317 research outputs found

    A Likelihood-Based Approach for Computing the Operating Characteristics of the Standard Phase I Clinical Trial Design

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    In phase I clinical trials, the standard ‘3+3’ design has passed the test of time and survived various sample size adjustments, or other dose-escalation dynamics. The objective of this study is to provide a probabilistic support for analyzing the heuristic performance of the ‘3+3’ design. Our likelihood method is based on the evidential paradigm that uses the likelihood ratio to measure the strength of statistical evidence for one simple hypothesis over the other. We compute the operating characteristics and compare the behavior of the standard algorithm under different hypotheses, levels of evidence, and true (or best guessed) toxicity rates. Given observed toxicities per dose level, the likelihood-ratio is evaluated according to a certain k threshold (level of evidence). Under an assumed true toxicity scenario the following statistical characteristics are computed and compared: i) probability of weak evidence, ii) probability of favoring H1 under H1(analogous to 1-α), iii) probability of favoring H2 under H2 (analogous to 1-β). This likelihood method allows consistent inferences to be made and evidence to be quantified regardless of cohort size. Moreover, this approach can be extended and used in phase I designs for identifying the highest acceptably safe dose and is akin to the sequential probability ratio test

    Brief Report: Factors Associated with Asthma Management Self-Efficacy Among 7th and 8th Grade Students

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    Objective Examine correlates of asthma self-management among 12,154 adolescents with physician-diagnosed asthma. Methods All 7th and 8th grade students in North Carolina completed a survey to assess asthma prevalence and self-management behaviors among those with asthma. Results Adolescents who were allowed to carry their inhaled medication at school, shown how to use a peak flow meter, and had access to more asthma care resources were more confident that they could prevent an asthma exacerbation. Adolescents who were allowed to carry their inhaled medication at school and who had a private doctor were more confident that they could control their symptoms. Adolescents taking anti-inflammatory medicine were less confident that they could prevent an exacerbation and control their symptoms. Conclusions Various indicators of autonomy and control were associated with greater self-efficacy for managing asthma. Adolescents who require anti-inflammatory medicines would benefit from additional intervention efforts to improve their asthma management self-efficacy

    Provider Demonstration and Assessment of Child Device Technique During Pediatric Asthma Visits

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    The purposes of this study were to (a) describe the extent to which children use metered dose inhalers, turbuhalers, diskuses, and peak flow meters correctly, and (b) investigate how often providers assess and demonstrate use of metered dose inhalers, turbuinhalers, diskuses, and peak flow meters during pediatric asthma visits

    Communication During Pediatric Asthma Visits and Self-Reported Asthma Medication Adherence

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    Our objectives were to examine how certain aspects of provider-patient communication recommended by national asthma guidelines (ie, provider asking for child and caregiver input into the asthma treatment plan) were associated with child asthma medication adherence 1 month after an audio-taped medical visit

    Relation between malodor, ambient hydrogen sulfide, and health in a community bordering a landfill

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    Municipal solid waste landfills are sources of air pollution that may affect the health and quality of life of neighboring communities

    Public Infrastructure Disparities and the Microbiological and Chemical Safety of Drinking and Surface Water Supplies in a Community Bordering a Landfill

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    The historically African-American Rogers-Eubanks community straddles unincorporated boundaries of two municipalities in Orange County, North Carolina, and predates a regional landfill sited along its border in 1972. Community members from the Rogers-Eubanks Neighborhood Association (RENA), concerned about deterioration of private wells and septic systems and a lack of public drinking water and sewer services, implemented a community-driven research partnership with university scientists and community-based organizations to investigate water and sewer infrastructure disparities and the safety of drinking and surface water supplies. RENA drafted memoranda of agreement with partners and trained community monitors to collect data (inventory households, map water and sewer infrastructure, administer household water and sewer infrastructure surveys, and collect drinking and surface water samples). Respondents to the surveys reported pervasive signs of well vulnerability (100%) and septic system failure (68%). Each 100-m increase in distance from the landfill was associated with a 600 most probable number/100 mL decrease in enterococci concentrations in surface water (95% confidence interval = −1106, −93). Pervasive private household water and sewer infrastructure failures and poor water quality were identified in this community bordering a regional landfill, providing evidence of a need for improved water and sanitation services

    Cognitive interviewing methodology in the development of a pediatric item bank: a patient reported outcomes measurement information system (PROMIS) study

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    <p>Abstract</p> <p>Background</p> <p>The evaluation of patient-reported outcomes (PROs) in health care has seen greater use in recent years, and methods to improve the reliability and validity of PRO instruments are advancing. This paper discusses the cognitive interviewing procedures employed by the Patient Reported Outcomes Measurement Information System (PROMIS) pediatrics group for the purpose of developing a dynamic, electronic item bank for field testing with children and adolescents using novel computer technology. The primary objective of this study was to conduct cognitive interviews with children and adolescents to gain feedback on items measuring physical functioning, emotional health, social health, fatigue, pain, and asthma-specific symptoms.</p> <p>Methods</p> <p>A total of 88 cognitive interviews were conducted with 77 children and adolescents across two sites on 318 items. From this initial item bank, 25 items were deleted and 35 were revised and underwent a second round of cognitive interviews. A total of 293 items were retained for field testing.</p> <p>Results</p> <p>Children as young as 8 years of age were able to comprehend the majority of items, response options, directions, recall period, and identify problems with language that was difficult for them to understand. Cognitive interviews indicated issues with item comprehension on several items which led to alternative wording for these items.</p> <p>Conclusion</p> <p>Children ages 8–17 years were able to comprehend most item stems and response options in the present study. Field testing with the resulting items and response options is presently being conducted as part of the PROMIS Pediatric Item Bank development process.</p

    PROMIS Pediatric Pain Interference Scale: An Item Response Theory Analysis of the Pediatric Pain Item Bank

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    An aim of the National Institutes of Health (NIH) Patient Reported Outcomes Measurement Information System (PROMIS) initiative is to develop item banks and computerized adaptive tests (CAT) that are applicable across a wide variety of chronic disorders. The PROMIS Pediatric Cooperative Group has concentrated on the development of pediatric self-report item banks for ages 8-17 years. The objective of the present study is to describe the Item Response Theory (IRT) analysis of the NIH PROMIS pediatric pain item bank and the measurement properties of the new unidimensional PROMIS Pediatric Pain Interference Scale. Test forms containing pediatric pain items were completed by a total of 3,048 respondents. IRT analyses regarding scale dimensionality, item local dependence, and differential item functioning were conducted. A pain item pool was developed to yield scores on a T-score scale with a mean of 50 and standard deviation of 10. The recommended 8-item unidimensional short form for the PROMIS Pediatric Pain Interference Scale contains the item set which provides the maximum test information at the mean (50) on the T-score metric. A simulated CAT was computed that provides the most information at five possible score locations (30, 40, 50, 60, and 70 on the T-score metric)
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