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Biomedical subjects

J O Prochaska

Publications and source records attributed to J O Prochaska.

87 records · Page 5Linked to original sources
PubMedDate not supplied

An empirical typology of subjects within stage of change.

The transtheoretical model of behavior change postulates five distinct, well-defined stages of change: Precontemplation, Contemplation, Preparation, Action, and Maintenance. Each stage has been regarded as reflecting a motivational posture and treated as if it is homogenous with respect to membership. This paper reports the results of four cluster analytic studies, one within each of the first four stages of change. The cluster analysis was based on three constructs of the model. Four distinct subtypes were found within Contemplation, Preparation, and Action, and three subtypes were found within Precontemplation. External validation for the clusters was provided using the 10 Processes of Change and 8 behavioral measures as dependent measures. At least one subtype corresponded to the existing stage definition but the other subtypes suggested alternative intervention strategies.

Adult↗
PubMedDate not supplied

A criterion measurement model for health behavior change.

Researchers in the field of health behavior change have traditionally relied on a univariate criterion measure to evaluate the efficacy of an intervention. Such measures have superficial face validity but suffer from a number of problems: (a) lack of precise definitions; (b) poor statistical power; and (c) a lack of meaningfulness for some aspects of the problem. As an alternative, a theoretical model is developed that attempts to define more appropriate multivariate sets of dependent variables for the study of health behavior change. The model involves three separate constructs: Positive Evaluation Strength, Negative Evaluation Strength, and Habit Strength. The pattern of change for each construct is described across four stages of change: Precontemplation, Contemplation, Action, and Maintenance. For each construct, two thresholds are proposed representing the ability of the environment to modify the construct. Four tests of the model are provided from existing data sets. First, a structural model analysis was used to test if the proposed measurement model adequately fits the data. Second, a dynamic typology approach produced profiles of change that are consistent with the model. Third, a time series analysis provided support for the assumed model. Fourth, longitudinal, five-wave panel design was employed to test if the relation between the two cognitive variables (Pros and Cons) and the behavioral measure (Habit Strength) was consistent with the model. Implications for alternative intervention strategies are discussed.

Behavior, Addictive↗
PubMedDate not supplied

A stage paradigm for integrating clinical and public health approaches to smoking cessation.

Clinical interventions for the addictions typically generate the highest abstinence rates but the lowest participation rates. Public health interventions reach the largest percentage of populations but have the lowest efficacy. Applying a stage paradigm to smoking cessation can integrate the clinical and public health approach and generate unprecedented impacts. Theoretical, empirical, and practical examples are provided for enhancing five issues in intervention: recruitment, retention, progress, process and outcomes.

Combined Modality Therapy↗
PubMedDate not supplied

Stage of change, decisional balance, and temptations for smoking: measurement and validation in a large, school-based population of adolescents.

Developing interventions for reducing adolescent smoking rates based on the Transtheoretical Model (TTM) requires the development of quality measures of the key constructs of the model. The goal of this investigation was to evaluate the psychometric properties of measures of Stage of Change, Decisional Balance and Situational Temptation for both smokers and nonsmokers and to test if the predicted relationships between these constructs were confirmed in a large (N=2808) sample of adolescents. A correlated three factor model (Social Pros, Coping Pros and Cons) provided an excellent fit to the 12-item Decisional Balance inventory for both smokers (CFI=0.957) and nonsmokers (CFI=0.963). A hierarchical four factor model (negative affect, positive social, habit strength and weight control) provided an excellent fit to the eight-item Situational Temptations inventory for smokers (CFI=0.969). A hierarchical five-factor model (same four as smokers plus Curiosity) provided an excellent fit to the 10-item Situational Temptations inventory for nonsmokers (CFI=0.943). The relationships between both the Decisional Balance and temptation scales and the Stages of Change were verified for both smokers and nonsmokers. The measures for adolescents are similar to but not the same as the measures of these constructs for adults.

Adolescent↗
PubMedDate not supplied

Evaluating a population-based recruitment approach and a stage-based expert system intervention for smoking cessation.

A stage-matched expert system intervention was evaluated on 4144 smokers in a two-arm randomized control trial with four follow-ups over 24 months. Smokers were recruited by random digit-dial calls, and 80.0% of the eligible smokers were enrolled. Individualized and interactive expert system computer reports were sent at 0, 3, and 6 months. The reports provided feedback on 15 variables relevant for progressing through the stages. The primary outcomes were point prevalence and prolonged abstinence rates. At 24 months, the expert system resulted in 25.6% point prevalence and 12% prolonged abstinence, which were 30% and 56% greater than the control condition. Abstinence rates at each 6-month follow-up were significantly greater in the Expert System (ES) condition than in the comparison condition with the absolute difference increasing at each follow-up. A proactive home-based stage-matched expert system smoking cessation program can produce both high participation rates and relatively high abstinence rates.

Adult↗
PubMedDate not supplied

Dynamic typology clustering within the stages of change for smoking cessation.

Dynamic typology clustering was employed to find homogeneous subgroups of smokers within each of three early stages of change (precontemplation, contemplation, preparation) in a representative sample of smokers. Individual change profiles were created by coding the stage of change for each subject at five consecutive assessment points over a 2-year period (baseline and 6, 12, 18, and 24 months). A total of 446 unique change profiles were found in the sample of 2,088 smokers who had complete data for all five time points. The sample was initially split into three groups determined by baseline stage of change. Within each initial stage, subgroups that shared similar patterns of change were interpreted by examining the shape and elevation of the change profiles. Four major types of profiles emerged: a stable profile, a progressing profile, a vacillating profile, and a regressing profile. External validation revealed significant differences among the dynamic typology subtypes on key transtheoretical model constructs (processes of change, decisional balance, situational temptations). These results both support and complement key construct relationships within the transtheoretical model and can provide important predictive information to direct and enhance treatment interventions for smoking cessation.

Adult↗
PubMedDate not supplied

Stages of acquisition and cessation for adolescent smoking: an empirical integration.

Adolescent cigarette smoking acquisition and cessation were integrated into a single nine-stages-of-change continuum using the transtheoretical model of change framework. Findings in a high school student sample (n > 700) showed that a few of the never smokers were planning to try smoking, and half of the current smokers were contemplating quitting. More than half of former smokers were long-term quitters. The high pros of smoking scores assessing coping benefits of cigarettes were related to smoking acquisition and the high con (disadvantages) scores to long-term abstinence. Never smokers were most tempted to try smoking when they anticipated that smoking would help reduce negative and increase positive mood. Current and former smokers were tempted due to peer cigarette offers and negative mood. These temptations were significantly reduced among ex-smokers.

Adolescent↗
PubMedDate not supplied

Smoking and diabetes: readiness for change and provider advice.

Smoking is a serious health risk, particularly for people with diabetes. This study was designed to examine important aspects of smoking in a large group of individuals with diabetes. A survey was mailed to 2,056 individuals with diabetes. The variables examined were the stages of change for smoking, prevalence of quitting advice given by health care providers, and the patterns of readiness for change. The majority (57.8%) of current smokers were in the precontemplation stage. Comparisons on the stage of change indicated that more individuals with Type 2 diabetes have quit while there are more current smokers among those with Type 1 diabetes. Comparisons on current smokers indicated no differences on stage of change across the Type 1 and Type 2 groups, across three subgroups of individuals with Type 2 diabetes, or across duration of diabetes. Those who reported that they were given cessation advice were further along in the stages of change. These results suggest that the majority of individuals with diabetes who smoke are in the precontemplation stage of change and provider advice is important in moving smokers toward change. The current findings underscore the importance of assessing stage of change and providing stage-matched interventions when working with smokers with diabetes.

Adult↗
PubMedDate not supplied

Testing 40 predictions from the transtheoretical model.

Sensitive measurement of behavior change requires dependent measures that are sensitive to the whole spectrum of change, not just a single aspect of change. Traditional outcome variables such as point prevalence for smoking cessation focus on a single discrete event and ignore all other progress. Alternatively, the criterion measurement model (CMM) is an approach that posits a three-construct outcome model (habit strength, positive evaluation strength, and negative evaluation strength), where different constructs are sensitive to change for different aspects of the temporal domain. In this article, a series of 40 differential a priori predictions were tested using a large representative sample of smokers. The focus was on the prediction of specific effect sizes rather than statistical significance. A series of comparisons involving stage transitions was examined using five variables representing the three CMM constructs. The predictions involved movement from one of three initial stages (precontemplation, contemplation, and preparation) to stage membership 12 months later. Thirty-six of the 40 predictions were confirmed, indicating that the outcome model has strong construct validity and accurately reflects movement between the stages of change.

Adolescent↗
PubMedDate not supplied

Cluster subtypes within stage of change in a representative sample of smokers.

In this paper a three-level conceptualization of approaches to matching self-help behavior change strategies to individuals is presented based on the Transtheoretical Model of Change. Two of the model's intervention approaches, tailoring to Stage-of-Change and creating completely individualized interventions, have already been developed and implemented in previous research. A third intervention approach, in between stage-tailored and individualized, is targeting subtype groups within each Stage of Change. The subtype targeted intervention approach is in the initial development stage of empirically determining and validating the stage subtypes. Three studies are presented which investigate stage subtypes within a representative sample of 4,144 smokers in the Precontemplation, Contemplation, and Preparation Stages of Change. Within each Stage-of-Change study, two cluster analyses were performed using the Pros, Cons, and Situational Temptations from the Transtheoretical Model to establish cluster replicability. Cluster solutions were externally validated using the 10 Processes of Change and 2 smoking behavior variables. Four distinct subtypes were found in Precontemplation and Contemplation, and five subtypes were found in Preparation. These subtypes closely replicate subtypes previously found in a convenience sample of smokers and provide strong evidence for the existence of subtypes within the first three Stages of Change.

Adaptation, Psychological↗
PubMedDate not supplied

The transtheoretical model of health behavior change.

The transtheoretical model posits that health behavior change involves progress through six stages of change: precontemplation, contemplation, preparation, action, maintenance, and termination. Ten processes of change have been identified for producing progress along with decisional balance, self-efficacy, and temptations. Basic research has generated a rule of thumb for at-risk populations: 40% in precontemplation, 40% in contemplation, and 20% in preparation. Across 12 health behaviors, consistent patterns have been found between the pros and cons of changing and the stages of change. Applied research has demonstrated dramatic improvements in recruitment, retention, and progress using stage-matched interventions and proactive recruitment procedures. The most promising outcomes to data have been found with computer-based individualized and interactive interventions. The most promising enhancement to the computer-based programs are personalized counselors. One of the most striking results to date for stage-matched programs is the similarity between participants reactively recruited who reached us for help and those proactively recruited who we reached out to help. If results with stage-matched interventions continue to be replicated, health promotion programs will be able to produce unprecedented impacts on entire at-risk populations.

Decision Making, Computer-Assisted↗
PubMedDate not supplied

What makes a good staging algorithm: examples from regular exercise.

PURPOSE: This study retrospectively compared subjects from three unrelated studies using eight algorithms to stage exercise behavior. SUBJECTS AND SETTINGS: Study One included 936 employees involved in a smoking cessation study at four worksites--a medical center, retail store, manufacturing firm, and a government agency. Study Two included 19,212 members of a New England HMO; and Study Three included a convenience sample of 327 adult New Englanders. MEASURES: The eight algorithms used different descriptions of stages based on the transtheoretical model, as well as different definitions of exercise and response formats. RESULTS: Algorithms using longer, more precise definitions of exercise resulted in larger numbers of subjects being staged in precontemplation and contemplation in comparison to algorithms using shorter definitions, which tended to stage subjects in preparation and action. Maintenance was the most and preparation the least consistently described stage across algorithms. CONCLUSIONS: Alteration of the descriptions of stage and the definition of exercise has consequences for the staging of subjects. Definitions need to be explicit, stating all parameters needed to meet criterion, and subjects must be able to assess themselves. Either a 5-Choice or a true/false response format is effective in assessing stage.

Adult↗