Biomedical subjects

Janet L Johnson

Publications and source records attributed to Janet L Johnson.

9 recordsLinked to original sources

PubMed2007

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↗

PubMed2007

Informing school sex education using the stages of change construct: sexual behaviour and attitudes towards sexual activity and condom use of children aged 13-16 in England.

A survey of 3820 school children in England aged 13-16 years examined sexual activity using the Transtheoretical Model (TTM) Stages of Change. A quarter (26%) of teens were sexually experienced, 44.8 per cent did not use contraception and 48.9 per cent did not use condoms, every time. Past history of condom and contraceptive use, and partner willingness to use condoms were the best predictors of being in Action or Maintenance stage for condom use. Of virgins, 19.82 per cent were in Contemplation or Preparation stages for intercourse, and 85.4 per cent would use condoms every time. Sex education should be tailored to Stage, and signposting to sexual health and contraception services.

Adolescent↗

PubMed2006

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↗

PubMed2006

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↗

PubMed2006

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↗

PubMed2006

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↗

PubMed2004

Size, consistency, and stability of stage effects for smoking cessation.

In the transtheoretical model (TTM), the stage effect is one of the most important determinants of health behavior change. Randomly assigned to 1 of 11 treatment conditions were 4653 smokers. A total of 66 stage effects were possible with 6 for each of the 11 treatment groups. The results suggest that brief stage-matched interventions that help populations progress one stage could produce 75% more abstinence. Interventions that help populations progress two stages could produce 300% more abstinence. The results also support the importance of replicating the stage effects across treatment conditions and over time.

Adult↗

PubMed2004

Assessing stage of change and informed decision making for Internet participation in health promotion and disease management.

The Internet is a potentially powerful source of low- or no-cost programs through which individuals can be guided in changing their behavior to improve health. Using the Transtheoretical Model and survey methodology, the authors sought to produce reliable and valid instruments for assessing "stage of change" and "informed decision making," and to generate cross-sectional and longitudinal stage-of-change data for a sample of Internet users, as they apply to Internet use for health promotion and disease management. They found that only 24.7% of their sample used the Internet for these purposes and concluded that considerably more research will be needed to determine how to help significant percentages of populations to progress toward enhancing their health through the Internet.

Adolescent↗

PubMedDate not supplied

Testing stage effects in an ethnically diverse sample.

The Transtheoretical Model (TTM) has been extensively validated in representative samples of adult smokers. Stage effects, i.e., the patterned relationships between Stage of Change (SOC) and other TTM variables, have been reported in a variety of samples. This study describes reliability data for the TTM variables and tests the stage effects with an ethnically diverse sample of 296 parents with young children. On the basis of theory and previous empirical evidence from a general population, it is possible to make quantitative predications about the magnitude of the expected effect sizes for the Decisional Balance, Situational Temptations, and Processes of Change subscales. For each variable, both a test of significance and a comparison with the expected effect sizes is reported. Results indicated significant stage differences for 8 of the 11 TTM subscales, and all quantitative predictions were confirmed. This study supports the use of TTM measures in an ethnically diverse sample.

Adult↗