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Biomedical subjects

James O Prochaska

Publications and source records attributed to James O Prochaska.

At least 19 recordsLinked to original sources

Efficacy and effectiveness trials: examples from smoking cessation and bullying prevention.

If health psychology is to maximize impacts on health, there will need to be a shift from relying primarily on efficacy trials to increasing reliance on effectiveness trials. Efficacy trials use homogeneous, highly motivated samples with minimal complications from a single setting receiving intensive treatments delivered under highly controlled conditions. Two effectiveness trials on bullying prevention illustrate the use of a heterogeneous population from multiple sites receiving a low intensity tailored treatment delivered under highly variable conditions. In spite of considerable noise the effectiveness trials produced robust results (odds ratios of about four) that bode well for population impacts under real-world dissemination.

Adolescent↗

Computer expert systems for African-American smokers in physicians offices: a feasibility study.

BACKGROUND: Stage-based computer expert systems (CES), delivered in physician offices, may offer unique opportunities to combine high participation and high efficacy, resulting in a high public health impact. Applying this technology in settings serving low-income African-American smokers, with the addition of practical tools for stress reduction, may help to reduce disparities in morbidity and mortality from smoking-related diseases. METHODS: Ninety-eight African-American smokers were recruited from a publicly funded, continuity care clinic waiting room to a study of computer interactive feedback and stress reduction audiotapes. The study was designed to assess: participation and retention rates; acceptability of both the computer expert system and the audiotapes; the fit of the transtheoretical model for the target population; and the 6-month shift in stages of change. RESULTS: Overall, 55.6% of invited smokers participated, 75.5% were seen at all three observation points. The CES and the audiotape were rated as highly interesting, relevant, and new, and most participants tried them. The predictable relationship between stage and decisional balance was reproduced in this low income African-American population. Significant stage progression occurred from baseline to 3 months (P = 0.011), from 3 to 6 months (P = 0.0001), and from baseline to 6 months (P = 0.0001). CONCLUSIONS: These data support the feasibility, acceptability and potential efficacy of stage-tailored computer interactive feedback plus stress reduction intervention delivered at the point of service to low-income African-Americans.

Black or African American↗

Identifying cluster subtypes for the prevention of adolescent smoking acquisition.

School-based smoking prevention programs are typically identical for all students. Tailoring prevention materials to focus on individual needs with an emphasis on students at highest risk is a promising alternative. Recent prevention programs have tailored materials based on the Stages of Acquisition, an extension of the Stages of Change used to tailor smoking cessation materials effectively for adults. Three stages of acquisition have been identified: Acquisition Precontemplation (aPC), Acquisition Contemplation (aC) and Acquisition Preparation (aPR). However, about 90% of nonsmoking adolescents classify themselves in the aPC stage. A cluster analysis was performed, using the Decisional Balance and Situational Temptations scales, for three random subsamples of adolescents within the aPC stage (N(1)=N(2)=N(3)=514). Four distinct subtypes were identified in each subsample: High Risk, Protected, Ambivalent, and Risk Denial. External validity was established using family support for nonsmoking, peer variables, and stage classification at follow-up assessment (12, 24, and 36 months). Family support for nonsmoking was related to subtype much more strongly than peer interactions. Subjects in the Protected subgroup were the most likely to remain in the aPC stage at each follow-up assessment. Subtype membership, along with membership in the aC and aPR stages, provides important additional information for tailoring smoking prevention materials. Tailored interventions can focus on those adolescents at highest risk and limit or avoid expending resources on those at very low risk.

Adolescent↗

Prevention profiles: Understanding youth who do not use substances.

This study replicates innovative profiles of prevention among students not using substances but who may be at different risks for acquisition. Using the Transtheoretical Model constructs of Decisional Balance and Temptations, cluster analyses were performed on four independent samples of students (n=1240) in the USA, England and Israel. For each sample, the same four distinct profiles emerged. ANOVAs indicated that the processes of prevention varied significantly across these profiles. The prevention profiles were extended to youth in Elementary, Middle, and High Schools and from a focus on single substances to multiple substances, including alcohol, tobacco, and illicit drugs. Implications for developing prevention programs are also discussed.

Adolescent↗

Psychometric evaluation of the smoking cessation Processes of Change scale in an adolescent sample.

The Processes of Change are the cognitions, behaviors, and emotions that people employ to change their behaviors. However, the processes of change remain the least studied dimension of the transtheoretical model. The present study presents a psychometric evaluation of the short form of the processes of change inventory for smoking cessation in an adolescent sample of 798 ninth-grade smokers from 22 Rhode Island high schools. The majority of the sample was white (87.2%), split approximately evenly as regards to gender (48.1% female), with an average age of 14.3 (SD=0.6) years of age. The same hierarchical model established on the adult sample was fit to the 20-item inventory. This model included 10 primary factors representing the processes of change and two second order factors that grouped the processes into five behavioral and five experiential processes of change. Model fit indices (RMSEA=0.08, CFI=0.92) supported the hypothesized structure. External validation was established by testing for stage differences in the use of the ten processes. A significant MANOVA (F(4,793)=18.517, p<0.001) and separate ANOVAs demonstrated that the use of all ten processes increased across the stages, as predicted by the transtheoretical model of behavior change. The processes of change help guide researchers, clinicians, and intervention program developers towards effective strategies to assist individuals at all stages of change progress towards healthier behaviors.

Adolescent↗

Evaluating nicotine replacement therapy and stage-based therapies in a population-based effectiveness trial.

Pharmacological interventions for smoking cessation are typically evaluated using volunteer samples (efficacy trials) but should also be evaluated in population-based trials (effectiveness trials). Nicotine replacement therapy (NRT) alone and in combination with behavioral interventions was evaluated on a population of smokers from a New England Veterans Affairs Medical Center. Telephone interviews were completed with 3,239 smokers, and 2,054 agreed to participate (64%). Participants were randomly assigned to one of four conditions: stage-matched manuals (MAN); NRT plus manuals (NRT + MAN); expert system plus NRT and manuals (EXP + NRT + MAN); and automated counseling plus NRT, manuals, and expert system (TEL + EXP + NRT + MAN). Assessments were completed at baseline, 10, 20, and 30 months. The point prevalence cessation rates at final follow-up (30 months) were MAN, 20.3%; NRT + MAN, 19.3%; EXP + NRT + MAN, 17.6%; and TEL + EXP + NRT + MAN, 19.9%. Stage-matched manuals provided cessation rates comparable with previous studies. The addition of NRT, expert system interventions, and automated telephone counseling failed to produce a further increase in intervention effectiveness.

Adult↗

Comparing intervention outcomes in smokers treated for single versus multiple behavioral risks.

This study examined treatment outcomes among smokers with single versus multiple behavioral risks. Data were drawn from smokers (N = 2,326) participating in 3 population-based, multibehavioral studies targeting cigarette smoking, high-fat diets, and high-risk sun exposure. Outcomes were compared for participants at risk for smoking only (13%), smoking plus 1 additional risk factor (37%), and smoking plus 2 additional risk factors (50%). The smoking only group tended to be female, older, more educated, lighter smokers, in the preparation stage of change for smoking, with more previous quit attempts and longer periods of abstinence. At 12 and 24 months follow-up, treatment of 1 or 2 coexisting risk factors did not decrease the effectiveness of smoking cessation treatment, and treatment for the coexisting factors was effective.

Adult↗

A randomized clinical trial of a population- and transtheoretical model-based stress-management intervention.

Stress has been associated with a variety of chronic and acute conditions and with higher use of health care services. This research reports on 18-month outcomes of a randomized clinical trial of a stress-management program based on the transtheoretical model (TTM; J. O. Prochaska & C. C. DiClemente, 1986). A national sample of 1,085 individuals participated (age range = 18-91 years, M = 55.33; 68.9% female, 31.1% male; 84.8% Caucasian; 15.2% non-Caucasian). Both the treatment and control groups received assessments at 0, 6, 12, and 18 months. In addition to the assessments, the treatment group received 3 individualized reports (0, 3, 6 months) and a manual. The 18-month assessment was completed by 778 individuals (72%). A random effects model indicated that participants completing the study in the treatment group had significantly more individuals reporting effective stress management at follow-up time points than did completers in the control group. Results also indicate that the intervention had significant effects on stress, depression, and specific stress-management behaviors. Results provide evidence for the effectiveness of this TTM population-based stress-management intervention.

Adolescent↗

Tailored communications for smoking cessation: past successes and future directions.

Tailored communications are one of the most promising approaches to smoking cessation interventions for entire populations. Assessments based on the Transtheoretical Model are processed by computer-based expert systems that generate feedback reports tailored to each individual to accelerate their progress through the stages of change for smoking cessation. Seven studies are reviewed that range from a more traditional clinical trial to trials on entire populations of smokers to population trials designed to change multiple behaviours, including smoking. A series of three tailored communications was found to produce long-term point prevalence abstinence rates within the narrow range of 22-26% abstinence. This same range of abstinence was found even when two or three other behaviours (e.g. diet and sun protection) were treated in the population. These results point to a future in which health behaviour risk interventions will be assessed not solely by their efficacy but by their population impact.

Behavior Therapy↗

Transtheoretical model intervention for adherence to lipid-lowering drugs.

An estimated 60% of individuals prescribed lipid-lowering medications are nonadherent. Failure to adhere increases morbidity, mortality, healthcare utilization, and healthcare costs. This study examined the effectiveness of a population-based, individualized Transtheoretical Model (TTM) expert system intervention to improve adherence and increase exercise and diet in a randomized 18-month trial involving 404 adults. Compared to usual care, treatment participants who started in a pre-action stage were significantly more likely to be in the Action and Maintenance (A/M) stages for adherence at end of treatment (55.3% versus 40%, z = 2.11, p < 0.05, h = 0.31) and at 18-months (56% versus 37.8%, z = 2.38, p < 0.01, h = 0.36). The treatment group scored significantly better on two measures of adherence at six and 12 months post-treatment (all p < 0.05, odds ratios [OR] 1.49-3.67). Among those who began in A/M, treatment participants were significantly more likely to remain in A/M at 18 months (85.2% versus 55.6%, z = 2.63, p < 0.01, h = 0.67). Those receiving treatment were significantly more likely to progress to A/M for exercise and dietary fat reduction (43.3% versus 24.7% for exercise, and 24.7% versus 12.5% for diet). TTM expert system interventions can have a significant impact on entire populations for adherence. Results for dietary fat and exercise suggest covariation of treatment effects.

Adult↗

Efficacy of a transtheoretical model-based expert system for antihypertensive adherence.

Blood pressure is not controlled in as many as 50%-75% of hypertensive patients, primarily because of inadequate adherence to treatment. This paper examines the efficacy of a Transtheoretical Model (TTM)-based expert system intervention designed to improve adherence with antihypertensives in a sample of 1,227 adults. Participants were proactively recruited and randomly assigned to receive usual care or three individualized expert system reports and a stage-matched manual over 6 months. Participants were surveyed at baseline, and 6, 12, and 18 months. Significantly more of the intervention group participants reported being in Action and Maintenance at follow-up time points (ie, 73.1% of the treatment group versus 57.6% of the control group at 12 months and 69.1% of the treatment group versus 59.2% of the control group at 18 months). Scores on a behavioral measure of nonadherence differed significantly at follow-up time points. TTM-based expert system interventions have the potential for a significant impact on entire populations of individuals who fail to adhere, regardless of their readiness to change.

Adult↗

Stage of change for making an informed decision about Medicare health plans.

OBJECTIVE: To assess the applicability of the transtheoretical model of change (TTM) to informed choice in the Medicare population. DATA SOURCES/STUDY SETTING: Two hundred and thirty-nine new Medicare enrollees randomly selected from the Center for Medicare and Medicaid Services' October 2001 Initial Enrollee File, a repository of data for persons who are going to turn 65 and become entitled to enroll in Medicare in the next 3 months. STUDY DESIGN: Study participants completed TTM measures of stage of change, decisional balance, and self-efficacy for informed choice, as well as measures of Medicare knowledge, perceived knowledge, and information seeking. Model testing was conducted to determine whether well-established relationships between stage of change, decisional balance, and self-efficacy replicate for informed choice in the Medicare population, and whether Medicare knowledge and information-seeking increase across the stages. DATA COLLECTION/EXTRACTION METHODS: Survey data were collected using mail surveys with telephone follow-up for nonresponders. PRINCIPAL FINDINGS: Predicted relationships were established between stage of change for informed choice and decisional balance, self-efficacy, Medicare knowledge, and information seeking. The amount of variance accounted for by stage of change for informed choice was larger than that found for smoking cessation, where the TTM has had its greatest successes. CONCLUSIONS: The methods and findings lay the groundwork for development of TTM-based interventions for Medicare beneficiaries, and provide a prototype for the application of the TTM to informed decision making among other types of consumers who are being asked to take more responsibility for their health care.

Female↗

Acceptability of a school-based intervention for the prevention of adolescent obesity.

This article describes the development and pilot testing of a computer-based, multiple-behavior obesity prevention program for adolescents. Using the Transtheoretical Model as a framework, this intervention offers individualized feedback based on readiness to engage in physical activity, to consume fruits and vegetables, and to limit television viewing. Focus groups and interviews with students, teachers, school administrators, and experts guided the development. Forty-five students participated in a baseline intervention session and completed a 16-item acceptability measure. Ratings were positive, with item means ranging from 3.60-4.75 on a 5-point scale. Student responses to open-ended questions aided in the enhancement of the intervention, for which an effectiveness trial begins in September 2006. This formative work demonstrated the acceptability of this school-based intervention approach, which can be promoted and prescribed by school nurses. Further, if found effective, it can be disseminated as an efficient, low-cost, population-based approach designed to address the epidemic of obesity.

Adolescent↗

Replication of subtypes for smoking cessation within the precontemplation stage of change.

The Transtheoretical Model constructs have been used in the development of effective tailored interventions for smoking cessation. Recent studies have suggested the existence of clusters within each stage of change, based on measures of the Pros, Cons and the Situational Temptations. The goal of this study is to replicate cluster subtypes within the Precontemplation stage of change in a secondary analysis of data from a sample of current smokers (N=3967). Four random samples ranging from 312 to 400 participants were selected from the Precontemplators subgroup. The cluster analyses were performed using Ward's Method on the standard scores from the three scales. Interpretability of the pattern, pseudo F test, and dendograms were used to determine the number of clusters. Four cluster subtypes were found and replicated across samples. The ten processes of change and two smoking behavior variables were used in the external validation of clusters. Statistically significant multivariate effects were found for the processes of change (p<.05) and the smoking behavior variables (p<.001) in all samples. The cluster patterns closely replicate earlier findings and provide evidence for the existence of clusters subtypes within the Precontemplation stage of change.

Adaptation, Psychological↗

Online health behavior and disease management programs: are we ready for them? Are they ready for us?

Advancing the science and practice of health promotion and disease management on the Internet requires a systematic program of research examining the population impact of such programs. With impact described as the combination of effectiveness and participation, such research needs to include the examination of the quality and effectiveness of programs that are available to the general public, as well as descriptive and predictive knowledge about population readiness to participate in such programs. There have been few studies examining the quality of interactive health behavior change (HBC) programs on the Internet, and even fewer investigations of the effectiveness of such programs. Based on the review of over 300 HBC programs on the Internet using the "5 A's" of Health Behavior Change on the Internet (HBC-I Screener), which represent standard minimum guidelines for evaluation, it appears HBC on the Internet is in the early stages of development. As health behavior change on the Internet matures from the provision of health information to meeting the requirements necessary to produce health behavior change, and as program developers take advantage of the interactive nature of the Internet, the basic screening and expanded evaluation criteria developed in this project will provide templates for both consumers and developers of programs. The second component necessary for evaluating the impact of HBC on the Internet is the extent to which the population is ready to participate in such programs. We need to move beyond a narrow focus on early adopters and produce a population perspective that includes those not ready, those getting ready, and those ready to use such programs, as well as those already participating. By understanding participation levels of such programs, and what drives this participation, the development and dissemination of practical tailored and targeted interventions can help maximize population participation in Internet programs for health behavior change.

Attitude to Health↗

Replication of subtypes for smoking cessation within the Preparation stage of change.

OBJECTIVE: Recent cluster analyses based on the Pros and Cons and the Situational Temptations measures performed within the stages of change defined by the Transtheoretical Model have suggested the existence of distinct cluster subtypes. The goal of this study is to replicate cluster subtypes within the Preparation stage of change in a secondary analysis of data from a sample of current smokers (N=3967). Identification of stable cluster subtypes would permit the development of tailored interventions focusing on these subtypes. METHOD: Two random samples of approximately 340 subjects were selected from the 686 participants in the Preparation stage. The cluster analyses were performed using the Pros, Cons and Situational Temptations. Interpretability of the pattern, pseudo F test, and dendograms were used to determine the number of clusters. RESULTS: Four distinct cluster subtypes (Classic, Progressing, Early Preparation, and Disengaged) were found and replicated across samples. The clusters were externally validated using the ten processes of change and two smoking behavior variables. Statistically significant (p<0.05) multivariate effects were found for the ten processes of change and the smoking behavior variables (p<0.001) in the two samples. CONCLUSIONS: The cluster patterns replicate earlier findings and provide evidence for the existence of clusters subtypes within the Preparation stage of change.

Adaptation, Psychological↗