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Biomedical subjects

W F Velicer

Publications and source records attributed to W F Velicer.

At least 19 recordsLinked to original sources
PubMed1999

Stage distributions for five health behaviors in the United States and Australia.

BACKGROUND: A key variable for the design of individual and public health interventions is the Stage of Change. The five stages of readiness to change are Precontemplation, Contemplation, Preparation, Action, and Maintenance. The distribution of individuals across the stages of change can provide a valuable tool for designing health interventions. METHODS: The pattern of distribution across the stages of change for five behavioral risk factors is presented from five independent surveys, two from the United States and three from Australia. The five risk factors are smoking, low fat diet, regular exercise, reducing stress, and losing weight. Identical single-item questionnaire items for staging health behaviors were used in all surveys. RESULTS: The stage distributions for the five risk factors were similar across the five independent samples. In general, the pattern of stage distributions was stable across health risk factors, gender, country, and sample. CONCLUSIONS: Single-item survey measures of stage of change that are readily applicable to population studies appear to provide important information about the population characteristics of readiness to change behavioral risk factors. The stability of these distributions suggests that interventions matched by stage may have broad applicability.

Adolescent↗
PubMed1999

Stage of regular exercise and health-related quality of life.

BACKGROUND: Research on cognitive factors and motivational readiness for exercise is important for increasing our understanding of behavior change among those with sedentary lifestyles. This study examines stage of change for regular exercise and self-perceived quality of life. METHODS: Data are from 1,387 respondents to a random digit dial survey of health behaviors. Stage of change is assessed with a single item, and individuals are classified with respect to intention and exercise behavior. Quality of life is assessed with the SF-36, a multidimensional measure of health-related quality of life. RESULTS: Exercise stage is associated with self-perceived quality of life. The three areas most strongly related were physical functioning, general health perceptions, and vitality. Physical functioning scores were lowest in precontemplation and highest in maintenance. Vitality and mental health scales were related to exercise behavior, but not to intention. CONCLUSIONS: Cognitions about self-perceived quality of life vary across the stages of change, with those who are least prepared to adopt regular exercise reporting the lowest levels of quality of life. These findings suggest that cognitive-motivational messages designed to emphasize quality of life benefits associated with exercise may be useful intervention strategies for people who are less motivationally ready to change.

Adult↗
PubMed1999

An expert system intervention for smoking cessation.

The Pathways to Change system (PTC) is an expert system intervention for smoking cessation. Assessments are performed either by mail or by a telephone interview and each smoker receives a three- to four-page report that provides individualized recommendations matched to the individual's needs and readiness-to-change. The Transtheoretical Model of Change provides the theoretical basis for the expert system. Four different studies have demonstrated the efficacy of this intervention in a general population, with cessation rates of 22 to 26%. Furthermore, the difference between the groups was larger at each follow-up assessment point, indicating that the effects of the treatment increased long after the end of treatment. The studies involved two proactively recruited samples, demonstrating that a large proportion (85.3% and 82.5%) of the population of smokers could be successfully recruited into a smoking cessation program. Expert system interventions have the potential to have an extremely high impact on a total population of smokers.

Computer-Assisted Instruction↗
PubMed1999

Interactive versus noninteractive interventions and dose-response relationships for stage-matched smoking cessation programs in a managed care setting.

This study compared interactive and noninteractive smoking cessation interventions for a population of smokers who were all members of 1 division of a managed care company. In addition, it examined whether a dose-response relationship existed. Screening was completed for 19,236 members who were contacted by telephone or mail. Of the 4,653 who were identified as smokers, 85.3% were enrolled. A 2 Intervention (interactive or noninteractive) x 4 Contacts (1, 2, 3, or 6 contacts) x 4 Occasions (0, 6, 12, and 18 months) design was used. The interactive intervention was stage-matched expert-system reports plus manuals; the noninteractive intervention was stage-matched manuals. Contact occurred in 1 of 4 series (1, 2, 3 or 6 contacts) at 3-month intervals. The expert system outperformed the stage-matched manuals, but there was no clear dose-response relationship for either intervention.

Adult↗
PubMed1999

Stages of change across ten health risk behaviors for older adults.

Owing to the recent success of the Transtheoretical Model of behavior change and the possible relationships between health behaviors, this study investigated the stage distribution of 10 healthy behaviors (seatbelt use, avoidance of high fat food, eating a high-fiber diet, attempting to lose weight, exercising regularly, avoiding sun exposure, sunscreen use, attempting to reduce stress, stopping smoking, and conducting cancer self-exams) and their interrelationships in a representative sample of health maintenance organization (HMO) members. The majority of older adults were found to be in either precontemplation or maintenance, illustrating the need to target interventions to precontemplation. Most older individuals were in precontemplation for losing weight and/ or sunscreen use and exercise, making these behaviors a priority for intervention research. Possible gateway behaviors to general health could be identified; however, these results are preliminary and require longitudinal follow-up.

Aged↗
PubMed1999

Decisional balance for immoderate drinking in college students.

Immoderate drinking in college is common and is associated with significant negative sequelae. In this study, measures of Decisional Balance for Immoderate Drinking were developed. This construct is proposed to represent the basic decision-making process that is used by students when deciding whether to drink at immoderate levels or not. Furthermore this construct is embedded in a larger model of behavior change, the Transtheoretical Model of Change, which has been shown to be effective in understanding many health-related behaviors across a wide variety of populations. A total of 629 college students were administered a 25-item decisional balance questionnaire in 1993-1994. Exploratory and confirmatory analyses suggested two different solutions, a two-factor solution and a three-factor solution, but did not provide clear evidence for the psychometric superiority of one over the other. The three-factor solution was chosen as it was seen as an elaboration of the two-factor solution, and validity evidence for this solution is presented. The three factors were labeled the Pros, the Cons-Actual, and the Cons-Potential of Immoderate Drinking. The Cons-Actual scale is a measure of negative affective states associated with current drinking whereas the Cons Potential measures the risk of more concrete negative effects of drinking. External validity was established by the significant and meaningful differences on a number of alcohol-related variables including consumption variables, three measures of negative sequelae of immoderate drinking, and Stage of Change, the organizing construct of the Transtheoretical Model of Change.

Adolescent↗
PubMed1998

Time series analysis in historiometry: a comment on Simonton.

Time series analysis (TSA) is one of a number of new methods of data analysis appropriate for longitudinal data. Simonton (1998) applied TSA to an analysis of the causal relationship between two types of stress and both the physical and mental health of George III. This innovative application demonstrates both the strengths and weaknesses of time series analysis. Time series is applicable to a unique class of problems, can use information about temporal ordering to make statements about causation, and focuses on patterns of change over time, all strengths of the Simonton study. Time series analysis also suffers from a number of weaknesses, including problems with generalization from a single study, difficulty in obtaining appropriate measures, and problems with accurately identifying the correct model to represent the data. While careful attempts are made to minimize these problems, each is present in the Simonton study, although sometimes in a subtle manner. Changes in how the data could be gathered are suggested that might help to solve some of these problems in future studies. Finally, the advantages and disadvantages of employing alternative methods for analyzing multivariate time series data, including dynamic factor analysis, are discussed.

Data Interpretation, Statistical↗
PubMed1998

Measuring support for tobacco control policy in selected areas of six countries.

OBJECTIVE: To explore the validity, reliability, and applicability of using a short, psychometrically sound survey instrument to measure population attitudes toward tobacco control policies. DESIGN: Surveys. SUBJECTS AND SETTING: Student respondents attending university in Australia (n = 403), Hong Kong (n = 336), the Netherlands (n = 351), South Africa (n = 291), the United Kingdom (n = 164) and the United States (n = 241); total n = 1786. MAIN OUTCOME MEASURE: The Smoking Policy Inventory (SPI), a 35-item scale. SPI scores were adjusted for age, income, gender, and smoking status. Estimates of internal consistency and tests of factorial invariance were conducted in each sample. RESULTS: Across all six countries, the SPI was found to be highly reliable and to have a consistent factor structure, indicating that the SPI scale represents a higher order construct that assesses general attitudes about tobacco control policy with five dimensions. In general, the degree of endorsement of anti-tobacco policies as measured by the SPI reflected the extent and strength of tobacco control legislation in those countries. Dutch students were the least likely, and Australian and Hong Kong students the most likely, to support tobacco control policies. CONCLUSIONS: It is possible to develop appropriate and meaningful measurement tools for assessing support of tobacco control policies. Strong evidence was found for internal reliability and structural invariance of the SPI. The SPI may be a useful mechanism for monitoring ongoing policy initiatives, making cross-cultural comparisons, and evaluating population receptiveness to proposed policy approaches.

Adolescent↗
PubMed1998

Computer-based smoking cessation interventions in adolescents: description, feasibility, and six-month follow-up findings.

The impact of adolescent smoking cessation clinics has been disappointing due to low participation rates, high attrition, and low quit rates. This paper describes two computerized self-help adolescent smoking cessation intervention programs: 1) a program utilizing the expert system which is based on the transtheoretical model of change and 2) a popular action-oriented smoking cessation clinic program for teens which was modified for computer presentation. High participation rates in the program among 132 smokers demonstrate the high feasibility and acceptability of the programs. Quit rates of up to 20% were observed during the intervention, and an additional 30% made unsuccessful quit attempt(s). The 6-month follow-up findings indicated that adolescents were poorly prepared to maintain abstinence.

Adolescent↗
PubMed1996

Latent transition analysis for longitudinal data.

Assessing outcome is a critical problem for the study of addictive behaviors. Traditional approaches often lack power and sensitivity. Latent Transition Analysis is an alternative procedure that is applicable to categorical latent variable models such as stage models. The method involves four different types of parameters, each of which may be relevant to different research questions. Two examples that employ the Stages of Change construct are used to illustrate the method. In the first example, three different models of longitudinal change are compared. In the second example, the effects of an expert system intervention for smoking is compared to a control condition. The method permits the investigation of a series of specific comparisons: (1) the effectiveness of the intervention for individuals in different stages can be assessed; (2) the effectiveness of the intervention can be evaluated for different time intervals; and (3) the effects of intervention on both progression through the stages and regression through the stages or relapse can be assessed. Other potential applications of the method are also discussed.

Alcoholism↗
PubMed1995

Distribution of smokers by stage in three representative samples.

OBJECTIVES: A key variable for the design of individual and public health interventions for smoking cessation is Stage of Change, a variable which employs past behavior and behavioral intention to characterize an individual's readiness to change. Reactively recruited samples distort estimates of the stage distribution in the population because such samples attract a disproportionate number of late-stage participants. Three representative samples are described which provide accurate estimates of the stage distribution in the population. These samples are of adequate size to permit within-sample comparisons with respect to sex, age, Hispanic or non-Hispanic origin, race, and education level. The implications of using stage distribution as a tool for planning intervention is discussed. METHOD: The first sample of 4,144 smokers was from the state of Rhode Island and involved a random-digit-dial survey. The second sample of 9,534 smokers was from the state of California and involved a stratified random-digit-dial survey. The third sample of 4,785 smokers was from a total of 114 worksites located in four different geographic locations. RESULTS: The stage distributions were approximately identical across the three samples, with approximately 40% of the sample in Precontemplation, 40% in Contemplation, and 20% in Preparation. The stage distribution was generally stable across age groups with the exception of the 65 years and older group. Education level did affect the stage distribution with the proportion of the sample in Precontemplation decreasing as education level increased. In all three samples, minor differences in stage distribution were related to Hispanic origin and race, but the pattern was not consistent across the samples. CONCLUSIONS: The pattern of stage distribution has important implications for the design of interventions. Existing interventions are most appropriate for the Preparation stage, but the majority of the three samples were in the first two stages, resulting in a likely mismatch between the smoker and the intervention. The stability of distribution across age suggests that interventions that are appropriately matched to stage can be applied across all age groups. The differences found with respect to education, Hispanic origin, and race can serve as a guide to the tailoring of intervention materials.

Adult↗
PubMed1995

Contraceptive and condom use adoption and maintenance: a stage paradigm approach.

The Transtheoretical Model of Behavior Change was examined for its applicability to contraceptive and condom use adoption and maintenance using N = 248 heterosexually active college-age men and women. The model posits that individuals do not go directly from old behaviors to new behaviors to new behaviors, but progress through a sequence of stages: precontemplation, contemplation, preparation, action, and maintenance. The stages of change offer a temporal dimension that provides information regarding when a particular shift in attitudes, intentions, and behavior may occur. The model also postulates a set of or outcome variables--the pros and cons of change and self-efficacy. The results demonstrated that individuals were furthest along in the stages of change for general contraceptive use, followed closely by condom use with other (e.g., casual) partners, and then condom use with main partners. Although no sex differences were found for the stages for the three separate contraceptive behaviors, males and females differed on the pros and cons and levels of self-efficacy when engaging in intercourse with the two types of partners. MANOVA/ANOVA results indicated that the relationship between stages and other constructs follows predicted patterns suggesting that the transtheoretical model may provide a useful framework or paradigm for understanding contraceptive and condom use behavior.

Adolescent↗
PubMed1994

Stages of change and decisional balance for 12 problem behaviors.

This integrative study investigated the generalization of the transtheoretical model across 12 problem behaviors. The cross-sectional comparisons involved relationships between two key constructs of the model, the stages of change and decisional balance. The behaviors studied were smoking cessation, quitting cocaine, weight control, high-fat diets, adolescent delinquent behaviors, safer sex, condom use, sunscreen use, radon gas exposure, exercise acquisition, mammography screening, and physicians' preventive practices with smokers. Clear commonalities were observed across the 12 areas, including both the internal structure of the measures and the pattern of changes in decisional balance across stages.

Adult↗
PubMed1994

The transtheoretical model of change and HIV prevention: a review.

The transtheoretical model of health behavior change is described and supporting empirical work is presented that reviews the central constructs of the model: the stages of change, processes of change, decisional balance, confidence, and temptation. Model-based applications to a broad range of problem behaviors are summarized. Applications to human immunodeficiency virus (HIV) prevention behavior changes are highlighted for each variable. Finally, several questions about the area of sexual behavior change to reduce risk of HIV exposure are explored and future research ideas are described within the context of this model.

Attitude to Health↗
PubMed1994

Time series models of individual substance abusers.

Time series analysis is a statistical procedure appropriate for repeated observations on a single subject or unit. The goal of the analysis may be to determine the nature of the process that describes an observed behavior or to evaluate the effects of a treatment or intervention. Model identification involves specifying which of several alternative Autoregressive Integrated Moving Average (ARIMA) models best describes the series and may be used to investigate basic processes. This is illustrated by an example involving selecting the model of nicotine regulation that best represents smokers. Intervention analysis involves determining if there are any changes in level or direction for the series as a result of the intervention. Two types of applications have potential for the substance abuse area: (1) evaluation of the effects of an intervention on a single individual, and (2) evaluation of organizational-level changes (i.e., program evaluation). This is illustrated by an example that examines the effect of relaxation therapy on blood pressure. Pooled time series procedures are employed to combine the data from several different individuals or units, either by cross-sectional analysis or meta-analysis. In addition, several other issues are discussed that are critical to performing a time series analysis: selection of an appropriate computer program, alternative procedures for handling missing data, procedures for multiple observations at each occasion, and corrections for seasonal data.

Humans↗
PubMed1993

Standardized, individualized, interactive, and personalized self-help programs for smoking cessation.

Smokers (N = 756) were randomly assigned by stage of change to (a) standardized self-help manuals (ALA+ condition), (b) individualized manuals matched to stage (TTT condition), (c) interactive expert-system computer reports plus individualized manuals (ITT condition), or (d) a personalized condition with 4 counselor calls, stage manuals, and computer reports (PITT condition). Over 18 months, the ITT group's results more than doubled those of the ALA+ group on abstinence measures. The ALA+ and TTT conditions were equivalent over 12 months, but at 18 months the TTT condition was more effective. The ITT condition was the best or comparable with the best treatment at all follow-ups for smokers at all stages of change. Results suggest that an effective expert system has been developed, and discussion focuses on delivering this system to entire populations of smokers.

Adult↗