Recruitment and Intervention
A quasi-experimental study of patients with documented coronary artery disease and identified cardiac risk factors was carried out with ethics approval in a routine clinical practice setting at the Department of Cardiology, Medical University of Innsbruck.
Both a control group (CG) and an intervention group (IG) of patients who met the below criteria were recruited:
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1.
Diagnosis of coronary artery disease (acute coronary syndrome ACS or stable angina pectoris)
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2.
Sufficient knowledge of German
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3.
Ability to complete a set of surveys (i.e. no physical or mental impairments)
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4.
Physical agility (patients had to be able to reach the seminar room by foot)
The CG was recruited 2 months prior to implementing the intervention. Integration of the intervention in a routine cardiology setting prevented randomisation between the CG and IG.
Patients independently representing the CG and the IG signed an informed consent form prior to completing an identical survey (t0) at the time of recruitment. For the IG, prior baseline assessment was a requirement for group participation. Postal follow-up data were collected for both groups 2 (t1) and 6 months (t2) after discharge.
The intervention designed to fit within the clinical routine of an acute cardiac ward included direct patient participation in a 1-h group education session with a qualified and trained nurse. The intervention was carried out once a week for a 1-year time period and each IG patient participated only once.
The intervention comprised three parts: (a) information; (b) activation: developing personal action and coping plans; and (c) group discussion.
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a.
Information about everyday physical activities for cardiac patients was presented and participants were invited to ask questions.
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b.
Subsequently, patients were encouraged to develop their own personal action and coping plans concerning physical activity. Action plans are simple “when,” “where” and “how” plans to concretize the prospective healthy behaviour. A connection between situation (when, where) and behaviour (how) is built. An example of such an action plan could include: “I will run for 30 min along the river every evening.” Action planning helps to act in the intended way [17] and to initiate goal behaviour faster [6]. Coping planning serves as support to overcome potential obstacles and barriers that may frustrate planned behaviour by linking them to suitable coping strategies. For example: “It’s raining so I will go and swim for 30 min instead.”
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c.
At the end of the session, patients were invited to discuss their plans within the group.
Instruments
Data on socio-demographic and clinical variables were collected, and patient charts were reviewed for diagnosis and treatment. Self-reported risk factor items regarding level of physical activity, smoking, diabetes, hypertension, hypercholesterolemia and depression were asked. Depression was screened for with the two questions of the PHQ-2 questionnaire (a: “Over the past month, how often you have been bothered by feeling down, depressed or hopeless?” b: “Over the past month, how often have you been bothered by little interest or pleasure in doing things?”). A positive response to the two-item instrument has a sensitivity of 96 % (95 % confidence interval, 90–99 %) and a specificity of 57 % (95 % confidence interval, 53–62 %) in detecting depression [18]. Patients also provided information about potential confounding variables (participation in an inpatient or outpatient rehabilitation programme in the follow-up period, subjective assessment of satisfaction with physical activity and perceived impact of physical activity on health). Consistent with the HAPA model (Fig. 1), the survey included the following measures:
General Self-Efficacy (GSE). To assess general perceived self-efficacy [19], the ten-item German version of the GSE using a 4-point response format “Not at all true,” “Hardly true,” “Moderately true” and “Exactly true” was included. A composite score is calculated with higher scores reflecting higher GSE. Prior studies revealed internal consistency ranging from 0.80 to 0.90 [20]. Criterion-related validity has been well documented [21].
Measurement of intention, action and coping planning and action control. Items measuring intention (seven items), action planning (five items), coping planning (five items) and action control (six items) for physical activity were included with slight wording modifications to fit the context of this study from those adopted by Sniehotta et al. [22] Example items included: I intend to be physically active several times a week (intention); I have made a detailed plan regarding when to be physically active (action planning); I have made a detailed plan regarding what to do if something interferes with my plans (coping planning); and, I have really tried hard to be physically active regularly (action control). Furthermore, the intention item “I intend to live healthy” was added to allow for a global appraisal. All items adopted a 4-point response format with 1 = not at all true to 4 = exactly true.
Self-reported items on physical activity. To control for the presence of potential confounding effects with respect to the patients’ subjective assessment of physical activity as well as the perceived impact of physical activity on health, two items derived from the German questionnaire on health behaviour (FEG) [23] were included. The two items: “How satisfied are you with your physical activity?” and “How does your physical activity impact your health?” were assessed on a 7-point scale from “extremely dissatisfied/negative” (− 3) to “extremely satisfied/positive” (3).
Assessment of physical exercise. An adaptation of the Kaiser Physical Activity Survey cf. Sniehotta et al. [15] for cardiac patients was included. Patients revealed how often and for how long per week (on average) they were active in each of five domains of physical activity: vigorous exercise (e.g. swimming, cycling), exercise to train muscle strength, fitness activities (e.g. gymnastics), game sports (e.g. football) and prescribed exercises (e.g. back exercises). For patients who did not act out any of the specified activities, the option “I did not act out any of the activities” was provided. The amount of physical activity per domain was calculated by multiplying days per week with minutes per session. To form a sum score, the five domains were aggregated.
Statistical methods
Analysis commenced with an exploration of the data to ensure that no breeches regarding normal distribution were evident. The only measure revealing non-normality was physical activity. Consequently, based on the distribution, the Student’s t test or the Mann–Whitney U test was used to compare differences at baseline and changes over time between groups. The Wilcoxon signed-rank test was used to compare changes over time within groups. In addition, univariate and multivariate outliers were removed where appropriate. Frequencies and means (± SD) as well as median and quartiles (Q1; Q3) were used to describe clinical and socio-demographic variables (Table 1). Analysis of covariance was used to examine differences over time adjusted for baseline values and for significant baseline differences between groups. To determine and compare the effect size of the intervention and the CG Cohen’s r [r = z/√N] as an effect size for nonparametric data was calculated. Values: r > 0.1 represents a small effect, r > 0.3 a middle effect and r > 0.5 a large effect [24].