118 research outputs found

    SiC Cantilevers For Generating Uniaxial Stress

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    This paper demonstrates the first beam resonators fabricated from bulk high purity semi-insulating 4H Silicon Carbide wafers (HPSI 4H-SiC). Our innovations include: (1) Multi-level front-side, back-side inductively coupled plasma-deep reactive ion etching (ICP-DRIE) technology to fabricate thin, low-mass, bending-mode resonators framed by the SiC substrate (2) Laser Doppler Vibrometer (LDV) measurements of mechanical quality factors (Q) > 10,000 with frequencies ranging from 300 kHz to 8MHz and (3) Calculated uniaxial in-plane surface stress 20 MPa at top surface of resonator base when operating at resonance in vacuum.Comment: 4 pages, 5 figures, 1 table. Conference paper for Transducers 201

    Health care provider decision-making and the quality of maternity care: an analysis of postpartum care in Kenyan hospitals

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    Evidence suggests that health care providers' non-adherence to clinical guidelines is widespread and contributes to poor patient outcomes across low- and middle-income countries. Through observations of maternity care in Kenya, we found limited adherence to guideline-recommended active monitoring of patients for signs of postpartum hemorrhage, the leading cause of maternal mortality, despite providers' having the necessary training and equipment. Using survey vignettes conducted with 144 maternity providers, we documented evidence consistent with subjective risk and perceived uncertainty driving providers' decisions to actively monitor patients. Motivated by these findings, we introduced a simple model of providers' decision-making about whether to monitor a patient, which may depend on their perceptions of risk, diagnostic uncertainty, and the value of new information. The model highlights key trade-offs between gathering diagnostic information through active monitoring versus waiting for signs and symptoms of hemorrhage to manifest. Our work provides a template for understanding provider decision-making and could inform interventions to encourage more proactive obstetric care

    Health care providers' knowledge of clinical protocols for postpartum hemorrhage care in Kenya: a cross-sectional study

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    BACKGROUND: Postpartum hemorrhage (PPH) remains the leading cause of maternal death worldwide despite its often-preventable nature. Understanding health care providers' knowledge of clinical protocols is imperative for improving quality of care and reducing mortality. This is especially pertinent in referral and teaching hospitals that train nursing and medical students and interns in addition to managing emergency and referral cases. METHODS: This study aimed to (1) measure health care providers' knowledge of clinical protocols for risk assessment, prevention, and management of PPH in 3 referral hospitals in Kenya and (2) examine factors associated with providers' knowledge. We developed a knowledge assessment tool based on past studies and clinical guidelines from the World Health Organization and the Kenyan Ministry of Health. We conducted in-person surveys with health care providers in three high-volume maternity facilities in Nairobi and western Kenya from October 2018-February 2019. We measured gaps in knowledge using a summative index and examined factors associated with knowledge (such as age, gender, qualification, experience, in-service training attendance, and a self-reported measure of peer-closeness) using linear regression. RESULTS: We interviewed 172 providers including consultants, medical officers, clinical officers, nurse-midwives, and students. Overall, knowledge was lowest for prevention-related protocols (an average of 0.71 out of 1.00; 95% CI 0.69-0.73) and highest for assessment-related protocols (0.81; 95% CI 0.79-0.83). Average knowledge scores did not differ significantly between qualified providers and students. Finally, we found that being a qualified nurse, having a specialization, being female, having a bachelor's degree and self-reported closer relationships with colleagues were statistically significantly associated with higher knowledge scores. CONCLUSION: We found gaps in knowledge of PPH care clinical protocols in Kenya. There is a clear need for innovations in clinical training to ensure that providers in teaching referral hospitals are prepared to prevent, assess, and manage PPH. It is possible that training interventions focused on learning by doing and teamwork may be beneficial

    Health-related quality of life associated with bullying and aggression: a cross-sectional study in English secondary schools.

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    Associations between adolescent health-related quality of life (HRQoL), bullying, and aggression are not well understood. We used baseline data from a large-cluster randomized school trial to study the relationship between HRQoL, bullying experience, and other demographic factors. Cross-sectional self-reported questionnaires collected pre-randomization from the on-going INCLUSIVE trial. The questionnaires were completed in the classroom. The Gatehouse Bullying Scale measured bullying victimization and the Edinburgh Study of Youth Transitions and Crime school misbehavior subscale (ESYTC) measured aggressive behaviors. HRQoL was assessed using the Child Health Utility 9 Dimensions (CHU-9D) and general quality of life using the Pediatric Quality of Life Inventory (PedsQL). Participants were a cohort of year 7 students (age 11-12 years) from 40 state secondary schools in England. Descriptive statistics for the CHU-9D and PedsQL were calculated using standard methods with tests for differences in median scores by sex assessed using quantile regression. Correlation between HRQoL measures was conducted using Spearman's rank correlation coefficients. Predictors of HRQoL were identified using univariate and multiple regressions. A total of 6667 students filled out the questionnaire. The CHU-9D was correlated with the PedsQL (0.63, p < 0.001). The multivariable regression results suggest that if students were bullied frequently and upset it resulted in a decrement in CHU-9D scores of (-0.108) and fall in PedsQL score of (-16.2). The impact of the antisocial/aggressive behavior on the ESYTC scale resulted in a utility decrement of -0.004 and fall of -.5 on the PedsQL. Adolescents' involvement in bullying and aggression is a strong correlate of HRQoL. These data have important implications for the potential cost-effectiveness of reducing bullying and aggression in schools

    The use of mediation analysis in evaluation of complex health interventions

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    This article presents an application of the causal inference approach to mediation analysis using the example of a complex intervention that aimed to improve the quality of care at health centres in Uganda. Mediation analysis is a statistical method that aims to isolate the causal mechanisms that make an intervention work in a given context. We combined data from a cluster randomized control trial and a mixed-methods process evaluation. We developed two causal models following our hypotheses of how the intervention was intended to work through mechanisms at health centres to improve health outcomes in the community. In adjusted analyses, there was evidence of an effect of the intervention on some health centre mechanisms; however, these did not lead to improvements in community health outcomes. We discuss the practical and epistemological challenges encountered when using mediation analysis to evaluate a complex intervention. These findings will inform future evaluations. Trial registration: The trial reported in this article is registered at: clinicaltrials.gov, NCT01024426. Registered 2 December 2009, https://clinicaltrials.gov/ct2/show/record/NCT01024426?term=NCT01024426&draw=2&rank=

    A Rapid Assessment of the Quality of Neonatal Healthcare in Kilimanjaro Region, Northeast Tanzania.

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    While child mortality is declining in Africa there has been no evidence of a comparable reduction in neonatal mortality. The quality of inpatient neonatal care is likely a contributing factor but data from resource limited settings are few. The objective of this study was to assess the quality of neonatal care in the district hospitals of the Kilimanjaro region of Tanzania. Clinical records were reviewed for ill or premature neonates admitted to 13 inpatient health facilities in the Kilimanjaro region; staffing and equipment levels were also assessed. Among the 82 neonates reviewed, key health information was missing from a substantial proportion of records: on maternal antenatal cards, blood group was recorded for 52 (63.4%) mothers, Rhesus (Rh) factor for 39 (47.6%), VDRL for 59 (71.9%) and HIV status for 77 (93.1%). From neonatal clinical records, heart rate was recorded for3 (3.7%) neonates, respiratory rate in 14, (17.1%) and temperature in 33 (40.2%). None of 13 facilities had a functioning premature unit despite calculated gestational age <36 weeks in 45.6% of evaluated neonates. Intravenous fluids and oxygen were available in 9 out of 13 of facilities, while antibiotics and essential basic equipment were available in more than two thirds. Medication dosing errors were common; under-dosage for ampicillin, gentamicin and cloxacillin was found in 44.0%, 37.9% and 50% of cases, respectively, while over-dosage was found in 20.0%, 24.2% and 19.9%, respectively. Physician or assistant physician staffing levels by the WHO indicator levels (WISN) were generally low. Key aspects of neonatal care were found to be poorly documented or incorrectly implemented in this appraisal of neonatal care in Kilimanjaro. Efforts towards quality assurance and enhanced motivation of staff may improve outcomes for this vulnerable group

    A school-based social-marketing intervention to promote sexual health in English secondary schools: the Positive Choices pilot cluster RCT

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    Background: The UK still has the highest rate of teenage births in western Europe. Teenagers are also the age group most likely to experience unplanned pregnancy, with around half of conceptions in those aged < 18 years ending in abortion. After controlling for prior disadvantage, teenage parenthood is associated with adverse medical and social outcomes for mothers and children, and increases health inequalities. This study evaluates Positive Choices (a new intervention for secondary schools in England) and study methods to assess the value of a Phase III trial. Objectives: To optimise and feasibility-test Positive Choices and then conduct a pilot trial in the south of England assessing whether or not progression to Phase III would be justified in terms of prespecified criteria. Design: Intervention optimisation and feasibility testing; pilot randomised controlled trial. Setting: The south of England: optimisation and feasibility-testing in one secondary school; pilot cluster trial in six other secondary schools (four intervention, two control) varying by local deprivation and educational attainment. Participants: School students in year 8 at baseline, and school staff. Interventions: Schools were randomised (1 : 2) to control or intervention. The intervention comprised staff training, needs survey, school health promotion council, year 9 curriculum, student-led social marketing, parent information and review of school/local sexual health services. Main outcome measures: The prespecified criteria for progression to Phase III concerned intervention fidelity of delivery and acceptability; successful randomisation and school retention; survey response rates; and feasible linkage to routine administrative data on pregnancies. The primary health outcome of births was assessed using routine data on births and abortions, and various self-reported secondary sexual health outcomes. Data sources: The data sources were routine data on births and abortions, baseline and follow-up student surveys, interviews, audio-recordings, observations and logbooks. Results: The intervention was optimised and feasible in the first secondary school, meeting the fidelity targets other than those for curriculum delivery and criteria for progress to the pilot trial. In the pilot trial, randomisation and school retention were successful. Student response rates in the intervention group and control group were 868 (89.4%) and 298 (84.2%), respectively, at baseline, and 863 (89.0%) and 296 (82.0%), respectively, at follow-up. The target of achieving ≥ 70% fidelity of implementation of essential elements in three schools was achieved. Coverage of relationships and sex education topics was much higher in intervention schools than in control schools. The intervention was acceptable to 80% of students. Interviews with staff indicated strong acceptability. Data linkage was feasible, but there were no exact matches for births or abortions in our cohort. Measures performed well. Poor test–retest reliability on some sexual behaviour measures reflected that this was a cohort of developing adolescents. Qualitative research confirmed the appropriateness of the intervention and theory of change, but suggested some refinements. Limitations: The optimisation school underwent repeated changes in leadership, which undermined its participation. Moderator analyses were not conducted as these would be very underpowered. Conclusion: Our findings suggest that this intervention has met prespecified criteria for progression to a Phase III trial. Future work: Declining prevalence of teenage pregnancy suggests that the primary outcome in a full trial could be replaced by a more comprehensive measure of sexual health. Any future Phase III trial should have a longer lead-in from randomisation to intervention commencement

    The complex relationship between iron status and anemia in pregnant and postpartum women in India: analysis of two Indian study cohorts of uncomplicated pregnancies

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    Low hemoglobin is widely used as an indicator of iron deficiency anemia in India and other low-and-middle income counties, but anemia need not accurately reflect iron deficiency. We examined the relationship between hemoglobin and biomarkers of iron status in antenatal and postnatal period. Secondary analysis of uncomplicated singleton pregnancies in two Indian study cohorts: 1132 antenatal women in third trimester and 837 postnatal women 12–72 h after childbirth. Associations of hemoglobin with ferritin in both data sets, and with sTfR, TSAT, and hepcidin in the postnatal cohort were examined using multivariable linear regression. Multinomial logistic regression was used to examine the association between severity of anemia and iron status. Regression models were adjusted for potential confounders. Over 55% of the women were anemic; 34% of antenatal and 40% of postnatal women had low ferritin, but 4% antenatal and 6% postnatal women had high ferritin. No evidence of association between hemoglobin and ferritin was observed (antenatal: adjusted coefficient [aCoef] −0.0004, 95% confidence interval [CI] −0.001, 0.001; postnatal: aCoef −0.0001, 95% CI −0.001, 0.001). We found a significant linear association of hemoglobin with sTfR (aCoef −0.04, 95% CI −0.07, −0.01), TSAT (aCoef −0.005, 95% CI −0.008, −0.002), and hepcidin (aCoef 0.02, 95% CI 0.02, 0.03) in postnatal women. Likelihood of low ferritin was more common in anemic than non-anemic women, but high ferritin was also more common in women with severe anemia in both cohorts. Causes of anemia in pregnant and postpartum women in India are multifactorial; low hemoglobin alone is not be a useful marker of iron deficiency
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