Long-Term Survival Differences Among Low-Anxious, High-Anxious and Repressive Copers Enrolled in the Montreal Heart Attack Readjustment Trial

Transcription

1 Long-Term Survival Differences Among Low-Anxious, High-Anxious and Repressive Copers Enrolled in the Montreal Heart Attack Readjustment Trial NANCY FRASURE-SMITH, PHD, FRANÇOIS LESPÉRANCE, MD, GINETTE GRAVEL, MSC, ALINE MASSON, MSC, MARTIN JUNEAU, MD, AND MARTIAL G. BOURASSA, MD Objective: This study reports 5-year outcomes from the Montreal Heart Attack Readjustment Trial, a randomized, controlled trial of monthly telephone monitoring of psychological distress and home nursing visits in a sample of 1376 patients. It focuses on differences in long-term program impact associated with patients sex and baseline anxiety/ repressor coping styles. The potential mediating roles of medications, medical care utilization, and changes in negative emotions over the program are also explored. Methods: Three subgroups were defined using median splits on the State Anxiety Inventory and Marlowe-Crowne Scale administered at baseline: truly low anxious, repressors, and high anxious. Quebec medicare data were used to track survival through 5 years. Results: The trend toward worse prognosis in women in the treatment group and no evidence of treatment impact in men that were seen during the program year were maintained during the follow-up. Analysis of results in terms of coping styles showed a significant long-term survival benefit of treatment in highly anxious men, for whom reductions in somatic symptoms of depression mediated program impact. However, the program was also associated with significantly worse survival in repressors of both sexes. By the end of the program, repressors in the treatment group were more likely to be prescribed benzodiazepines and to have visited emergency rooms without being readmitted than those in the control group, suggesting that the program may have increased distress in repressors. Conclusions: Patients coping style is important in determining outcomes of psychosocial treatments and should be taken into account when tailoring interventions. Key words: myocardial infarction, psychosocial intervention, mortality, repressor, anxiety. ACE angiotensin converting enzyme; BDI Beck Depression Inventory; GHQ General Health Questionnaire; MC Marlowe-Crowne Social Desirability Scale; M-HART Montreal Heart Attack readjustment Trial; MI myocardial infarction; PSSS Perceived Social Support Scale; S-STAI Spielberger State Anxiety Inventory. From the Department of Psychiatry (N.F.-S., F.L.) and School of Nursing (N.F.-S.), McGill University; the Research Center, Montreal Heart Institute (N.F.-S., F.L., G.G., A.M., M. J., M.G.B.); the Departments of Psychiatry (N.F.-S., F.L.) and Medicine (M. J., M.G.B.), University of Montreal; and the Research Center, Centre Hospitalier de l Université de Montréal (N.F.-S., F.L.), Montreal, Canada. Address reprint requests to: Nancy Frasure-Smith, PhD, Montreal Heart Institute Research Center, 5000 Bélanger St. E., Montreal, QC, Canada, H1T 1C8. frsm@icm.umontreal.ca Received for publication May 31, 2001; revision received September 12, DOI: /01.PSY F8 INTRODUCTION The M-HART was a large (N 1376), randomized, controlled trial of psychosocial interventions for post-mi patients (1). It was designed to screen for and treat nonspecific psychological distress by means of a nursing, case-management approach. The approach was based on the evidence that increases in life stress can have negative prognostic consequences for post-mi patients (2), and it was reasoned that intervening at the time of peaks in distress could potentially improve outcomes. Patients randomized to the treatment group participated in a 1-year program of monthly telephone calls to monitor their psychological symptoms of distress using the 20-item GHQ (3). Those with high levels of distress at any call (GHQ 5) or who were rehospitalized received home-based nursing interventions. The nurses used a multifactorial, case management-type approach to help patients deal with their current sources of distress. Although a preliminary study showed evidence of positive program outcomes in men, no women were included, and methodological difficulties prevented drawing firm conclusions (4, 5). We conducted M-HART to test the hypothesis that program participation would reduce cardiac mortality for both women and men during the first post-mi year. One-year results were disappointing (1). Although more than three-quarters of patients in the intervention group received interventions consisting of an average of five to six 1-hour-long nursing visits, there was no overall impact on either survival or psychological outcomes. Furthermore, preplanned analyses by sex showed evidence of treatment-related increases in cardiac (p.064) and all-cause mortality (p.051) among women, with no evidence of any positive or negative impact for men. Considering the reasons for these outcomes, we speculated that the monthly telephone monitoring calls coupled with systematic intervention for even minor levels of psychological distress might have interfered with patients normal coping processes and, paradoxically, interfered with the trajectory of adjustment in some patients. We have now used Quebec medicare data to follow M-HART participants prognosis through 5 years after hospital discharge. This allowed us to explore two /02/ Copyright 2002 by the American Psychosomatic Society 571

2 N. FRASURE-SMITH et al. issues: 1) whether after the end of the program, the sex-related patterns of program impact on prognosis continued in the same directions and 2) whether longterm outcomes varied in relation to patients coping style at the time of the baseline interview (low anxiety, repression, or high anxiety) (6 8). METHODS Because the methods used in the M-HART study are described in detail in previous publications (1, 9), they will only be summarized here. Participants were recruited among patients hospitalized for an acute MI between January 15, 1991, and October 11, Before beginning recruitment, the protocol was approved by ethics committees in all 10 participating hospitals, and patients signed informed consent agreements describing randomization and study procedures and providing access to long-term follow-up data from Quebec medicare records. During hospitalization, 903 men and 473 women completed baseline interviews assessing background factors and medical history, as well as self-report measures of depression symptoms (BDI) (10), state anxiety (S-STAI) (11), anger (Spielberger Anger Expression Scale) (12), and social support (PSSS) (13). The 13-item version of the MC (14) was also administered. At discharge, 692 patients (234 women) were randomly assigned to the M-HART treatment program, and 684 (239 women) were assigned to usual care. Home interviews were conducted 1 year later with 92.2% (N 1209) of the survivors. The primary outcome for the long-term follow-up was cardiac deaths that occurred between randomization (hospital discharge) and 5 years after discharge. Patients with any physician contacts recorded in Quebec medicare data after 1825 days postdischarge were categorized as living at the end of follow-up. For other patients, additional information was obtained from hospital charts and death certificates. Survival status at 5 years was ascertained for all but 3.1% of patients (N 42). A cardiologist and a trained research assistant, blind to study group and interview data, each independently coded the causes of death as cardiac and noncardiac. Disagreements were resolved by discussion with a second physician who also classified the data. Statistical Analyses Data analysis was carried out using SPSS for Windows (version 10.07) (15). All tests were two-tailed, with p values.05 considered statistically significant and p values.05 but.10 representing potentially meaningful trends. Visual inspection of log cumulative hazards plots for survival times over 5 years supported the proportional hazards assumption, and we used Cox proportional hazards regression analysis to assess the long-term prognostic impact of treatment group and other baseline measures both before and after adjustment for covariates. To examine the potential role of patients baseline coping tendencies, we used median splits on the baseline S-STAI ( 35.0) and MC ( 9.0) scales to define three groups: subjects with scores below the median on both measures (truly low anxious), subjects above the median on the MC and below the median on the S-STAI (repressors), and subjects above the median on the S-STAI regardless of their MC scores (highly anxious). We used the approach of Shaw et al.(8) and did not divide the high-anxious patients into defensive and nondefensive groups because of previous research showing little difference between them. The survival times for the three coping groups were compared using Cox proportional hazards regression including assessment of the two-way and three-way interaction effects of the repression/anxiety subgroups, sex, and treatment group. To identify imbalances in background characteristics between treatment and control group patients in the sex by treatment and repression/anxiety subgroups involved in significant interactions, we used logistic regression to compare treatment and control patients for dichotomous factors and analysis of variance for continuous factors. Baseline factors differing at p.10 were adjusted in subsequent Cox regression analyses. RESULTS Long-Term Program Outcomes in Women and Men Among the 1334 patients whose survival status at 5-years was known, there were 236 deaths, including 180 of cardiac causes and 56 noncardiac deaths. Table 1 shows that as was the case during the program year, there was no evidence of long-term program impact on mortality for men. In contrast, before covariate adjustment, for women there was a trend suggesting a treatment-related increase in cardiac mortality (p.054) and a significant difference in all-cause mortality over 5 years (p.041). As with results for the program year, adjustment for baseline imbalances in smoking and age increased the probability for program impact to.10. The adjusted Kaplan-Meier survival curves (with noncardiac deaths censored on the day of death) for men and women appear in Figure 1. Long-Term Program Outcomes in Relation to Baseline Repression and Anxiety Levels In our consideration of the 1-year results (1), a major hypothesis for the lack of treatment impact in men and the evidence of a negative impact in women was that by repeated telephone contacts for all treatment group patients and repeated home visits for those with high distress scores (the great majority of patients), the program may have interfered with normal coping in some patients, preventing them from completing the natural process of adjustment and paradoxically increasing distress. Although the number of deaths during the program year was too small to explore this hypothesis in sex-specific subgroups likely to have differed in coping styles, long-term follow-up increased the number of cardiac deaths from 56 (4%) to 180 (13%), making subgroup analysis possible. We used median splits on the baseline S-STAI ( 35.0) and MC scores ( 9.0) to define three groups suggested by Weinberger et al. (6): those with truly low anxiety (N 274), the repressors (N 408), and those with high anxiety levels, who have also been referred to as sensitizers (N 676). The S-STAI and/or MC were missing for 18 patients. Although repressors were less likely than the truly low-anxious or high-anxious patients to have any high GHQ scores during the year and to receive nursing 572

3 REPRESSION, INTERVENTION, AND POST-MI MORTALITY TABLE 1. Long-Term Cardiac Mortality Among Men and Women in the M-HART Treatment and Control Groups % Cardiac Mortality (N) HR for Treatment Over Treatment Control Time Period (95% Confidence Interval) p Value a Men (N 458 treatment; 445 control) Program Year 2.4% (11) 2.5% (11) 0.97 ( ) 0.94 First post-program year (among 1-yr survivors) 3.2% (14) 2.3% (10) 1.36 ( ) Postprogram years (among 1-yr survivors) 7.4% (33) 8.6% (37) 0.86 ( ) 0.53 Full 5-yr follow-up 9.6% (44) 10.8% (48) 0.88 ( ) 0.56 Women (N 234 treatment; 239 control) Program year 9.4% (22) 5.0% (12) 1.92 ( ) (0.15) b First postprogram year (among 1-yr survivors) 1.4% (3) 4.0% (9) 0.35 ( ) 0.12 (0.11) b 4 Postprogram years (among 1-yr survivors) 14.3% (30) 10.6% (24) 1.32 ( ) 0.31 (0.44) b Full 5-yr follow-up 22.2% (52) 15.1% (36) 1.52 ( ) (0.13) b a Based on the Wald statistic. b Adjusted for baseline imbalances between treatment and control women in age and smoking. visits (p.001), the great majority did receive visits (70% compared with 85% of the low anxious and 89% of the high anxious). Repressors also had the shortest duration of contact with nurses over the program year (on average 198 days vs. 214 days for the low anxious and 232 for the high-anxious group). There were no sex differences in these patterns in the three anxiety/ repression subgroups. There was a significant difference in long-term cardiac mortality among the anxiety/repression subgroups (unadjusted p.026), with patients in the truly low-anxious group having better long-term prognosis than the repressors or the highly anxious. However, this overall difference was complicated by a significant interaction involving anxiety/repression and treatment group (p.021), as well as a significant three-way interaction of the anxiety/ repression subgroups, sex, and treatment group (p Fig. 1. Cumulative covariate-adjusted survival over 1825 days postdischarge in men and women in the treatment and control groups of the M-HART Program. 95% CI 95% confidence interval..015). To explore these results, we assessed the two-way interaction of group by sex separately within each of the anxiety/repression subgroups. The interaction was not significant for the truly low anxious (p.11) or the repressors (p.95), but was highly significant for the high-anxiety group (p.002). Table 2 shows the data for long-term cardiac mortality in relation to these subgroups. The lack of a significant interaction between sex and treatment group among the low anxious and the repressors indicates a common pattern for both men and women. As indicated in Table 2, patients with truly low levels of anxiety at the baseline interview had very good prognosis with only 22 cardiac deaths over 5 years (8.0%), and there was no evidence of treatment impact. In contrast, there was a significant negative impact of treatment in repressors. Although treatment group repressors were more likely to have low education levels (p.022) and to be diabetic (p.024) than repressors in the usual care group, the long-term negative impact of treatment remained after controlling for these factors. The adjusted survival curves for the repressors in the treatment and control groups appear in Figure 2. Further analyses in the high-anxiety group revealed that although the treatment had no apparent impact during the program year for men (N 416), it had a significantly positive, unadjusted impact on long-term cardiac prognosis over the full follow-up period, as well as in the patients who survived the program year. These differences remained after control for diabetes, the only baseline factor for which there was any evidence (p.091) of imbalance between the treatment and control groups. The adjusted survival curves for highly anxious men appear in Figure 3. In contrast to the positive results for men, in women with high anxiety levels (who constituted the majority of women; N 260), results paralleled the results for women as a 573

4 N. FRASURE-SMITH et al. TABLE 2. Long-Term Comparisons for Cardiac Mortality Between Treatment and Control Patients According to Baseline Anxiety/Repressor Subgroups % Cardiac Mortality (N) Treatment Control HR for Treatment Over Time Period (95% Confidence Interval) p Value a Repressors (N 196 treatment; 212 control) Program year 6.6% (13) 3.3% (7) 2.05 ( ) 0.13 (0.17) b First postprogram year (among 1-yr survivors: 3.3% (6) 2.9% (6) 1.13 ( ) 0.83 (0.95) b 181 treatment, 204 control) 4 Postprogram years (among 1-yr survivors) 13.8% (25) 7.4% (15) 1.90 ( ) (0.14) b Full 5-yr follow-up 19.4% (38) 10.4% (22) 1.95 ( ) (0.047) b Truly low anxious (N 137 treatment; 137 control) c Program year 1.5% (2) 2.9% (4) 0.49 ( ) 0.41 First postprogram year (among 1-yr survivors: 1.5% (2) 2.3% (3) 0.65 ( ) treatment, 133 control) 4 Postprogram years (among 1-yr survivors) 4.4% (6) 7.5% (10) 1.13 ( ) 0.40 Full 5-yr follow-up 5.8% (8) 10.2% (14) 0.55 ( ) 0.18 High-anxious men (N 225 treatment; 191 control) Program year 1.8% (4) 2.6% (5) 0.67 ( ) 0.56 (0.73) d First postprogram year (among 1-yr survivors: 2.7% (6) 3.3% (6) 0.83 ( ) 0.75 (0.88) d 219 treatment, 184 control) 4 Postprogram years (among 1-yr survivors) 5.5% (12) 12.0% (22) 0.44 ( ) (0.028) d Full 5-yr follow-up 7.1% (16) 14.1% (27) 0.48 ( ) (0.032) d High-anxious women (N 124 treatment; 136 control) Program year 11.3% (14) 5.1% (7) 2.26 ( ) (0.17) e First postprogram year (among 1-yr survivors: 2.8% (3) 3.1% (4) 0.88 ( ) 0.87 (0.68) e 109 treatment, 128 control) 4 Postprogram years (among 1-yr survivors) 16.5% (18) 10.9% (14) 1.50 ( ) 0.25 (0.43) e Full 5-yr follow-up 25.8% (32) 15.4% (21) 1.76 ( ) (0.13) e a Based on the Wald statistic. b Adjusted for baseline imbalances between treatment and control group repressors in education and diabetes. c No baseline imbalances between low-anxious patients in the treatment and control groups. d Adjusted for baseline imbalances between high-anxious men in the treatment and control groups in diabetes. e Adjusted for baseline imbalances between high-anxious women in the treatment and control groups in index revascularization and diabetes. whole. There was somewhat worse prognosis during the program year (unadjusted p.078) and significantly worse long-term cardiac prognosis associated with treatment (unadjusted p.045). However, women with high anxiety in the treatment group were less likely to have been revascularized during the index admission (p.031) and somewhat more likely to be diabetic (p.089) than those in the control group, and, as in the women in general, controlling for these imbalances increased the p value associated with longterm treatment impact to.10. Potential Mechanisms for Outcomes in Repression and Anxiety Subgroups To explore potential mediators for the program s apparently negative impact among repressors and possible long-term beneficial impact in anxious men, we examined two types of mechanisms. The first potential mechanism is concerned with differences in medical care and/or prescription of medications. We wondered whether, possibly because of the availability of the M-HART nurses, repressors in the treatment group might have relied on the nurses for much of their care and thus received less medical care than their counterparts in the control group. We also wondered whether the nurses presence might have facilitated and encouraged use of the health care system in highly anxious men. To examine these possibilities, we looked at outpatient physician contacts (all physicians, cardiologists, noncardiologists, and psychiatrists), visits to the emergency room (with and without hospital admissions), and revascularization procedures during the year as indicated by Quebec medicare data, as well as information on prescribed medications recorded at the 1-year interview (beta-blockers, ACEinhibitors, calcium channel blockers, long-acting nitrates, triple anti-ischemic therapy, benzodiazepines, and antidepressants). The second alternative set of mechanisms for long-term program impact has to do with changes in negative emotions themselves, and we analyzed 1-year self-reports of depression (including 574

5 REPRESSION, INTERVENTION, AND POST-MI MORTALITY Fig. 2. Cumulative covariate-adjusted survival over 1825 days postdischarge in repressors in the treatment and control groups of the M-HART Program. overall scores on the BDI, as well as cognitive and somatic symptom subscales), anxiety, anger, and perceived social support after controlling for baseline measures. Our analyses of mediators were based on the criteria suggested by Baron and Kenny (16) that to be a mediator, a mechanism must be linked to both treatment group and treatment outcome and must remain linked to outcome after control for treatment group. If these three criteria are fulfilled, control for the mediator will also eliminate a large portion of the apparent impact of the treatment. Table 3 summarizes the results of these analyses for those potential mechanisms significantly linked to treatment group in the repressors and in the men with high anxiety. Data for the mechanistic variables not significantly related to treatment in these groups are not shown. Among the repressors, there were no significant treatment/usual care group differences in the frequency of outpatient physician visits. There was, however, a significantly greater proportion of treatment than control group repressors who went to the emergency room at least once without being readmitted, and this variable fulfilled all of Baron and Kenny s criteria for mediation. In contrast, although treatment group repressors were significantly less likely to be revascularized during the program year than control group repressors (p.042), there was no impact of revascularization on survival after control for treatment group, suggesting that the mechanism for worse outcomes in the treatment group was not explained by lack of revascularization. In fact, only one additional potential mechanism met all three criteria for mediation: prescription of benzodiazepines at 1 year. Significantly more treatment group repressors than control group repressors were taking benzodiazepines at the time of the 1-year interview, and this contrast remained after control for covariates. Benzodiazepines were linked to worse long-term prognosis, and this link remained independent of treatment group, thus control for benzodiazepine prescription accounted for most of the impact of treatment group on outcome. There had been no difference in prescriptions for benzodiazepines at the time of discharge after the MI (p.80), and further analysis revealed that not only was there a tendency for treatment group repressors who had been prescribed benzodiazepines at the time of hospital discharge to be more likely than usual care repressors to still be taking benzodiazepines at the 1-year interview (p.055), but also they were significantly more likely to be put on benzodiazepines (p.024) over the course of the year. Furthermore, although there was a tendency for treatment group repressors to have higher 1-year scores than the usual care patients on the BDI (unadjusted p.098), as well as its somatic symptom subscale (unadjusted p.084), these differences were largely eliminated by adjustment for education and diabetes, the baseline imbalances between the groups (adjusted p values were.16 and.33, respectively). In summary, there is some indirect evidence that the repressors in the treatment group may have experienced increases in distress associated with program participation. Because by definition, repressors tend to not recognize or report their feelings, it is not surprising that most of the treatment-related increase in their self-report measures of depression involved somatic symptoms of depression. Paralleling this was a markedly higher rate of prescriptions for benzodiaz- Fig. 3. Cumulative covariate-adjusted survival over 1825 days postdischarge in highly anxious men in the treatment and control groups of the M-HART Program. 575

6 N. FRASURE-SMITH et al. TABLE 3. Potential Mechanisms for Differences in Cardiac Prognosis Between Treatment and Control Group Repressors and Between Treatment and Control Group Men With High Anxiety Who Survived the Program Year p Value for Group Adjusted for Mechanism a HR Associated With Group Over Subsequent 4 yr Adjusted for Mechanism (95% Confidence Interval) p Value for Mechanism Adjusted for Group a HR Associated With Mechanism Over Subsequent 4 yr Adjusted for Group (95% Confidence Interval) p Value for Group Difference in Mechanism Treatment Control Repressors ER visits without admissions (%) (0.051) b 1.94 ( ) ( ).10 (N 180) (N 203) Revascularized during year (%) (0.042) b 0.41 ( ) ( ).088 Benzodiazepines (%) (0.014) b 2.56 ( ) ( ).23 (N 173) (N 183) High-anxious men Psychiatrist visits (%) (0.014) c 0.44 ( ) ( ).030 (N 217) (N 183) Somatic symptoms of depression (mean (0.027) c 1.17 ( ) ( ).36 BDI somatic subscale SD) (N 202) (N 168) Anxiety symptoms (mean S-STAI SD) (0.053) c 1.00 ( ) ( ).13 (N 203) (N 169) a Based on Wald Statistic. b Adjusted for baseline differences in education and diabetes. c Adjusted for baseline differences in diabetes. epines and a greater tendency to go to the emergency room for problems that did not result in readmissions, both possibly signaling greater anxiety over bodily symptoms. This suggests that the M-HART program may have increased distress levels in repressors to the extent that their physicians saw the necessity of prescribing benzodiazepines and that the long-term negative impact of the program in repressors may have been linked to continuing use of benzodiazepines over the follow-up period. Our examination of potential medical care differences between the highly anxious men in the treatment and usual care groups revealed no differences in overall contacts with physicians or in contacts with cardiologists. However, a greater percentage of them were seen by psychiatrists during the year than was the case for highly anxious men in the usual care group. Nonetheless, adjustment for psychiatric contact did not remove the impact of treatment group, suggesting that psychiatric care was not a mechanism explaining group impact. In addition, despite their higher frequency of psychiatrist contacts, there were no group differences in prescription of antidepressants or benzodiazepines. There were, however, significant unadjusted treatment/usual care group differences for somatic symptoms of depression and anxiety at 1 year, and evidence of these differences remained after control for diabetes, the only imbalanced background variable for the highly anxious men. Exploration of Baron and Kenny s criteria for mediation showed that changes in anxiety were unrelated to outcome after control for treatment group, but that changes on the somatic subscore of the BDI continued to predict the long-term survival of anxious men after control for treatment group. In fact, adjustment for changes in somatic depression symptoms removed the positive impact of treatment in highly anxious men, suggesting that treatment-related beneficial changes in somatic symptoms may have been a mechanism associated with their improved long-term prognosis. DISCUSSION Follow-up of the original M-HART cohort to 5 years after their index MI allowed us to examine patterns of program impact on mortality after the end of the program. We observed no overall long-term program impact for men. Among women, the trend toward negative impact of treatment participation during the first year remained over the full follow-up. As with the difference at the end of the program, the evidence of a long-term trend for treatment impact was reduced after adjustment for age and smoking, the two major treatment/control group imbalances in measured background factors in women. 576

7 REPRESSION, INTERVENTION, AND POST-MI MORTALITY We also observed a striking pattern of outcomes in relation to the anxiety/repression categorization of both men and women. There was evidence of a longterm negative impact of treatment in repressors regardless of their sex. Assessment of the potential programrelated mechanisms underlying the worse prognosis in treated repressors showed that although there were no differences in discharge prescriptions for benzodiazepines, there were almost twice as many treatment as control group repressors with prescriptions for benzodiazepines at the time of the 1-year interview. Treated patients were also more likely to have gone to an emergency room for something minor enough that they were not admitted to hospital. Subsequent analyses supported the role of both benzodiazepines and emergency room utilization as mediators of the long-term impact of treatment in repressors. Although there has been some speculation in the literature that anxiolytic use may be linked to increased mortality risks in some patients (17), the existing data are mostly based on older medications (primarily barbiturates). Therefore, there is no evidence that prescription of benzodiazepines per se was responsible for the difference in cardiac mortality. Instead, we believe that these results suggest that the type of person most likely to be prescribed benzodiazepines and to go to an emergency room for relatively minor problems was at greater risk in the treatment group. Although the literature on defensiveness and related constructs like denial and repression varies in the way they are operationalized (18 20), repression is usually defined as a form of defensiveness in which individuals are not consciously aware of their heightened arousal to various anxiety-provoking stimuli, but nonetheless use defensive strategies to avoid the stimuli (6). The term repressor is also used to describe individuals with a coping style in which information that is potentially threatening is avoided. This type of coping style has also sometimes been referred to as blunting or information/avoidance (21, 22). Despite some conflicting data, several studies with undergraduate students and young adults have shown that although repressors do not directly report elevated levels of negative emotions or physical symptoms in response to stressors, indirect and physiological measures, including skin resistance, heart rate, blood pressure, cortisol, and measures of immune function, indicate high levels of arousal (20, 23). The present results fit in well with this literature. We speculate that the greater physiological emotional arousal in the repressors in the treatment group may have been sufficient to provoke enough concern in patients and family members to lead to increased emergency room visits and enough concern in physicians to have increased prescriptions of benzodiazepines, but may not have been perceived by patients as changes in their emotional state and so was not reported as such. However, it is also possible that by the time of the 1-year measurement, repressors anxiety levels had been reduced by benzodiazepine use. Clearly, for there to have been no overall program impact as well as a negative impact in repressors, there must have been a positive impact of the program in some subgroup. In fact, we observed an improvement in long-term prognosis in men who had high levels of anxiety during their index hospitalization. In contrast, there was evidence of a negative prognostic impact in women with high anxiety. However, as for the women in general, adjustment for baseline imbalances between treatment and usual care women reduced the apparent negative impact of the program. For highly anxious men, adjustment for baseline differences did not alter the long-term positive impact of treatment. Furthermore, analysis of the potential mediators of this outcome suggest that improvements in depression symptoms, in particular in the somatic symptoms of depression, explained the long-term beneficial impact of treatment for highly anxious men. Intriguingly, this is the group for whom the program was originally designed and initially positively evaluated in the Ischemic Heart Disease Life Stress Monitoring Program (4, 5). However, we can only speculate as to why the treatment-related difference in prognosis in high-anxious men did not begin to become apparent until more than 1 year after the end of the program. One factor, may have been that consequent to the treatment-related reduction in the somatic symptoms of depression, a significantly greater proportion of high-anxious men in the control group (37.5%) had total 1-year BDI scores 10 than their counterparts in the treatment group (27.6%, p.042). Scores at this level on the BDI are considered indicative of at least mild to moderate levels of depressive symptoms, and when measured during hospitalization for an MI, such scores have been linked to cardiac prognosis (24). However, our recent long-term analyses of BDI scores in hospital and at 1 year in patients receiving usual care (25) suggest that although both scores have prognostic importance, the impact is less marked at 1 year. Outside the pathophysiological instability during the first few months after an acute MI, it may take longer for chronic depression to influence prognosis. An early study, carried out by Shaw et al. (7) in a sample of 30 post-mi patients, suggested that the degree of fit between repressive style and cardiac rehabilitation approaches might influence outcomes. Selfreported outcomes at 6 months suggested that repressors (high MC scores but low in anxiety) who 577

8 N. FRASURE-SMITH et al. had retained high levels of information at discharge had more subsequent complications and worse psycho-medical functioning (sleep, depression, and tension) than those with low levels of knowledge. In contrast, highly anxious patients with high levels of knowledge had better social functioning than those with low knowledge. Shaw s group speculated that repressors may be more comfortable with low levels of information about cardiac disease, and that higher levels result in information overload and increases in arousal. However, the highly anxious or sensitizers may do better when provided with additional information that may act to lower anxiety. All M-HART patients who were visited by nurses received some degree of education about cardiac disease and risk factors. In addition, it is likely that the monthly telephone monitoring calls from a telephonist who identified herself as from the Montreal Heart Attack Readjustment Trial kept most treatment group patients awareness of their cardiac conditions at fairly high levels. Although this may have been comforting for the type of patient who seeks out information or health care system contact as a form of reassurance, it may well have been a source of distress for patients whose preferred mode of coping was repression, or information avoidance. Our research has several limitations. First, although this is the first report of the long-term follow-up of the M-HART study, it nonetheless constitutes a secondary data analysis and shares the limitations of the original study. However, in an attempt to minimize the problems associated with multiple statistical testing of subgroups, we focused on two questions: the durability of sex differences in outcomes observed during the first program year and the possibility that the program had different outcomes depending on the coping style of the participants. Nonetheless, there were many tests involved in assessing the various potential mediators in each anxiety and repression subgroup, and this limitation should be kept in mind when considering results. We used median splits for the S-STAI and MC scales in the overall sample to define the repressor/ anxiety groups. Medians for these scales differed for men and women. Nonetheless, when patients were classified using the sex-specific medians, the pattern of results was the same. The literature varies in exactly how the combination of the S-STAI and MC scores is used to define various repressor groups (20). Some authors have used sample-specific means, some have used medians, and others have used upper quartiles. Our choice of median splits was based on an attempt to assure adequate power in the resulting subgroups. However, the lack of consistent thresholds for defining repressor and anxiety subgroups makes the reliability of the classifications questionable across studies. Despite these potential limitations, the mechanisms our analyses identified as potentially responsible for the treatment-related success in highly anxious men and poor prognosis in treatment group repressors make sense in terms of the existing literature and are internally consistent, lending additional support to the repressor/sensitizer concept. There is increasing evidence that repressors have worse health outcomes than their less defensive peers (20). Although the clinical importance of information coupling or tailoring has been discussed for years (22), we know very little about the best way to assure that cardiac patients with repressive coping styles receive enough information to assure compliance with needed lifestyle changes without increasing psychological distress. The development and evaluation of treatment packages optimizing the fit between intervention styles; disease-specific treatment needs; and patients personalities and social and family realities constitutes a major clinical and research challenge for the future. The long-term follow-up study was supported by grants from the Medical Research Council of Canada (Grant FRN:15152) and the Montreal Heart Institute Research Fund (FRICM). It was also supported by a salary award from the Pierre David Research Fund (to F.L.). 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