ARTICLE IN PRESS. Longitudinal study of patients after myocardial infarction: Sense of coherence, quality of life, and symptoms

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1 Longitudinal study of patients after myocardial infarction: Sense of coherence, quality of life, and symptoms Eva Bergman, RN, MScN, a Dan Malm, RN, MScN, PhD, a,b Jan-Erik Karlsson, MD, PhD, a and Carina Berterö, RN, MScN, PhD c BACKGROUND: Myocardial infarction has pronounced effects on an individual that demand changes in lifestyle. Health is influenced by whether the individual experiences the world as comprehensible, meaningful, and manageable, that is, has a sense of coherence (SOC). High SOC scores indicate that the individual probably manages the situation by understanding the context and connections: action and effect. OBJECTIVE: The study objective was to identify the SOC, assess the quality of life (Short Form-12 Health Survey Questionnaire), assess the symptoms using the Seattle Angina Questionnaire, and create health curves from a baseline for patients with a first myocardial infarction. METHODS: A longitudinal and predictive study of 100 participants in the heart care unit of a county hospital in southern Sweden was performed. RESULTS: Women score lower on SOC than men. Persons with high SOC scores have fewer angina attacks, are more physically active, drink more alcohol, are more satisfied with their treatments, and have better disease perception. CONCLUSION: By following SOC scores, a trend emerges that suggests it may be a useful tool for identifying those who will need extra support. (Heart Lung 2008;xx:xxx.) Cardiovascular disease is responsible for approximately 10% of disability-adjusted life years in low- and middle-income countries and 18% in high income countries. Disability-adjusted life years indicate the total burden of a disease, not only a negative result- death. Coronary heart disease is now the leading cause of mortality worldwide and accounts for the death of 3.8 million men and 3.4 million women each year. 1 Registries in From the a Department of Internal Medicine, Division of Cardiology, County Hospital Ryhov, Jönköping, Sweden; b School of Health Sciences Jönköping University, Jönköping, Sweden; and c Department of Medicine and Health Sciences, Division of Nursing Science, Faculty of Health Sciences, Linköping University, Sweden. This study was partly funded by the Medical Research Council of Southeast Sweden. Corresponding author: Carina Berterö, RN, MScN, PhD, Department of Medicine and Health Sciences, Division of Nursing Science, Faculty of Health Sciences, Linköping University, Linköping, Sweden /$ see front matter Copyright 2008 by Mosby, Inc. doi: /j.hrtlng European countries show myocardial infarction as the cause of 9% to 13% of all deaths, except in France, where the figure is approximately 5%. The figure is approximately 12% in Australia and 8% in the United States. 2 In Sweden, cardiovascular disease is the most common cause of death today and is responsible for approximately 30% of all deaths. Myocardial infarction is the cause of approximately 13% of these 30% of deaths in Sweden. 3 The major risk factors for myocardial infarction are heredity, hypertension, increased blood cholesterol, smoking, diabetes, insufficient physical activity, abdominal fat, and diet. 3,4 A strong connection between stress and coronary vessel disease has been found, 3 although daily consumption of fruit, vegetables, and small quantities of alcohol, along with daily physical activity, was associated with lower risk. 4 After a myocardial infarction, a difficult period ensues for the patient. There is time to face what effect the myocardial infarction may have on one s life and what lifestyle constraints it might bring. 3 The primary responsibility for rehabilitation HEART & LUNG VOL. XX, NO. X 1

2 and readjustment to life lies with the individual. Rehabilitation may include secondary prevention actions with the aim of preventing or delaying recurrence. 3 Few studies have examined how patients with myocardial infarction manage their lifestyle changes and what their motivation is to make such changes. 5,6 Antonovsky 7 proposes that health is influenced by how the individual experiences the world as comprehensible, meaningful, and manageable, that is, a sense of coherence (SOC). We conducted a longitudinal study with the goal of identifying the SOC in individuals with a first myocardial infarction, assessing quality of life and symptoms, and creating personal health curves from a baseline on discharge from the hospital and at 2 and 4 weeks after discharge. This article presents the results of these baseline assessments. MATERIALS AND METHODS Participants Between November of 2003 and June of 2005, we consecutively recruited 100 participants between the ages of 36 and 70 years who had received a first-time diagnosis of myocardial infarction. The participants were recruited at the heart care unit of the Division of Cardiology at a hospital in the southwest part of Sweden. We excluded those who had been diagnosed within 1 year of the study s inception, who did not belong to the geographic area served by the hospital, and who did not understand or speak Swedish. Recruitment was done among those diagnosed and treated for myocardial infarction. The first author (E.B.) collected data at the hospital before discharge and again at 2 weeks after discharge. Four weeks after discharge, participants were sent a questionnaire by mail that they were asked to complete. All participants gave their informed consent. This study was approved by the Hospital Ethics Committee and Research Ethics Committee. Instruments The SOC scale, a Swedish version of Antonovsky s 13-item short version of the SOC scale, was used to measure the degree to which the respondent found the world comprehensible, manageable, and meaningful. 7 A 7-point Likert-type scale was used with responses ranging from 1 ( very often ) to 7 ( very seldom or never ). Scores ranges from 13 (lowest SOC) to 91 (highest SOC). Internal consistency testing of the 13-item SOC scale produced a Cronbach s alpha ranging from.82 to.95. 7,8 In our study, the Cronbach s alpha score was.83. The Short Form-12 Health Survey Questionnaire (SF-12) is a generic health-related quality of life instrument measuring different aspects of health. 9 The SF-12 is a 12-item version of the Short Form-36 Health Survey Questionnaire (SF-36) 10 and includes 8 health concepts measured on 2 scales: a physical component summary (PCS-12) and mental component summary (MCS-12). A scoring algorithm is used to transform the score to a number between 0 and 100 for each scale. A higher score indicates greater health. 11 The SF-12 has demonstrated good validity and reliability in studies with varying samples, 12,13 including populations with heart disease. 14 Internal consistency for the SF-12 has produced a Cronbach s alpha, which in the present study was.80 for PCS-12 and.87 for MCS-12. The Seattle Angina Questionnaire (SAQ) is a disease-specific instrument measuring the health status of patients with coronary artery disease. 15 The SAQ is a 19-item self-administered questionnaire measuring 5 dimensions of coronary artery disease: physical limitation, anginal stability, anginal frequency, treatment satisfaction, and disease perception/quality of life. Each dimension is transposed onto a scale from 0 and 100, whereby high scores indicate better function (eg, less physical limitations and less angina). Because of the unique dimension of each scale, no global score is obtained. The SAQ is a valid, reliable instrument that measures the 5 dimensions and correlates significantly with other measures of diagnosis and patient function. 16 Internal consistency for the SAQ produced a Cronbach s alpha of.78 for the present study. The Health Curve is a questionnaire with a structured dialogue and includes 13 factors. Five factors address lifestyle: physical activity, dietary habits, alcohol consumption, smoking patterns, and psychosocial strain/psychologic illness. These factors are followed by 5 effect factors that include biological risk markers: serum cholesterol concentration, body mass index, waist to hip ratio, blood pressure, and the experience of mental strain and mental disability. Any family history of cardiovascular disease was also recorded. Each factor is assigned 1 of 3 or 4 levels, with 1 indicating low risk and 4 indicating high risk. 17 Data management and analysis All statistical analyses were performed using the Statistical Package for the Social Sciences Internal missing values in the SF-12, SAQ, and SOC were treated in accordance with the instructions supplied with each instrument. Univariate logistic 2 MONTH 2008 HEART & LUNG

3 Table I Demographic and clinical characteristics of the participants (n 100) Total Men Women Social status Married/cohabit Single Occupation Employed Retired Unemployed Related disease Diabetes mellitus Hypertension Atrial defibrillation Hyperlipidemia Other diseases noted: stroke, enterologic diseases, chronic obstructive pulmonary disease, rheumatoid arthritis, different cancer diagnosis, fibromyalgia, and polio. Treatment for MI PCI without stent PCI with stent CABG Fibrinolytic drugs Aspirin platelet inhibitors/warfarin blockers ACE inhibitors Diuretics Lipid-lowering drugs Antidepressive drugs Long-acting nitroglycerine Hospital stay Mean (Range) Mean (Range) Mean (range) 6.9 d (2 30 d) 6.9 d (2 30 d) 6.7 d (2 22) MI, Myocardial infarction; PCI, percutaneous coronary intervention; CABG, coronary artery bypass surgery; ACE, angiotensinconverting enzyme. regression analysis was used to evaluate gender differences. To explore differences between SOC groups, univariate and multiple stepwise logistic regression analyses were used. 19 Because there were statistically significant gender differences, correction for gender was included in all models comparing SOC groups in which both men and women were dealt with simultaneously. To compare data profiles between groups independently of the different units of measurement across covariates, data were Z-transformed for each covariate. This procedure yields profiles with all covariates presented as standard normal distributions. In all analyses, a P value less than.05 was considered significant and all confidence intervals presented are at the 95% level. 20 RESULTS The study participants consisted of 79 men and 21 women ranging in age from 36 to 70 years, with a median age of 57 years. Seventy-four participants were married or living together, 66 participants were employed, and the remaining 34 participants were retired or unemployed; 61 participants had an educational level above comprehensive school. There was a variety of other diseases in the sample than cardiovascular disease, for example, gastroenterologic diseases, chronic pulmonary diseases, rheumatoid arthritis, fibromyalgia, and cancer. Only 3 of 100 patients received antidepressive drug therapy. More characteristics of the participants treatment are shown in Table I. HEART & LUNG VOL. XX, NO. X 3

4 Table II Sense of coherence grouping versus the Short Form-12 Health Survey Questionnaire, Seattle Angina Questionnaire, and Health Curve measurement baseline Characteristics Low SOC Medium SOC High SOC Gender No. (%) n 99 Female 10 (47.6) 8 (38.1) 3 (14.3) Male 17 (21.5) 42 (53.2) 19 (24.1) Short Form Health Questionnaire-12 mean (SD) n 98 MCS at discharge 42.5 (11.1) 52.1 (11.2) 54.8 (10.7) MCS 2 wk after discharge 43.9 (11.8) 50.3 (10.9) 51.8 (8.5) PCS at discharge 40.6 (10.3) 43.3 (10.3) 42.8 (10.5) PCS 2 wk after discharge 36.9 (10.0) 37.1 (7.7) 40.3 (9.5) Seattle Angina Questionnaire mean (SD) n 98 Physical limitation 68.8 (27.6) 75.7 (20.6) 76.6 (19.0) Anginal stability 72.2 (30.5) 77.6 (26.1) 85.7 (24.5) Anginal frequency 71.5 (22.7) 82.4 (20.4) 90.5 (15.3) Treatment satisfaction 81.3 (17.0) 85.2 (17.7) 91.0 (9.2) Disease perception/qol 47.8 (19.6) 60.2 (22.5) 65.9 (20.9) Health Curve mean (SD) n 98 Physical activity (kcal/wk) (961.8) (1988.2) (1468.0) Fat points 47.3 (22.3) 60.9 (28.6) 59.1 (34.2) Fiber points 12.0 (3.4) 12.5 (2.3) 12.4 (2.5) Dietary points 6.0 (2.3) 6.8 (2.4) 7.0 (2.6) Alcohol intake (cl/wk) 17.7 (26.1) 12.6 (14.6) 20.7 (17.4) Cigarettes/day before MI 6.6 (9.8) 3.4 (7.2) 1.8 (3.9) Psychosocial strain.93 (1.3).4 (1.1).73 (1.6) Stress/psychologically unhealthy 3.0 (2.1) 2.2 (1.8) 1.8 (2.0) BMI kg/m (4.0) 27.6 (4.7) 27.8 (3.9) Hip/waist quota.9 (.1).9 (.1) 1.0 (.1) Serum cholesterol (mmol/l) 5.7 (1.3) 5.1 (1.4) 5.9 (1.5) LDL (mmol/l) 3.6 (1.2) 3.2 (1.2) 3.8 (1.2) HDL (mmol/l) 1.3 (.4) 1.2 (.6) 1.3 (.4) SOC, Sense of coherence; SD, standard deviation; QOL, quality of life; MCS, mental component summary; PCS, physical component summary; MI, myocardial infarction; BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein. Sense of coherence SOC scores were available for 99 participants (the score was unavailable for 1 male patient). The mean value was 69.4 (standard deviation [SD] 11.6), the median was equal to 71, and the scores ranged from 39 to 91. This is in accordance with the SOC scores for the corresponding age interval in a large Swedish random sample (n 39,656), in which a median equal to 71 and a mean value of 69.6 were found. 21 It is notable that the 3 persons with antidepressive drug therapy are dissipated in all 3 SOC groups (not shown). Short Form-12 Health Survey Questionnaire All participants answered the PCS-12 and MCS-12 at discharge; these measurements were repeated 2 weeks after discharge. There were no significant differences between the 2 measurements on a group or individual level (Tables II and III). The MCS-12 score in norm data in the Swedish population in a middle-sized town was a mean of 53.4 for men and for women. The PCS-12 score in norm data was a mean of 51.5 for men and 50.0 for women. 22 Comparing the patients PCS-12 and MCS-12 (Table 4 MONTH 2008 HEART & LUNG

5 Table III Gender, Short Form-12 Health Survey Questionnaire, Seattle Angina Questionnaire, and Health Curve in sense of coherence grouping Total Men Women Gender, n SOC score, mean (SD) 69.4 (11.6) 71.0 (10.3) 63.5 (14.4) Short Form-12 Health Survey Questionnaire MCS at discharge, mean (SD) 50.0 (11.9) 51.8 (10.4) 43.3 (14.7) MCS after discharge, mean (SD) 48.7 (11.1) 50.2 (10.0) 42.8 (14.5) PCS at discharge, mean (SD) 42.5 (10.3) 43.7 (10.0) 37.9 (10.1) PCS after discharge, mean (SD) 37.8 (8.8) 39.0 (9.0) 33.3 (6.1) Seattle Angina Questionnaire Physical limitation, scale points (SD) 75.0 (21.5) 76.3 (21.7) 70.3 (20.8) Anginal stability 78.1 (27.2) 82.5 (23.0) 61.9 (35.0) Anginal frequency 81.2 (20.9) 83.2 (20.9) 73.8 (19.9) Treatment satisfaction 85.5 (16.2) 86.9 (15.9) 80.5 (16.9) Disease perception/qol 59.9 (22.1) 62.2 (20.7) 42.1 (20.2) Health Curve Physical activity (kcal/wk) (1688.2) (1831.5) (959.2) Fat point 56.6 (28.6) 60.3 (29.8) 42.7 (18.5) Fiber point 12.3 (2.7) 12.2 (2.7) 12.8 (2.5) Dietary points 6.6 (2.4) 6.7 (2.5) 6.1 (1.9) Alcohol intake (cl/wk) 15.8 (19.0) 18.9 (20.0) 3.9 (5.6) Cigarettes/day before MI 3.9 (7.6) 3.1 (6.2) 6.9 (11.1) Psychosocial strain.6 (1.3).6 (1.4).6 (.8) Stress/psychologically unhealthy 2.3 (2.0) 2.1 (1.8) 3.1 (2.2) BMI kg/m (4.3) 27.7 (4.1) 29.4 (5.1) Waist/seat quota.9 (.1) 1.0 (.1).9 (.1) Cholesterol/s (mmol/l) 5.4 (1.4) 5.3 (1.4) 5.8 (1.5) LDL (mmol/l) 3.4 (1.2) 3.4 (1.2) 3.6 (1.3) HDL mmol/l 1.2 (.5) 1.2 (.5) 1.2 (.3) Weight (kg) 85.4 (14.9) 87.2 (14.4) 78.6 (15.2) Waist (cm) 98.2 (11.3) 98.9 (10.3) 95.6 (14.3) Seat (cm) (8.8) (7.2) (12.1) SOC, Sense of coherence; SD, standard deviation; MCS, mental component summary; PCS, physical component summary; QOL, quality of life; MI, myocardial infarction; BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein. 3) with scores from a study with first myocardial infarction patients the mean scores were quite similar; PCS-12, 37.0 vs 42.5 and MCS-12 mean of 46.2 vs Seattle Angina Questionnaire The response rate on the SAQ was high. Only 1 participant lacked data in 2 of the 5 dimensions. Fifty percent of the participants had an angina stability of 100%, and only 11% of the participants had angina stability less than 50%. Many participants (42/99) had an angina frequency of 100%, that is, these patients exhibited no angina (Tables II and III). Health Curve questionnaire All participants answered the Health Curve questionnaire. The majority of those surveyed were nonsmokers (71%) and consumed no alcohol or only small quantities ( 15 cl) (59%). Eighty-seven percent of participants reported satisfactory psychosocial circumstances, and most of the participants (61%) had no stress-related problems. Hereditary of diabetes was found in 18 participants. The fathers of 19 participants and the mothers of 11 participants had developed cardiovascular disease at an early age ( 65 years). Body mass index values indicated overweight in 62% of the participants, and 58% had HEART & LUNG VOL. XX, NO. X 5

6 60,0% Gender female male 50,0% 40,0% 30,0% 20,0% 10,0% 0,0% Fig 1 Distribution according to gender in each SOC group. SOC, Sense of coherence. a high or very high waist-to-hip quotient. Information from the Health Curve is presented in more detail in Tables II and III. Differences between genders Differences according to gender and SOC grouping are shown in Fig 1. The most significant differences between men and women found in this study are shown in Fig 2. There were no statistically significant gender differences in regard to demographic characteristics. Seventy-six percent of the men and 67% of the women were married or living with a partner. Seventy percent of the men and 52% of the women were employed. An educational level above comprehensive school was found in 60% of the men and 67% of the women. The median age was 57 years for the men and 59 years for the women. Men had a significantly higher SOC score than women (odds ratio [OR] 1.06, ) with a mean value equal to 71 (SD 10.3) for men and 63.5 (SD 14.4) for women. In the SF-12, men had statistically significant higher scores in both the PCS-12 and MCS-12 at discharge and 2 weeks after discharge; P.05 (Table III). Men had higher values in all 5 SAQ dimensions compared with women. Angina stability was significantly higher (P.01) with an OR of 1.03 ( ), as was disease perception with an OR of 1.05 ( ) (P.001) (Table II). In the Health Curve, there were no gender differences concerning smoking and physical activity, fiber intake, body mass index, waist-to-hip quotient, psycho-social circumstances, heredity of diabetes, maternal cardiovascular disease, cholesterol concentration, or diastolic blood pressure. Men had an alcohol intake of 16 cl or more per week, more frequent than women (OR 3.7, ); men also had a higher fat intake (OR 1.03, ). Women experienced elevated levels of stress compared with men, whose stress levels were low (OR 5.1, ) or moderate (OR 5.3, ). Among the men, 52% had a father with cardiovascular disease, 18% at less than 66 years of age; the corresponding figures for women were 28% and 24%, respectively, which does not indicate a statistically significant gender difference (P.06). Information from the Health Curve is presented in more detail in Table III. Differences between SOC groups Three SOC groups, low, medium, and high, were defined on the basis of the quartile values found in the large Swedish random sample mentioned above. 20 The low SOC group comprised 27 participants with SOC scores ranging from 39 to 61 (mean 54.4, SD 6.7); the medium SOC group comprised 50 participants with values ranging from 62 to 79 (mean 71.0, SD 4.5); and the high SOC group comprised 22 participants with values ranging from 80 to 91 (mean 83.9, SD 3.0). Among the women, 48% 6 MONTH 2008 HEART & LUNG

7 1,00 0,80 Female Male 0,60 0,40 0,20 0,00-0,20-0,40-0,60-0,80-1, MCS-12 at discharge from hospital 2. Angina frequency 3. Disease perception 4. Treatment satisfaction 5. Angina stability 6. Physical activity 7. Alcohol 8. Cholesterol Fig 2 Z-score profiles of each gender, including some characteristics found most important in explaining SOC. MCS, mental component summary. were in the low SOC group, 38% were in the medium SOC group, and 14% were in the high SOC group. The corresponding figures for men were 22%, 54%, and 24%, respectively. There was some (although not statistically significant) difference between gender and SOC group affiliation. Because of gender differences in the covariates, men and women should be treated separately when exploring differences between SOC groups. However, because this was not possible in the present study because there were too few women, the total sample (including both men and women) was explored together with correction for gender as the first step of each logistic regression analysis. High SOC group versus low SOC group The 22 participants in the high SOC group (19 men and 3 women) had better mental health with a higher MSC-12 score value at discharge (OR 1.1), lower angina frequency (OR 1.06), greater treatment satisfaction (OR 1.07), higher disease perception (OR 1.05), and more physical activity (OR 9.5) compared with the 27 participants (17 men and 10 women) in the low SOC group (Tables III and IV). The differences between the high and low SOC groups were thus mainly due to the disease-specific health parameters in the SAQ instrument. The proportion of women was considerably greater in the low SOC group than in the high SOC group, possibly affecting the results, despite gender correction. The women were too few to be analyzed separately; but, by excluding the women and analyzing the male subsample, any female influence on the differences between high and low SOC groups could at least be indirectly expressed. The analyses performed on the male subsample proved, in accordance with the findings in the total sample, that the men in the high SOC group had higher disease perception, greater treatment satisfaction, and lower angina fre- HEART & LUNG VOL. XX, NO. X 7

8 Table IV Univariate and multiple logistic regression analyses comparing sense of coherence groups Univariate analyses Multiple analyses Covariates OR 95% CI Sign OR 95% CI Sign Step High vs low SOC n 49 Gender Male NS Female 1.0 MCS-12 at discharge High value Low value 1.0 Treatment satisfaction Angina frequency High value Low value 1.0 Disease perception High value Low value 1.0 Physical activity 2000 kcal/wk kcal/wk NS 500 kcal/wk 1.0 Medium vs low SOC n 77 Gender Male Female 1.0 MCS-12 at discharge High value Low value 1.0 High vs medium SOC n 72 Gender Male 1.21 NS Female 1.0 Cholesterol High value Low value 1.0 Alcohol 15 cl/wk cl/wk 1.0 Angina stability 100% % 1.0 OR, Odds ratio; CI, confidence interval; SOC, sense of coherence; NS, not significant. quency when compared with the men in the low SOC group. The increased physical activity and better mental health in the high SOC group could not be verified in the male subsample and might thus be interpreted as a female contribution to the differences between the 2 SOC groups. High SOC group versus medium SOC group The medium SOC group consisted of 50 participants (42 men and 8 women). The participants in the high SOC group had higher cholesterol levels 8 MONTH 2008 HEART & LUNG

9 0,80 0,60 low SOC medium SOC high SOC 0,40 0,20 0,00-0,20-0,40-0,60-0, MCS-12 at discharge from hospital 2. Angina frequency 3. Disease perception 4. Treatment satisfaction 5. Angina stability 6. Physical activity 7. Alcohol 8. Cholesterol Fig 3 Z-score profiles of all 3 SOC groups, including some characteristics found most important in explaining SOC. SOC, Sense of coherence; MCS, mental component summary. (OR 1.6), consumed more alcohol (OR 3.7), and had greater angina stability (OR 3.1) compared with those in the medium SOC group (Tables II and IV). The differences between the high and medium SOC groups seemed mainly to be an outcome of differences in lifestyle. The analyses repeated on the male subsample gave the same result, with exception of the angina stability, which was not significantly higher in the high SOC group of the male subsample. All women in the high SOC group had an angina stability of 100%. Medium SOC group versus low SOC group The only difference found between these 2 groups was in regard to mental health: There was a higher MCS-12 score value at discharge in the medium SOC group than in the low SOC group (Tables II and IV). The analyses performed on the male subsample confirmed this finding but also revealed some differences in lifestyle. The male medium SOC group had lower alcohol intake (OR 1.03), lower cholesterol values (OR 1.8), and greater frequency of angina (OR 1.03) compared with the male low SOC group. The most important differences between the 3 SOC groups found in this study are presented in Fig 3. DISCUSSION In our study sample, women had lower SOC scores than men. The literature contains contradictory reports about gender affecting SOC scores The same is true of reports about age affecting SOC scores: Some find that SOC tends to increase with age through the whole life span, 26,27 whereas others report that their calculations show SOC scores decreasing with age, 25 especially when disease is taken into consideration. 28,29 We found that there were some differences regarding these factors. Women did score significantly HEART & LUNG VOL. XX, NO. X 9

10 lower than men on the dimensions of angina stability and disease perception/quality of life. Another study 30 showed that satisfaction with in-hospital rehabilitation was slightly higher in women, but that there were no gender differences in preference for cardiac rehabilitation features. Disease perception, measured in the SAQ, is the parameter that presents the largest difference between women and men, and that seems to have the most significance in gender comparisons and comparisons between SOC score groups (Fig 2). A recent study 31 showed that lower disease perception may also have a heightened dropout rate from an outpatient cardiac rehabilitation program. Disease perception seems to be a variable with significant prediction values in indicating capacity to make lifestyle changes. One may speculate that we should attempt to increase the SOC scores of patients with low SOC scores and low disease perception, especially women. When looking at SF-12 measurements, our study found no significant differences between men and women. In comparison with mean scores for chronic conditions associated with myocardial infarction shown in a recent study, 32 our patient groups scored lower. Our findings indicate that the low SOC group feels worse than the medium SOC group at the time of discharge from the hospital. It is noteworthy that this difference is no longer apparent at the 2-week measurement (Fig 3). The different SOC groups showed no differences at that time. Antonovsky 33 investigated whether there is a stronger and more direct relationship between SOC and emotional well-being than between SOC and physical wellbeing. A previous study showed that the relationship between SOC and physical health is weaker than its link with mental health. 34 It has also been noted in a study of healthy lifestyle choices 35 that persons in the high SOC group are more physically active and drink more alcohol than those in the other 2 SOC groups. This finding about alcohol consumption may seem contrary to those with a lower SOC, but this is what this study showed. Our low SOC group had the lowest scores regarding angina instability of all the other SOC groups in the previous 4 weeks. The question posed was, Compared with 4 weeks ago, how often do you have chest pain, chest tightness, or angina when doing your most strenuous level of activity? 15 The question was difficult to answer because no alternatives were given for those patients who never had angina or experienced angina pectoris. The SAQ is an instrument designed to assess anginal symptoms, so what should one answer if there are no symptoms? Respondents may have recorded something they did not have because the question required them to choose at least a minimum frequency. Spertus et al 15 has discussed this issue. Patients with atypical symptoms may also have difficulty answering some of these questions, limiting the use of SAQ in certain populations. According to Spertus et al, the angina stability scale examines recent changes in symptoms, and those reporting a significant deterioration in their angina during the proceeding month had a higher 1-year mortality rate than others. We believe we must continue to follow our respondents to be able to judge the outcome value of these items in the SAQ. In all 5 dimensions physical activity, anginal stability, anginal frequency, treatment satisfaction, and disease perception/quality of life the low SOC group scored the lowest. As a result, the low SOC group was found to be less physical active and more unstable, to have more frequent attacks of angina, and to be less satisfied with their medical treatment and have lower disease perception/quality of life in comparison with those in the medium- and high SOC groups. Antonovsky 7 points out that those persons with high SOC perceive their health to be better than persons with low SOC scores. It is also notable that the medium SOC group represents approximately half of our sample cohort, so we think it is important that we follow all 3 SOC groups further, although this issue does not seem to arise in other articles about SOC. 36,37,38 It would be of interest to see if the patients in the medium SOC group will remain stable or if their SOC scores will decrease or increase. There seems to be a lack of consensus about the stability of SOC. Anginal frequency seems to be an important consequence of what SOC score group an individual is placed in. Which way does it work? Do high SOC scores indicate lower anginal frequency? It has been reported that patients with higher angina frequency have lower scores than patients with less frequent symptoms. 39 In our study, patients with low SOC had the most angina and the least disease perception regarding heart disease and were the least satisfied with their treatment. Is it possible to boost these patients into a higher SOC score group through patient education? Can their disease perception and understanding of myocardial infarction be altered to enable positive lifestyle changes, making them more pleased with life and improving their quality of life by reducing their symptoms? Lifestyle can include several identifiable factors affecting risk for myocardial infarction, and these factors may differ by gender. Women have lower fat 10 MONTH 2008 HEART & LUNG

11 and dietary points than men, not to a significant degree, but noticeable as another study also pointed out. 40 These lifestyle factors are shown to have an impact on cardiovascular disease, 4,41 so it would be important to track them over time. Can support, information, and education change such lifestyle behaviors, and if so, will the SOC change in accordance with this? Genetic factors are also important predictors. 3,42 The family history of patients with cardiovascular disease shows that 31% of them had a parent with coronary heart disease before the age of 66 years. Could this be a factor affecting their SOC? Such an experience might increase one s SOC, but it could trigger a sense of denial, causing one to avoid the issue. It may be important to try and reach those whose SOC levels affect their self-care and attitude toward lifestyle changes and who may already be at risk for genetic factors to reduce mortality. Lifestyle changes seems to have a profound influence on morbidity and mortality. 17 These baseline findings are suggestive and if pursued may show SOC to be a useful tool in predicting which people could benefit from extra efforts to support and assist them in making lifestyle changes. According to several studies, 43,44,45 a person s SOC can change. Studies have also shown that SOC scores can be raised and that the possibility of successful rehabilitation is improved with higher SOC scoring. 26,38,44 STUDY LIMITATIONS Only 21 women participated in our study, limiting our ability to draw conclusions. However, this distribution gives the picture of the population. The issue of reporting angina stability on the SAQ is problematic, because no alternative is given for those not experiencing chest pain, thus forcing a respondent into an answer that is not in agreement with his/her situation. Because this would affect the dimension of anginal stability, conclusions concerning anginal stability should be reviewed with caution and skepticism. The SAQ could be an appropriate tool if there is awareness of these limitations. DIRECTIONS FOR FURTHER RESEARCH The study provided a basis on which further studies may be projected. Studies conducted longitudinally would continue the exploration of factors identified and address questions left unanswered by the present study, such as the following: Is SOC a factor to be taken into consideration with regard to coronary artery disease? Can SOC be a useful tool in rehabilitation and secondary prevention? Is SOC itself a predictor or are there predictive factors hidden in the scale? Can SOC predict a disposition for change? We will attempt to pursue these questions in studies subsequent to this baseline investigation. CONCLUSIONS Few gender differences were found, even though women scored lower than men in SOC. Persons who seem to live the good life, who have higher values of serum cholesterol, consume more alcohol, are more physically (and perhaps more mentally and socially) active, and tend to experience life as meaningful, manageable, and comprehensible achieve high SOC scores and may be best able to handle life-altering changes in their personal health circumstances. In this context, SOC may turn out to be a useful predictor of a patient s possibilities for rehabilitation after a myocardial infarction. We are grateful to all who participated in this project. We thank statistician Birgit Ljungquist, PhD, for fruitful discussions and valuable comments on our material. REFERENCES 1. World Health Organization. WHO Cardiovascular disease. Available at: Accessed October 5, World Health Organization. WHO s mortality database. Available at: Accessed February 21, Socialstyrelsen. The Swedish National Board of Health and Welfare s Guidelines for Cardiac Care Available at: 2.htm Accessed October 5, Yusuf S, Hawken S, Ounpuu S, Dans T, Avezum A, Lanas F, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (The INTERHEART Study): case-control study. Lancet 2004;364: Bergman E, Berterö C. Grasp life again. A qualitative study of the motive power in myocardial infarction patients. Eur J Cardiovasc Nurs 2003;2: Bergman E, Berterö C. You can do it if you set your mind to it: a qualitative study of patients with coronary artery disease. J Adv Nurs 2001;36: Antonovsky A. Unraveling the mystery of health. London: Jossey-Bass Publishers; Antonovsky A. The structure and properties of the sense of coherence scale. Soc Sci Med 1993;36: Ware JE, Kosinski M, Keller S. A 12-item short-form health survey construction of Scales and preliminary tests of reliability and validity. Med Care 1996;34: Sullivan M, Karlsson J, Taft C. Swedish manual and interpretation guide. 2nd edition. Gothenburg: Sahlgrenska University Hospital; HEART & LUNG VOL. XX, NO. X 11

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