Use of remotely sensed data to evaluate the relationship between living environment and blood pressure.

BACKGROUND: Urbanization has been correlated with hypertension (HTN) in developing countries undergoing rapid economic and environmental transitions. OBJECTIVES: We examined the relationships among living environment (urban, suburban, and rural), day/night land surface temperatures (LST), and blood pressure in selected regions from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. Also, the linking of data on blood pressure from REGARDS with National Aeronautics and Space Administration (NASA) science data is relevant to NASA's strategic goals and missions, particularly as a primary focus of the agency's Applied Sciences Program. METHODS: REGARDS is a national cohort of 30,228 people from the 48 contiguous United States with self-reported and measured blood pressure levels. Four metropolitan regions (Philadelphia, PA; Atlanta, GA; Minneapolis, MN; and Chicago, IL) with varying geographic and health characteristics were selected for study. Satellite remotely sensed data were used to characterize the LST and land cover/land use (LCLU) environment for each area. We developed a method for characterizing participants as living in urban, suburban, or rural living environments, using the LCLU data. These data were compiled on a 1-km grid for each region and linked with the REGARDS data via an algorithm using geocoding information. RESULTS: REGARDS participants in urban areas have higher systolic and diastolic blood pressure than do those in suburban or rural areas, and also a higher incidence of HTN. In univariate models, living environment is associated with HTN, but after adjustment for known HTN risk factors, the relationship was no longer present. CONCLUSION: Further study regarding the relationship between HTN and living environment should focus on additional environmental characteristics, such as air pollution. The living environment classification method using remotely sensed data has the potential to facilitate additional research linking environmental variables to public health concerns.

Design of the supervised asthma therapy study: implementing an adherence intervention in urban elementary schools.

BACKGROUND: Inhaled corticosteroids, when properly used, can offer considerable protection against asthma-related morbidity. However, adherence to prescribed inhaled steroids among children is low and rates differ markedly by population. The lowest rates of adherence and highest rates of morbidity are among inner-city and low income populations. PURPOSE: To describe the design of a school-based clinical trial in a largely minority population that is examining the efficacy of a school-based intervention intended to increase adherence to daily inhaled corticosteroids. METHODS: The supervised asthma therapy study is a two-group randomized longitudinal trial. Children were randomly assigned to either school-based supervised asthma therapy or parent supervised asthma therapy. Children were followed longitudinally for 15 months. The primary outcome of the study is the time-averaged difference between the two groups in the percentage of children experiencing at least one asthma exacerbation each month. RESULTS: A web-based data collection system was designed to capture data at school. A total of 295 students, recruited from community and school sites, who attended one of 36 urban elementary schools enrolled in the study and 290 were randomized. The average age of the students was 10.0 years (sd=2.1), 91% were African American, 8% were white, and 1% were of other racial groups. 57% of students were male. The study has been recently completed and results are being analyzed. CONCLUSIONS: Intervention studies requiring daily medication supervision and daily data collection can be successfully conducted within the elementary school environment.

A likelihood approach to analyzing clinical trial data when treatments favor different outcomes.

It is increasingly common in clinical trials to design studies for which more than one primary outcome exists. Methods that exist for more than one outcome are generally concerned with identifying one of two situations: (1) improvement in all outcomes from one treatment, as compared to the other treatment(s); or (2) improvement in a single efficacy endpoint, without an excess of toxicity. In contrast, the Colpopexy and Urinary Reduction Effort (CARE) Study is a randomized clinical trial comparing two treatments that presents a slightly different scenario. In this study, there are two outcomes, and it was anticipated by the investigators that each treatment may favor a different outcome. Few statistical methods exist to address the specific challenges encountered by this design. We designed a method to address the specific analytic issues raised in the planning of the CARE study. We developed a likelihood ratio approach to test whether or not a treatment difference exists at the end of the study by considering both the absolute treatment differences and the direction of the differences with respect to the treatments. This method involves simultaneously testing each component of a composite null hypothesis, while maintaining an overall type I error rate. A simulation study is performed to evaluate the operating characteristics of this test, in which we find that our joint likelihood-ratio test has a power as high as, or higher than, other commonly used methods for multiple outcomes, while maintaining a nominal type I error rate.

Effects of examination technique modifications on pelvic organ prolapse quantification (POP-Q) results.

The pelvic organ prolapse quantification system (POP-Q) is currently the most quantitative, site-specific system for describing pelvic organ prolapse. To ensure that anatomic outcomes can be optimally assessed, investigators in the Pelvic Floor Disorders Network evaluated the impact of specific technique variations on POP-Q measurements performed on 133 patients by 16 examiners at seven sites. Values for genital hiatus and perineal body were higher when measured with maximal strain than on resting. With the exception of TVL, internal points did not differ significantly when measured with or without a speculum. The maximum extent of prolapse was best seen with the patient standing. These results suggest that genital hiatus and perineal body should be measured at rest and during straining, as the measurements may assess different aspects of pelvic floor function, and that internal points can be measured with or without a speculum. They also emphasize the value of the standing examination to observe the maximum extent of pelvic organ prolapse.