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Item Establishing the minimal sufficient number of measurements to validate a 24h blood pressure recording(2018-05-17) Agarwal, Rajiv; Tu, WanzhuBackground: Ambulatory blood pressure (BP) monitoring (ABPM) remains a reference standard but the number of readings required to make the measurement valid has not been empirically validated. Methods: Among 360 patients with chronic kidney disease and 38 healthy controls, BP was recorded 2 per hour during the night and 3 per hour during the day over 24h using a validated ABPM device; all had at least 90% of the expected readings. From this full set of ABPM recording, a variable number of BP measurements were selected and we compared the performance of the selected readings against that of the full sample using random or sequential selection schemes. To address the question whether random or sequential selection schemes affect the diagnostic performance in diagnosing hypertension control we compared the diagnostic decisions reached with the subsample and the full sample using area under the receiver operating-characteristic curves (AUC ROC). To answer the question regarding the number of readings needed to achieve over 90% coverage of the mean BP of the full ABPM sample we ascertained the point and confidence interval (CI) estimates based on the selected data. Results: To diagnose hypertension control, the number of readings randomly drawn to establish lower bound with 2.5% error of area under the receiver operating-characteristic curve (AUC ROC) of 0.9 was 3, 0.95 was 7, and 0.975 was 13 . In contrast, the corresponding number of readings with serial selections was 18, 30 and 39 respectively. With a random selection scheme, 18 readings provided 80% coverage of the 90th percentile of CI of the true systolic BP mean, for 90% coverage, 26 readings were needed, for 95% coverage 33. With serial selections, the number of readings increased to 42, 47, and 50 respectively. Similar results emerged for diastolic BP. Conclusions: For diagnosing hypertension control 3 random measurements or 18 serial measurements is sufficient. For quantitative analysis, the minimal sufficient number of 24h ambulatory BP is 26 random recordings or 42 serial recordings.Item Recommendations for the design of therapeutic trials for neonatal seizures(Springer Nature, 2019-06) Soul, Janet S.; Pressler, Ronit; Allen, Marilee; Boylan, Geraldine; Rabe, Heike; Portman, Ron; Hardy, Pollyanna; Zohar, Sarah; Romero, Klaus; Tseng, Brian; Bhatt-Mehta, Varsha; Hahn, Cecil; Denne, Scott; Auvin, Stephane; Vinks, Alexander; Lantos, John; Marlow, Neil; Davis, Jonathan M.; Pediatrics, School of MedicineAlthough seizures have a higher incidence in neonates than any other age group and are associated with significant mortality and neurodevelopmental disability, treatment is largely guided by physician preference and tradition, due to a lack of data from well-designed clinical trials. There is increasing interest in conducting trials of novel drugs to treat neonatal seizures, but the unique characteristics of this disorder and patient population require special consideration with regard to trial design. The Critical Path Institute formed a global working group of experts and key stakeholders from academia, the pharmaceutical industry, regulatory agencies, neonatal nurse associations, and patient advocacy groups to develop consensus recommendations for design of clinical trials to treat neonatal seizures. The broad expertise and perspectives of this group were invaluable in developing recommendations addressing: (1) use of neonate-specific adaptive trial designs, (2) inclusion/exclusion criteria, (3) stratification and randomization, (4) statistical analysis, (5) safety monitoring, and (6) definitions of important outcomes. The guidelines are based on available literature and expert consensus, pharmacokinetic analyses, ethical considerations, and parental concerns. These recommendations will ultimately facilitate development of a Master Protocol and design of efficient and successful drug trials to improve the treatment and outcome for this highly vulnerable population.Item RIPARIAN ZONE HYDROLOGY AND HYDROGEOMORPHIC SETTING OF A GLACIATED VALLEY IN CENTRAL INDIANA(2007) Smith, Andrew Philip; Vidon, Philippe G.; Tedesco, Lenore P.; Doss, Paul K.This study investigates the hydrological functioning of a riparian zone in central Indiana in a glaciated valley with concave topography (16% slope gradient) and ground water seeps on the valley walls. Unlike sites found in most riparian zone studies with lateral ground water inputs (Clement et al., 2003; Jordan et al., 1993; Blicher-Mathiesen and Hoffman, 1999; Hoffman et al., 2000), the site in this study is connected to thin, permeable upland sediments (≈2 m). The objectives of this research include: 1) understanding the influence of the hydrogeomorphic (HGM) setting on riparian hydrology (including determining the sources of water to the site), 2) determining how the HGM setting influences riparian zone water quality functioning, and 3) comparing the results from this site with conceptual models of riparian zone hydrologic functioning. Water chemistry and hydrometric data were collected over a 16-month period. Three factors influence riparian zone hydrological functioning at the site: 1) the nature of water contributions from upland sources, 2) riparian zone soil texture, and 3) the location of a preWisconsinan till unit. When the uplands are contributing water to the riparian zone a shallow water table is found near the hillslope and ground water flows from the hillslope to the stream. Conversely, when upland contributions cease a large water table drop occurs and ground water flows in a downvalley direction. Fine textured soils near the hillslope result in shallow water tables and small ground water fluxes. Hydrometric data, water chemistry, and statistical analyses suggest water from an intertill layer adjacent to the site is the primary source of water to the site. NO3- concentrations decreased in ground water flow in the riparian zone suggesting the site is removing nutrients. A preWisconsinan glacial till deposit at shallow depths in the riparian zone limits ground water flow to horizontal flow paths. Overall, the hydrologic functioning of the site agrees well with riparian zone conceptual models (Vidon and Hill, 2004a; Vidon and Hill, 2004b; Devito et al., 1996; Hill, 2000; Baker et al., 2001; Burt et al., 2002). The results of this study are important additions towards conceptualizing riparian zone hydrologic functioning.