Although risk perception is a key concept in many health behavior theories, little research has explicitly tested when risk perception predicts motivation to take protective action against a health threat (protection motivation). The present study tackled this question by (a) adopting a multidimensional model of risk perception that comprises deliberative, affective, and experiential components (the TRIRISK model), and (b) taking a person-by-situation approach. We leveraged a highly intensive within-subjects paradigm to test features of the health threat (i.e., perceived severity) and individual differences (e.g., emotion reappraisal) as moderators of the relationship between the three types of risk perception and protection motivation in a within-subjects design. Multi-level modeling of 2968 observations (32 health threats across 94 participants) showed interactions among the TRIRISK components and moderation both by person-level and situational factors. For instance, affective risk perception better predicted protection motivation when deliberative risk perception was high, when the threat was less severe, and among participants who engage less in emotional reappraisal. These findings support the TRIRISK model and offer new insights into when risk perceptions predict protection motivation.

Objective: We conducted a meta-analysis of randomized controlled trials (RCTs) to promote health behavior change based on self-determination theory (SDT). The review aimed to (a) quantify the impact of SDT interventions on health behaviors, (b) test mediation by theoretically specified variables (autonomous motivation and perceived competence), and (c) identify moderators of intervention effectiveness. Method: Computerized searches and additional strategies identified 56 articles that yielded 65 independent tests of SDT interventions. Random effects meta-analysis and metaregressions were conducted via STATA; meta-analytic structural equation modeling (MASEM) was used to test mediation. Results: The sample-weighted average effect size for SDT interventions was d ϩ ϭ .23, and there were significant effects for physical activity, sedentary behavior, diet, alcohol consumption, and smoking cessation (.16 Ն d ϩ Ն .29). Effect sizes exhibited both publication bias and small sample bias but remained significantly different from zero, albeit of smaller magnitude, after correction for bias (d ϩ Ն .15). MASEM indicated that autonomous motivation and perceived competence mediated intervention effects on behavior. Metaregression analyses indicated that features of the sample, intervention, or methodology generally did not moderate effect sizes. Conclusion: The present review indicates that SDT interventions have a significant but small effect on health behavior change and suggests several directions for future research. What is the public health significance of this article?This review examines the efficacy of health behavior interventions based on self-determination theory. Findings indicate that interventions have a significant but small effect on behavior change.

Promoting physical activity among cancer survivors: meta analysis and metacart analysis of randomized controlled trials Article (Accepted Version) (2019) Promoting physical activity among cancer survivors: meta-analysis and meta-cart analysis of randomized controlled trials. Health Psychology.We thank Jennifer Walker and Rachael Posey (Medical Librarians) for invaluable assistance with the computerized literature searches. AbstractObjective: We conducted a meta-analysis of physical activity interventions among cancer survivors in order to (a) quantify the magnitude of intervention effects on physical activity, and (b) determine what combination of intervention strategies maximizes behavior change.Methods: Out of 32,626 records that were located using computerized searches, 138 independent tests (N = 13,050) met the inclusion criteria for the review. We developed a bespoke taxonomy of 34 categories of techniques designed to promote psychological change, and categorized sample, intervention, and methodological characteristics. Random effects meta-analysis and meta-regressions were conducted; effect size data were also submitted to Meta-CART analysis. Results: The sample-weighted average effect size for physical activity interventions was d+ = .35, equivalent to an increase of 1,149 steps per day. Effect sizes exhibited both publication bias and small sample bias but remained significantly different from zero, albeit of smaller magnitude (d+ ≥ .20), after correction for bias. Meta-CART analysis indicated that the major difference in effectiveness was attributable to supervised versus unsupervised programs (d+ = .49 vs. .26). Greater contact time was associated with larger effects in supervised programs. For unsupervised programs, establishing outcome expectations, greater contact time, and targeting overweight or sedentary participants each predicted greater program effectiveness, whereas prompting barrier identification and providing workbooks were associated with smaller effect sizes. Conclusion: The present review indicates that interventions have a small but significant effect on physical activity among cancer survivors, and offers insights into how the effectiveness of future interventions might be improved.

Situation selection involves choosing situations based on their likely emotional impact and may be less cognitively taxing or challenging to implement compared to other strategies for regulating emotion, which require people to regulate their emotions "in the moment"; we thus predicted that individuals who chronically experience intense emotions or who are not particularly competent at employing other emotion regulation strategies would be especially likely to benefit from situation selection. Consistent with this idea, we found that the use of situation selection interacted with individual differences in emotional reactivity and competence at emotion regulation to predict emotional outcomes in both a correlational (Study 1; N = 301) and an experimental field study (Study 2; N = 125). Taken together, the findings suggest that situation selection is an effective strategy for regulating emotions, especially for individuals who otherwise struggle to do so.

Objective: We conducted meta-analyses and meta-analytic structural equation modeling of longitudinal studies among cancer survivors to (a) quantify associations between psychosocial predictors and physical activity, (b) test how psychosocial predictors combine to influence physical activity, and (c) identify study, demographic, and clinical characteristics that moderate associations. Method: Eligible studies used a longitudinal, observational design, included a sample of cancer survivors, and measured both a psychosocial predictor at baseline and physical activity at a later time-point. Of 2,431 records located through computerized searches, 25 independent tests (N ϭ 5,897) met the inclusion criteria for the review. Random effects meta-analyses and meta-analytic structural equation modeling were conducted. Results: Eight psychosocial predictors of physical activity were identified. Self-efficacy (r ϩ ϭ 0.26) and intentions (r ϩ ϭ 0.33) were the strongest predictors in bivariate analyses. The structural equation models included attitudes, injunctive norms, self-efficacy, intentions, and physical activity (k ϭ 22, N ϭ 4,385). The model with the best fit, 2 (2) ϭ 0.11, p ϭ .95, root mean square error of approximation ϭ .00, comparative fit index ϭ 1.00, Tucker-Lewis index ϭ 1.00, indicated that all specified paths were significant. Intentions were the strongest predictor of physical activity (␤ ϭ 0.27, p Ͻ .001), and attitudes and self-efficacy were strong predictors of intentions (both ␤s ϭ 0.29, ps Ͻ .001). Few significant moderators were observed. Conclusion: This review indicates that self-efficacy and intentions are direct predictors of physical activity in cancer survivors. Further, attitudes and norms predict physical activity through intentions. Findings inform intervention development to increase physical activity engagement among cancer survivors.