The illness perceptions of patients with percutaneous coronary intervention compared to patients with no percutaneous intervention, for acute myocardial infarction, in cardiac rehabilitation.

PURPOSE: Patients who receive percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) have been found to have low attendance at cardiac rehabilitation (CR). It has been suggested that this is because PCI patients have a benign perception of their coronary disease; however, this has never been quantitatively investigated. The aim of this prospective study was to evaluate the illness perceptions (IP) of patients with AMI treated with PCI. METHODS: The Heart Health Illness Perception Questionnaire (modified version of the Brief Illness Perception Questionnaire) and the Cardiac Beliefs Questionnaire were used to assess patients' IP and cardiac disease misconceptions, respectively. Patients in phase 2 of CR were recruited from the Royal Alexandria Hospital, Paisley, UK. One hundred two patients were identified from the cardiac unit database over a 16-week period and sent questionnaires. RESULTS: Fifty-six patients returned questionnaires suitable for analysis (54.9% response rate). There was a significant difference in the IP scores of the 3 groups [primary-PCI (pPCI) = 0.18 ±â€…1.44, elective-PCI = 5.27 ±â€…15.65, non-PCI = 9.94 ±â€…11.19; P = 0.046]. PCI patients had a significantly lower IP score than non-PCI patients (PCI = 1.62 ±â€…12.76, non-PCI = 9.94 ±â€…11.19; P = 0.027). pPCI patients had a significantly lower IP score than non-pPCI patients (pPCI = 0.18 ±â€…11.44, non-pPCI = 8.04 ±â€…13.11; P = 0.021). Of the PCI patients 22.9% agreed they were 'fixed for life' and a lower IP score was found to predict this opinion (P = 0.032). CONCLUSION: PCI patients, particularly pPCI patients, perceive their coronary disease to be relatively benign. Further research is required to investigate if this predicts poor attendance at CR.

Impact of ecological redundancy on the performance of machine learning classifiers in vegetation mapping.

Vegetation maps are models of the real vegetation patterns and are considered important tools in conservation and management planning. Maps created through traditional methods can be expensive and time-consuming, thus, new more efficient approaches are needed. The prediction of vegetation patterns using machine learning shows promise, but many factors may impact on its performance. One important factor is the nature of the vegetation-environment relationship assessed and ecological redundancy. We used two datasets with known ecological redundancy levels (strength of the vegetation-environment relationship) to evaluate the performance of four machine learning (ML) classifiers (classification trees, random forests, support vector machines, and nearest neighbor). These models used climatic and soil variables as environmental predictors with pretreatment of the datasets (principal component analysis and feature selection) and involved three spatial scales. We show that the ML classifiers produced more reliable results in regions where the vegetation-environment relationship is stronger as opposed to regions characterized by redundant vegetation patterns. The pretreatment of datasets and reduction in prediction scale had a substantial influence on the predictive performance of the classifiers. The use of ML classifiers to create potential vegetation maps shows promise as a more efficient way of vegetation modeling. The difference in performance between areas with poorly versus well-structured vegetation-environment relationships shows that some level of understanding of the ecology of the target region is required prior to their application. Even in areas with poorly structured vegetation-environment relationships, it is possible to improve classifier performance by either pretreating the dataset or reducing the spatial scale of the predictions.

Peer support to promote physical activity after completion of centre-based cardiac rehabilitation: evaluation of access and effects.

BACKGROUND: Patients with heart disease receive little support for sustaining physical activity over the long-term. This study compared the characteristics of patients choosing to join a peer support program to promote use of physical activity and assessed its effects on physical activity. AIMS: To compare characteristics of those choosing to join the peer support (PS) program versus those who did not, and to assess the effect on physical activity patterns at 12 months of the PS program. METHODS: Based on health status from 225 people who completed centre-based cardiac rehabilitation, 109 patients with heart disease who had completed a program of hospital-based cardiac rehabilitation were suitable for the peer support program. Health status and characteristics of patients opting to join the program (n = 79) were compared to patients who did not wish to join (n = 30). A longitudinal study was then conducted to determine the objective effects on physical activity levels of program membership at 12 months as measured by self-report and pedometers. RESULTS: Patients who joined the peer support program tended to be older (p < 0.001), and female compared to those who were eligible but did not join (p = 0.04). Over the next 12 months, those who did not participate in the peer support program reported a decline of 211 min in the total amount of physical activity accumulated in an average week (1382.5 ± 238.2 to 1171.5 ± 220.1 min week(-1) p = 0.003), whereas program members sustained similar levels of physical activity as was recorded at the completion of cardiac rehabilitation (1021.1 ± 141.9 to 1070 ± 127.8 min week(-1)). Objective measures of physical activity indicated that groups increased moderately total step count per week (p = 0.68 and p = 0.25) and in their average steps per day (p = 0.68 and p = 0.25 respectively) from baseline to 12 months. CONCLUSION: Peer support programs have good potential to help people with heart disease maintain physical activity after cardiac rehabilitation. Importantly, they may offer particular benefits for older patients and females.

Design matters in secondary prevention: individualization and supervised exercise improves the effectiveness of cardiac rehabilitation.

BACKGROUND: Hospital or centre-based cardiac rehabilitation (CR) can lengthen and improve life. However, most existing trials do not examine the effects of design characteristics. To examine the effects of these characteristics, this study compared an individualized cardiac rehabilitation programme to a standardized programme and examined what factors contributed most to programme effects. DESIGN: A prospective cohort analysis was done comparing patients using an individualized centre-based cardiac rehabilitation programme (ICR) in a mixed urban-rural region of the west of Scotland, to a standardized cardiac rehabilitation programme (SCR) provided at the same site three years previously. Both inter- and intra-programme differences in outcomes were explored. RESULTS: More patients were referred to ICR than SCR (749 versus 414 patients, p = 0.002) and the proportion of patients who subsequently attended was around 30% higher (p < 0.0001) although the overall rate of referral to ICR was lower (70% versus 62%, p = 0.002). ICR was associated with a reduction in hospital admission compared to SCR (HR: 0.664: 95% confidence interval (CI) 0.554 to 0.797). ICR patients also had significantly shorter hospitalizations (mean: 8.02 days versus 5.84 days, p < 0.05). ICR patients who attended at least 75% of the exercise sessions were significantly less likely to be hospitalized than individuals who partially attended (HR 2.39, 95% CI: 1.659 to 3.488) or did not participate in exercise sessions (HR 2.16, 95% CI: 1.482 to 3.143). CONCLUSIONS: Individualized content and supervised exercise components are key design characteristics for improving outcomes from centre-based CR in clinically representative populations.

Participation in community-based exercise maintenance programs after completion of hospital-based cardiac rehabilitation: a mixed-method study.

OBJECTIVE: To understand the characteristics associated with participation in community-based exercise maintenance programs in patients with coronary heart disease (CHD) after completion of hospital-based cardiac rehabilitation in Scotland. METHODS: A mixed-methods approach was used (survey and focus groups) to explore determinants of participation in community-based exercise maintenance programs. RESULTS: Of 112 patients (67% male), 81 patients responded (73% response rate). Knowledge was high of the importance (19.2%) or high importance (75.6%) of physical activity to cardiac health. However, the focus groups identified that use of community-based exercise maintenance programs was affected by personal confidence, perceived meaningful support for people with CHD, and suitability of exercises to CHD patients. CONCLUSIONS: Decisions regarding the use of community-based exercise maintenance programs after hospital-based cardiac rehabilitation appear to be impacted by a range of factors linked to the views of exercise, confidence, and suitability of the program regimen to the individual with CHD.

Validity of self-reported smoking status: Comparison of patients admitted to hospital with acute coronary syndrome and the general population.

Many studies rely on self-reported smoking status. We hypothesized that patients with acute coronary syndrome (ACS), a smoking-related condition, would be more prone to misclassify themselves as ex-smokers, because of pressure to quit. We compared patients admitted with ACS with a general population survey conducted in the same country at a similar time. We determined whether ACS patients who classified themselves as ex-smokers (n = 635) were more likely to have cotinine levels suggestive of smoking deception than self-reported ex-smokers in the general population (n = 289). On univariate analysis, the percentage of smoking deceivers was similar among ACS patients and the general population (11% vs. 12%, p = .530). Following adjustment for age, sex and exposure to environmental tobacco smoke, ACS patients were significantly more likely to misclassify themselves (adjusted OR = 14.06, 95% CI 2.13-93.01, p = .006). There was an interaction with age whereby the probability of misclassification fell significantly with increasing age in the ACS group (adjusted OR = 0.95, 95% CI 0.93-0.97, p<.001), but not in the general population. Overall, smoking deception was more common among ACS patients than the general population. Studies comparing patients with cardiovascular disease and healthy individuals risk introducing bias if they rely solely on self-reported smoking status. Biochemical confirmation should be undertaken in such studies.

A critical realist approach to understanding and evaluating heart health programmes.

Secondary prevention programmes for Coronary Heart Disease (CHD) aim to reduce cardiovascular risks and promote health in people with heart disease. Though programmes have been associated with health improvements in study populations, access to programmes remains low, and quality and effectiveness is highly variable. Current guidelines propose significant modifications to programmes, but existing research provides little insight into why programme effectiveness varies so much. Drawing on a critical realist approach, this article argues that current research has been based on an impoverished ontology, which has elements of positivism, does not explore the social determinants of health or the effects on outcomes of salient contextual factors, and thereby fails to account for programme variations. Alternative constructivist approaches are also weak and lacking in clinical credibility. An alternative critical realist approach is proposed that draws on the merits of subjectivist and objectivist approaches but also reflects the complex interplay between individual, programme-related, socio-cultural and organizational factors that influence health outcomes in open systems. This approach embraces measurement of objective effectiveness but also examines the mechanisms, organizational and contextual-related factors causing these outcomes. Finally, a practical example of how a critical realist approach can guide research into secondary prevention programmes is provided.

Effect of an exercise consultation on maintenance of physical activity after completion of phase III exercise-based cardiac rehabilitation.

BACKGROUND: Many patients do not maintain physical activity levels after completion of phase III exercise-based cardiac rehabilitation. DESIGN: This study determined the effect of an exercise consultation on maintenance of physical activity and cardiorespiratory fitness 12 months after completion of a phase III exercise programme. Seventy cardiac patients were randomized to the experimental (exercise consultation and exercise information) or control groups (exercise information only). METHODS: Outcomes recorded at baseline, 6 and 12 months were: physical activity (stage of change, 7-day recall, accelerometer), cardiorespiratory fitness, lipids, quality of life, anxiety and depression. RESULTS: Both groups were regularly active at baseline. The between-group difference for the change in total activity (min/week) assessed by the 7-day recall was significant from baseline to 12 months [98% confidence interval (CI) -295, -20]. Total activity was maintained in the experimental group (98% CI -63, 154) and significantly decreased in the control group (115 min/week; 98% CI -228, -28) from baseline to 12 months. The between-group difference for the change in accelerometer counts/week was not significant from baseline to 6 (98% CI -1 143 720, 607 430) or 12 months (98% CI -1 131 128, 366 473). A comparable, significant decrease in peak oxygen uptake occurred from baseline to 12 months in experimental (1.8 ml/kg per min; 98% CI -3.2, -0.3) and control participants (2.3 ml/kg per min; -3.8, -0.8). Lipids, quality of life, anxiety and depression were normal at baseline and did not significantly change in either group over time. CONCLUSION: Exercise consultation was effective in maintaining self-reported physical activity, but not peak oxygen uptake, for 12 months after completion of phase III.

A realist study of the mechanisms of cardiac rehabilitation.

AIM: The aim of this paper is to report patients' experiences of cardiac rehabilitation and perceptions of the mechanisms and contexts influencing its long-term effectiveness. BACKGROUND: Cardiac rehabilitation programmes for the secondary prevention of coronary heart disease are common. The effects of these programmes, however, can be inconsistent and little is known of the personal and contextual factors that influence service effectiveness. METHOD: Forty-seven participants with a formal diagnosis of coronary heart disease who had attended a programme of cardiac rehabilitation in Scotland 3 years previously were included in focus groups to discuss their perceptions and experiences (30 males and 17 females). The data were generated in 2002 and analysed using the realist approach of Pawson and Tilley (1997). RESULTS: Participants' accounts indicated that the didactic content of cardiac rehabilitation was not strongly linked to longer-term health behaviour change. The main positive effects of cardiac rehabilitation were related to the effect of participation on mediating social and body-focused mechanisms that were triggered when the rehabilitation setting was perceived to be safe. Social mechanisms identified included social comparisons, camaraderie, and social capital. Body-focused mechanisms included greater knowledge of personal physical boundaries and a greater trust in the heart-diseased body. Collectively, these mechanisms had a positive effect on confidence that was perceived as being imperative to maintain health behaviour change. CONCLUSIONS: More support is required to promote health behaviour change after the completion of cardiac rehabilitation. Use of community-based exercise services and conventional or web-based support groups for coronary heart disease patients should be encouraged, as these appear to extend the positive health effects of the mechanisms that promote behaviour change. At the completion of cardiac rehabilitation programmes, patients should be referred to safe and appropriate community-based exercise services. Further research is needed to examine the effects on health outcomes of mechanisms and contexts related to cardiac rehabilitation.

Promoting and maintaining physical activity in people with type 2 diabetes.

BACKGROUND: Limited research has investigated how to promote physical activity in people with type 2 diabetes. This study evaluated physical activity counseling over 12 months in people with type 2 diabetes. DESIGN: Participants were given standard exercise information and randomly assigned to receive physical activity counseling or not. Data were collected from September 2000 through to September 2002 and analyzed from October 2002 to February 2003. SETTING/PARTICIPANTS: Diabetes outpatient clinic. Seventy inactive people with type 2 diabetes. INTERVENTION: Physical activity counseling, based on the transtheoretical model, combined motivational theory and cognitive behavioral strategies into an individualized intervention to promote physical activity. Consultations were delivered at baseline and 6 months, with phone calls at 1 and 3 months post-consultation. MAIN OUTCOME MEASURES: Changes from baseline at 12 months in physical activity (7-day recall and accelerometer), stages and processes of exercise behavior change. RESULTS: Between-group differences were recorded in physical activity (recall and accelerometer) at 12 months (p <0.01). Experimental participants significantly increased total activity (median difference, 115 minutes; 95% confidence interval [CI]=73-150 minutes). Control participants recorded no significant change (median difference, -15 minutes; 95% CI=-53-13 minutes). The accelerometer experimental participants recorded no significant change (mean difference, 416,632 counts; 95% CI=-27,743, 1,051,007 counts/week), while control participants recorded a significant decrease (mean difference, -669,061 counts; 95% CI=-1,292,285, -45,837 counts/week). At 12 months, more experimental participants compared to controls were in active stages of behavior(6-month chi(2)=26.4, p <0.01; 12-month chi(2)=19.9, p <0.01, respectively). Between-group differences were recorded at 12 months for the frequency of using all processes (p <0.01), except dramatic relief and stimulus control. CONCLUSIONS: Physical activity counseling was effective for promoting physical activity over 12 months in people with type 2 diabetes.

Promoting participation in cardiac rehabilitation: patient choices and experiences.

BACKGROUND: Cardiac rehabilitation can be an effective means for the secondary prevention of coronary heart disease, but a majority of eligible individuals fail to attend or drop out prematurely. Little research has examined patients' decisions about attendance. AIMS: This paper reports a study examining patients' beliefs and decision-making about cardiac rehabilitation attendance. METHODS: A purposive sample of patients from a mixed urban-rural region of Scotland was studied in 2001 using focus groups. Those who were eligible for a standardized 12-week cardiac rehabilitation programme were compared, with separate focus groups held for individuals with high attendance (>60% attendance; n = 27), high rates of attrition (<60% attendance; n = 9) and non-attendance (0% attendance; n = 8). A total of 44 patients (33 men; 11 women) took part in eight focus groups. RESULTS: Participants from all groups held sophisticated and cohesive frameworks of beliefs that influenced their attendance decisions. These beliefs related to the self, coronary heart disease, cardiac rehabilitation, other attending patients, and health professionals' knowledge base. An enduring embarrassment about group or public exercise also influenced attendance. Those who attended reported increased faith in their bodies, a heightened sense of fitness and a willingness to support new patients who attended. CONCLUSIONS: Reassurance to ease exercise embarrassment should be given before and during the early stages of programmes, and this could be provided by existing patients. Strategies to promote inclusion should address the inhibiting factors identified in the study, and should present cardiac rehabilitation as a comprehensive programme of activities likely to be of benefit to the individual irrespective of personal characteristics, such as age, sex or exercise capacity.