JOURNAL OF ORGANIZATIONAL BEHAVIOUR, Vol. 11, 171-185 (1990)

Lower health risk with increased job control among white collar workers

ROBERT KARASEK Department of Industrial and Systems Engineering, University of Southern California, Los Angeles, California, 90089, U.S.A.

Summary Associations between increased job control and health status were tested with questionnaire data from a random sample of full-time workers ( n 8504) from the national Swedish white collar labor federation, TCO (representing 25 per cent of the Swedish work force). Of these subjects, 1937 had undergone a company-initiated job reorganization during the previous several years. Workers in the job reorganization group who had influence in the reorganization process and obtained increased task control as a result had lower levels of illness symptoms on 11 of 12 health indicators controlling for age and sex (1 1 of 12 associations significant for males, four of 12 associations significant for females).

A previously validated measure of coronary heart disease was significantly lower in circumstances of increased job control for males (8.6 per cent symptom frequency with decreased control versus 3.4 per cent with increased control; p 0.05). Absenteeism was lower: 10.7 per cent versus 5.0 per cent (0.01). Depression was lower 27.8 per cent to 13.7 per cent (0.001). However, smoking was significantly higher for women 11.0 per cent versus 23.5 per cent (0.01). All illness indicators showed that the process of job reorganization itself was associated with significantly higher symptoms (‘change stress’). However for males (only) symptoms levels when reorganization was accompanied by increased control were often as low or lower than symptom levels for no reorganization at all. Unfortunately, job reorganizations involving employee influence and increased task control were Zess frequent than job reorganizations involving reduced influence and no increased control, especially for women and older workers.

Introduction The Quality of Worklife approach has traditionally focused on the joint improvement of employee well-being and opportunities for democratic participation in combination with im- proved firm productivity (with successes well documented in reviews by Lawler (1986), Kopelman (1989, Katzell, Beinstock and Faerstein (1977) and Glaser (1974). However, employee well-being, at least in the U.S. has of late received less attention, partially because of shifting political priorities, but also because of theoretical ambiguities in the traditional ‘job satisfaction’ approach to assessing employee well-being (Lawler, 1986; Aldag, Barr and Brief, 1981; Vroom, 1964).

Renewed attention might be focused on employee well-being by the QWL movement if it could be demonstrated that QWL job change techniques had significant impact on the more rigorously defined occupational health and safety outcomes - which are at least as important measures of well-being to employees as job satisfaction. However, except for the last decade of research in Sweden involving, for example, Gardell (1971), occupational health researcher and QWL researchers have rarely joined forces. Occupational health and safety professionals, for example,

0894-3796/90/030171-15$07.50 0 1990 by John Wiley & Sons, Ltd.

Received 24 February 1987 Final Revision 8 June 1988

172 R . KARASEK

have traditionally not made use of the possibilities for social restructuring of the work process in major ways that QWL practitioners engage in routinely. Simultaneously, almost none of the major QWL studies in the U.S. or Western Europe document the health consequences of the QWL job redesigns strategies (such as increasing skill or task autonomy levels) and occupational health research has only recently begun to examine the effects of psycho-social job characteristics which are the basis of QWLjob design. In this paper I will attempt to demonstrate such linkages on large representative data base of Swedish white collar workers.

Some rigorous studies have documented associations between increased employee participation and reduced levels of psychological strain (Jackson, 1983; Wall and Clegg, 198 1). Furthermore, some recent research has begun to document associations between, for example, low job skill and low autonomy levels (combined with high psychological demands) and coronary heart disease (CHD) and other stress-related physical illnesses. These CHD studies have included nationally representative cross-sectional studies involving a broad range of occupations in both the U.S. and Sweden (Karasek et al., 1988; Johnson, 1986; Karasek, Baker, Marxer, Ahlbom and Theorell, 1981), as well as four longitudinal studies bolstering causal interpretation of these associations (Alfredsson, Spetz and Theorell, 1985; La Croix, 1984; Alfredsson, Karasek and Theorell, 1982; Karasek et al., 1981). However, these studies have not yet tested the implications of these associa- tions in an experimental Gob change) context.

Of course, company -initiated job change processes are occurring constantly in economies such as the U.S. and Sweden, usually with the goal of increasing productivity, but the health consequences of these changes are rarely monitored. In this research study we have the opportunity to measure health consequences of just such company-induced job changes in a randomly selected national survey. We use a nationally representative data base of Swedish male and female full-time workers in the white collar labor federation TCO (n 8504). Health data include a validated self-report indicator of CHD and 11 other health status and health-related behavior measures.

Our primary focus in this study is global: to test for some clear association between the broad concept of workplace control and improved health status. To simplify presentation of findings and improve the robustness of our independent variable we will aggregate several measures of control (after empirical justification). However, the study structure also allows examination of some theoretical distinctions that are currently being discussed relating to different forms of workplace control (Frese, 1988). Is control over micro level task or control and influence in the workplace decision making processes at the macro level more important for worker well being? We can address this question because we have information about worker’s macro level influence in the job change process as well as information on micro level task changes. Unfortunately, another important question (Kasl, 1988), whether control over work processes in general (autonomy) is more important than the empirically and theoretically related concept of discretion over use of skills (variety) will only be partly addressed. Influence over the work process at the macro level is separately assessed, but at the micro level we have used a combined measure of autonomy and variety similar to that used by Karasek (1979), Kohn and Schooler (1973) and Gardell (1971). It should be noted that common job design philosophies used by management enforce the simultaneous application of these two aspects of control (similar to ‘decision latitude’, Karasek, 1979) at the task level.

Reducing stress-related health risks by changing job structures introduces a further, little- discussed problem: whether the organizational change process itself could be so ‘stressful’ as to cancel out the beneficial effects of an intervention. Certainly the stressful life events literature (see for example: Dohrenwend and Dohrenwend (1974) provides evidence that major life changes in themselves increase risk. Job termination, for example, has certainly been found to have adverse health impacts (Cobb and Kasl, 1977). Of course job reorganizations probably represent less

HEALTH RISK AND JOB CONTROL 173

disruptive changes than unemployment, but still the short term costs of stressful change might have to be balanced against the long term ‘stress reducing’ gains. Of course, since many job changes are already occurring, with little concern for employee health, the true criterion should be whether such ‘productivity-focused’ job changes might be modified to improve their health consequences without hindering economic and technical goals. Thus, we will separately address health consequences of control in the change process itself as well as health consequences of decision latitude in the resulting psycho-social task structures.

Method Data The data was collected in a large random (1: 70) survey of all white collar workers in Sweden’s Federation of White Collar Unions, TCO (Tjanstemannens Centralorganizationen) in 1976. The survey is considered to be both rather homogenous with respect to social class and highly representative of the Swedish white collar work force (very highly unionized). The highest levels of managers and university educated professionals are not included. The survey response rate was 87 per cent and selection of full time males and females has resulted in final sample sizes of 4881 males and 3623 females. The sample and its measures were described in detail recently in this journal (Karasek et al., 1987). (For further discussions of the survey see: Wahlund and Nerell, 1976; Lindell, 1982; Karasek, Gardell and Lindell, 1985).

While the data are drawn from a cross sectional survey, there are several features which make it a basis for substantially stronger causal inferences than could normally be drawn from cross- sectional data. In time ordering job changes generally precede health status information. Job changes are exogenously determined by ‘random’ company actions; initiation of these actions was beyond the major influence of the subjects. A large non-change population exists to serve as a spontaneous, random control group (job changes affected 25 per cent of males and 21 per cent of females). The interventions were randomly applied by relatively ‘blind’ experimenters. The interventions were implicitly ‘sampled’ from a cross-section of all companies in the Swedish economy. Companies did not select themselves for willingness to undergo changes or to report results (thus fulfilling all of Hackman’s (1984) rigorous field study criteria). Thus although data is retrospectively reported, in several ways this study is similar to quasi-experimental longitudinal studies in experimental inference structure, and it is much stronger than most quasi-experimental studies in representativeness. It is thus one of the closest approximations to a large population ‘intervention’ study, (in medical terminology) that exists for some health conditions, such as heart disease.

The vast majority of job changes precede health status reports. The question wording relating to the timing of job changes (‘During the past several years . . .’) implies that the job changes occurred during the prior two to four years in common Swedish usage. Major job changes occur at a constant rate and events are probably recalled with a fairly linear frequency (albeit slowly diminishing over time). Health status is recorded during the ‘previous 12 months’. However, questionnaire health status reports overwhelmingly represent near term health status of the individual (past month or two (Tiagha, 1982)). Thus, the actual probabilities of job change preceding health reports are probably higher than 95 per cent.’ Further confirming this causal

I Making the more conservative assumptions that both time distributions were ‘normally distributed’ (with 95 per cent of events within the specified time interval) and assuming a three-year change period, then job changes would precede health status reports in 92 per cent of the cases.

174 R. KARASEK

ordering is the fact that most major job changes have many of their significant health effects in anticipation of the event by as much as six months (Cobb and Kasl, 1977).

Secondarily, we will discuss mechanisms of causal association related to the ordering of the two different types of data we have on control at the job: process influence and resulting task control. When a job change occurs, the first question is whether the employee has influence over the change. The second question is whether more control (roughly ‘decision latitude’) over the task results from the change process. These both are followed in time by reported health status. Our primary tables report associations for both types of control combined, since the effects are usually similar magnitude and in the same direction (separate impacts of change influence and increased task control can be ascertained in the Appendix).

Dependent variables Six indicators of physical illness and three indicators of psychological distress were developed using factor analysis of questionnaire responses, and scale construction techniques. Three indicators of health-related behavior were also available. The indicators include coronary heart disease (CHD), gastro-intestinal problems, respiratory problems, muscular skeletal aches, dizziness, headaches, depression, exhaustion, and job dissatisfaction, pill consumption, absenteeism (over four times/ year) and smoking (over 16 cigarettes/day). Each indicator was dichotomized to define evidence of a significant health problem - usually defined as a report of at least one ‘very often’ response on three to five questions within a health problem area such as ‘muscular skeletal aches’ (scale components, construction techniques, and response frequencies are discussed in detail in this journal (Karasek et al., 1987) as well as in Karasek et al. (1985).

The frequencies of reported illness by age and sex are generally comparable to levels reported in other Swedish nationally representative surveys (with some discrepancy for dizziness). Data accuracy for such questionnaire data in Sweden has been judged acceptable for reporting of Swedish national health status (Johansson, 197 l), although a long tradition of research using self-reported measures of psychological health has shown the need for substantial interpretive caution. While the self-reported physical illness conditions may underestimate some illness there are few ‘false positive’ cases reported (see Karasek et al., 1985). Specific validations of these self-report indicators exist for absenteeism (Lindell, 1982) and the coronary heart disease (CHD) scale.

The CHD scale used in the study has been rather systematically validated: questions were reviewed for their theoretical relevance by the author and Dr Tores Theorell (Institute of Psychosocial Environmental Medicine, Karolinska Hospital, Stockholm) to replicate the CHD self-report scale developed using national Swedish data (Karasek et al., 1981) which predicted a 5.0 : 1 relative risk of CHD mortality in Sweden. The TCO scale includes three out of four of those measures: self-reports of high blood pressure, chest pains, and trouble breathing (the presence of chest pain after exertion is further available on our survey, which should augment its precision (Rose, 1968, 1971). When dichotomized at the level of two symptoms (Karasek et al., 1981), the prevalence of CHD is very similar to the national Swedish study; and the clear age associations help to confirm the measure’s content validity.

Independent variables Change influence The occurrence of company-induced job reorganization and the employee’s possibility of influencing the change of his/ her work situation were measured by the following questions: (1)

HEALTH RISK AND JOB CONTROL 175

‘During the past several [2-41 years, has there been a substantial change in your work situation due to relocation or notice of relocation; reorganizations; technological or administrative efficiency programs; completely new working methods; work force cutback; etc.?’ (Coding: relocation, or other changes = change; No substantial change = no change). (2) ‘Were you able to participate in decisions concerning the transformation of your work situation?’ (Coding: Yes, definitely; Yes, up to a point = change influence; Neither yes or no; No, not really; Definitely not = no change influence).

Task control (decision latitude) changes In addition the following questions were asked relating to resulting changes from this process (only workers reporting changes were questioned): (1) ‘Has your work changed in the following respects: (a) Variety at work. (b) Possibilities of deciding for yourself how to plan and conduct your daily work. (c) Future possibilities [for skill development] in your work’. (Coding: ‘More’ on at least one of these three measures = ‘more control’; otherwise, ‘no more control3.2 (2) The following questions were also available for related analyses: ‘Has your work changed in the following respects: alertness and concentration required; responsibilities at work, psychological stressors at work, level of skill and difficulty of your work?’

The overall measure of control reported in Tables 1, 2 and 3 - influence over the change process and the level of control in the resulting job - was created by combining the dichotomous variables above: ‘change influence’ (yes, no), and ‘more control’ (yes, no) into a three category variable: yes, to both (A); yes or no to either (B); no, to both (C).

Analysis Our sample is restricted to full-time white collar employees stratified by age (20 to 39,40 to 65), separately analyzed for men and women in Tables 2 and 3. Table 1 presents two kinds of information. Symptom rates for the coronary heart disease indicator only are shown at the top of each cell. Population denominator information, shown at the bottom of each cell, represents the distribution of job changes and employee control in the job change process within the study population and also applies to the symptom rates in Tables 2 and 3. Tables 2 and 3 show the percentage of individuals with health problems in each change and control classification for all of the indicators. Significant differences are tested using a generalization of the Mantel-Haenszel test for multi-leveled, rank-ordered, stratified comparisons (Breslow and Day, 1980, using the conservative approximation [equation 4.421, which generates a Chi-square statistic) with age as a simultaneous control (the significance of ‘A-BB-C’, Tables 2 and 3). Of course, when only two levels are involved, this generalization is equivalent to a Mantel-Haenszel test). This test allows verification of a very rough, qualitative increment-based ‘dose-response’ relationship across three levels of control (a more rigorous ‘dose-response’ test would require verification of interval equality and equivalence of the two types of control effects which we have not thoroughtly tested). Illness is hypothesized to be greater for job changes and for changes without control: here we use one-tailed tests. However, no directionality is hypothesized for the comparison of job change with control versus no change (two-tailed test). We also report associations between influence in the job change process and the type of job changes that occur. Other researchers have reviewed job change frequencies for each of 19 separate occupational and industry groups (Lindell, 1982).

*Analyses were also run with only variety and self-planning with similar results to those reported below,

176 R. KARASEK

Table 1. Coronary heart disease symptom rates for male and female white collar workers involved in a job reorganization under different levels of employee control

(n = 1762) (22.7) Male 40+

A Had process influence and obtained more job control.* B Influence or greater job control.* C = Had no influence and obtained similar or reduced job control.* *Job change resulted in a job with greater variety; greater development possibilities or obtained more task planning autonomy.

The population denominators in Table 1 first show that the percentage of employees experiencing a job change during the previous two to four years was roughly 25 per cent for men and women over 40, but slightly less for younger workers, particularly women (17.8 per cent). Most striking are the numbers of job changes that involve ‘more control’ (486) compared with those involving ‘reduced control’ (748) comparing columns A and C respectively in Tables 1,2, and 3. Thus, more job changes for white collar workers in Sweden involved reduced control rather than increased control, and this relationship was even stronger for older workers and women.

In Tables 1,2, and 3 we find consistent support for our primary hypothesis that illness symptom levels are substantially lower for workers who have obtained more control in the work process (comparison across columns A, B, and C). For men these associations are significant for all health indicators (except smoking) controlling for age, including CHD (p < 0.05). For ten of the 12 indicators for men a monotonic negative association with risk is associated with the higher control levels. This is surprisingly consistent and comprehensive support for a health status hypothesis (smoking is not a health status indicator). For women with increased levels of control depression, dissatisfaction, exhaustion, and muscular aches are significantly lower (with positive trends for all others except respiratory illness). However, smoking is significantly higher, for women, with increased control, contrary to hypothesis. Older women show stronger support for the control hypothesis than younger especially for heart disease, headaches, dizziness, pill consumption and absenteeism (there is a non-significant reversal for heart disease symptoms among young women). By far the strongest associations with increased control are shown for job dissatisfaction which is almost 70 per cent lower for both men and women.3

3These findings are methodologically stronger than many of the cross-sectional findings linking job satisfaction with QWL changes. They also avoid much of the ‘shared method’ problem. Perhaps methodological weaknesses are an explanation of Aldag et d ’ s (1981) pessimistic observation that in most available studies even job satisfaction improvements are hard to establish as consequences of new job redesign efforts.

HEALTH RISK A N D JOB CONTROL 177

Table 2. Illness rates with job reorganization under different levels of employee control

Men

Job reorganization population

20-39 depress exhaust dissat. heart dizzy

Physical head

respir. aches pills

absent smoke

i

2 40 depress exhaust dissat. heart dizzy

Physical head

respir. aches

illness stomach

pills absent smoke

Total depress exhaust dissat. heart dizzy

Physical head illness stomach

respir. aches pills

absent smoke

i \

A B C ncreased Intermed. Decrease( control control control

12.4 18.2 29.4 39.1 51.2 50.0 12.4 27.3 48.8

1.9 2.7 3.5 2.5 8 .o 11.8 7.5 11.8 18.8

18.0 25.7 22.4 11.8 16.1 20.7 16.2 21.9 17.1 2.5 5.3 7.7 6.8 7.5 18.2

21.1 17.1 18.8

15.1 18.6 26.8 40.3 51.0 53.9 5.0 21.1 43. I 5.0 10.9 11.9 1.9 6.5 8.9 3.8 8.5 11.5

15.7 18.6 25.7 8.8 5.1 12.6

21.4 21.1 30.5 5.7 6.5 11.5 3. I 8.1 6.0

14.5 15.4 11.5

13.7 18.4 27.8 39.5 51.1 52.4 8.7 23.8 45.3 3.4 7.4 8.6 2.2 7.1 10.0 5.7 9.9 14.3

16.9 21.7 24.4 10.3 9.8 15.7 18.8 21.4 25.3 4.1 6.0 10.2 5.0 7.8 10.7

17.8 16.1 14.3

Total Sign$* reorg. ‘A’-B-‘C’ rates

20.1 t 29.7 t

7.5 t 12.7 1 16.2 §

10.8 t

44.4

2.7

22.2

18.5 5.2

18.9

21.0 r 51.1 9 26.1 t 9.9 § 6.4 § 8.6 0

20.7 §

24.9 § 8.3 §

11.7

6.1 13.6

20.6 t 48.2 1 27.7 t

6.8 § 6.9 t

10.4 t 22.2 § 13.7 § 22.1 5

7.0 i 8. I 1

15.9

~ ~~

No-change population

Total Sign$* Sign$*

rates versus versus Non-chg. change ‘A’

no-chg. no-chg.

11.0 31.8 21.4

1.9 3.8 7.0

15.7 8.2

14.9 2.8 8.0

14.9

15.4 t . 38.8 t ‘ 15.1 t r 7.1 0 . 5.1 8.8

15.2 t ‘ 7.1 t .

21.1 0 . 8.4 5.2

14.7

13.3 t . 35.5 t § (-1 18.1 t t 4.6 § . 4.5 t . 8.0 0 ’

15.4 t ‘ 7.6 t .

18.1 1 ’ 5.7 6.6 § .

14.8 . § ( - I * Significanr difference in rates are caicuiatea with simultaneous control for age in the ‘total population’ rows.

6 p 5 0.05.

t p50 .001 . :p50 .01 .

Tables 1, 2, and 3 also display rather uniformly higher levels of psychological and physical illness indicators associated with job change itself, controlling for age and sex. Symptoms, o n average, are about 40 per cent higher, with differences significant (controlling for age) at the 0.05 level for allindicators for both men and women, except health behavior for men (especially older men). For coronary heart disease the symptom percentages for employees experiencing a job change versus those who have not are 6.8 per cent versus 4.6 per cent for men and 7.3 per cent versus 3.7 per cent for women.

178 R. KARASEK

Table 3. Illness rates with job reorganization under different levels of employee control

Women

Job reorganization population

~~

20-39 depress exhaust dissat.

dizzy Physical I”” head

respir. aches pills absent smoke

2 4 0 depress exhaust dissat.

dizzy Physical I”” head illness \ stomach

respir. aches pills absent smoke

Total depress exhaust dissat.

dizzy Physical Ihea* head

respir. aches pills absent smoke

‘4 B C ncreased Intermed. Decreased control control control

16.1 33.5 39.3 53.8 43.6 53.3 10.8 23.4 35.3 7.5 6.4 4.0

15.1 24.7 16.7 30.1 28.4 31.3 30.1 30.3 32.7 23.7 22.2 20.7 24.7 25.9 34.7

7.5 8.9 6.0 24.7 21.5 26.7 3 1.2 17.7 16.7

27.4 23.4 32.1 57.5 47.7 64.0 2.7 12.6 27.7 5.5 9.0 10.7

11.0 6.3 14.7 13.7 16.2 20.1 13.7 23.4 18.4 12.3 15.4 12.6 27.4 29.7 40.9 12.3 11.7 20.1 9.6 13.5 17.0

13.7 8.1 5.7 21.1 29.3 35.6 55.4 45.3 59.2 7.2 18.9 31.4 6.6 7.5 7.4

1.3.3 17.1 15.7 22.8 23.4 25.5 22.9 27.4 23.3 18.7 19.4 16.5 25.9 27.5 37.9 9.7 9.8 13.3

18.1 18.8 21.7 23.5 14.4 11.0

Total Sign$* reorg. ‘A’-B-‘C’ rates

31.7 t 49.6 . 24.9 t

5.7 . 19.5 . 29.9 . 31.2 . 21.9 . 28.9 .

7.5 . 24.2 . 20.5 (-)

28.3 . 57.8 17.5 t 9.0 .

11.1 . 17.5 . 19.0 . 13.4 . 34.4 15.7 . 14.3 . 8.2 .

30.1 +

21.5 t 7.3 .

15.6 . 24.2 . 25.5 . 18.0 .

11.9 . 18.9 . 13.8 1 (-)

53.4 I

31.5 1

No-change population

Total Sign$* Sign$*

rates versus versus Non-chg. Change ‘A’

no chg. no chg.

21.4 t 40.0 t

2.7 $ 19.5 cj

20.2 7 19.7 t 14.8 t 22.7 1 4.6 Q

19.4 Q 13.0 t

14.7

18.3 § (-1 46.7 t § (-1

8.3 t 6.3 . 8.0 .

16.5. . 14.8 . 7.1 t

26.6 1 10.5 9.7 0 9.0 .

20.3 t 42.4 1 t (-1 15.5 t § 4.0 t

12.3 $ 18.9 t 17.9 t 12.0 t t (-1

15.9 1 11.6 I(-) t (-1

24.1 t 6.7 t

*Significant differences in rates are calculated with simultaneous control for age in the ‘total population’ rows.

§ p 5 0.05.

tp 5 0.001. :p 5 0.01.

Tables 2 and 3 show that for all indicators for men over 40, (except smoking) and for seven indicators for women over 40, the symptoms levels with a job change involving more control are as low or lower than the levels found in the group which underwent no job changes at all. In fact the symptom levels are significantly lower than the non-job-change population for job dissatisfaction, with positive trends for pill consumption, absenteeism, dizziness, headaches, and heart disease among men. However, among women only job dissatisfaction displays such a

HEALTH RISK AND JOB CONTROL 179

significant ‘ameliorative’ association. Particularly for women ages 20 to 39, ‘more control’ (while itself associated with symptom reductions) is not enough to offset the negative impact of the job change process. For exhaustion, smoking, and respiratory problems, post-change symptoms for women job changers are significantly higher than for any of the non-job change groups.

Further findings from the Appendix relate the separate effects of influence over the change process and resulting changes in task control levels. Their separate effects are almost always similar in direction and are usually roughly similar in magnitude, particularly for men and women over 40, (justifying their combination into our single ‘control’ indicator used in Tables 1,2 and 3). However younger men who have process influence followed by no improvements in control in the resulting job have worse health status than young men with improved control in their tasks but no influence (for all health indicators).4

Table 4 shows related findings about the job change process: employees with significant influence in the job change process were more likely to find positive results in terms not only of increased control (utilized in Tables 1, 2 and 3), but often in terms of decreased psychological demands. These associations with process influence, while not strong in magnitude, are significant for increased variety, increased chances for own task decisions, increase skill level and difficulty, increased future opportunities, increased responsibilities, and decreased psychologica1 stressors. Concentration requirements increase significantly.

Table 4. Associations between the influence in the job changes process and increased levels of selected job characteristics (men plus women, n 2263), Cramers V,significance (two-tailed)

Cramers V Significance (17 5)

A. Variety at work 0.143 / 0.000 B. Possibilities of deciding for 0.175 / 0.000

yourself how to plan and conduct your daily work

development at work

required of your work

C. Future possibilities for 0.198 / 0.000

D. Level of skill and difficulty 0.127 / 0.000

E. Responsibilities at work 0.151 / 0.000 F. Psychological stressors at work -0.045 / 0.055 G. Alertness and concentration 0.088 / 0.000

As would be expected, almost all illness indicators show higher levels increased with increases in task psychological demands, specifically for younger women (this is found in a separate analyses, not reported here). This is not true for ‘responsibility’, which confirms our contention (Karasek et al., 1987) that it combines control and demand aspects. Also, for young women lower levels of control often have little association with higher levels of symptoms, if job demands are also low. Together, these observations imply that for younger women in our sample the work role may be secondary to another role (presumably family).

Other insights into the nature of the job change for this sample can be gained by examination of nineteen of the largest occupation groups within TCO (statistics are available in Lindell (1982) Appendix 5). In general the percentages of employees with job reorganization show only minor

4This effect is also observed for women and CHD in the Appendix.

180 R. KARASEK

variations across these groups (which also reflect some differences in industry, public versus private sector and authority l e ~ e l ) . ~

Discussion Our findings represent strongly suggestive evidence that increased control and participation on the job could reduce illness among full-time workers, including coronary heart disease among males. While the study is actually cross-sectional, it has many strengths that overcome the usual objections to causal inferences drawn from cross-sectional data. The study retrospectively assesses previously occurring, company-induced job changes, insuring time ordering. In addition, the study randomly samples the full national white collar Swedish population which overcomes company-related response ‘selectivity’ which limits generalization from many single-plant studies. Furthermore, incremental increases in control are associated with incrementally lower illness rates, suggesting a crude ‘dose-response’ relationship. These findings are also consistent with other evidence, particularly for coronary heart disease among males. Causal associations between low job control, high demand jobs and increased incidence of CHD have been found in Sweden and the U S . (Karasek et d., 1981; Alfredsson el al., 1982, 1985; La Croix 1984; consistent cross- sectional findings also exist, see p. 172). The limitations that still exist among these congruent and suggestive studies are a strong argument for more conclusive ‘intervention’ studies to test the efficacy of job redesign strategies to reduce illness.

The findings were directly controlled for age and sex, and indirectly controlled for broad social class (Karasek er af., 1987) and race (quite homogenous in the Swedish white collar work force). The fact that control has strong associations controlling for social class, and even for white collar workers who already have relatively high levels of job autonomy also addresses questions raised about the breadth of job control’s affects (Ganster, 1989). While conventional predictors of some of our illness outcomes are not controlled - such as blood pressure and serum cholesterol in the case of CHD, other literature (Pieper, La Croix and Karasek, 1988) suggests that their omission is not likely to wholely negate the conclusions, since such risk factors are often similarly affected by both stressful job circumstances and changes in control. (Here we find, of course, that smoking is differently affected). Our findings are also consistent with an accumulating body of evidence from Quality of Work Life job redesign experiments showing that increased control reduces psychological strain, job dissatisfaction and absenteeism (see discussion in Karasek and Theorell (1990), Kopelman (1985), Gardell and Svenson (1981) and Arnetz, Eyre and Theorell, 1983).

The findings of health improvements with increased inflaence and control are remarkably uniform across our 12 health indicators. Only smoking, which is actually self-initiated behavior and not a direct indicator of health, shows contrary results. The associations with job control are stronger for full-time men than full-time women, especially for women ages 20-39. Although we have no specific data, we expect that this is due to family responsibilities for younger women. Hibbard and Pope (1985) also find that women over 40 are more affected by work roles than younger women. However, this weaker control association for women is not consistent with other findings utilizing this same data base.6 For men and women over age 40 the ameliorative effects of increased job control are often more than enough to negate the impact of stressful change

5Women’s slightly lower overall level of job changes reflects lower levels among ward personnel and teachers (17 per cent) (administrative personnel in commerce had more changes than average). Men’s higher change rates occurred primarily for sales administrators in public agencies (37 per cent) as well as for administrative personnel in banking and technicians in private industry. 6Correlations between job control and illness in the full cross-sectional survey (Karasek et al., 1987) are often somewhat stronger for women than men.

HEALTH RISK AND JOB CONTROL 181

process and result in the health improvements. This is true for job dissatisfaction (regardless of age or sex), and for heart disease, pill consumption, absenteeism, dizziness, and headache, for men.

One potential problem with this study is that both job reorganization and health status are retrospectively reported by the subjects, a technique strongly criticized in earlier CHD research involving recovering cardiac patients in hospital wards (Mausner and Bahn, 1974). However those critiques - that the investigated population ‘explained’ their present (catastrophic) illness by selective interpretation of previous events or that they were predisposed to such events - seem much less applicable to our almost entirely well, fully employed population experiencing company- initiated interventions. We can also find no strong reasons to believe that job reorganizations are applied to primarily sick people (age is associated with increased illness but age is controlled in our analyses), or that sick people cause job reorganizations. Also, the effects of self report distortions in control or our illness measures, if they do exist, do not seem to be strong, particularly in the case of such concrete events as the occurrence of major job reorganizations (indeed, even a very easily biased measure in the study [not reported here], the question ‘how stressful is your job perceived to be’ shows less variation across control levels than the illness measures which are reported [the age and sex trends are similar to those of the other measures]).

Another potential difficulty is that illness status may precede job changes for a very small percentage of subjects, but this percentage is probably less than 5 per cent. (This is a standard statistical confidence interval, and this consideration is probably also statistically independent of our control hypotheses, implying a very low joint probability of null hypothesis confirmation). The well known anticipatory stresses of major job changes (Cobb and Kasl, 1977) would further diminish the importance of this difficulty. Nevertheless, more objective data on both job reorganizations and health status will be needed for conclusive tests of these hypotheses.

A review of our detailed findings shows the importance of ‘influence over the job change process’ as the first step toward increased job control: having such influence is associated with significantly greater chances of a future job with increased control. While such process influence may be a necessary first step, it does not appear to be sufficient to insure improved health. Indeed among young men, having process influence without getting a job which has increased control, leads to worse outcomes than a job change with no influence but increased control for every health indicator (except smoking). This implies a problem when expectations are aroused but not fulfilled by the job change process.

One of the most disturbing conclusions of the study is that white collar job changes more often involved reduced control than increased control. This is especially true for older workers and women, presumably the less aggressive groups in the labor market, so that for older women diminished job control situations outnumbered increased control situations two to one (even odds for young men). It must be noted that we have examined the changes in control only in the subgroup of white collar workers which reported undergoing a rather substantial job changes, but it is still surprising in light of the strong traditions of employee participation in Sweden since the early 1970s.’ Frederick Taylor’s Principles of Scientific Management, which recommends restriction of decision-making for operative workers, came late to Sweden, having its primary impact in the late 1950s and 1960s (‘rationalizering’), and it may still represent a major current shaping Swedish work structures.

The primary conclusion of our study is that even if changes in working life are inevitable, stress-related illness consequences from them may not be. At least for men, and women over 40,

’The changes in control level could be more favorable for employees overall in Sweden. Indeed, evidence from national surveys (with less precise questions) does show overall national increases in employee discretion over use of skills and task authority (Level of Living Studies 1968, 1974, 1981. (SCB, 1982)).

182 R. KARASEK

control in the work process could well be an antidote for the ‘inevitable’ stresses of industrial change (Toffler, 1971). We also clearly see in Tables 1,2 and 3 that the already stressful process of job reorganization can be much worse for employees when they are denied influence over the process or when changes lead to decreased control (Frese, 1987). This last point highlights the potential risks involved in many computer/ automation related changes now occurring. Many of these changes are considered ‘technical’ and thus beyond direct employee concern and influence in the U.S. (if not in Sweden) in spite of the obvious impacts they have on task structures (Turner and Karasek, 1984). The result of such neglect is liable to be the major stress-related complaints observed in computer system installations by Smith, Cohen, Stammerjohn and Happ, (1981), Shaiken (1984), and Howard (1985).

Increases in job control are suggestive of such strong ameliorative effects that participatory change processes might be instituted to reduce illness and health care costs for their own sake. Certainly short term costs of change and long term gains must be balanced, but presumably these results would even further improve as the disruption of the job change process recedes into the background.8 Productivity is unlikely to suffer as a result, (indeed absenteeism declines significantly in this study). The enormous volume of QWL studies involving participatory changes in many countries generally show productivity improvements which now may be reinforced by improved health status (Karasek and Theorell, 1990). While this study only addresses Scandinavian workers, other studies have found U.S./ Scandinavian similarities in the area of work-related psychosocial stress. Now that health care costs consume close to 12 per cent of the GNP in the U.S. and are still rising (9 per cent in Sweden) the time may be arriving for ‘health risk reduction first’ job change strategies in a range of industrialized countries.

Acknowledgements I would like to thank the Swedish Tjanstemannens Centralorganization, the Swedish Arbetsmiljo- fonden and Swedish Arbetslivscentrum for their support and assistance for this project. I would also like to thank Jan Ihde l l and Bertil Gardell for their assistance in research conceptualization; Randy Madden and John Hadi of University of Southern California for editorial and typing assistance and Ulla Stajarnborg for computing assistance.

Appendix Illness rates with job reorganization under different levels of employee control

Subdivided Column ‘B’ Tables 1, 2, 3 (n)*

No Influence w/ Increased Job Control

Influence w / o Increased Job Control

Men 20-39 depress exhaust dissat. heart dizzy [ !:t:ach respir. aches

Physical illness

22.6 51.2 31.0 3.6 8.3

17.9 32.1 19.1 25.0

14.7 37.9 24.3

1.9 7.8 6.9

20.4 13.6 19.4

*In our sample, the average job change probably preceded health status judgments by a little over a year.

HEALTH RISK AND JOB CONTROL 183

Subdivided Column ‘B’ Tables 1, 2, 3 (n)*

Influence w/ o Increased Job Control

No Influence w/ Increased Job Control

pills 10.7 1 .o absent 4.8 9.1 smoke 15.5 !8.5

2 40 depress 20.5 15.4 exhaust 50.0 52.8 dissat. 25.0 14.3 heart 11.5 9.9 dizzy 7.7 4.4 head 8.3 8.8 stomach 18.6 18.7 respir. 14.1 9.9 aches 21.2 20.9 pills 8.3 3.3 absent 10.9 3.3 smoke 18.6 9.9

30.0 35.7 exhaust 43.3 43.8 dissat. 20.0 25.5 heart 11.7 3.1 dizzy 18.3 28.6

23.3 31.6 28.3 31.6 stomach

respir. 25.0 20.4 aches 25.0 26.5 pills 11.7 7.1 absent 25.0 19.4 smoke 13.3 20.4

2 40 depress 22.2 24.6 exhaust 42.6 52.6 dissat. 16.7 8.8 heart 14.8 3.5 dizzy 5.6 7.0 head 16.7 15.8 stomach 22.2 24.6 respir. 5.6 24.6 aches 29.6 29.8 pills 13.0 10.5 absent 13.0 14.0 smoke 3.7 12.3

I Physical illness

Women 20 -39 depress

Physical head i 11 n e s s i

I Physical illness

* n: Influence w/o ctrl No influence w/ ctrl

Men 20-39 40-65

Women

40-65 20-39

84 156

60 54

103 91

98 51

184 R. KARASEK

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