Basics of qualitative research: Grounded theory procedures and techniques

The Theory of Planned Behaviour (TPB) has received considerable attention in the literature. The present study is a quantitative integration and review of that research. From a database of 185 independent studies published up to the end of 1997, the TPB accounted for 27% and 39% of the variance in behaviour and intention, respectively. The perceived behavioural control (PBC) construct accounted for significant amounts of variance in intention and behaviour, independent of theory of reasoned action variables. When behaviour measures were self-reports, the TPB accounted for 11% more of the variance in behaviour than when behaviour measures were objective or observed (R2s = .31 and .21, respectively). Attitude, subjective norm and PBC account for significantly more of the variance in individuals' desires than intentions or self-predictions, but intentions and self-predictions were better predictors of behaviour. The subjective norm construct is generally found to be a weak predictor of intentions. This is partly attributable to a combination of poor measurement and the need for expansion of the normative component. The discussion focuses on ways in which current TPB research can be taken forward in the light of the present review.

/pdf/efficacy-of-the-theory-of-planned-behaviour-a-meta-analytic-32gm69pazu.pdf

Efficacy of the Theory of Planned Behaviour: a meta-analytic review.

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

/pdf/quantity-and-quality-of-exercise-for-developing-and-1fohxlhqop.pdf

Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise

The primary purpose of this narrative review was to evaluate the current literature and to provide further insight into the role physical inactivity plays in the development of chronic disease and premature death. We confirm that there is irrefutable evidence of the effectiveness of regular physical activity in the primary and secondary prevention of several chronic diseases (e.g., cardiovascular disease, diabetes, cancer, hypertension, obesity, depression and osteoporosis) and premature death. We also reveal that the current Health Canada physical activity guidelines are sufficient to elicit health benefits, especially in previously sedentary people. There appears to be a linear relation between physical activity and health status, such that a further increase in physical activity and fitness will lead to additional improvements in health status.

/pdf/health-benefits-of-physical-activity-the-evidence-17tsp10zcy.pdf

Health benefits of physical activity: the evidence

Conceptual and methodological ambiguities surrounding the concept of perceived behavioral control are clarified. It is shown that perceived control over performance of a behavior, though comprised of separable components that reflect beliefs about self-efficacy and about controllability, can nevertheless be considered a unitary latent variable in a hierarchical factor model. It is further argued that there is no necessary correspondence between self-efficacy and internal control factors, or between controllability and external control factors. Self-efficacy and controllability can reflect internal as well as external factors and the extent to which they reflect one or the other is an empirical question. Finally, a case is made that measures of perceived behavioral control need to incorporate self-efficacy as well as controllability items that are carefully selected to ensure high internal consistency.

Summary and Conclusions
Perceived control over performance of a behavior can account for consider- able variance in intentions and actions. However, ambiguities surrounding the concept of perceived behavioral control have tended to create uncertainties and to impede progress. The present article attempted to clarify conceptual ambiguities and resolve issues related to the operationalization of perceived behavioral control. Recent research has demonstrated that the overarching concept of perceived behavioral control, as commonly assessed, is comprised of two components: self-efficacy (dealing largely with the ease or difficulty of performing a behavior) and controllability (the extent to which performance is up to the actor). Contrary to a widely accepted view, it was argued that self-efficacy expectations do not necessarily correspond to beliefs about internal control factors, and that controllability expectations have no necessary basis in the perceived operation of external factors. Instead, it was suggested that self-efficacy and controllability may both reflect beliefs about the presence of internal as well as external factors. Rather than making a priori assumptions about the internal or external locus of self-efficacy and controllability, this issue is best treated as an empirical question.

Also of theoretical significance, the present article tried to dispel the notion that self-efficacy and controllability are incompatible with, or independent of, each other. Although factor analyses of perceived behavioral control items provide clear and consistent evidence for the distinction, there is sufficient commonality between self-efficacy and controllability to suggest a two-level hierarchical model. In this model, perceived behavioral control is the overarching, superordinate construct that is comprised of two lower-level components: self-efficacy and controllability. This view of the control component in the theory of planned behavior implies that measures of perceived behavioral control should contain items that assess self-efficacy as well as controllability. Depending on the purpose of the investigation, a decision can be made to aggregate over all items, treating perceived behavioral control as a unitary factor, or to distinguish between self-efficacy and controllability by entering separate indices into the prediction equation.

Perceived Behavioral Control, Self-Efficacy, Locus of Control, and the Theory of Planned Behavior

Purpose: Exercise adherence is difficult during cancer treatments, but few studies have examined the predictors of such exercise. Here, we report the predictors of adherence to supervised exercise training during breast cancer chemotherapy.

Methods: Breast cancer patients (N = 242) initiating adjuvant chemotherapy in Edmonton, Ottawa, and Vancouver were randomly assigned to usual care (n = 82), supervised resistance exercise (n = 82), or supervised aerobic exercise (n = 78) for the duration of their chemotherapy. Baseline data on standard demographic, medical, behavioral, fitness, and psychosocial variables as well as motivational variables from the Theory of Planned Behavior were collected. Adherence was assessed by objective attendance records.

Results: Adherence to supervised exercise was 70.2%. Univariate analyses indicated significant or borderline significant associations between exercise adherence and location/center (r = 0.30; P < 0.001), V[spacing dot above]O2peak (r = 0.21; P = 0.008), muscular strength (r = 0.21; P = 0.008), percent body fat (r = -0.21; P = 0.012), disease stage (r = 0.17; P = 0.031), education (r = 0.15; P = 0.053), depression (r = -0.14; P = 0.073), and smoking (r = -0.14; P = 0.081). In multivariate analysis, location/center ([beta] = 0.28; P = 0.001), V[spacing dot above]O2peak ([beta] = 0.19; P = 0.016), disease stage ([beta] = 0.18; P = 0.015), and depression ([beta] = -0.16; P = 0.033) remained significant and explained 21% of the variance in exercise adherence. Participants in Vancouver, with higher aerobic fitness, more advanced disease stage, and lower depression, achieved better adherence.

Conclusion: Adherence to supervised exercise training was predicted by unique aspects of the location/center, disease stage, aerobic fitness, and depression but not motivational variables. Location/center in our trial may have been a proxy for the amount of one-on-one attention received during supervised exercise. These findings may have implications for improving adherence during breast cancer chemotherapy

Predictors of supervised exercise adherence during breast cancer chemotherapy

A comprehensive review of the recent literature reveals that exercise has a positive effect on a broad range of quality-of-life parameters after patients are diagnosed as having cancer. The general exercise prescription is moderate-intensity exercise, 3 to 5 days per week, 20 to 30 minutes per session. Conditions that warrant prescription modification include fatigue periods during treatment, acute or chronic physical impairments that may have resulted from surgery or adjuvant therapy, and the presence of bone cancer. Research suggests that physicians who prescribe exercise improve motivation and adherence in their patients who have cancer.

Coping with cancer: can exercise help?

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.

/pdf/case-control-study-of-lifetime-physical-activity-and-breast-54ze7d5q9o.pdf

Case-Control Study of Lifetime Physical Activity and Breast Cancer Risk

Recent research has applied the theory of planned behavior (TPB) to understanding exercise after a cancer diagnosis, but studies are few and have been limited by retrospective designs, self-report measures of exercise and varied results. In the present study, we extended this research by using a prospective design and an objective measure of exercise adherence. Participants were a convenience sample of 24 breast cancer survivors attending a twice weekly, 12-week training program in preparation for a dragon boat race competition. Participants completed a baseline questionnaire that assessed demographic and medical variables, past exercise, and the TPB (i.e. beliefs, subjective norm, attitude, perceived behavioral control and intention). Program attendance was monitored over a 12-week period by the class instructor. Overall, participants attended 66% of the training sessions. Multiple regression analyses indicated that: (a) intention was the sole determinant of program attendance and explained 35% of the variance; (b) the TPB constructs explained 49% of the variance in intention with subjective norm being the most important determinant; and (c) the key underlying beliefs were support from physician, spouse, and friends, and confidence in being able to attend the training class when having limited time, no one to exercise with, fatigue, and other health problems. Based on this preliminary study, it was concluded that the TPB may provide a good framework on which to base interventions designed to promote exercise in breast cancer survivors.

Exercise adherence in breast cancer survivors training for a dragon boat race competition: a preliminary investigation.

More than 1.2 million Americans are diagnosed with cancer each year, and many receive intensive medical treatments. Currently, exercise is not considered a standard quality-of -life intervention for cancer patients. In this article, 11 studies are reviewed that have examined exercise interventions concurrent with cancer treatment. The key conclusion is that exercise improves a wide range of biopsychosocial outcomes in cancer patients, but much more reserch is needed.

Kerry S. Courneya

Papers

Predictors of supervised exercise adherence during breast cancer chemotherapy

Coping with cancer: can exercise help?

Case-Control Study of Lifetime Physical Activity and Breast Cancer Risk

Exercise adherence in breast cancer survivors training for a dragon boat race competition: a preliminary investigation.

Exercise interventions during cancer treatment: biopsychosocial outcomes.