Mediation analysis of decisional balance, sun avoidance and sunscreen use in the precontemplation and preparation stages for sun protection

Processes of Change for Colonoscopy: Limited Support for Use Among Navigated Latinos

This study assessed the role of the processes of change (POC), a construct of the transtheoretical model, in colorectal cancer (CRC) screening among Latinos. Latinos participate in CRC screening less often and are diagnosed with CRC at a later stage than whites. POC items were administered to 344 English- and Spanish-speaking Latinos at average risk for CRC who had not had a colonoscopy in the past 5 years and received a colonoscopy referral. POC were measured at three timepoints: following informed consent (T1) at time of referral, 2 weeks prior to scheduled colonoscopy (T2), and 1 month after scheduled colonoscopy (T3). Participants received patient navigation as part of a randomized controlled trial to promote screening colonoscopy. POC scores were examined for changes during the course of the intervention, and logistic regression models assessed the relationship between POC scores and CRC screening adherence. Total POC scores decreased between T1 and T2 (p = 0.03) but were unchanged between T1 and T3. CRC screening adherence was not significantly associated with POC scores or change in POC scores over time. The POC instrument was not found useful for predicting colonoscopy adherence among Latinos in conjunction with patient navigation. Total POC scores did not increase during a patient navigation intervention despite high colonoscopy completion rates.

Psychometric assessment of the processes of change scale for sun protection

The fourteen-factor Processes of Change Scale for Sun Protection assesses behavioral and experiential strategies that underlie the process of sun protection acquisition and maintenance. Variations of this measure have been used effectively in several randomized sun protection trials, both for evaluation and as a basis for intervention. However, there are no published studies, to date, that evaluate the psychometric properties of the scale. The present study evaluated factorial invariance and scale reliability in a national sample (N = 1360) of adults involved in a Transtheoretical model tailored intervention for exercise and sun protection, at baseline. Invariance testing ranged from least to most restrictive: Configural Invariance (constraints only factor structure and zero loadings); Pattern Identity Invariance (equal factor loadings across target groups); and Strong Factorial Invariance (equal factor loadings and measurement errors). Multi-sample structural equation modeling tested the invariance of the measurement model across seven subgroups: age, education, ethnicity, gender, race, skin tone, and Stage of Change for Sun Protection. Strong factorial invariance was found across all subgroups. Internal consistency coefficient Alpha and factor rho reliability, respectively, were .83 and .80 for behavioral processes, .91 and .89 for experiential processes, and .93 and .91 for the global scale. These results provide strong empirical evidence that the scale is consistent, has internal validity and can be used in research interventions with population-based adult samples.

Extending Theory-Based Quantitative Predictions to New Health Behaviors

BACKGROUND

Traditional null hypothesis significance testing suffers many limitations and is poorly adapted to theory testing.

PURPOSE

A proposed alternative approach, called Testing Theory-based Quantitative Predictions, uses effect size estimates and confidence intervals to directly test predictions based on theory.

METHOD

This paper replicates findings from previous smoking studies and extends the approach to diet and sun protection behaviors using baseline data from a Transtheoretical Model behavioral intervention (N = 5407). Effect size predictions were developed using two methods: (1) applying refined effect size estimates from previous smoking research or (2) using predictions developed by an expert panel.

RESULTS

Thirteen of 15 predictions were confirmed for smoking. For diet, 7 of 14 predictions were confirmed using smoking predictions and 6 of 16 using expert panel predictions. For sun protection, 3 of 11 predictions were confirmed using smoking predictions and 5 of 19 using expert panel predictions.

CONCLUSION

Expert panel predictions and smoking-based predictions poorly predicted effect sizes for diet and sun protection constructs. Future studies should aim to use previous empirical data to generate predictions whenever possible. The best results occur when there have been several iterations of predictions for a behavior, such as with smoking, demonstrating that expected values begin to converge on the population effect size. Overall, the study supports necessity in strengthening and revising theory with empirical data.

Transtheoretical Model Constructs' Longitudinal Prediction of Sun Protection Over 24 Months

PURPOSE

This research examined dynamic transtheoretical model (TTM) constructs for adopting sun protection practices. This secondary data analysis pooled four large population-based TTM-tailored intervention studies and examined use of constructs across three groups, organized by longitudinal progress: maintainers, relapsers, and stable non-changers.

METHODS

A total of 3463 adults, in the USA, who met criteria for unsafe sun exposure at baseline received a TTM-tailored computerized intervention at baseline, 6 months, and 12 months. The final analytic sample consisted of 1894 participants; the majority were female, White, married, and middle-aged. The three groups were assessed with reliable and valid scales assessing use of TTM constructs at baseline, 6 months, 12 months, and 24 months. Analyses included a MANOVA followed by a series of ANOVAs, with Tukey follow-up tests assessing differences in use of TTM constructs across the three groups at each timepoint.

RESULTS

Findings demonstrated that relapsers and maintainers were similar in their use of most TTM processes of change at baseline, with the exception of Consciousness Raising, Stimulus Control, Reinforcement Management, and Self-Liberation.

CONCLUSIONS

These findings suggest that although relapsers reverted to unsafe sun practices, their overall greater use of processes of change indicates that their change efforts remain better than that of stable non-changers.