Large-scale latitudinal and vertical distributions of NMHCs and selected halocarbons in the troposphere over the Pacific Ocean during the March-April 1999 Pacific Exploratory Mission (PEM-Tropics B)

Nonmethane hydrocarbons (NMHCs) and selected halocarbons were measured in whole air samples collected over the remote Pacific Ocean during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) in March and early April 1999. The large-scale spatial distributions of NMHCs and C2Cl4 reveal a much more pronounced north-south interhemispheric gradient, with higher concentrations in the north and lower levels in the south, than for the late August to early October 1996 PEM-Tropics A experiment. Strong continental outflow and winter-long accumulation of pollutants led to seasonally high Northern Hemisphere trace gas levels during PEM-Tropics B. Observations of enhanced levels of Halon 1211 (from developing Asian nations such as the PRC) and CH3Cl (from SE Asian biomass burning) support a significant southern Asian influence at altitudes above 1 km and north of 10° N. By contrast, at low altitude over the North Pacific the dominance of urban/industrial tracers, combined with low levels of Halon 1211 and CH3Cl, indicate a greater influence from developed nations such as Japan, Europe, and North America. Penetration of air exhibiting aged northern hemisphere characteristics was frequently observed at low altitudes over the equatorial central and western Pacific south to ∼5° S. The relative lack of southern hemisphere biomass burning sources and the westerly position of the South Pacific convergence zone contributed to significantly lower PEM-Tropics B mixing ratios of the NMHCs and CH3Cl south of 10° S compared to PEM-Tropics A. Therefore the trace gas composition of the South Pacific troposphere was considerably more representative of minimally polluted tropospheric conditions during PEM-Tropics B. Copyright 2001 by the American Geophysical Union

Length of patient-physician relationship and patients' satisfaction and preventive service use in the rural south: a cross-sectional telephone study

BACKGROUND: Physicians and patients highly value continuity in health care. Continuity can be measured in several ways but few studies have examined the specific association between the duration of the patient-doctor relationship and patient outcomes. This study (1) examines characteristics of rural adults who have had longer relationships with their physicians and (2) assesses if the length of relationship is associated with patients' satisfaction and likelihood of receiving recommended preventive services. METHODS: Cross-sectional telephone survey of health care access indicators of adults in selected non-metropolitan counties of eight U.S. predominantly southern states. Analyses were restricted to adults who see a particular physician for their care and weighted for demographics and county sampling probabilities. RESULTS: Of 3176 eligible respondents, 10.8% saw the same physician for the past 12 months, 11.8% for the previous 13–24 months, 20.7% for the past 25–60 months and 56.7% for more than 60 months. Compared to persons with one year or less continuity with the same physician, respondents with over five years continuity more often were Caucasian, insured, a high school graduate, and more often reported good to excellent health and an income above $25,000. Compared to those with more than five years of continuity, participants with either less than one year or one to two years of continuity with the same physician were more often not satisfied with their overall health care (OR 2.34; OR 1.78), participants with less than one year continuity were more often not satisfied with the concern shown them by their physician (O.R. 1.90) and having their health questions answered, and those with one to two years continuity were more often not satisfied with the quality of their care (OR 2.37). No significant associations were found between physician continuity and use rates of any of the queried preventive services. CONCLUSION: Over half of this rural population has seen the same physician for more than five years. Longer continuity of care was associated with greater patient satisfaction and confidence in one's physician, but not with a greater likelihood of receiving recommended preventive services

Physician Counseling on Colorectal Cancer Screening and Receipt of Screening among Latino Patients

BACKGROUND: Latinos have lower rates of colorectal cancer (CRC) screening and later stage diagnosis than Whites, which may be partially explained by physician communication factors. OBJECTIVE: We assessed associations between patient-reported physician counseling regarding CRC screening and receipt of CRC screening among Latino primary care patients. DESIGN: This was a cross-sectional telephone survey. PARTICIPANTS: The participants of this study were Latino primary care patients 50 years of age or older, with one or more visits during the preceding year. MAIN MEASURES: We developed patient-reported measures to assess whether physicians provided explanations of CRC risks and tests, elicited patients’ barriers to CRC screening, were responsive to patients’ concerns about screening, and encouraged patients to be screened. Outcomes were patient reports of receipt of endoscopy (sigmoidoscopy or colonoscopy) and fecal occult blood test (FOBT) within recommended guidelines. KEY RESULTS: Of 817 eligible patients contacted, 505 (62 %) completed the survey; mean age was 61 years (SD 8.4), 69 % were women, and 53 % had less than high school education. Forty-six percent reported obtaining endoscopy (with or without FOBT), 13 % reported FOBT only, and 41 % reported no CRC screening. In bivariate analyses, physician explanations, elicitation of barriers, responsiveness to concerns, and greater encouragement for screening were associated with receipt of endoscopy (p < 0.001), and explanations (p < 0.05) and encouragement (p < 0.001) were associated with FOBT. Adjusting for covariates, physician explanations (OR = 1.27; 95 % CI 1.03, 1.58) and greater physician encouragement (OR = 6.74; 95 % CI 3.57, 12.72) were associated with endoscopy; patients reporting quite a bit/a lot of physician encouragement had six times higher odds of obtaining the FOBT as those reporting none/a little encouragement (OR = 6.54; 95 % CI 2.76, 15.48). CONCLUSIONS: Among primarily lower-socioeconomic status Latino patients, the degree to which patients perceived that physicians encouraged CRC screening was more strongly associated with screening than with providing risk information, eliciting barriers, and responding to their concerns about screening. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11606-014-3126-0) contains supplementary material, which is available to authorized users

The seasonal evolution of NMHCs and light alkyl nitrates at middle to high northern latitudes during TOPSE

The Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment was designed to follow the role of photochemistry in the evolution of the springtime maximum of tropospheric ozone (O3) in the Northern Hemisphere (NH) at high latitudes. Determination of the composition and seasonal evolution of volatile organic carbon (VOC) species, which take part in and are good indicators for photochemical processes in the troposphere, was an important part of this study. We report measurements of a large number of C2–C10 nonmethane hydrocarbons (NMHCs), selected C1–C2 halocarbons, and C1–C4 alkyl nitrates. These gases were quantified in whole air samples collected aboard the National Center for Atmospheric Research (NCAR) C‐130 aircraft at altitudes between 30 m and 8 km. Seven TOPSE sampling trips were flown between early February and mid‐May 2000 covering the region from Colorado (40°N) to Churchill (in Manitoba, Canada), Thule (in northern Greenland), and as far north as 85°N. These measurements represent the most comprehensive spatial characterization of the North American Arctic to date and revealed strong latitudinal, vertical, and temporal NMHC gradients. In the midtroposphere north of Churchill (58°N), ΣNMHCs decreased by ∼6.2 ppbC between February and May (1.6 ppbC month−1) and the magnitude of this change diminished with altitude. Over the same period, midtropospheric O3 levels increased by ∼16 ppbv (4.2 ppbv month−1). Free tropospheric NMHC decreases were consistent with removal by hydroxyl (OH) radicals at an average mixing ratio for mid‐March to mid‐May of 4.1 × 105 mol cm−3. The alkyl nitrates, which are a reservoir species for tropospheric reactive odd nitrogen (NOY), revealed similar latitudinal, vertical, and temporal gradients to their parent NMHCs. Their total decreased by ∼4 pptv month−1, representing 10% or less of NOY. In conjunction with meteorological trajectory analysis, different trace gas signatures provided significant clues to the origins of individual polluted air masses. Several of these air masses were rapidly advected over the Pole from source regions in northeastern and western Europe as well as an air mass that originated over the southwestern United States/Baja California that contained unusually high levels of alkanes. In addition, episodes of low boundary layer (BL) O3 associated with low NMHC mixing ratios and trajectories from over the Arctic Ocean were frequently sampled toward the latter part of the experiment. The TOPSE data described here provide a unique picture of NH trace gas evolution from winter to summer that will be invaluable to models investigating the role that anthropogenic emissions play in high latitude O3 chemistry

Managed Care, Primary Care, and the Patient-practitioner Relationship

OBJECTIVES: This study examines how specific attributes of managed health plans influence patients' relationships with their primary care practitioners (PCPs) and determines whether these effects are mediated by access to, continuity with, or perceived choice of PCPs. DESIGN, SETTING, PATIENTS: The data source was the nationally representative 1996/97 Community Tracking Study Household Survey (cumulative response rate 65%). The study population (N = 19,415) was composed of 18- to 64-year-old adults whose most recent visit in the past 12 months was made to their primary care delivery site. MAIN OUTCOME MEASURE: Patients' ratings of their interpersonal relationships with their PCPs as measured by a 7-item scale. RESULTS: Gatekeeping arrangements that require patients to select a primary care physician or obtain authorization for specialty referrals were associated with lower ratings of the patient-PCP relationship. Health plan use of a provider network had no effect on the patient-PCP scale score. Although there were no significant differences across any insurance payer categories, uninsured adults rated their relationships with PCPs as significantly poorer than did their insured counterparts. Shorter office waits, having a specific clinician at the primary care site, better perceived choice of PCPs, and a longer duration of relationship with the primary care practitioner were associated with higher ratings of the patient-PCP relationship. Perceived choice of primary care practitioners, but not access to or continuity with PCPs, attenuated some of the negative effects of gatekeeping arrangements on patients' relationships with their primary care practitioners. CONCLUSIONS: Managed health plans that loosen restrictions on provider choice, relax gatekeeping arrangements, or promote access to and continuity with PCPs, are likely to experience higher patient satisfaction with their primary care practitioner relationships. Lack of health insurance impedes the development of patients' relationships with their primary care practitioners