Exercise as it relates to Disease/Can the protection motivation theory help predict exercise behaviours? Exploring the notion in patients with coronary artery disease

This page is critiquing the article “Predicting short and long-term exercise intensions and behaviour in patients with coronary artery disease: A test of protection motivation theory".

Basic Information
The article produced by Tulloch and colleagues explores the relationship between Protection Motivation Theory (PMT) and exercise intentions of patients with Coronary Artery Disease (CAD) (n=787). PMT draws a focus on cognitive factors that influence self-protection and coping mechanisms when dealing with harmful events. Following hospitalisation for CAD, patients completed a questionnaire measuring PMT’s threat and coping appraisal constructs in addition to exercise intensions and exercise behaviour. The results showed the PMT factors of self-efficacy, response efficacy and perceived severity, predicted exercise activity at the 6-month mark but was not reliable at predicting exercise at the twelve-month mark.

Context, Need and Real World Importance
Previous exercise behaviour research has lacked the use of strong exercise behaviour theories and the measurement problems associated with these theories are not well addressed. This has resulted in weak explanations of the relationships between disease and exercise behaviour. This study addresses this issue by allowing for PMT variables to be compared against exercise over short and long periods of time.

The current research exploring theoretical frameworks has been successful in identifying important and adjustable exercise determinants, however the research fails to explore these relationships in patients with CAD. This research addresses this research gap.

Improving exercise behaviours reduces the risks associated with CAD as exercise helps to manage risk factors. For example by decreasing blood pressure, decreasing inflammation, controlling body weight and reducing psychosocial stress. In addition to this, by addressing PMT factors, individuals that need assistance in exercise motivation and maintenance can be identified, thus decreasing their likelihood of CAD complications and reoccurrence.

Where is this research from?
This article has been produced by Heather Tulloch and her colleagues from the University of Ottawa Heart Institute Canada and the Centre for Health Promotion Studies University of Alberta, Canada. Published in March 2009 by Psychology and Health, as of September 2018 the article has 432 recorded views. Tulloch is a Clinical, Health and Rehabilitation Psychologist known for her research in exercise behaviour and has regularly published work in health psychology since 2013. Her colleague Robert Reid is a Professor of Medicine and leads research in cardiovascular health and disease management programs. Both Tulloch and Reid are considered leaders in their fields, have many sound published works and continue to conduct research in health.

What kind of research is this?
This research is a cohort study comparing survey results of PMT factors with exercise behaviour over time. The study follows a non-experimental design to test the reliability of PMT factors to predict exercise. Since this is a non-experimental design it lacks control and is based off self-reported data, thus the results that are produced are retrospective. The benefits of the study design allow the researchers to access a large amount of data from a large sample size over a long period of time. A major flaw in the design is the lack of a control group and a paired-case study would increase validity.

What did the research involve?
Participants (N = 787) were recruited from the tracking exercise after cardiac hospitalisation (TEACH) study by Reid and Colleagues (2006) which explored predictors of exercise in patients with CAD. The authors took parts of the TEACH questionnaire study in order to measure cardiovascular medical history as well as four appraisal/exercise measures including; threat appraisal, coping appraisal, exercise intensions and exercise behaviour.

Threat and Coping Appraisal
Threat appraisal measures accounted for perceived severity and vulnerability and were measured at baseline, two- and six-months post hospitalisation. Perceived severity was measured by asking about directly about the severity of the patient’s CAD and vulnerability was measured by asking about perceived future troubles relating to their heart problems. Coping appraisal explored measures of self-efficacy by asking about confidence to engage in exercise and response-efficacy was assessed by asking about perceived effectiveness of regular exercise. All responses were answered using a scale from one (defiantly not) to seven (definitely yes). Only one question was asked for each perceived severity and perceived vulnerability due to the taxing length of the TEACH questionnaire. To improve the reliability of these responses multiple indicators should have been used.

Exercise Intentions and Behaviour
Exercise behaviour measures were taken at baseline, six- and twelve-months post-hospitalisation. Exercise intentions were assessed with three items on the TEACH questionnaire involving their plans to exercise over the next month, 6 months and the frequency of which they planned to exercise. Again, this was measured on the same 1-7 scale as the above measures. According to the study results the three items demonstrated high internal consistency. Similar to the above measures, asking more questions with multiple indicator would have strengthened these measures. Exercise behaviour was measured using Godin leisure-time exercise0 questionnaire. The GLETQ measure has been shown by Jacobs and Colleagues (1993) to have good test-retest reliability and correlated with objective measures such as accelerometers and VO2 max.

What were the basic results?
The study showed that PMT was successful in predicting exercise behaviour in a large sample (n = 787) of patients with CAD over a short-term period (6 months) and was unsuccessful at predicting these same behaviours over a long-term period (12 months).

In the short-term model, PMT variables accounted for 23% of the variance in exercise intensions as coping appraisal constructs (self-efficacy and response efficacy) were strong predictors of exercise intensions. Threat appraisal (perceived severity and vulnerability) also had a smaller yet still significant impact. The PMT variables accounted for 20% of variance in exercise behaviour as intensions to exercise was the strongest indicator followed by self-efficacy. These results align well with previous research in cardiac populations. Whilst these results are strong, the use of a singular indicator (one question per construct) rather than multiple measures for each construct should be taken into consideration.

The long-term model showed mixed results between PMT and exercise. Suggesting that self-efficacy, response-efficacy and intentions play a role in exercise behaviour, but previous exercise and perceived exercise satisfaction are a stronger predictor of exercise behaviour. This is similar to work by Rothman (2000). Previous research argues that self-determined motivation (i.e. intrinsic motivation) is essential for the preservation of long-term behaviour and unfortunately this study lacks this measure.

What conclusions can we take from this research?
Overall, this study provides strong evidence that PMT factors can successfully predict exercise behaviour in patients with CAD over a six-month period. The importance for this study is relevant as predicting exercise behaviours can improve health for patients with CAD and patients with flagged PMT variables can prompted to gain further exercise assistance. The PMT factors or self-efficacy, response efficacy and previous exercise behaviour are the best predictors of exercise behaviour. The study did not support this prediction over a 12-month period. This research highlights that perceived vulnerability and intensions are not significant predictors of exercise behaviour and this knowledge can be used by health professionals to effectively motivate patients to exercise. These results align well with similar research in the field however the indicators used to measure PMT variables could be strengthen for future research.

Practical Advice
The results from this study demonstrate that positive coping messages and mechanisms should be used in health education to improve patient’s confidence regarding exercise and education should attempt to strengthen their belief that exercise provides health benefits as well as providing realistic information about the severity and complications of CAD. Since this study shows that an increase in threat perception will not necessarily improve health promoting behaviours, scare tactics in health promotion are not successful in this population and should be avoided.

Further Readings

 * Coronary Artery Disease from the Australian Heart Foundation.
 * Exercise Prescription for Patients with Coronary Artery Disease from the American College of Cardiology.
 * Meta-analyses of PMT studies addressing multiple health protective behaviours by Floyd, Prentice-Dunn & Rogers (2000).