Rebecca A. Ferrer

Efficacy of Exercise Interventions in Modulating Cancer-Related Fatigue among Adult Cancer Survivors: A Meta-Analysis

Background: The purpose of this meta-analysis was to explore the efficacy of exercise as a nonpharmacologic intervention to reduce cancer-related fatigue (CRF) among adult cancer survivors. We also investigated how different components of the exercise prescription (Ex Rx), methodologic considerations, and subject characteristics modulate CRF. Methods: A systematic search for randomized controlled trials was conducted using words related to cancer, exercise, and fatigue. Results: In total, 44 studies with 48 interventions qualified, including 3,254 participants of varying cancer types, stages of diagnosis, treatments, and exercise interventions. Cancer survivors in exercise interventions reduced their CRF levels to a greater extent than usual care controls, d+ = 0.31 (95% CI = 0.22–0.40), an effect that appeared to generalize across several types of cancer. CRF levels improved in direct proportion to the intensity of resistance exercise (β = 0.60, P = 0.01), a pattern that was stronger in higher quality studies (β = 0.23, P < 0.05). CRF levels also reduced to a greater extent when interventions were theoretically driven (β = 0.48, P < 0.001) or cancer survivors were older (β = 0.24, P = 0.04). Conclusions: Exercise reduced CRF especially in programs that involved moderate-intensity, resistance exercise among older cancer survivors and that were guided by theory. Impact: Our results indicate exercise interventions for adult cancer survivors should be multi-dimensional and individualized according to health outcome and cancer type. Cancer Epidemiol Biomarkers Prev; 20(1); 123–33. ©2011 AACR.

Exercise Interventions for Cancer Survivors: A Meta-Analysis of Quality of Life Outcomes

BackgroundExercise improves quality of life (QOL) in cancer survivors, although characteristics of efficacious exercise interventions for this population have not been identified.PurposeThe present meta-analysis examines the efficacy of exercise interventions in improving QOL in cancer survivors, as well as features that may moderate such effects.MethodStudies were identified and coded, and QOL effect sizes were calculated and analyzed for trends.ResultsOverall, exercise interventions increased QOL, but this tendency depended to some extent on exercise and patient features. Although several features were associated with effect sizes, models revealed that interventions were particularly successful if they targeted more intense aerobic exercise and addressed women. These tendencies emerged over longer periods of time and were more prominent in studies with higher methodological quality.ConclusionAppropriately designed exercise interventions enhance QOL for cancer survivors and this pattern is especially evident for women. Limitations are discussed.

The Efficacy of Exercise in Reducing Depressive Symptoms among Cancer Survivors: A Meta-Analysis

Introduction The purpose of this meta-analysis was to examine the efficacy of exercise to reduce depressive symptoms among cancer survivors. In addition, we examined the extent to which exercise dose and clinical characteristics of cancer survivors influence the relationship between exercise and reductions in depressive symptoms. Methods We conducted a systematic search identifying randomized controlled trials of exercise interventions among adult cancer survivors, examining depressive symptoms as an outcome. We calculated effect sizes for each study and performed weighted multiple regression moderator analysis. Results We identified 40 exercise interventions including 2,929 cancer survivors. Diverse groups of cancer survivors were examined in seven exercise interventions; breast cancer survivors were examined in 26; prostate cancer, leukemia, and lymphoma were examined in two; and colorectal cancer in one. Cancer survivors who completed an exercise intervention reduced depression more than controls, d + = −0.13 (95% CI: −0.26, −0.01). Increases in weekly volume of aerobic exercise reduced depressive symptoms in dose-response fashion (β = −0.24, p = 0.03), a pattern evident only in higher quality trials. Exercise reduced depressive symptoms most when exercise sessions were supervised (β = −0.26, p = 0.01) and when cancer survivors were between 47–62 yr (β = 0.27, p = 0.01). Conclusion Exercise training provides a small overall reduction in depressive symptoms among cancer survivors but one that increased in dose-response fashion with weekly volume of aerobic exercise in high quality trials. Depressive symptoms were reduced to the greatest degree among breast cancer survivors, among cancer survivors aged between 47–62 yr, or when exercise sessions were supervised.

Risk Perception Measures' Associations With Behavior Intentions, Affect, and Cognition Following Colon Cancer Screening Messages

OBJECTIVE Risk perception is important for motivating health behavior (e.g., Janz & Becker, 1984), but different measures of the construct may change how important that relationship appears. In two studies, we examined associations between four measures of risk perception, health behavior intentions and possible behavioral determinants. METHODS Participants in these studies, who were due for colorectal cancer screening, read an online message about the importance of screening to reduce the chance of cancer. We examined bivariate and multivariate associations between risk perception measures, including absolute, comparative, and feelings-of-risk, and behavioral intentions to screen, general worry, and knowledge and attitudes related to screening. RESULTS Results across the two studies were consistent, with all risk perception measures being correlated with intentions and attitudes. Multivariate analyses revealed that feelings-of-risk was most predictive of all variables, with the exception of general worry, for which comparative measures were the most predictive. CONCLUSIONS Researchers interested in risk perception should assess feelings-of-risk along with more traditional measures. Those interested in influencing health behavior specifically should attempt to increase feelings of vulnerability rather than numerical risk.

Worry and Risk Perceptions as Independent and Interacting Predictors of Health Protective Behaviors

Worry and risk perceptions are generally found to be independently associated with health-promoting behaviors, although it is unknown whether they interact in ways that potentially dampen the effect of either construct on behavior. In this hypothesis-generating study, cancer-related worry and risk perception, and their interaction, were used to predict odds of meeting 5-a-day fruit and vegetable consumption guidelines and engaging in any exercise using data from a nationally representative sample (N = 10,230). Risk perception was not associated with either behavior; worry was associated only with exercise (OR = 1.77, 95% CI: 1.16, 2.70, p < .01). More important, their interaction was associated with these behaviors in a counterintuitive manner; among those higher in worry, higher levels of risk perception were associated with lower vegetable consumption (OR = 0.79, 95% CI: 0.62, 1.00, p < .05) and exercise (OR = 0.77, 95% CI: 0.63, 0.95, p = .01). These results suggest the hypothesis that, among people high in worry, attempts to increase risk perception could be counterproductive. These and related findings suggest the importance of distinguishing worry from risk perception, and future research is necessary to determine the causal nature of these associations.

Association of cancer worry and perceived risk with doctor avoidance: an analysis of information avoidance in a nationally representative US sample

Fear of receiving bad news about one’s health can lead people to avoid seeking out health information that, ironically, may be crucial for health maintenance. Using a nationally representative US sample, the present study examined whether perceived likelihood of developing cancer and worry about cancer were associated with reports of avoiding visits to one’s doctor, in respondents under and over age 50. Cancer worry, but not perceived risk of cancer, predicted doctor avoidance in respondents aged 50 and older, whereas the opposite pattern held for respondents under age 50. Moreover, in respondents aged 50 and older, cancer worry and perceived cancer risk interacted such that cancer worry was linked to doctor avoidance only when respondents also perceived a high likelihood of cancer. The latter result is consistent with the notion that worry may motivate information seeking when people expect information to dispel worry and information avoidance when the information is seen as highly likely to confirm one’s fears. Findings suggest a need for communication strategies that can influence worry and perceived risk differentially. Research should also assess the effectiveness of other behavioral strategies (e.g., automatic scheduling of appointments) as a means for reducing doctor avoidance.

Physicians’ attitudes about communicating and managing scientific uncertainty differ by perceived ambiguity aversion of their patients

Background  Medical interventions are often characterized by substantial scientific uncertainty regarding their benefits and harms. Physicians must communicate to their patients as part of the process of shared decision making, yet they may not always communicate scientific uncertainty for several reasons. One suggested by past research is individual differences in physicians’ tolerance of uncertainty. Relatedly, an unexplored explanation is physicians’ beliefs about their patients’ tolerance of uncertainty.

Effects of Self-Affirmation on Implementation Intentions and the Moderating Role of Affect

Self-affirmation may offset defensiveness to threatening messages, increase intentions to engage in protective behaviors, and facilitate actual change. Relatively little is known about the conditions under which self-affirmation is most beneficial. The authors examined whether self-affirmation facilitates the forming of implementation intentions–plans to engage in specific steps that facilitate behavior change—and whether effects differ by affective state. Undergraduate female drinkers (N = 265) were self-affirmed or not prior to reading an article linking excessive alcohol consumption to breast cancer susceptibility. They then had the opportunity to report implementation intentions, by listing specific steps they planned to take to reduce consumption. Consistent with predictions, self-affirmation promoted formation of implementation intentions, an effect found only among individuals manifesting positive (as opposed to negative) affect following receipt of the message. Self-affirmation may facilitate behavior change by encouraging development of implementation intentions, an effect that is likely enhanced among those experiencing positive affect.

An affective booster moderates the effect of gain- and loss-framed messages on behavioral intentions for colorectal cancer screening

Previous research has demonstrated that loss-framed messages are more effective than gain-framed messages in motivating detection behaviors such as screening. The present study examined whether affective context moderates the degree to which message frame is associated with behavioral intentions to engage in colorectal cancer screening. In particular, we buttressed a framing manipulation with an “affective booster” to increase anticipated and anticipatory emotions associated with the framed messages. Consistent with previous research, we found that loss-framed messages are more effective in increasing intentions to screen. However, we found that among individuals who received gain-framed messages (but not loss-framed messages), the affective booster increased message persuasiveness. This effect on intentions was partially mediated by self-efficacy for engaging in screening. This study indicates that in the presence of emotional boosters, loss-framed messages may lose their advantage over gain-framed messages in motivating detection behaviors, and that self-efficacy may partially explain these effects.

Changing deliberative and affective responses to health risk: a meta-analysis

Perceptions of risk for health outcomes are integral to many theories of health behaviour, and are often targeted in interventions. Evidence suggests that affective responses to risk, including worry, are empirically distinguishable from commonly used perceived risk measures such as perceived susceptibility. The aims of this meta-analysis were to (1) examine if perceived susceptibility and worry can be independently influenced, and what manipulation types are most effective at changing each construct and (2) examine the efficacy of interventions to change worry and perceived susceptibility. Thirty-eight studies using 43 separate samples provided 78 independent comparisons that were meta-analysed using the inverse variance method with random-effects modelling. The overall effect size (d) was 0.50, 95% CI [0.362, 0.632] for perceived susceptibility; and 0.25, 95% CI [0.148, 0.349] for worry. Effect sizes for perceived susceptibility were significantly related to those for worry, B=0.495, p < 0.001. Moderators of these effects are discussed. The present meta-analysis provides further evidence that perceived susceptibility and worry are distinguishable but related constructs, and that it is possible to perturb one and not the other.