to transfusion. The baseline characteristics were generally well matched. Women who were not exposed to a perioperative blood transfusion were more likely to have a normalized CA125 prior to undergoing cytoreductive surgery. Preoperative hemoglobin concentration was lower in the transfusion group (10.5 g/dLvs 11.5 g/dL, p < 0.009). Perioperative transfusion was not associated with a significant difference in progression free survival (PFS = 7.6 months for transfused, 9.4 months for not transfused; log-rank test p = 0.4617). Similarly, there was no observed difference between groups for overall survival (OS = 23.6 months for transfused, 22.5 months for not transfused; log-rank test p = 0.1723). Conclusions Women undergoing neoadjuvant chemotherapy for ovarian cancer are at high risk of exposure to blood transfusion at the time of interval cytoreductive surgery. Future studies will continue to evaluate the safety and impact of transfusion on ovarian cancer survival in this at risk population.https://deepblue.lib.umich.edu/bitstream/2027.42/146137/1/12885_2018_Article_4882.pd

Seasonal and Geographic Patterns in Seeking Cardiovascular Health Information: An Analysis of the Online Search Trends

Objective: To ascertain whether temporal and geographic interest in seeking cardiovascular disease (CVD) information online follows seasonal and geographic patterns similar to those observed in real-world data.Methods: We searched Google Trends for popular search terms relating to CVD. Relative search volumes (RSVs) were obtained for the period January 4, 2004, to April 19, 2014, for the United States and Australia. We compared average RSVs by month and season and used cosinor analysis to test for seasonal variation in RSVs. We also assessed correlations between state-level RSVs and CVD burden using an ecological correlational design.Results: RSVs were 15% higher in the United States and 45% higher in Australia for winter compared with summer (

Nutrition and Exercise Strategies to Prevent Excessive Pregnancy Weight Gain: A Meta-analysis

Abstract Objective To evaluate nutrition-only, exercise-only, and nutrition-plus-exercise interventions for optimizing gestational weight gain (GWG) based on the 2009 Institute of Medicine (IOM) guidelines. Study PubMed, Google Scholar, and 2015 Cochrane Review were searched. Analysis of variance was used to determine if significant GWG differences exist between strategies, with additional subanalyses on overweight (OV) or obese women based on 2009 IOM guidelines. Results Of 66 identified studies, 31 contributed data (n = 8,558). Compared with routine prenatal care, nutrition-only interventions were significantly associated with reduced GWG and are most likely to produce weight gain within IOM recommendations (p = 0.013). Exercise-only (p = 0.069) and nutrition-plus-exercise (p = 0.056) interventions trended toward GWG within IOM guidelines, but did not reach statistical significance. Supervised (p = 0.61) and unsupervised (p = 0.494) exercise programs had similar effectiveness. Subanalyses on OV or obese women produced similar results to studies that did not differentiate results based on body mass index: nutrition only (p = 0.011), exercise only (p = 0.308), and nutrition plus exercise (p = 0.129). Conclusion Preventing excessive GWG is crucial, especially for OV or obese women. In the current study, nutrition-based intervention is the health system strategy that showed significant impact on preventing excessive GWG compared with routine prenatal care. Among women who are OV or have obesity, nutrition-only interventions hold the most promise compared with routine prenatal care

Comparing appropriateness of antibiotics for nursing home residents by setting of prescription initiation: a cross-sectional analysis

Abstract Background The pervasive, often inappropriate, use of antibiotics in healthcare settings has been identified as a major public health threat due to the resultant widespread emergence of antibiotic resistant bacteria. In nursing homes (NH), as many as two-thirds of residents receive antibiotics each year and up to 75% of these are estimated to be inappropriate. The objective of this study was to characterize antibiotic therapy for NH residents and compare appropriateness based on setting of prescription initiation. Methods This was a retrospective, cross-sectional multi-center study that occurred in five NHs in southern Wisconsin between January 2013 and September 2014. All NH residents with an antibiotic prescribing events for suspected lower respiratory tract infections (LRTI), skin and soft tissue infections (SSTI), and urinary tract infections (UTI), initiated in-facility, from an emergency department (ED), or an outpatient clinic were included in this sample. We assessed appropriateness of antibiotic prescribing using the Loeb criteria based on documentation available in the NH medical record or transfer documents. We compared appropriateness by setting and infection type using the Chi-square test and estimated associations of demographic and clinical variables with inappropriate antibiotic prescribing using logistic regression. Results Among 735 antibiotic starts, 640 (87.1%) were initiated in the NH as opposed to 61 (8.3%) in the outpatient clinic and 34 (4.6%) in the ED. Inappropriate antibiotic prescribing for urinary tract infections differed significantly by setting: NHs (55.9%), ED (73.3%), and outpatient clinic (80.8%), P = .023. Regardless of infection type, patients who had an antibiotic initiated in an outpatient clinic had 2.98 (95% CI: 1.64–5.44, P < .001) times increased odds of inappropriate use. Conclusions Antibiotics initiated out-of-facility for NH residents constitute a small but not trivial percent of all prescriptions and inappropriate use was high in these settings. Further research is needed to characterize antibiotic prescribing patterns for patients managed in these settings as this likely represents an important, yet under recognized, area of consideration in attempts to improve antibiotic stewardship in NHs

An acute and sub-acute toxicological assessment of Reissantia indica plant extract in male Sprague-Dawley rats: Hematological, serum biochemical and histopathology

The traditional use of medicinal plants in Sub-Saharan health management lacks thorough toxicological evaluations, particularly concerning lethal dose levels. This study aims to assess the acute and sub-acute toxicity of Reissantia indica whole-plant extract (RIE) in male Sprague-Dawley rats, with a focal point on delineating its safety profile while exploring potential therapeutic applications.RIE, obtained through precise cold maceration in 70 % ethanol, underwent rigorous analysis, revealing diverse secondary metabolites, including alkaloids, flavonoids, terpenoids, and glycosides. Renowned for antioxidant, anti-inflammatory, and anticancer properties, these compounds enhance RIE's pharmacological potential.In the acute toxicity study, RIE was orally administered at 500 and 5000 mg/kg. Sub-acute toxicity involved oral administration of the extract at various doses (5, 50 and 500 mg/kg) over 28 days, with comprehensive assessments, including hematological, biochemical, and histopathological evaluations.Results from the acute toxicity showed no mortality, suggesting a median lethal dose (LD50) exceeding 5000 mg/kg and indicating a substantial margin of safety. Sub-acute toxicity investigations, spanning 28 days revealed no significant changes in body and organ weights, hematological and biochemical parameters, or histopathological signs compared to the control group. Histological examination of kidney, liver, heart, and lung sections from treated animals showed no signs of degeneration.This study, to our knowledge, pioneers a comprehensive investigation into the toxicity profile of Reissantia indica's whole-plant ethanolic extract, addressing a significant gap in existing literature on medicinal plant safety in the Sub-Saharan region

Probing the Effect of Governance of Tourism Development, Economic Growth, and Foreign Direct Investment on Carbon Dioxide Emissions in Africa: The African Experience

The environmental repercussions of extensive carbon dioxide (CO2) emissions on the environment are crucial for policymakers and scholars. The repercussions of and connection between economic growth (ECG), tourism (TOUR), and foreign direct investment (FDI) on CO2 emission mitigation have been measured and argued from empirical and theoretical perspectives by scholars. Notwithstanding, the extant body of knowledge has failed to incorporate and investigate the function of governance in decarbonizing tourism activities and FDI from CO2 emissions to attain a healthy and quality environment in Africa. Hence, this current research investigates governance&rsquo;s role in the reduction processes of CO2 emissions grounded in environmental Kuznets curve (EKC) conceptual assumptions for panel data spanning 2000 through 2020 for 27 African countries. This research utilized the Westerlund panel cointegration approach for the investigation of the cointegration of the selected variables. This study applied the Driscoll&ndash;Kraay regression approach for the long-term estimation. In addition, the dynamic ordinary least squares (DOLS) and the pooled mean group (PMG) were used for robustness checks. The findings of this research indicated that the governance (GOV) indicators employed have a statistically significant effect on the CO2 emission reduction. Besides, this study found that the appreciation of the income of the nations gives credence to the formation of the EKC theory and contributes to the decline in CO2 emissions within the selected African nations. The findings revealed that tourism, FDI, ECG, and GOV are positive and significant factors leading to increased CO2 emissions in Africa. Furthermore, the results showed that effective governance and control of FDI inflows and tourism activities can support decarbonization. These findings suggest the merits of governance in ensuring effective decarbonization policies of the environment, and policy suggestions are accordingly put forward

Probing the Effect of Governance of Tourism Development, Economic Growth, and Foreign Direct Investment on Carbon Dioxide Emissions in Africa: The African Experience

The environmental repercussions of extensive carbon dioxide (CO2) emissions on the environment are crucial for policymakers and scholars. The repercussions of and connection between economic growth (ECG), tourism (TOUR), and foreign direct investment (FDI) on CO2 emission mitigation have been measured and argued from empirical and theoretical perspectives by scholars. Notwithstanding, the extant body of knowledge has failed to incorporate and investigate the function of governance in decarbonizing tourism activities and FDI from CO2 emissions to attain a healthy and quality environment in Africa. Hence, this current research investigates governance’s role in the reduction processes of CO2 emissions grounded in environmental Kuznets curve (EKC) conceptual assumptions for panel data spanning 2000 through 2020 for 27 African countries. This research utilized the Westerlund panel cointegration approach for the investigation of the cointegration of the selected variables. This study applied the Driscoll–Kraay regression approach for the long-term estimation. In addition, the dynamic ordinary least squares (DOLS) and the pooled mean group (PMG) were used for robustness checks. The findings of this research indicated that the governance (GOV) indicators employed have a statistically significant effect on the CO2 emission reduction. Besides, this study found that the appreciation of the income of the nations gives credence to the formation of the EKC theory and contributes to the decline in CO2 emissions within the selected African nations. The findings revealed that tourism, FDI, ECG, and GOV are positive and significant factors leading to increased CO2 emissions in Africa. Furthermore, the results showed that effective governance and control of FDI inflows and tourism activities can support decarbonization. These findings suggest the merits of governance in ensuring effective decarbonization policies of the environment, and policy suggestions are accordingly put forward