Meta-analyses of prospective studies on coronary heart disease, type A personality, and hostility.

BACKGROUND: Several large-scale prospective studies have failed to find an association between Type A personality (TAP) or hostility and coronary heart disease (CHD). The existing meta-analyses on this topic have several shortcomings, such as a selective search of the literature, the failed use of effect sizes, and methodological flaws. METHODS: The present meta-analyses cover all prospective studies until the end of 1998. The correlation coefficient r is used as effect size to yield information on the population effect size R and variance. Several analyses have been carried out to stratify for disease endpoints, samples (healthy population, CHD patients), and methods used to determine TAP or hostility. RESULTS: The population effect size (weighted average of all correlation coefficients) for TAP and CHD is R=0.003 (n=74,326, P=0.213), and for hostility and CHD R=0.022 (n=15,038, P=0.003). CONCLUSIONS: The population effect size for TAP and CHD is not significant. Hostility yields a significant association with CHD; however, the effect size is so low that it has as yet no practical meaning for prediction and prevention.

Stress and strain of blue and white collar workers during work and leisure time: results of psychophysiological and behavioral monitoring.

This study of 29 blue and 57 white collar workers (mean age 50 and 51 yr) investigated behavior and the level of subjective stress and objective strain during work and leisure time. Physiological and psychological parameters as well as behavioral activities were assessed simultaneously using a special ambulatory monitoring device capable of storing 23 h records. Total strain was operationalized by heart rate (HR), physical strain by physical activity, emotional strain by non-metabolic HR, and mental strain by HR variability. Analysis of the physiological parameters for the working hours from 8 to 16 h revealed differences between the hours for physical activity, HR, and non-metabolic HR but not for HR variability. Between 12 and 13 h, physical activity was somewhat lower and non-metabolic HR higher, presumedly caused by the lunch break. Physical activity and HR were higher for blue than white collar workers due to the different tasks of the workers. Self-reports of excitement and enjoyment during the working hours showed no main effects in the MANOVA. Comparison between total working time and leisure time revealed lower physical activity and HR but higher non-metabolic HR for leisure time. In the self-reports, however, leisure time was rated less exciting and more pleasant than working time. There was no indication of higher emotional strain for one or the other group, but mental strain at work was somewhat higher for the blue collar workers. In a questionnaire, white collar workers reported having significantly more stress at work and outside work than blue collar workers. Analysis of the behavior during leisure time (physical activity, activity, social contacts) showed only minor differences between the groups.

Factors associated with work resumption: a 5 year follow-up with cardiac patients.

Physiological and psychological parameters of 41 cardiac patients who retired after an inpatient rehabilitation treatment in Germany were compared with those of 41 patients (matched exactly according to sex, age, and diagnosis) who worked after a 5 year follow-up. Both samples were selected from a large pool of 733 consecutive cardiac patients participating in the rehabilitation program with follow-ups at 1, 3 and 5 years. The following physiological parameters were assessed: clinical characteristics such as biochemical variables and functional parameters of the left ventricle, performance and electrocardiogram during ergometric exercise, and medication. Psychological parameters assessed with questionnaires comprised: life satisfaction, physical complaints, and illness behavior, socioeconomic and anamnestic data. No substantial differences were observed for medical data, but psychological parameters showed striking differences. Retired patients were characterized by lower work satisfaction, complaints of being more handicapped by the disease, higher 'propensity for pension', more frequent complaints concerning their general state of health, and lower education level.

Occupational stress and strain of female students: results of physiological, behavioral, and psychological monitoring.

This study of 50 female students (mean age 23) investigated the level of acute and chronic subjective stress, objective strain of everyday university life, and behavior (time budget during a normal day). Physiological parameters, behavioral activities, and psychological parameters were assessed simultaneously both while at the university and at home using a special ambulatory monitoring device capable of storing 23-h records. Comparison between typical study (seminar, lecture) and leisure activities (resting, conversation, etc.) revealed lower heart rate variability during university-related activities, indicative of increased mental load. Physical activity was higher during leisure activities, but heart rate was even higher during study time. Students rated leisure activities to be more enjoyable but less exciting or arousing than studies. Two-factorial MANOVAs with the factors "stay' (at the university, at home) and "chronically stressed by studies', a rating made one week before the monitoring (stressed versus non-stressed students), showed significantly higher heart rates for the chronically stressed students, particularly while at the university as opposed to at home. These students also showed decreased heart rate variability as compared to the non-stressed students, indicating greater mental workload. No differences between the groups were found in socioeconomic variables and personality traits (neuroticism, extraversion, achievement motivation). The results are discussed in the context of the stress concept.

Blood pressure publication guidelines. Society for Psychophysical Research.

Blood pressure is one of the most commonly recorded functions in physiology and medicine, and it has become a major variable in recent psychophysiological and behavioral medicine research. Many methods have been developed for the measurement of blood pressure in clinical, laboratory, and natural settings. The broad objectives of this report are to summarize the most critical methodological issues in the measurement of blood pressure and to present principles and recommendations for the evaluation of blood pressure methods and findings in published studies.

Perception of emotions in everyday life: studies with patients and normals.

Five studies with nearly 500 subjects recruited from the university, the work place, and from rehabilitation clinics served to investigate the perception of emotional events in everyday life. Physiological parameters (heart rate, physical activity, additional heart rate) and psychological parameters (excitement, enjoyment) were assessed simultaneously throughout the day using a special ambulatory monitoring device capable of storing 23-h records. Emotional events were identified by an increase of heart rate without an accompanying increase in physical activity (additional heart rate) and under special requirements a feedback signal was given which requested subjects to answer predefined questions. Between these 'true' feedbacks, 'random' feedbacks were interspersed with no indication of emotional arousal. Subjects were unaware that the feedback signal was triggered by their own heart rate. Laboratory experiments with films of different emotional quality showed that the method is suitable for the detection of emotional arousal. Comparisons of true feedbacks (emotional events) with random feedbacks (neutral situations) did not show significant differences for excitement and enjoyment ratings for any of the normal samples and for one of the patient samples. Only a sample of coronary heart disease patients showed small differences in the psychological variables which were significant due to the large sample size. From the results it may be concluded that the perception of physiological changes indicating emotional arousal in everyday life is quite different from the results suggested by laboratory experiments. The findings are discussed within the theoretical framework of 'competition of cues' and 'cognitive schemas' proposed by Pennebaker (1982, The psychology of physical symptoms, New York: Springer).

Physical, mental, emotional, and subjective workload components in train drivers.

This study, using 12 train drivers on a high speed track and 11 drivers on a mountain track, tried to differentiate between the physical, emotional, mental, and subjective workload components imposed on the drivers during work. With the simultaneous recording and on-line analysis of heart rate and physical activity, the emotional component in terms of the so-called additional heart rate was separated from the physical component. Mental workload was calculated by the heart rate variability and by shifts in the T-wave amplitude of the ECG. Speed of the train, mode of driving, and stress of the situation were rated by two observers who accompanied the drivers in the cabin. During speeds up to 100 km/h as compared to standstills no heart rate changes occurred, but with speeds from 100 km/h up to 200 km/h heart rate decreased indicating a monotony effect. However, heart rate variability, and T-wave amplitude indicated higher mental load during driving in most speed categories. Starting the train and coming to a halt showed greater emotional workload as compared to moving. Observer ratings of stress and subjective ratings of stress by the drivers revealed several discrepancies. Discrepancies were also seen between workload as indicated by the physiological parameters, and corresponding stress ratings by the observers or by the drivers.

Differences between patients with asymptomatic and symptomatic myocardial infarction: the relevance of psychological factors.

Several hypotheses describe the phenomenon asymptomatic myocardial infarction (MI) blockade of afferent cardiac nerves, pain inhibition by endogenous opioids, and insufficient severity of myocardial ischaemia. Psychological factors, however, are rarely considered. The present study involved 35 asymptomatic (AMI) and 35 symptomatic patients (SMI) selected from a sample of 199 patients with myocardial infarction. During observation in a rehabilitation clinic, the following were assessed: biochemical variables; ECG at rest, at exercise, and during Holter monitoring; and a special 23 h monitoring of physical activity, ECG changes, and subjective feelings. Psychological assessments with questionnaires were also performed and comprised: personality evaluation; physical complaints; possible predisposing features for the development of MI; expectations regarding the benefit of rehabilitation; circumstances at the time of infarction; and socioeconomic and historical data. The hypothesis that physiological factors might explain the differences between AMI and SMI is not substantiated by our results. However, the hypothesis of the role of psychological factors is supported. As opposed to AMI patients, SMI patients are characterized by frequent complaints of poor health, neuroticism, and introversion. At the time of infarction, SMI patients had more frequent premonitory symptoms of longer duration. Moreover, SMI patients had more frequent previous hospital or nursing home admissions. At the end of the rehabilitation treatment, only 43% of the SMI patients were judged by their physician as fit for work as against 71% of the AMI patients.

Covariation and reliability of ECG parameters during 24-hour monitoring.

Although diverse ECG parameters are used in psychophysiology, relatively little is known of the covariation and reliability of these parameters. In the present study with 31 male cardiac patients, 24-h ambulatory ECG monitoring was used to describe the covariation and reliability of 18 ECG parameters. Analysis of the ECG parameters was done beat-by-beat and averaged on a 5-min basis. To describe different aspects of covariation, partitioning of covariance was used, yielding within-subjects, within-time periods, and residual correlations. Moreover, reliability was assessed for different time lags between 5 min and 22 h. Results indicate that the ECG parameters are only partly redundant, since several correlation clusters emerged with low correlations between these clusters. In order to utilize more information from the ECG, at least heart rate, heart rate variability, ST-amplitude, QRS-duration, and one of the main ECG waves (P-, R-, T-wave) would be necessary. Reliability was high for all parameters except heart rate variability measures.

Diurnal variations of ECG parameters during 23-hour monitoring in cardiac patients with ventricular arrhythmias or ischemic episodes.

ECG and physical activity (recorded with motion detectors) were continuously monitored during 23 hours in 31 male cardiac patients (81% with myocardial infarction). According to the occurrence of ventricular arrhythmias (VA) or ischemic episodes (IE), each patient was grouped in one of three diagnostic categories: neither VA nor IE, VA with or without IE, and IE only. Analysis of the ECG parameters was done beat-by-beat and averaged on a 1-min basis. Results were derived from the 2-hour means between 2 p.m. and 12 p.m. MANOVA revealed significant group differences for heart rate variability (greater for the group with VA), R-wave amplitude (higher for the group with IE), and P-wave amplitude (higher for the group with VA). Significant time effects were observed for all variables except QRS- and P-wave durations. As may be expected, physical activity and heart rate were lower at night. Heart rate variability, PQ-interval, PR-segment, QT-interval, ST-segment, and T-wave duration increased during the night. R-wave amplitude also increased but the relative P- and T-wave amplitudes decreased. The corrected QT-interval, QTc, was shorter at night and the ST-segment, J + 60-point, S-wave, and J-point amplitudes were less negative. Group X Time interactions were observed for T-wave amplitude. For this amplitude, the decrease during the night was prominent only for the VA group. The results of this study suggest that the three diagnostic groups can be differentiated by diverse ECG parameters.

Detection of emotionally induced ECG changes and their behavioural correlates: a new method for ambulatory monitoring.

Heart rate is a well-established indicator of emotional arousal and can serve to detect emotional events. One difficulty, however, is in separating emotional heart rate increases from those increases due to physical activity. On-line analysis of both heart rate and physical activity (recorded with motion detectors) with a portable minicomputer may be able to solve this problem. We have developed a special algorithm that compares the values for heart rate and activity of a particular minute with the values of the previous minutes. If heart rate of a specific minute exceeds the rate of the previous minutes without an accompanying increase of activity, an emotional event may possibly be assumed. In such a case, the patient is requested by a beep signal to answer relevant questions about what he is doing, how he feels, etc. Moreover the patient is allowed to activate the system for himself for special events, e.g. chest pain. Methodological results of a first feasibility study with 32 cardiac patients are presented.

Comparison of rehabilitation outcome between patients with psychophysiologic disorders and organic diseases.

Two groups of patients with either psychophysiologic disorders or organic diseases were examined four weeks prior to an in-patient rehabilitation treatment, at the beginning and at the end of the rehabilitation, and six months thereafter. Data were collected through questionnaires assessing personality dimensions, physical complaints, hypochondriac behaviour, mood, disease concepts, living habits, and socio-economic as well as medical data. The groups were comparable according to a wealth of socio-economic and medical data but differed in extraversion, emotional lability, physical complaints, mood, disease concepts, and performance during ergometric exercise. Even before treatment there were changes in some variables between the examination at home and the examination at the onset of the treatment. Many short-term and long-term positive treatment effects could be observed but some adverse trends also emerged. Changes in personality dimensions, mood, and disease concepts revealed differential trends for both groups. The results are discussed in the context of the illness behaviour concept.

[Life satisfaction and the course of rehabilitation--a study of cardiovascular patients]. / Lebenszufriedenheit und Rehabilitationsverlauf--Eine Untersuchung an Herz-Kreislauf-Patienten.

At the beginning and at the end of inpatient cardiac rehabilitation, 105 male cardiac patients were examined with a newly designed questionnaire for life satisfaction assessment (Fragebogen zur Lebenszufriedenheit-FLZ). Data collection moreover included the Freiburg Personality Inventory, the Freiburg Somatic Complaints Lists, an adjective list assessing current mood, questionnaires on anamnestic data, treatment expectancies and life habits, as well as medical data. Significant correlations found between the FLZ and subjective or objective criteria of rehabilitation outcome indicate the importance of life satisfaction, with more content patients showing better outcomes. No mean value differences were found in respect of medical data, less content patients, however, reported more previous hospital stays and rehabilitation treatments. Also, there is a tendency for physician to discharge these patients as "unfit for work". 83 of these 105 patients participated in the follow-up study twelve months later. Life satisfaction is now lower, somatic complaints and emotional lability have increased. 90 percent of the patients with high life satisfaction, but only 66 percent of those with low life satisfaction, are back at work on follow-up. Fitness for work at follow-up, though primarily related to the rating given at the end of inpatient cardiac rehabilitation, is influenced to a high degree by non-medical factors. The results obtained underline the significance of patient illness behaviour, and point to a need for further improving individual psychological counseling during cardiac rehabilitation.

Life satisfaction, illness behaviour, and rehabilitation outcome: results of a one year follow-up study with cardiac patients.

One year after an inpatient cardiac rehabilitation programme, 83 out of 105 male cardiac patients were subjected to a follow-up study. Data collection comprised the Life Satisfaction Questionnaire, the Freiburg Personality Inventory, the Freiburg Somatic Complaint List, an adjective list for current mood, and a follow-up questionnaire assessing life habits, health and work status. One year after discharge, reported life satisfaction is lower than at the end of the treatment, with the exception of the areas health and leisure time. Physical complaints and emotional liability increased as well. On the other hand, patients' ratings of the success of the rehabilitation programme remain unchanged, with positive evaluations on completion of treatment as well as at follow-up one year later. At the start of rehabilitation, patients were divided into two groups with high or low life satisfaction according to their questionnaire scores. Various medical variables showed no differences between these groups. However, at follow-up, 90% of the patients with high life satisfaction and only 66% of those with low satisfaction were back at work. Resumption of work, although depending on the physician's rating, is influenced to a high degree by non-medical factors. These diverse factors are discussed in connection with patients' illness behaviour.

The law of initial value: a rare exception.

The well-known negative correlation between initial value and difference score, referred to as the law of initial value (LIV), is analyzed in the present study. It is shown that whenever the correlation between the initial and final values is less than 1.00, the negative correlation is influenced by the a(a - b) effect. By relating values to the first principal component axis, this spurious effect can be eliminated, thus allowing analysis of any real dependency on initial values. Data collected in a psychophysiological experiment were used to test this hypothesis. A subject sample of 125 male students experienced various challenges (Cold Pressor Test, breath holding, reaction time measurement, digit-series test) while several physiological variables (e.g. blood pressure, stroke volume, electrodermal activity) were monitored. Results fail to support the LIV as originally advanced by Wilder. On the contrary, after eliminating the a(a - b) effect, a positive dependency as indicated by the slope of the first principal component axis (anti-LIV) was observed. The reciprocal relationship between the LIV and anti-LIV is discussed with respect to the measures employed. Advantages and disadvantages of various methods to correct for the initial value dependency are presented.