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Biomedical subjects

A Cheadle

Publications and source records attributed to A Cheadle.

At least 37 records · Page 2Linked to original sources
PubMed1995

Optimal survey design for community intervention evaluations: cohort or cross-sectional?

Community intervention evaluations that measure changes over time may conduct repeated cross-sectional surveys, follow a cohort of residents over time, or (often) use both designs. Each survey design has implications for precision and cost. To explore these issues, we assume that two waves of surveys are conducted, and that the goal is to estimate change in behavior for people who reside in the community at both times. Cohort designs are shown to provide more accurate estimates (in the sense of lower mean squared error) than cross-sectional estimates if (1) there is strong correlation over time in an individual's behavior at time 0 and time 1, (2) relatively few subjects are lost to followup, (3) the bias is relatively small, and (4) the available sample size is not too large. Otherwise, a repeated cross-sectional design is more efficient. We developed methods for choosing between the two designs, and applied them to actual survey data. Owing to drop-outs and losses to followup, the cohort estimates were usually more biased than the cross-sectional estimates. The correlations over time for most of the variables studied were also high. In many instances the cohort estimate, although biased, is preferred to the relatively unbiased cross-sectional estimate because the mean squared error was smaller for the cohort than for the cross-sectional estimate. If these results are replicated in other data, they may result in guidelines for choosing a more efficient study design.

Cohort Studies↗
PubMed1995

School-level application of a social bonding model to adolescent risk-taking behavior.

Adolescent bonding--attachment to, commitment to, and involvement in conventional social activities-decreases the likelihood of engaging in some risk-taking behaviors. The extent to which bonding opportunities in the school environment affect individual's bonding and risk-taking behaviors is less explored. This study tested a model that includes individual and environmental indicators of bonding to predict cigarette smoking, drinking, drug use, and sexual activity among ninth grade students. Survey data representing students in 20 schools in seven western states are reported. Twelfth grade students' bonding and other demographic variables aggregated by school served as environmental indicators of bonding opportunities to predict ninth grade students' bonding and risk-taking behavior. Path analyses indicate the school environment has a direct influence on ninth grade students' bonding and, in turn, on the likelihood they will engage in risky behavior. Implications of these findings for future research directions and intervention design are discussed.

Adolescent↗
PubMed1995

Voluntary public health insurance for low-income families: the decision to enroll.

A dominant issue in the health reform debate is whether insurance coverage should be voluntary or mandatory. Clearly, the factors that determine who will seek voluntary coverage are relevant to this policy issue. This article uses experience from Washington State's Basic Health Plan to examine the enrollment choices of low-income families in a state-subsidized voluntary insurance plan offered through managed care organizations. We hypothesize that the decision to enroll, which encompasses the decisions to purchase insurance coverage and to select a particular plan, is influenced by four factors: the family's financial vulnerability, their risk perception, the price of coverage, and the transition costs of enrolling. Our enrollment model is supported by the data and has important implications for the design of voluntary programs. Families who choose to enroll are more likely to have a female head of household, young children, and a family member who has a part-time job and some college education. Higher premiums and availability of other insurance coverage decrease the probability of enrolling.

Adult↗
PubMed1994

Race- and ethnicity-specific characteristics of participants lost to follow-up in a telephone cohort.

The purpose of this study was to describe race- and ethnicity-specific characteristics of subjects lost to follow-up. For a study of community-based health interventions, adult subjects from 11 US communities were initially recruited by random digit dialing and interviewed by telephone in 1988; 2 years later, they were recontacted, and the same survey was administered a second time. Associations with loss to follow-up were assessed in separate models for whites, African Americans, Hispanic Americans, and Asian Americans. After 2 years, 40.8% of the 5,851 participants were lost to follow-up; cohort attrition was highest among African Americans (51.3%) and lowest among whites (37.5%). Age, aspects of employment, education, marital status, and income were significant independent predictors of loss to follow-up for one or more of the four racial and ethnic groups. Characteristics of subjects lost to follow-up in this telephone cohort differed among various racial and ethnic groups. After adjustment for demographic, socioeconomic, and health status variables, the important behavioral predictors of loss to follow-up were current smoking for whites (p < 0.05), having a high fat diet for African Americans (p < 0.10), consuming one or more alcoholic drinks per day for Hispanic Americans (p < 0.10), and high levels of physical activity for Asian Americans (p < 0.05).

Adolescent↗
PubMed1994

Differences in sociodemographic, health status, and lifestyle characteristics among American Indians by telephone coverage.

BACKGROUND: Telephone interviews are often used to obtain population-based estimates of health-related behaviors but they have serious limitations if phone coverage is poor and people without telephones differ from those with telephones. In this article we examine differences in selected sociodemographic, health status, and lifestyle factors among a sample of American Indian adults with and without telephones. METHODS: In-person interviews were conducted with 410 adult residents of a Rocky Mountain state American Indian reservation. The interview included a question asking about telephone coverage. We compared respondents with and without telephones on demographics, health status, and lifestyle practices. The comparison was repeated for health status and lifestyle practices after adjusting for differences in demographic characteristics. RESULTS: Residents without phones generally were less educated, had lower income and were more likely to be unemployed. The prevalence of unhealthful lifestyle practices/factors was consistently higher for residents without telephones. Many of the differences were reduced by adjusting for demographic characteristics, but significant differences remained for alcohol and marijuana use. CONCLUSIONS: These results suggest that developing estimates of sociodemographic, health, and lifestyle characteristics on a Native American Indian reservation using a telephone survey method may result in significant noncoverage biases. Adjusting for demographic characteristics eliminated most of these differences. However, significant differences were still apparent with alcohol and marijuana use.

Adolescent↗
PubMed1994

Factors influencing the duration of work-related disability: a population-based study of Washington State workers' compensation.

OBJECTIVES: The purpose of this study was to examine factors predictive of duration of work-related disability. METHODS: Multivariate survival analysis techniques were used to conduct a population-based, retrospective cohort study on a random sample of 28,473 workers' compensation claims from Washington State filed for injuries occurring in 1987 to 1989. The principal outcome measure was length of time for which compensation for lost wages was paid, used as a surrogate for duration of temporary total disability. RESULTS: The findings suggest that, even after adjusting for severity of injury, older age, female gender, and a diagnosis of carpal tunnel syndrome or back/neck sprain significantly predict longer duration of disability. Other predictors that were stable and significant, but involved lower magnitudes of effect included divorced marital status, firm size of fewer than 50 employees, higher country unemployment rates, and construction and agricultural work. CONCLUSIONS: Greater disability prevention efforts targeting these higher risk subgroups could have significant economic and public health effects. The greatest impact may be on claimants who remain disabled at 6 months after an injury that did not require hospitalization.

Actuarial Analysis↗
PubMed1994

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.

Humans↗
PubMed1993

Can measures of the grocery store environment be used to track community-level dietary changes?

BACKGROUND: This article examines whether an in-store unobtrusive survey of grocery store product displays can be used to track community-level dietary behavior. METHODS: The survey was conducted in 12 western communities two different times to measure two aspects of the grocery store environment: (a) the relative availability of low-fat and high-fiber products and (b) the amount of store-provided health-education information. Self-reported dietary intake of residents was obtained in the same 12 communities using a telephone survey. We compared the individual and store-level measures both cross-sectionally and over time. RESULTS: We found positive and statistically significant correlations between the availability of healthful products in stores and the reported healthfulness of individual diets in cross-sectional analyses, but correlations between changes over time in the two measures were weaker and not statistically significant. The variance of the grocery store measures was nonetheless sufficiently small that a grocery store survey of 15 stores in each of 8 communities (n = 120 surveys) had power comparable to that of a telephone survey of 200 individuals/community (n = 1,600) surveys, at a fraction of the cost. CONCLUSION: Although the results provide further validation of cross-sectional measures of the grocery store environment, additional efforts are required to establish the validity of the grocery store survey as a method of measuring dietary change.

Advertising↗
PubMed1993

Do communities differ in health behaviors?

Communities differ in the prevalence of various health behaviors, but it is not known to what extent these differences are due to "different types" of people living in them. We used data from the evaluation of the Henry J Kaiser Family Foundation Community Health Promotion Grant Program to study individual-level and community-level variation in health behaviors for 15 communities. Our results show (1) there was significant variation among these communities in prevalences of smoking, consumption of alcohol and dietary fat, and use of seatbelts; (2) these differences persisted after control for demographic, health status, and other health behavioral characteristics of the people in the communities; (3) the community effect on a particular person's behavior, as represented by R2, was very small (less than 1%); and (4) the adjusted differences in prevalences among communities were potentially large (for example, a 7 percentage point difference in the probability of smoking). Unique features of communities may influence health behaviors. These findings affirm the potential importance of contextual effects on individual health behavior and thus support the theory that changing the community environment may offer effective ways to change individual health behavior.

Adolescent↗
PubMed1993

Who enrolled in a state program for the uninsured: was there adverse selection?

Managed care plans may hesitate to participate in programs for uninsured persons because they fear adverse selection, whereby only the sickest people or highest users would choose to join the program. We studied this issue in Washington State's Basic Health Plan, a demonstration program that provides subsidized health insurance for families earning less than 200% of the poverty level. We interviewed people in three counties who enrolled in the program, and compared them to people in the same counties who were eligible but did not enroll. There were substantial differences between enrollees and eligibles in education, age, income, employment, race, and insurance status. In spite of these demographic and access differences, health status was remarkably similar for enrollees and eligibles, with the few significant differences favoring the enrollees. In addition, previous and subsequent use of health services was similar or lower for enrollees. The results for health status and utilization were similar across the three counties, even though the counties and the providers were quite different. We conclude that there is no evidence of adverse selection. This is welcome news for the health plans, but suggests that the BHP may not have reached those most in need of insurance.

Age Factors↗
PubMed1993

Activating communities for health promotion: a process evaluation method.

OBJECTIVES: To date, evaluations of community-based prevention programs have focused on assessing outcomes, not the process of organizing communities for health promotion. An approach was developed to analyze community organization efforts aimed at advancing community health objectives. These organizational processes are referred to as community activation. METHODS: Information was gathered from 762 informants through a key informant survey conducted in 28 western communities. The data collected included informant ratings of community activation and information about interorganizational activities analyzed through network analytic techniques. RESULTS: Activation levels, as measured by informant ratings, varied across communities. Program coordination, as measured by network analysis, occurred, on average, approximately 30% of the time. Higher income communities tended to be more activated than lower income communities. CONCLUSIONS: There is a widely recognized need for improved information about health-related community organization activities. It appears possible to gather such information through key informant surveys and to develop measures of community organization status that can be used in the evaluation of community health promotion programs.

Community Participation↗
PubMed1992

Assessing response bias in random-digit dialling surveys: the telephone-prefix method.

Knowledge of the characteristics of survey non-respondents is important to determine generalizability to the population of interest. In a recent random-digit dialling survey of health behaviours only 73 per cent of the households contacted provided any information about household composition, and only 74 per cent of those actually completed the extended interview, for an overall response rate of 54 per cent. To identify possible biases we grouped all attempted phone numbers by their prefix, and looked for the association between the response rate for that prefix and other summary variables known about the prefix. A simulation study showed that the method can identify non-response biases if certain assumptions are correct. The analysis suggested that our survey data under-represent older people and those with a college education. We found no significant biases in health behaviours, possibly because the basic assumptions did not hold. This method may assist in identification of non-response bias in other studies.

Adult↗
PubMed1991

Sampling elderly in the community: a comparison of commercial telemarketing lists and random digit dialing techniques for assessing health behaviors and health status.

A study of health behaviors in four communities in the western United States in 1988 provided the opportunity to compare two methods of sampling elderly respondents for a telephone interview. The Polk telemarketing lists were used to identify 1,407 respondents aged 65 years and older in four communities, where 253 respondents in the same age group were also identified by the method of random digit dialing. Individuals identified from the Polk lists received a letter prior to the initial telephone contact. The overall response rate was 49.3% for random digit dialing and 57.3% for the Polk lists. On the average, the identification of one elderly respondent using the Polk lists required about 20-25% as much interviewer time per subject identified as was required by the random digit dialing method. The elderly identified by the Polk lists were significantly older than those identified by random digit dialing, and the proportions of the Polk sample who were married, white, or had an income of greater than $10,000 were slightly higher than those of the random digit dialing sample. Among 40 variables measuring various health behaviors, indicators of health status, and participation in health-related programs and classes, only three differed significantly between the two samples. The authors conclude that sampling from commercial telemarketing lists was an efficient method of identifying elderly respondents and that in these four communities, the estimates of health behaviors and health status were comparable with those obtained by random digit dialing techniques.

Aged↗
PubMed1991

Community-level comparisons between the grocery store environment and individual dietary practices.

BACKGROUND: This article examines the relationship at the community level between individual dietary practice and the grocery store environment. METHODS: Individual dietary practice was measured in 12 communities using a telephone survey to obtain self-reported diet. A protocol was developed to measure two aspects of the grocery store environment in these same 12 communities: the relative availability of healthful (low-fat and high-fiber) products, and the amount of health-education information provided. Comparisons were made between individual and store-level measures at two levels of geographic aggregation: community (typically a county) and zip code within community (n = 34). RESULTS: We found positive and statistically significant correlations at both the community and the zip code level between the availability of healthful products in stores and the reported healthfulness of individual diets. Positive correlations were also found between measures of the amount of health-education material provided by stores and the healthfulness of individual diets, but these correlations did not reach statistical significance. CONCLUSIONS: The results provide support for including measures of the grocery store environment as part of a community-level assessment of dietary behavior.

Adult↗
PubMed1991

The evaluation of the Henry J. Kaiser Family Foundation's Community Health Promotion Grant Program: design.

The Kaiser Family Foundation's Community Health Promotion Grant Program (CHPGP) provides funding and technical assistance in support of community-based efforts to prevent major health problems. The first phase of the program was implemented in 11 communities in the western United States. This paper describes the evaluation design of the CHPGP in the West, the methods of data collection, and the baseline comparability of intervention and control communities. Major features of the evaluation design include: (1) the randomization of qualified communities making application into funded and unfunded comparison groups; (2) a second set of matched control communities for some intervention sites; (3) data gathering through repeated surveys of community residents (probability samples of adults and adolescents) and institutions (health-related organizations and randomly sampled grocery stores and restaurants); and (4) the use of secondary data to monitor health events. Selected baseline data show that intervention and control communities differ in racial/ethnic composition, but relevant health behaviors and ratings of community activation for health promotion appear comparable.

Adolescent↗
PubMed1991

Data analysis and sample size issues in evaluations of community-based health promotion and disease prevention programs: a mixed-model analysis of variance approach.

The growing interest in community-based approaches to health promotion and disease prevention (HP/DP) has been accompanied by a growing need to evaluate the effectiveness of such programs. Special issues that arise in these evaluation studies include (1) entire communities are assigned to intervention and control groups, (2) only a small number of communities can usually be studied, (3) the time course of changes in behavior and other outcomes is often of interest, and (4) surveys to measure such changes over time can be conducted with either repeated cross-sectional samples or with longitudinal samples. This paper shows how these issues can be addressed under a mixed-model analysis of variance approach. This approach serves to unify several ideas in the literature on evaluation of community studies, including use of time-series regression and the question of whether the individual or the community should be the unit of analysis. We also describe how the method can be used to estimate sample size requirements, statistical power, or minimum detectable program effect.

Analysis of Variance↗
PubMed1991

Estimating county percentages of people without health insurance.

County data on the percentage of people without health insurance are seldom available, although state program planning requires such information. As part of an evaluation of Washington's Basic Health Plan (BHP), we conducted a telephone survey in nine Washington counties to estimate the percentage of people under the age of 65 who were uninsured. We used regression analysis to estimate the percentage uninsured in a county as a function of the percentage unemployed. Two validation approaches yielded very good results, suggesting that the equation could be used to estimate the percentage uninsured in unsurveyed counties. The variation ranged from 15% to 23% uninsured in the 9 surveyed counties, and was estimated to range from 9% to 35% among the state's 39 counties. With proper caution, estimates based on this equation can probably be used in other states if better data are unavailable.

Data Collection↗