Bounding Global Aerosol Radiative Forcing of Climate Change.

Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m-2, or -2.0 to -0.4 W m-2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds.

Economic evaluation of aquatic exercise for persons with osteoarthritis.

OBJECTIVES: To estimate cost and outcomes of the Arthritis Foundation aquatic exercise classes from the societal perspective. DESIGN: Randomized trial of 20-week aquatic classes. Cost per quality-adjusted life year (QALY) gained was estimated using trial data. Sample size was based on 80% power to reject the null hypothesis that the cost/QALY gained would not exceed $50,000. SUBJECTS AND METHODS: Recruited 249 adults from Washington State aged 55 to 75 with a doctor-confirmed diagnosis of osteoarthritis to participate in aquatic classes. The Quality of Well-Being Scale (QWB) and Current Health Desirability Rating (CHDR) were used for economic evaluation, supplemented by the arthritis-specific Health Assessment Questionnaire (HAQ), Center for Epidemiologic Studies-Depression Scale (CES-D), and Perceived Quality of Life Scale (PQOL) collected at baseline and postclass. Outcome results applied to life expectancy tables were used to estimate QALYs. Use of health care facilities was assessed from diaries/questionnaires and Medicare reimbursement rates used to estimate costs. Nonparametric bootstrap sampling of costs/QALY ratios established the 95% CI around the estimates. RESULTS: Aquatic exercisers reported equal (QWB) or better (CHDR, HAQ, PQOL) health-related quality of life compared with controls. Outcomes improved with regular class attendance. Costs/QALY gained discounted at 3% were $205,186 using the QWB and $32,643 using the CHRD. CONCLUSION: Aquatic exercise exceeded $50,000 per QALY gained using the community-weighted outcome but fell below this arbitrary budget constraint when using the participant-weighted measure. Confidence intervals around these ratios suggested wide variability of cost effectiveness of aquatic exercise.

Functional status and perceived quality of life in adults with and without chronic conditions.

The objective of this study was to evaluate the association between self-reported functional status and quality of life in adults with and without chronic conditions. Data were obtained on functional status (Sickness Impact Profile, SIP), and perceived quality of life (Perceived Quality of Life Scale, PQoL) from 454 persons in nine groups with widely varying levels of functional status and disability. Multiple regression was used to analyze the association controlling for demographic characteristics (age, gender, educational level, income, marital status), self-rated health status, and depressive symptoms. PQoL was lowest for persons using wheelchairs and highest for older well adults. Scores decreased as SIP scores increased. Overall, being older, reporting better functional status, and having fewer depressive symptoms were significantly associated with higher quality of life (adjusted R(2) = 0.60). This pattern held for most subgroups, although the association was much lower for adults with AIDS and younger well adults where ceiling effects were observed in functional status. Functional status and perceived quality of life are highly associated but are distinct in many populations. Depressive symptoms and self-rated health are important mediators of the relationship to include in future studies. Amelioration of depressive symptoms through environmental modification and individual treatment are potential strategies for improving on this association in adults with chronic conditions.

'Finding a good thing': the use of quantitative and qualitative methods to evaluate an exercise class and promote exercise for adults with mobility impairments.

PURPOSE: Physical inactivity in people with severe disabilities is common and has severe consequences. Conditioning classes are one way to increase activity and promote its health related outcomes. This paper reports the results of an evaluation of a community based conditioning class for adults with mobility impairments. METHOD: The study uses two methods with two samples: a quantitative self-report methodology and a quantitative interview. RESULTS: The quantitative evaluation found no significant increases in standard self-report measures of physical activity, functional status, quality of life, depression, or exercise self-efficacy. The lack of significant quantitative results may be due to limits in study design. The open-ended qualitative interviews with 16 class participants show important physical, social and psychological improvements. The juxtaposition of these two perspectives allows researchers to recognize the limitations in their choice of methods and the challenges faced by researchers evaluating small community based programmes for this limited population. CONCLUSION: In this case, the qualitative evaluation captured the positive experiences of the exercise class participants.

Correlates of exercise maintenance among people with mobility impairments.

PURPOSE: This paper describes correlates of exercise maintenance in a sample of adults with mobility impairments. Understanding processes that promote exercise is important if one is to increase access to exercise for people with disabilities. METHOD: A model of variables predicting 6-month maintenance of regular exercise was examined, using data from a self-administered questionnaire given to a community sample of 113 adults with long-term mobility impairments. Descriptive analyses and logistic regression were used. RESULTS: Logistic regression showed that people with lower motivational barriers and higher exercise self-efficacy had a higher probability of exercise maintenance. Demographic characteristics and disability-related and environmental barriers did not differentiate between those who did and did not continue to exercise. CONCLUSIONS: Long-term sustained exercise by people with mobility impairments might be promoted by efforts to increase motivation to exercise: involve health professionals as one source of support and expand opportunity by increasing access to appropriate sites and programming.

Recruiting adults with osteoarthritis into an aquatic exercise class: strategies for a statewide intervention.

OBJECTIVE: Although research suggests that regular exercise can be helpful in reducing the dysfunction and discomfort of osteoarthritis, promoting exercise among older adults within this population is neither straightforward nor easily accomplished. This article describes the various methods, and their relative success rates, that were employed to recruit older adults throughout the state of Washington into an aquatic exercise program. METHODS: Strategies included a recruitment letter distributed to Arthritis Foundation (AF) members in Washington state, local media news coverage, physician referrals, and advertisements in local papers and newsletters. RESULTS: The most successful methods for enrolling participants were through the AF recruitment letters and local television coverage. The AF recruitment letter was the most expensive method of generating responses, while the television coverage was the least expensive. CONCLUSIONS: Collaborating with a well-reputed community-based organization and capitalizing on available publicity resources are important strategies researchers can use to gain access to a difficult and geographically dispersed population.

Efficient detour-phase encoding of one-dimensional multilevel phase diffractive elements.

We show that detour-phase encoding with a multilevel blaze structure as a carrier grating is especially suited to the implementation of diffractive elements with relatively high complexity in one axis. For our proposal the carrier grating is aligned perpendicularly to this axis. In this way the element can be encoded with a high space-bandwidth product and a high phase resolution by use of a moderate carrier frequency. Moreover, this frequency can be adjusted to isolate the reconstructed field from the noise resulting from high diffraction orders of the carrier grating or caused by etching errors during fabrication.

Work site-based cancer prevention: primary results from the Working Well Trial.

OBJECTIVES: This paper presents the behavioral results of the Working Well Trial, the largest US work site cancer prevention and control trial to date. METHODS: The Working Well Trial used a randomized, matched-pair evaluation design, with the work site as the unit of assignment and analysis. The study was conducted in 111 work sites (n = 28,000 workers). The effects of the intervention were evaluated by comparing changes in intervention and control work sites, as measured in cross-sectional surveys at baseline and follow-up. The 2-year intervention targeted both individuals and the work-site environment. RESULTS: There occurred a net reduction in the percentage of energy obtained from fat consumption of 0.37 percentage points (P = .033), a net increase in fiber densities of 0.13 g/1000 kcal (P = .056), and an average increase in fruit and vegetable intake of 0.18 servings per day (P = .0001). Changes in tobacco use were in the desired direction but were not significant. CONCLUSIONS: Significant but small differences were observed for nutrition. Positive trends, but no significant results, were observed in trial-wide smoking outcomes. The observed net differences were small owing to the substantial secular changes in target behaviors.

Cancer-risk-related health behaviors and attitudes of older workers. Working Well Research Group.

BACKGROUND: The National Cancer Institute's Working Well Trial was a randomized controlled trial of a two-year, comprehensive, worksite-based cancer control intervention. METHODS: Data from 19,582 respondents to the baseline survey were analyzed to determine the relationships between grouped age (18-29, 30-49, 50-54, 55-59, and > 60 years), dietary and smoking behaviors, and attitudes related to participation in health promotion activities. RESULTS: Workers over 50 had more positive health behaviors, stronger beliefs about the value of healthy behavior, and better self-assessed health; they were more likely to hold attitudes associated with participation in worksite health promotion, more positive about work conditions, attributed greater concern about worker health to management, and were more willing to believe that they would be allowed to attend worktime health promotion activities. CONCLUSIONS: Age may be an useful variable in targeting worksite cancer control programming. Workers in their 50s could be supported in weight management, since rates of overweight and obesity are higher in this group. Other health behaviors might be addressed for older workers.

School policy in COMMIT: a promising strategy to reduce smoking by youth.

Organizational smoking policy has been identified as a potentially effective way to influence health behavior, particularly in worksites. Examining the elements of existing school smoking policies for both students and employees can provide insight into the potential effectiveness of these policies in changing young people's smoking behavior. This paper examines selected components of existing school smoking policies in a national sample of schools at all levels of education as part of the Community Intervention Trial for Smoking Cessation. Schools were questioned about their school smoking policies, related resources, and compliance. The data show much variation in the elements of school tobacco use policy to change smoking behavior. Existing policies in schools differ among grade levels, thus providing different messages about the appropriateness of smoking. Policies differ for students and adults, providing another opportunity for confusion about the messages that policy can deliver. In general, resources available to support existing policies are lacking. Many schools offer classes on knowledge of negative health effects of smoking but do not teach the psychosocial skills necessary to resist tobacco use. In its present forms, school policy has great potential for an effective tool for health promotion, but considerable reform is needed to overcome current barriers.

The Working Well Trial: baseline dietary and smoking behaviors of employees and related worksite characteristics. The Working Well Research Group.

BACKGROUND: The Working Well Trial, the largest randomized worksite health promotion trial to date, tests the effects of cancer prevention and control interventions on dietary and smoking behaviors of employees and the worksite environment. The trial is a 5-year cooperative agreement conducted in 57 matched pairs of worksites in 16 states by four study centers, a coordinating center, and the National Cancer Institute. The dual aims of this paper are to: (a) present a baseline description of the dietary and smoking habits of 20,801 employees, who are predominantly blue-collar workers; and (b) describe the social and physical environments of their worksites that may facilitate or hinder health behavior changes. METHODS: The self-administered baseline survey of individuals consisted of a core set of questions common across all study centers on diet and smoking. The organizational survey consisted of eight instruments administered via interviews with key informants in each worksite. Continuous variable were analyzed by a mixed linear model and binary data were analyzed by the Generalized Estimating Equation. RESULTS: The population represented is largely male (67.5%) and blue collar (53.5%). Mean levels of fat and fiber intakes were close to the national averages (36.6% of calories as fat and 13.1 g of fiber). Smoking prevalence (25.2%) was slightly lower than the national average. The worksites had a high level of health promotion activities (42% had nutrition programs, 53% had smoking control programs), but lacked environmental support for dietary behavior change and perceived support for smoking cessation. CONCLUSIONS: These findings replicate and extend previous research results to a large sample of diverse, largely blue-collar worksites. In addition the baseline results lay a foundation for the development of new insights into the relationship between individual and organizational level variables that may interact to influence behavioral and cultural norms.

The validity of self-reported smoking: a review and meta-analysis.

OBJECTIVES: The purpose of this study was to identify circumstances in which biochemical assessments of smoking produce systematically higher or lower estimates of smoking than self-reports. A secondary aim was to evaluate different statistical approaches to analyzing variation in validity estimates. METHODS: Literature searches and personal inquiries identified 26 published reports containing 51 comparisons between self-reported behavior and biochemical measures. The sensitivity and specificity of self-reports of smoking were calculated for each study as measures of accuracy. RESULTS: Sensitivity ranged from 6% to 100% (mean = 87.5%), and specificity ranged from 33% to 100% (mean = 89.2%). Interviewer-administered questionnaires, observational studies, reports by adults, and biochemical validation with cotinine plasma were associated with higher estimates of sensitivity and specificity. CONCLUSIONS: Self-reports of smoking are accurate in most studies. To improve accuracy, biochemical assessment, preferably with cotinine plasma, should be considered in intervention studies and student populations.

Work-site smoking policies: their population impact in Washington State.

This article presents data from a population-based, random-digit dialing telephone survey of 1228 employed adults in Washington State, conducted 1989 through 1990. Eighty-one percent of men and 91% of women reported work-site smoking restrictions. Employees in work sites with no-smoking policies were less likely to be current smokers; men in work sites with policies restricting smoking smoked fewer cigarettes on both workdays and nonworkdays. Forty-eight percent of male and 53% of female smokers reported reduced smoking as a result of work-site policy. Work-site smoking policies, intended to protect against smoke exposure, may also reduce employee smoking.

Comparisons of strategies to prevent breast cancer mortality.

A health system should meet the health needs of the population. Given limited resources, choices are made about problems--typically, diseases--to attack. Then, choices must be made as to how to identify, treat, and ultimately, prevent their occurrences. This process is the subject of this article; it uses the case of breast cancer to examine allocation of resources to disease prevention and treatment. The paper reviews current allocation patterns among three strategies for prevention: primary, secondary, and tertiary. Each varies with respect to where the disease process is halted and in the amount of technological support required. Currently, the U.S. health care system allocates most resources to tertiary prevention, with scant support of primary and limited support of secondary prevention. Possible explanations for the current allocation patterns are discussed. Areas where social sciences have made contributions are highlighted. Finally, cost-effectiveness analyses are presented to illustrate a relatively balanced method for making decisions about future allocations.

Effects of enhanced calling efforts on response rates, estimates of health behavior, and costs in a telephone health survey using random-digit dialing.

Public health researchers frequently rely on random-digit dialing (RDD) telephone surveys in monitoring trends in health behavior and evaluating health promotion interventions. RDD response rates have declined during the past decade, and cost-effective methods to increase response rates are needed. The authors evaluated two levels of enhanced calling efforts in an RDD survey of cancer-related health behavior in the State of Washington. The first level of enhanced calling effort was 1 month after 11 original calling attempts to a household, when the authors attempted up to 11 recalls. The second level was 6 months after the first answered call, when the authors recalled those persons who could not be interviewed. Enhanced calling efforts increased the overall survey response rate by 11 percent. Nine percentage points of the increase were attributable to call backs. There were demographic differences among the participants reached at different levels of calling effort, but no consistent associations of level of calling effort with health behavior related to alcohol use, smoking, diet, or health screening. Marginal costs for interviews completed with enhanced calling efforts were about 50 percent higher than costs for interviews reached in the first 11 calls. The authors concluded that enhanced calling efforts may be justified, because they increase confidence in the generalizability of survey results. However, the authors found very little change in survey results by including interviews from persons who were difficult to reach and to interview.

Randomized telephone smoking-intervention trial initially directed at blue-collar workers.

Although smoking prevalence in the United States has declined markedly in recent years, prevalence among blue-collar workers remains high and few successful methods of reaching this group have been identified. The present study was designed to test the relative efficacy of two different approaches to telephone smoking-cessation counseling for blue-collar workers. Our study built on the experience of the National Cancer Institute's Cancer Information Service (CIS) and compared the past CIS smoking-cessation counseling procedure and a modified version of the present procedure. In our trial, callers to a special telephone hotline who asked for information on smoking cessation were randomly assigned to receive counseling under one of two protocols: 1) the past CIS procedure, in which general information was given and cessation materials were sent to the callers, and 2) a version of the present CIS stage-model procedure, adapted by us for use with blue-collar workers, in which callers were given counseling specific to their stage in the smoking-cessation process. The general-information group contained 185 subjects; the stage-model group contained 197. Despite extensive efforts in the present study, it was not possible to recruit the number of blue-collar workers planned for our statistical analysis. Consequently, of a total of 382 subjects recruited, 93 (24.3%) were blue-collar workers, 181 (47.4%) were white-collar workers, and 108 (28.3%) were retired persons who worked part time, student workers, or the unemployed. Our results show no statistically significant differences in either short-term or long-term nonsmoking rates between the general-information group and the stage-model group.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence and restrictiveness of smoking policies in King County, Washington, manufacturing worksites.

This study examined prevalence of smoking policies and of significant smoking restrictions in a 1988 random sample of 1,528 manufacturing companies in the Seattle, Washington area, and related these characteristics to worksite size and industry type. Sixty-nine percent of companies had formal smoking policies and 85 percent regulated smoking to some degree. Workforce size was directly related to prevalence of significant smoking restrictions, but when type of industry was controlled, the linear trend in the size/prevalence relationship was sustained in only three of the 18 industry groupings.