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D E Abbey

Publications and source records attributed to D E Abbey.

30 records · Page 2Linked to original sources

Utilization of the clinical dietetic technician.

The changing role of the clinical dietitian has resulted in evaluation of the clinical dietetic technician's role. The American Dietetic Association (ADA) has recognized that effective utilization of the dietetic technician will allow continued growth of the dietitian. In 1981, the ADA published Role Delineation for Entry-Level Clinical Dietetics, including responsibilities for the clinical dietetic technician. A revised role delineation which included verification of actual role performance to the defined role was published by the ADA in 1984, subsequent to the completion of this research report. This research was conducted to verify the degree to which clinical dietetic technicians were performing tasks identified for their role, to identify educational deficiencies and/or excesses, and to analyze demographic and other descriptive data obtained. Telephone and mail questionnaires were used to obtain data from dietetic technicians selected by systematic sampling from the ADA listing of 914 technician members. Responsibilities outlined in the ADA role delineation study were the basis for the tasks utilized in the survey of the clinical dietetic technicians' performance and training. The mean percentage of tasks performed indicated agreement between the defined role and actual performance of clinical dietetic technicians.

Allied Health Personnel↗

COPD prevalence in nonsmokers in high and low photochemical air pollution areas.

The prevalence of respiratory symptoms, as ascertained by questionnaire, was evaluated in 6,666 nonsmokers who had lived for at least 11 years in either a high photochemical pollution area (4,379 individuals) or a low photochemical pollution area (2,287 individuals). Of these, 5,178 had never smoked, and none was currently smoking. The risk estimate for "definite" COPD, as defined in this study, was 15 percent higher in the high pollution area (p = 0.03), after adjusting for sex, age, race, education, occupational exposure, and past smoking history. Past smokers had a risk estimate 22 percent higher than never smokers (p = 0.01). Multivariate analysis showed a significant effect of air pollution on the prevalence of "definite" COPD which univariate analysis failed to demonstrate.

Adult↗

Relationships of mortality with the fine and coarse fractions of long-term ambient PM10 concentrations in nonsmokers.

In a cohort of 6338 California Seventh-day Adventists, we previously observed for males associations between long-term concentrations of particulate matter (PM) with an aerodynamic diameter less than 10 microm (PM10) and 15-year mortality due to all natural causes (ANC) and lung cancer (LC) listed as underlying causes of death and due to nonmalignant respiratory disease listed as either the underlying or a contributing (CRC) cause of death. The purpose of this analysis was to determine whether these outcomes were more strongly associated with the fine (PM2.5) or the coarse (PM2.5-10) fractions of PM10. For participants who lived near an airport (n=3769), daily PM2.5 concentrations were estimated from airport visibility, and on a monthly basis, PM2.5-10 concentrations were calculated as the differences between PM10 and PM2.5. Associations between ANC, CRC, and LC mortality (1977-1992) and mean PM10, PM2.5, and PM2.5-10 concentrations at study baseline (1973-1977) were assessed using Cox proportional hazards models. Magnitudes of the PM10 associations for the males of this subgroup were similar to those for the males in the entire cohort although not statistically significant due to the smaller numbers. In single-pollutant models, for an interquartile range (IQR) increase in PM10 (29.5 microg/m3), the rate ratios (RRs) and 95% confidence intervals (CI) were 1.15 (0.94, 1.41) for ANC, 1.48 (0.93, 2.34) for CRC, and 1.84 (0.59, 5.67) for LC. For an IQR increase in PM2.5 (24.3 microg/m3), corresponding RRs (95% CI) were 1.22 (0.95, 1.58), 1.64 (0.93, 2.90), and 2.23 (0.56, 8.94), and for an IQR increase in PM2.5-10 (9.7 microg/m3), corresponding RRs (95% CI) were 1.05 (0.92, 1.20), 1.19 (0.88, 1.62), and 1.25 (0.63, 2.49), respectively. When both PM25 and PM2.5-10 were entered into the same model, the PM2.5 estimates remained stable while those of PM2.5-10 decreased. We concluded that previously observed associations of long-term ambient PM10 concentration with mortality for males were best explained by a relationship of mortality with the fine fraction of PM10 rather than with the coarse fraction of PM10.

Adult↗

Chronic obstructive pulmonary disease symptom effects of long-term cumulative exposure to ambient levels of total oxidants and nitrogen dioxide in California Seventh-Day Adventist residents.

To assess the risk of chronic obstructive pulmonary disease symptoms due to long-term exposure to ambient levels of total oxidants and nitrogen dioxide (NO2), symptoms were ascertained using the National Heart, Lung, and Blood Institute (NHLBI) respiratory symptoms questionnaire. A total of 7,445 Seventh-day Adventist (SDA) nonsmokers who were 25 yr of age or older and had resided at least 11 yr in areas of California with high to low photochemical air pollution were included in this study. Cumulative exposures to each pollutant in excess of four thresholds were estimated for each participant, using zip codes for months of residence and interpolated dosages from state air-monitoring stations. Multiple logistic regression analyses were conducted individually and together for pollutants and included eight covariables, including passive smoking. A statistically significant association with chronic symptoms was seen for total oxidants above 10 pphm (196 mcg/m3) (p less than .004, relative risk of 1.20 for 750 hr/yr). Chronic respiratory disease symptoms were not associated with relatively low NO2 exposure levels in this population. When these pollutant exposures were studied with exposures to total suspended particulates (TSP) and sulfur dioxide (SO2), only TSP exposure above 200 mcg/m3 showed statistical significance (p less than .01). Exposure to TSP is either more strongly associated with symptoms of chronic obstructive pulmonary disease than the other measured exposures or is the best single surrogate representing the mix of pollutants present.

Adult↗

Estimating cumulative ambient concentrations of air pollutants: description and precision of methods used for an epidemiological study.

Methods for estimating cumulative ambient air pollution concentrations for individuals enrolled in an epidemiological cohort study are described and studied. Monthly interpolations from fixed-site monitoring stations in California to zip code centroids were used. The precision of the interpolation methods for total suspended particulates and ozone was assessed, and fixed-site monitoring stations were used in turn as receptor sites. Actual versus interpolated 2-y mean concentrations did not differ significantly and were correlated with a Pearson correlation coefficient of .78 for total suspended particulates and .87 for ozone. The impact of the change from monitoring total oxidants to ozone on oxidant/ozone cumulations was evaluated, and monthly mean concentrations for total oxidants were compared with ozone for 435 station months during which both pollutants were measured simultaneously. Average concentrations did not differ significantly and were highly correlated (r = 0.94). Exceedance frequency statistics, which averaged slightly higher for ozone than for total oxidants, were also highly correlated.

Air Pollutants↗

Long-term ambient concentrations of total suspended particulates, ozone, and sulfur dioxide and respiratory symptoms in a nonsmoking population.

Seventh-day Adventist nonsmokers, who, subsequent to 1966, had resided within 8 km (5 miles) of their 1977 residence (N = 3,914), completed the National Heart and Lung Institute (NHLI) respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations of total suspended particulates (TSP), ozone, and sulfur dioxide (SO2) in excess of several cutoff levels were estimated by month and by interpolating ambient concentrations from state air-monitoring stations to their residential and workplace zip codes for the month. Statistically significant relationships between ambient concentrations of TSP and ozone, but not SO2, were found with several respiratory disease outcomes. Multivariate analyses adjusted for past and passive smoking and occupational exposures. Results are discussed within the context of standards setting for TSP and ozone.

Air Pollutants↗

Estimated long-term ambient concentrations of PM10 and development of respiratory symptoms in a nonsmoking population.

Site- and season-specific regressions of particulates less than 10 mu in diameter (PM10) on total suspended particulates (TSPs) were formed throughout California during years when both were monitored. The regressions were then applied to monitored TSPs for the years 1973 to 1987, and indirect estimates of PM10 were formed. These estimates of PM10 were validated by interpolating them to other monitoring stations. The split-halves correlation between the estimated and monitored mean concentrations, obtained when both were first cumulated for a 2-y period, was .86. Indirect estimates of PM10 at monitoring stations were interpolated, by month, to zip code centroids of home and work location and were cumulated for a cohort of 3,914 California Seventh-day Adventist (SDA) nonsmokers. Multivariate analyses, adjusted for several covariates, showed statistically significant (p < .05), but small, positive associations between PM10 and development of (a) definite symptoms of overall airway obstructive disease, (b) chronic productive cough, and (c) increased severity of airway obstructive disease and asthma. The relative risk (RR) associated with 1,000 h/y (42 d) exposure to concentrations of PM10 that exceeded 100 micrograms/m3 for development of airway obstructive disease was 1.17 (95% confidence interval [CI]: 1.02, 1.33); for development of productive cough, the RR was 1.21 (CI 1.02, 1.44); and for development of asthma, the RR was 1.30 (CI, 0.97, 1.73). Stronger associations were observed for those who were exposed occupationally to dusts and fumes. The RR of developing airway obstructive disease as an adult for those who had airway obstructive disease as a child was 1.66 (CI 1.15, 2.33).

Adult↗

Chronic obstructive pulmonary disease symptom effects of long-term cumulative exposure to ambient levels of total suspended particulates and sulfur dioxide in California Seventh-Day Adventist residents.

Risk of chronic obstructive pulmonary disease symptoms due to long-term exposure to ambient levels of total suspended particulates (TSP) and sulfur dioxide (SO2) symptoms was ascertained using the National Heart, Lung, and Blood Institute (NHLBI) respiratory symptoms questionnaire on 7,445 Seventh-Day Adventists. They were non-smokers, at least 25 yr of age, and had lived 11 yr or more in areas ranging from high to low photochemical air pollution in California. Participant cumulative exposures to each pollutant in excess of four thresholds were estimated using monthly residence zip code histories and interpolated dosages from state air monitoring stations. These pollutant thresholds were entered individually and in combination in multiple logistic regression analyses with eight covariables including passive smoking. Statistically significant associations with chronic symptoms were seen for: SO2 exposure above 4 pphm (104 mcg/m3), (p = .03), relative risk 1.18 for 500 hr/yr of exposure; and for total suspended particulates (TSP) above 200 mcg/m3, (p less than .00001), relative risk of 1.22 for 750 hr/yr.

Adult↗

Chronic respiratory symptoms associated with estimated long-term ambient concentrations of fine particulates less than 2.5 microns in aerodynamic diameter (PM2.5) and other air pollutants.

Seventh-Day Adventists (SDAs), nonsmokers who had resided since 1966 in the vicinity of nine airports throughout California (n = 1,868), completed a standardized respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations of fine particulates less than 2.5 microns (microns) in aerodynamic diameter (PM2.5) were estimated from airport visibility data. Long-term ambient concentrations of estimated PM2.5 in excess of 20 micrograms per cubic meter (micrograms/m3) were found to be associated with development of definite symptoms of chronic bronchitis between 1977 and 1987. Estimated mean concentrations of PM2.5 were associated with increasing severity of respiratory symptoms related to general airway obstructive disease, chronic bronchitis, and asthma. It was felt that the observed relationships, with the exception of the relationship between increasing severity of chronic bronchitis symptoms and PM2.5, could be due to surrogate relationships with other ambient pollutants.

Adult↗

Estimating fine particulates less than 2.5 microns in aerodynamic diameter (PM2.5) from airport visibility data in California.

Methods were developed for estimating fine particulates less than 2.5 microns in aerodynamic diameter (PM2.5) from airport visibility data which detected seasonality and allowed for possible site- and season-specific regressions of PM2.5 on visibility. The methods were applied to nine airports in California in order to produce estimates of PM2.5 for the years 1966-1986 based on 1,767 paired PM2.5/visibility data points where PM2.5 had been measured at a monitoring station near the airport. General F-tests indicated that site- and season-specific regression equations resulted in a statistically significant reduction in residual error. The split halves correlation for estimating PM2.5 from visibility over all areas was 0.82. The methods were used to estimate long-term concentrations of ambient PM2.5 for an epidemiological cohort of 1,868 individuals.

Air Pollutants↗

Chronic disease associated with long-term concentrations of nitrogen dioxide.

A prospective epidemiologic cohort study of 6,000 residentially stable and non-smoking Seventh-day Adventists (SDA) in California was conducted to evaluate long-term cumulative levels of ambient nitrogen dioxide (NO2) in association with several chronic diseases. These diseases included respiratory symptoms, cancer, myocardial infarction (MI), and all natural causes mortality. Cumulative ambient concentrations of NO2 were estimated for each study subject using monthly interpolations from fixed site monitoring stations and applying these estimates to the monthly residence and work place zip code histories of study participants. In addition, a personal NO2 exposure study on a randomly selected sample of 650 people in southern California was conducted to predict total personal NO2 exposure using household and lifestyle characteristics and ambient NO2 concentrations. It was found that good predictability could be obtained (correlation coefficient between predicted and observed values = 0.79) from a model predicting personal NO2. The resulting regression equations from the personal NO2 exposure study were applied to the epidemiologic study cohort to adjust ambient concentrations of NO2.

Adult↗