original paper
The provision of secondary cardiac prevention measures in a hospital cardiac clinic population and the relationship to psychological variables
The provision of secondary cardiac prevention measures in a hospital cardiac clinic population and the relationship to psychological variables M Lynch1,2, AW Murphy1, J Walsh2, K Daly3, M Hynes4 Departments of General Practice1, Psychology2, National University of Ireland, Galway, Department of Cardiology3, University College Hospital, Galway, Department of Public Health4, Western Health Board, Galway, Ireland
Abstract Background Implementing preventive measures in patients with established heart disease is one of the most effective health promotion activities, but there is little research on the relationship between cognition and secondary preventive behaviour.
Aim To determine the provision of secondary cardiac prevention measures among patients with established heart disease attending a cardiac outpatient clinic.
Methods The study was conducted in an outpatient department over a 14-week period in 1999. Management of risk markers was noted from the medical records and lifestyle and psychological variables were self-reported.
Results Of 294 patients with heart disease, 41% were available for study. Fourteen per cent were current smokers, one-quarter of males and one-third of females had a body mass index (BMI) greater that 30. Almost 90% attend their GP bimonthly, 67% had a normal systolic and 88.3% a normal diastolic pressure, 34% had normal cholesterol levels and 75% were on aspirin. Lifestyle variables were significantly affected by patient cardiac knowledge, sense of control over their heart disease and perceptions of their illness.
Conclusions These results highlight the potential health gain available to patients with established heart disease. The results also suggest that psychological factors may play a role in patients’ health behaviours.
Introduction Implementing preventive measures in patients with established heart disease (history of myocardial infarction, angina or revascularisation by angioplasty or bypass grafting) is one of the most effective available health promotion activities.1,2 Patients with established coronary heart disease (CHD) have an increased absolute five year risk of more than 20% of a subsequent vascular event.3 Although representing about 5% of the population, about half of all CHD deaths occur in this population. UK evidence suggests that many at-risk patients remain unidentified or are receiving suboptimal treatment.4,5 The Report of the Irish Cardiovascular Health Strategy Group recommended that secondary prevention for most patients with cardiovascular disease should be provided in the general practice setting.6 Current secondary preventive practices among Irish patients with established heart disease are unclear as there are no data for the provision of secondary prevention measures in the community because of difficulty in identifying eligible patients, lack of a universal prescribing database and small practice sizes. Bradley et al7 suggested that the lack of success of many secondary preventive programmes is that patients’ personal models of their illness are not taken into account. Horne reported a 29% variance in adherence behaviour attributable to illness and treatment perceptions.8 There has been little research on the relationship between cognitions and secondary 24
preventive behaviour among patients with cardiac disease. The aim of this study was to determine the provision of secondary prevention measures among patients with known CHD attending a cardiac out-patient clinic and to investigate the relationship between such uptake and psychological variables.
Methods The study was conducted in the cardiac out-patient clinic of University College Hospital, Galway, from 24 February to 9 June 1999. Approval was obtained for the study from the hospital ethics board. A qualified health psychologist (ML) collected all data. Eligible patients were those with a documented history of acute myocardial infarction (AMI), angina pectoris or revascularisation (CABG or PTCA). Age, gender, marital status, living arrangements, education, insurance status and frequency of GP attendance in the previous three months were all recorded. Medical management of risk markers was noted from the medical records and changes in lifestyle assessed using self-report measures. The Duke Activity Status Index (DAIS) (range 0-65) was used to determine physical function status.9 The Illness Perception Questionnaire (IPQ) evaluated mental representations of CHD, including patients’ perceptions of disease identity (range 0-17), cure/control (range 0-5), time-line (range 0-5) and consequences of the disease (range 0-5).10 A cardiac knowledge questionnaire (range 019) assessed the levels of knowledge about AMI and cardiac Irish Journal of Medical Science • Volume 171 • Number 1
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rehabilitation.11 A pilot study highlighted the difficulties in securing protected space in a busy out-patient department. The following procedure for identification and interview of patients was therefore adopted. The researcher went to the medical record department two days prior to the clinic date and reviewed all charts for the up-coming clinic. All eligible patients’ charts were labelled. At the clinic as patients registered, and were available, the researcher invited the person to participate in the study. Each interview lasted approximately 20 minutes. A convenience sample size of 100 patients was agreed. All data were scored and entered into a database and analysed using the SPSS for Windows (Version 8). One-way ANOVAs and t-tests were conducted to compare means across categories of patients where the data fulfilled parametric assumptions. In all other cases, Mann-Whitney tests were carried out.
Table 1. Patient demographics; n = 120 Demographics Gender Male Age (mean) (standard deviation) Male Female Marital Status Married Single Widowed Other Divorced or Separated Final Educational Status Primary Certificate not achieved Primary Level Intermediate Certificate Leaving Certificate Third Level Other Employment Status Full-time Part-time Retired Unemployed Other Insurance Type GMS Private Other
Percentage (%)
75 61.3 years (9) 62.6 years (13.6) 65.3 12.7 16.7 5.0 5.0 67.2 18.2 6.7 2.5 5.0 17.7 12.7 35.6 6.8 27.1 75.4 10.2 14.4
exercise. The median distance reported (n=48) was 12 miles per week, with a range of 7.5 miles to 30 miles. Self-reported and unvalidated measures of change in behaviour following the original diagnosis of CHD are presented in Table 3. Over 60% of the participants were receiving treatment for hypertension. The mean systolic blood pressure reading (n=103) was 139mmHg (standard deviation [SD] 20mmHg). Sixty-seven per cent of those whose blood pressure was recorded had a systolic reading within the recommended level of 140mmHg or less.1 The mean diastolic blood pressure for the clinic participants (n=103) was 82 (SD 9.9mmHg). Of those with their blood pressure recorded, 88.3% had diastolic readings within the recommended level of 90mmHg or less.1 The mean cholesterol value of the clinic participants (n=84) was 5.4mmols (SD 1.13mmol). Thirty-four per cent of those with values recorded were within the recommended level of 5mmol or less.1 Seventy-five per cent of patients were taking aspirin, with 7.5% being prescribed anti-coagulation therapy. The mean score for the Dukes Activity Scale was 34.7 (SD 15.8) and the mean cardiac knowledge score was 11.7 (SD 2.9). The mean IPQ scores for the different subscales were: timeline 3.6 (SD 0.6); consequences 3.2 (SD 0.7) and control/cure 3.5 (SD 0.6). Sixty-four per cent of patients reported either no change or a decrease in the level of exercise taken since diagnosis. The relationship between the provision of secondary cardiac preventive measures and psychological factors was analysed. A number of significant results were found. A significantly higher cardiac knowledge score was noted among those taking aspirin (mean=12.12 vs 10.43, t=2.84, df=118, p=0.005) and those who had increased their level of exercise versus those who had not (12.62 vs 11.13, f=3.15, df [3, 115], p=0.03). Patients who decreased their weight had a significantly higher sense of control over their heart disease (mean=12.63) than those whose weight remained unchanged (mean=11.70) or increased (mean=11.26), (f=3.192, df [2, 115], p=0.05). A sense of greater control over the illness was also related to increased frequency of cholesterol monitoring by patients compared with those whose frequency of monitoring did not change (mean=3.70 vs 3.30, t=2.32, df=100, p=0.03). Patients who viewed their illness as having significantly more serious consequences were more likely to have increased their level of exercise than those whose level of exercise remained unchanged (mean=3.53 vs 2.98, t=2.78, df=100, p=0.01). Finally, patients who perceived their disease as having more serious consequences showed a decrease in fat intake versus those who did not have this perception (median 3.43 vs 2.86, U=594, p=0.04).
Results
Discussion
Two hundred and ninety-four patients with CHD attended the cardiac out-patients clinic during the study period; results are reported on 120 (40.8%). Almost all of the remainder did not participate due to accommodation difficulties for the researcher; minor reasons included time restraints and refusal. Demographic characteristics are presented in Table 1. Median time in years since diagnosis was three years (range 1-24 years). The following previous personal cardiac history was noted: AMI 55.8%; angina 75.8%; CABG 28.3%; PTCA 24.2% and hypertension 65%. Thirty-one per cent had a first-degree family history of CHD before the age of 60. Of the 120 participants, 8.5% attended their GP once in the previous three months, 31.4% once every two months, 50% once a month, 8.5% weekly and 1.7% not at all. Lifestyle markers are described in Table 2. Over 76% of the clinic patients cited walking as their method of
This study must be interpreted cautiously as the sample is small and from one centre, based on routine medical records and includes a number of self-report measures. The sample also represents 40.8% of the potential population. However, selection bias is unlikely as nearly all patients were randomly excluded simply because of lack of consulting space. It is noteworthy that over three-quarters of the study population were GMS eligible, with the educational attainment of over two-thirds being limited to primary school level. This possibly limits the generalisability of the results to the general population but may be typical for attenders of this age cohort to a public cardiac clinic. The authors also examined the relationship between uptake of secondary cardiac prevention measures and psychological variables. Tables 2 and 3 and the reported figures relating to control of
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The provision of secondary cardiac prevention measures in a hospital cardiac clinic population and the relationship to psychological variables
Table 3. Self-reported change in behaviour following diagnosis of CHD for clinic patients (n = 120)
Table 2. Lifestyle markers for the clinic participants (n = 120) Lifestyle markers Smoking (n = 119) Current Ex-smoker (> 6 months) Never smoked Body Mass Index (male, n = 86) Underweight (BMI40) Body Mass Index (female , n = 29) Underweight (BMI40) Exercise None Stress Management Practice None
Percentage (%) Reported Change in Behaviour 14.3 65.5 20.0 2.3 23.3 50.0 23.3 1.2 0 20.7 41.4 37.9 0 13.4 92.5
hypertension and lipids highlight the potential health gain available to patients with established heart disease. Previous attempts to achieve these health gains — such as the Grampian, Southampton heart integrated care project (SHIP) and POST studies have met with mixed success.4,5,12 Bradley, in a landmark paper using the SHIP study as a case study, reviewed the interpretation of the results of complex health service interventions.7 She emphasised the importance of understanding people with whom, and the context within which, the intervention is operationalised. The psychological variables examined in this study — particularly the relationship of perceived disease control and perceived consequences of illness severity to the uptake of secondary preventive health behaviours — provide a valuable insight into the psychological status of patients with established heart disease. These exploratory results indicate that disease knowledge and patients’ perceptions of illness may be important variables to consider as determinants of secondary preventive behaviours among this group of patients. This suggests that ‘patient-centred’ approaches may form the basis for the development of health education interventions aimed at encouraging secondary preventive behaviour among Irish patients.13 The Report of the Irish Cardiovascular Health Strategy Group highlights the unique and invaluable potential role which general practice can play in the provision of secondary cardiac care. 6 The finding in this study, that almost 90% of patients with established cardiac disease attend their GP at least once every two months, emphasises the potential magnitude of such an organised contribution. This study utilised a population attending a hospital cardiac clinic that enabled the quick identification of an acceptable number of eligible patients. The ASPIRE study reported results from a similar UK hospital-based population; however direct comparison is difficult due to the format in which the ASPIRE results were presented.14 A similar methodology was used in the EUROASPIRE study which is reported with other hospital and community-based studies (see Table 4).15 The data reported in the present study appear comparable. The Report of the Irish Cardiovascular Health Strategy Group emphasises the importance of increasing the capacity of
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Smoking Stopped Decreased Unchanged Never Exercise None Unchanged Decreased Increased Weight Unchanged Increased Decreased Intake of low cholesterol options Unchanged Increased Intake of low-fat options Unchanged Increased Intake of fruit Unchanged Decreased Increased Intake of vegetables Unchanged Decreased Increased
Percentage (%)
31.7 12.5 32.5 23.3 13.4 26.1 18.5 42.0 39.5 31.9 28.6 32.5 67.5 14.3 85.7 34.2 1.7 64.2 46.7 0.8 52.5
Irish primary care in order to deliver anticipated health gains. 6 This paper may suggest the amount of workload, especially regarding hypertension and lipids management, which such a preventive role for Irish general practice will entail. The contribution of practice nurses to such a workload would appear both invaluable and crucial. However, extrapolation of these results to a similar population in Irish general practice cannot be assumed and further work is required to determine this.
Acknowledgements The authors wish to thank the nursing and medical staff of the cardiology out-patient department without whose patience and good humour this study would not have been possible. The authors would also like to thank the Department of Public Health, Western Health Board, which provided essential funding to the study.
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Table 4. Equivalent data from related international hospital and community studies
Year of study conduct Study location and centre Total sample Mean age (years) Proportion male (%) Mean systolic pressure (mmHg) Mean diastolic pressure (mmHg) Mean cholesterol (mmol) Aspirin uptake (%) Management of hypertension according to guidelines (%) Management of lipids according to guidelines (%) Current smokers (%) Body mass iIndex (%) Underweight (< 20) OK (20-24.9) Overweight (25-29.9) Obese (30-39.9) Very obese (> 40)
SHIP study4a
Grampian study5
POST study12a
EUROASPIREII15
Irving et al16
1995/6 Community Southampton 320 64 74
1996 Community Grampian 1,343 66.2 58
1995-7 Community Hackney 156 64.8 87
Hospital Trans-Europe 8,181 NA 75
1997 Hospital Edinburgh 761 NA NA
129
142
NA
137c
NA
81 6.1 85
81 6.5 63
NA NA 83
82c 5.2c 86
NA NA 80
NA
82
NA
50
88b
41 27
17 18
NA 35
42 21
50 12
NA
2 34 47
NA
NA 30 or higher: 25
17 1
a The figures reported from the SHIP and POST studies are the baseline characteristics of the control group. b This proportion refers to guidelines for systolic pressure only. c These figures are medians. NA = Not available
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Correspondence to: AW Murphy, Department of General Practice, National University of Ireland, Galway. Email:
[email protected]
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