155 research outputs found
The GirlStars Program: Challenges to Recruitment and Retention in a Physical Activity and Health Education Program for Adolescent Girls Living in Public Housing
BACKGROUND. Although physical inactivity is a concern for all adolescents, physical activity levels are especially low among minority adolescents and minimal among girls from low-income families. After-school programs can reduce high-risk behaviors and strengthen schools, families, and communities. CONTEXT. We conducted an operational research project that provided free access to a program of regular, organized physical activity combined with health education sessions for adolescent girls in 2 public housing developments in Boston, Massachusetts. METHODS. From July 2002 through October 2005, at each of 2 public housing sites, the GirlStars program participants met each week for two 2-hour sessions, 1 dedicated to physical activity and 1 dedicated to health education. Sessions were led by the project coordinator and a resident assistant at each development. OUTCOME. Participants in the GirlStars program increased their health knowledge, self-confidence, and decision-making skills, but rates of participation were low. Factors that affected participation included safety concerns, lack of community support for the program, interpersonal conflicts, attrition in staff, and conflicts with other activities. INTERPRETATION. Programs in public housing developments that address these barriers to recruitment and retention may be more successful and reach more girls
Isolation of Mycobacterium avium from Potable Water in Homes and Institutions of Patients with HIV Infection in Finland and the United States
Symptomatic disease by nontuberculous mycobacteria has been linked to potable water from institutional and domestic potable water systems. Potable water samples were collected from homes and institutions of patients with AIDS. Colonization of potable water with nontuberculous mycobacteria was demonstrated in 230 (15%) of 1489 samples collected from domestic and institutional water systems of patients with HIV infection in the United States and Finland. Mycobacterium avium was the most common species and colonization was favored at temperatures of 40-50 degrees C in recirculating hot water systems. Such systems are a plausible source of human infection and disease.Peer reviewe
Evaluation of exposure-specific risks from two independent samples: A simulation study
<p>Abstract</p> <p>Background</p> <p>Previous studies have proposed a simple product-based estimator for calculating exposure-specific risks (ESR), but the methodology has not been rigorously evaluated. The goal of our study was to evaluate the existing methodology for calculating the ESR, propose an improved point estimator, and propose variance estimates that will allow the calculation of confidence intervals (CIs).</p> <p>Methods</p> <p>We conducted a simulation study to test the performance of two estimators and their associated confidence intervals: 1) current (simple product-based estimator) and 2) proposed revision (revised product-based estimator). The first method for ESR estimation was based on multiplying a relative risk (RR) of disease given a certain exposure by an overall risk of disease. The second method, which is proposed in this paper, was based on estimates of the risk of disease in the unexposed. We then multiply the updated risk by the RR to get the revised product-based estimator. A log-based variance was calculated for both estimators. Also, a binomial-based variance was calculated for the revised product-based estimator. 95% CIs were calculated based on these variance estimates. Accuracy of point estimators was evaluated by comparing observed relative bias (percent deviation from the true estimate). Interval estimators were evaluated by coverage probabilities and expected length of the 95% CI, given coverage. We evaluated these estimators across a wide range of exposure probabilities, disease probabilities, relative risks, and sample sizes.</p> <p>Results</p> <p>We observed more bias and lower coverage probability when using the existing methodology. The revised product-based point estimator exhibited little observed relative bias (max: 4.0%) compared to the simple product-based estimator (max: 93.9%). Because the simple product-based estimator was biased, 95% CIs around this estimate exhibited small coverage probabilities. The 95% CI around the revised product-based estimator from the log-based variance provided better coverage in most situations.</p> <p>Conclusion</p> <p>The currently accepted simple product-based method was only a reasonable approach when the exposure probability is small (< 0.05) and the RR is ≤ 3.0. The revised product-based estimator provides much improved accuracy.</p
Randomized clinical trials to identify optimal antibiotic treatment duration
Background
Antibiotic resistance is a major barrier to the continued success of antibiotic treatment. Such resistance is often generated by overly long durations of antibiotic treatment. A barrier to identifying the shortest effective treatment duration is the cost of the sequence of clinical trials needed to determine shortest optimal duration. We propose a new method to identify the optimal treatment duration of an antibiotic treatment regimen.
Methods
Subjects are randomized to varying treatment durations and the cure proportions of these durations are linked using a logistic regression model, making effective use of information across all treatment duration groups. In this paper, Monte Carlo simulation is used to evaluate performance of such a model.
Results
Using a hypothetical dataset, the logistic regression model is seen to provide increased precision in defining the point estimate and confidence interval (CI) of the cure proportion at each treatment duration. When applied to the determination of non-inferiority, the regression model allows identification of the shortest duration meeting the predefined non-inferiority margin.
Conclusions
This analytic strategy represents a practical way to develop shortened regimens for tuberculosis and other infectious diseases. Application of this strategy to clinical trials of antibiotic therapy could facilitate decreased antibiotic usage, reduce cost, minimize toxicity, and decrease the emergence of antibiotic resistance
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Issues in design and interpretation of MDR-TB clinical trials: report of the first Global MDR-TB Clinical Trials Landscape Meeting
Recognizing that the current MDR-TB regimen is suboptimal and based on low-quality evidence, the Global MDR-TB Clinical Trials Landscape Meeting was held in December, 2014 to strategize about coordination of research and development of new treatment regimens for this disease that affects millions of people worldwide every year. Sixty international experts on multidrug-resistant tuberculosis (MDR-TB) met in Washington D.C. and Cape Town, South Africa to consider key MDR-TB trial-related issues, including: standardization of definitions; clinical trial capacity building and; regimens optimized to foster compliance, avoid the emergence of resistance and have clinical relevance for special populations, including children and those co-infected with HIV. Underpinning all of this is the generation of a sufficient evidence base to facilitate regulatory approval and improved normative guidance. Participants discussed treatment combinations currently being studied in Phase 2B and Phase 3 trials as well as other promising new regimens and combinations that may be evaluated in the near future. These include regimens designed specifically to enable shorter duration and all-oral treatment as a means of maximizing treatment completion. It is hoped that clear definition of these challenges will facilitate the process of identifying solutions that accelerate progress towards effective, non-toxic treatments that can be programmatically implemented
Clinical manifestations and epidemiology of adolescent tuberculosis in Ukraine
BACKGROUND: During adolescence, childhood and adult forms of tuberculosis (TB) overlap, resulting in diverse disease manifestations. Knowing which patient characteristics are associated with which manifestations may facilitate diagnosis and enhance understanding of TB pathophysiology.
METHODS: In this cross-sectional study, we included 10-19-year-olds in Ukraine\u27s national TB registry who started TB treatment between 2015 and 2018. Using multivariable regression, we estimated associations between patient characteristics and four presentations of TB: pleural, extrathoracic, cavitary and rifampicin-resistant (RR). We also described the epidemiology of adolescent TB in Ukraine.
RESULTS: Among 2491 adolescent TB cases, 88.4% were microbiologically confirmed. RR-TB was confirmed in 16.9% of new and 29.7% of recurrent cases. Of 88 HIV-infected adolescents, 59.1% were not on antiretroviral therapy at TB diagnosis. Among 10-14-year-olds, boys had more pleural disease (adjusted OR (aOR) 2.12, 95% CI: 1.08-4.37). Extrathoracic TB was associated with age 15-19 years (aOR 0.26, 95% CI: 0.18-0.37) and HIV (aOR 3.25, 95% CI: 1.55-6.61 in 10-14-year-olds; aOR 8.18, 95% CI: 3.58-17.31 in 15-19-year-olds). Cavitary TB was more common in migrants (aOR 3.53, 95% CI: 1.66-7.61) and 15-19-year-olds (aOR 4.10, 95% CI: 3.00-5.73); among 15-19-year-olds, it was inversely associated with HIV (aOR 0.32, 95% CI: 0.13-0.70). RR-TB was associated with recurrent disease (aOR 1.87, 95% CI: 1.08-3.13), urban residence (aOR 1.27, 95% CI: 1.01-1.62) and cavitation (aOR 2.98, 95% CI: 2.35-3.78).
CONCLUSIONS: Age, sex, HIV and social factors impact the presentation of adolescent TB. Preventive, diagnostic and treatment activities should take these factors into consideration
Emergence of a unique group of necrotizing mycobacterial diseases.
Although most diseases due to pathogenic mycobacteria are caused by Mycobacterium tuberculosis, several other mycobacterial diseases-caused by M. ulcerans (Buruli ulcer), M. marinum, and M. haemophilum-have begun to emerge. We review the emergence of diseases caused by these three pathogens in the United States and around the world in the last decade. We examine the pathophysiologic similarities of the diseases (all three cause necrotizing skin lesions) and common reservoirs of infection (stagnant or slow-flowing water). Examination of the histologic and pathogenic characteristics of these mycobacteria suggests differences in the modes of transmission and pathogenesis, though no singular mechanism for either characteristic has been definitively described for any of these mycobacteria
Extensively Drug-Resistant Tuberculosis in Women, KwaZulu-Natal, South Africa
To determine whether women in KwaZulu-Natal, South Africa, with drug-resistant tuberculosis (TB) were more likely than men to have extensively drug-resistant TB, we reviewed 4,514 adults admitted during 2003–2008 for drug-resistant TB. Female sex independently predicted extensively drug-resistant TB, even after we controlled for HIV infection. This association needs further study
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