Effects of labelling on income, work and social function among hypertensive employees

J ChronDis Vol. 37, No. 6, pp. 417-423. 1984 Printedin GreatBritain.All rightsreserved

Copyright

0

0021-9681/84 $3.00 f0.00 1984 Pergamon Press Ltd

EFFECTS OF LABELLING ON INCOME, WORK AND SOCIAL FUNCTION AMONG HYPERTENSIVE EMPLOYEES MARY

E. JOHNSTON’, EDWARD

R. BRIAN HAYNES’,

JANE I. SICURELLA’ ‘Department

of Clinical ‘Dominion

S. GIBSON*, C. WAYNE TERRY’,

D. WAYNE

TAYLOR’,

AMMIRANGAFNI’,

and DAVID L. SACKETT’

Epidemiology and Biostatistics, McMaster University Faculty Sciences, Hamilton, Ontario, Canada and Foundries and Steel Limited, Hamilton, Ontario, Canada (Received in revised form

of Health

22 December 1983)

Abstract-Two hundred

and thirty hypertensive Canadian steelworkers were followed for 5 years after screening and referral. Data on income, absenteeism and measures of work and social function were collected on these men and on a matched group of 230 normotensive employees. In the fifth year after screening, hypertensive employees earned an average of Can. $1093 less than normotensive employees despite similar incomes in the year before screening. This adverse effect on income was observed regardless of awareness of hypertension at the time of screening or compliance with treatment. Illness-related absenteeism among hypertensives rose in the year following screening and remained elevated for 4 years after screening. Normotensive and hypertensive employees reported similar levels of physical ability and psychological well-being. These findings need verification in other settings before inclusion in cost-effectiveness analyses of the management of hypertension.

INTRODUCTION

of premature morbidity and mortality is the long-term goal of programs for the detection and treatment of hypertension. However participation in such programs may also have adverse effects. Increased absenteeism from work and decreased scores on measures of psychological well-being have already been documented; there may be other undesirable psychological and behavioural changes which deserve investigation. Two studies have reported that employees who were aware that they were hypertensive before screening were absent from work because of illness more often than those who were unaware of their hypertension [l, 21. In a 1973 Harris poll of the general public, respondents who said they were hypertensive reported twice as‘many days away from work or usual activities as did other respondents [3]. In two cross-sectional studies, people who were aware of their hypertension had lower scores on an index of psychological well-being [4] and higher levels of psychological distress [5]. Prospectively, absenteeism has been shown to rise among previously unaware hypertensives in the year following labelling [ 1, 21. In our own study, participants at a large steel mill [6] showed that this increased level of absenteeism was maintained for 4 years. However. this result was not uniform as newly aware hypertensives who were prescribed antihypertensive medication and who complied with treatment experienced little or no REDUCTION

Reprint requests should be addressed to: Dr R. B. Haynes, McMaster University Health Sciences Centre, 1200 Main Street West. Hamilton, Ontario, Canada LgN 325. Supported by the Medical Research Council Grant No. MA-5159, Physicians’ Services Incorporated Foundation, Sun Life Assurance Company. Dominion Foundries and Steel Limited and Ontario Heart Foundation Grant No. OHF-15-16. CD

176

A

417

increase in absenteeism whereas hypertensives who were not compliant showed a substantial increase in absenteeism during the first 3 years after screening. In the same study, newly labelled steelworkers also suffered a decline in marital adjustment during the 12 months following screening [7]. Those who were prescribed antihypertensive medication also had lower scores on measures of self-esteem and self-perceived health although decreases in these scores did not reach statistical significance. To allow further exploration of the impact of screening for hypertension on participants in our original studies, we returned to the plant to gather new information on income and psychological well-being. In addition, new data on income, psychological well-being and absenteeism have been collected on a matched cohort of normotensive employees. METHODS

Preuious study The methods for the original study have been outlined in detail elsewhere [l, 6. 81. Briefly, a random two-thirds (5400) of the male employees of the Dominion Foundries and Steel Limited of Hamilton, Canada, were asked whether they had been told that they had high blood pressure, and were then screened for hypertension. A total of 245 men met the following criteria: average fifth-phase diastolic blood pressure > 95 mmHg (average of second and third of three readings taken with the patient sitting quietly on each of two separate occasions over a 3 month period); no antihypertensive therapy for at least 6 months before screening; no other daily medications; and no remediable secondary form of hypertension. After explanation of the nature of the study, 94:;) of these men agreed to participate. A summary of each man’s clinical findings was forwarded to his physician, who was free to decide whether and with what regimen to treat the hypertension. Twelve months after referral, we performed standardized measurements of treatment status, blood pressure control, and medication compliance. In addition, absenteeism from work was determined directly from routine company time-clock records for the year prior to screening and then forward in time from screening in 1973 until the end of 1977.

Because of the changes in absenteeism and psychosocial function observed in the study group in our original study, we returned to the plant in 1979 with three specific objectives: (1) to assemble a control group of men who were employed at the plant and normotensive at the time of screening in 1973 in order to determine whether the changes observed in hypertensive men were simply due to temporal changes among plant employees; (2) to provide long-term follow-up of the variables we had previously measured among the study cohort; and (3) to gather new information on income changes over the follow-up period beginning l-year prior to screening. These objectives were addressed in the manner described below. The company payroll roster for September 1, 1973 (when the original screening began) was assembled in alphabetical order and each study group subject was located in the file. Company medical records were retrieved for employees whose names on the payroll immediately followed a study group subject and, taken in strict alphabetical order, the first employee who met all of the following criteria was selected as a control: (a) male; (b) same payment category as the study group subject (“hourly wage”, “salary”, or “staff”); (c) date of birth within 5 years of the study group subject; (d) date of employment prior to 1973; (e) all diastolic blood pressures on medical chart prior to 1974 less than 90 mmHg; (f) no daily medications indicated on the medical record. For both study and control groups, the data were assembled as follows: (i) Income. Annual incomes for both groups for the years 197331978 were made available to one member of the research group for statistical analysis. Incomes for employees whose jobs were terminated after March but before December in any year were prorated.

Labelling

Among

Hypertensive

Employees

419

(ii) Absenteeism. Data on illness-related absenteeism for the year prior to screening and for 4 years thereafter were abstracted from company payroll records. (iii) Questionnaire. In 1979, study and control subjects completed a supervised, selfadministered questionnaire on (a) their level of physical activity and ability to perform exercise; (b) their general health, any cardiovascular morbidity, prescriptions for antihypertensive medications, current treatment status, and cigarette and alcohol consumption; (c) happiness with their financial situation, job, social life, home life and health in general, all on 6-point scales ranging from “extremely unhappy” to “extremely happy”; (d) whether or not they felt illness had prevented them from being promoted on any occasion since 1973. Statistical

analysis

(i) Income. The income data were analyzed in two ways. First, over the 5 years of follow-up, incomes in absolute dollar values were analysed using repeated measures analysis of covariance followed, when this first analysis was statistically significant, by Student’s t-tests between groups for individual years. Second, to assess the pay of individuals relative to others through the years, incomes were ranked for each year and then compared using the Mann-Whitney U Test. In order to permit relative ranking, only employees with complete income data for 1973-3978 were included in this analysis. The data were complete for 196 study subjects (85%) and 205 control subjects (8904) and the average incomes of those with partly missing data were not statistically different from those with complete data. Table 1 outlines the number of subjects on the company payroll in each year. TABLE I. NLMB~KW-D PERCENT, OF SLBJ~CISHA\IUG ,NCOM~DATAAVAILABLY FOK ~hALYS,S Hypertensive group Normotensive group

study study

1973

I974

1975

1976

1977

1978

230 (100)

229 (100)

220 (96)

212 (92)

205 (89)

;96 (85)

230 (100)

230 (100)

226 (98)

217 (94)

209 (91)

205 (89)

(ii) Absenteeism. The absenteeism data were positively skewed because of a large number of individuals in each year with no absenteeism and a small number with long periods of absenteeism. The data were, therefore, transformed by taking natural logarithms and then analysed by repeated measures analysis of variance. (iii) Questionnaire. Responses to the questionnaire were compared using the Chi-square test and Fisher’s exact test. (iv) Comparison groups. Comparisons of three sorts are reported: (a) between the hypertensive study group and the normotensive control group; (b) within the hypertensive study group, between subjects who were aware and those unaware of their hypertension at the time of screening, between subjects who were treated at 12-months after referral and those who were not, and between treated subjects who were compliant with medication at 12 months (> 80% of prescribed pills consumed) after referral and those who were not; and (c) within groups over time.

Income

RESULTS

Complete income data for the period starting in 1973 and ending in 1978 were available for 196 study subjects (85%) and 205 controls (89%). Analysis of covariance was performed on changes in income from 1973, with 1973 income used as the covariate. Increases in income are shown in Table 2 and Fig. 1. Although income rose every year from 1974 to 1978 for both groups, the rate of increase was significantly greater for the control group (p < 0.01). In 1978 the hypertensives earned an average of Can. $1093 less than the normotensives (p < 0.05) even though they had been earning Can. $83 more in 1973 (not significant), when the study began.

420

MARY

1973

E. JOHNSTON

1975

1974

et ul.

1976

1977

1978

Yeor FIG.

I.

Increases

in income

from 1973.

The study group can be divided into subgroups on the basis of awareness of hypertension at screening, treatment status at 12 months after screening and compliance with treatment. Mean increases in income for these groups are shown in Table 3. Although

Hypertenswe study group (N = 196) Normotenswe control group (N =20i)

1914

1975;’

1976’

1977*

197x*

Meall SE

1840 198.4

3017 1192

5552 145.1

6667 192 5

8021 261.1

MeaIl SE

1871 101 6

3562 124.5

6043 198.6

1322 203.6

8987 219.3

* **DdTerence between hypertenwrs (‘p < 0.05). (**p i 0.01).

and

normotensives

statlstlcally

significant

TABLt 3. INCRtASES IN ,NC”MTztK”M 1973 FOR HYPtRT~Ns,\‘~S 1974

1975

1976

1977

1978

Unaware (N = 134) Aware (N = 62)

Mean SE Meall SE

1983 280.9 1538 168.5

3008 152.3 3035 186.6

5644 176.0 5356 257.0

6619 216 I 6767 390 7

802 I 295.8 802 I 522.9

Pills (N = 113) No pills (N = 83)

MeaIl SE Mean SE

1997 327.0 1625 149.2

3007 1502 3005 198 5

5536 187.2 5562 236.0

6853 275.5 6365 260.3

8016 306.6 7988 465.6

Comphant (N = 61) Not compliant (N = 52)

Mean SE Mean SE

I988 114.5 2008 715.0

3274 196.9 2683 224.9

5972 220. I 5005 303.0

7134 315.4 6511 474.3

8571 392.9 7342 470.3

1973

1974

1975

1976

1977*

197x*

Hypertensive study group (N = 196)

202.2

19x.2

189.8

191 I

189.0

187.8

Normotensive study group (N = 205)

199.X

203 7

211.7

210.5

212.5

213.6

Lower rank means lower income. *Difference between hypertensivea @ < 0.05).

and

normotenblves

statistically

algnificant

no statistically significant differences were found among these six groups, it is interesting to note that those men who did not comply with treatment had the smallest mean increase in income. This group also had the highest rate of absenteeism [6]. Average income ranks for the study and control groups are shown in Table 4. Although the two groups have similar mean ranks in 1973, in the years following screening the hypertensive study group has a lower mean rank in each year after screening. The differences of 23.5 ranks in 1977 and 25.8 ranks in 1978 are statistically significant

Labelling

Among

Hypertensive

Employees

421

TABLE 5. AVERAGE INCOW RANKS FOR HYPERTENSIV~S 1973

1974

1975

I916

1977

1978

Unaware (N = 133) Aware (N = 63)

209.3 186.8

205.1 183.1

193.3 182.1

197.3 177 7

192.7 181.0

190.4 182.2

Pills (N = 113) No pills (N = 83)

206.1 196.9

201.9 193.0

193.3 185.0

193.1 188.3

193.1 183.3

188.5 186.9

Compliant (N = 62) Not compliant (N = 51)

220.7 188.3

227.2 171.2

215.1 166.7

217.0 164.1

215.0 166.6

206.2 167.0

Lower rank means lower income

(p < 0.05). There were no statistically and unaware, treated and untreated

significant differences in mean or compliant and noncompliant

rank between aware patients (Table 5).

Absenteeism Complete absenteeism data were missing for 28 subjects (12%) in the study group and 15 (7%) in the control group, because of missing records (in 17 cases) and termination of work (in 26 cases). The average number of days per year absent from work because of illness is shown in Table 6. In the year before screening, the control group experienced a higher rate of absenteeism than the study group. This difference is not statistically significant and thus may be due to natural variation in absenteeism rates. However, the TABLE 6. DAYS PER YEAR

..-.._-_. Hypertensive study group Normotensive control group

ABSENT

BECAUSEOF ILLNESS

Year before

1 year after*

2 years after*

3 years after

4 years

Mean SE N

4.36 0.712 226

8.38 I.272 221

8.12 I .759 210

11.63 I.917 203

8.71 202

Mean SE N

7.30 1.468 217

8.53 1.661 216

7.33 I.655 216

11.64 2.470 215

6.23 0.911 215

*Increase in absenteeism over year before screening statistically hypertensive study group.

significant

after

I .862

0, < 0.01) for

difference is sizeable and may reflect the fact that some of the control subjects were absent from the plant for extended periods during the time of screening whereas study subjects all had to be available at the plant at least some of the time during the screening period in order to be included in the study. Thus, the study subjects may have been somewhat healthier (or, at least, less absent from work) to begin with in comparison with control subjects. In any event, hypertensive subjects experienced a statistically significant rise in absenteeism (p i 0.01) in the 2 years following screening whereas the normotensive group did not. More complete data on absenteeism in the hypertensive group are available elsewhere [1,61. Periodic

health examination

questionnaire

Altogether the responses to 15 questions were analysed. Nine of 169 hypertensives and one of 163 normotensives (p = 0.011, Fisher’s exact test) answered “yes” to the question “Do you feel illness has prevented you from being promoted on any occasion during the last 6 years?” Forty-six subjects in the hypertensive group and 52 in the control group did not answer this question, Hypertensives and normotensives did not differ in their responses to any other questions. They reported similar levels of physical ability; equivalent happiness with finances, social life, home life, job and health; and similar levels of alcohol and cigarette consumption. Those who were aware of their hypertension at the time of screening were prescribed antihypertensive medication more often during the next 5 years than those who were unaware (p < 0.01). All 13 hypertensives who reported being told that they had “heart

422

MARY E. JOHNSTON PI ul

Hypertenwe \tucly group Age WI*

Mea11 SE No

Number of years working al Dofxsco* Sluft work* *Dilferences

Normotenswe control group

46.9 0 bh 209

46.6 0 70 211

Meall

I’)‘)

18.X

SE No.

0 60 191

0.62 lY6

x2 (42.9) 109 (57.1)

72 (36.7) 124(63 3)

No. ye, (“,,) No. no (‘I,,)

in sample sizes are due 10 mrssing data.

trouble” between screening and the 5-year follow-up were prescribed antihypertensive medication. Thus, the treated group had significantly more people reporting “heart trouble” than the untreated group 0, < 0.05). As illustrated in Table 7, even 5 years after entry hypertensives and normotensives were similar with respect to age and work experience.

DISCUSSION

We have found that hypertensive employees were earning Can. $1093 a year less on average than normotensive employees 5 years after screening, despite the comparable salaries of these two groups in the year preceding screening. This is new evidence of an unintended effect of a hypertensive screening program. A plausible explanation of this result is that the disease, hypertension, results in decreased work capacity. This explanation does not appear to apply in our investigation. Severe hypertensives were excluded from the study and most subjects were asymptomatic at the time of entry and reported comparable levels of physical activity and capability to those of normotensive controls at the end of the study. A second explanation is that decreased work capacity resulted from adverse effects of antihypertensive treatment. This explanation appears untenable as well, as the relative income erosion affected untreated and treated, but noncompliant, hypertensives as least as strongly as treated hypertensives. As there were no statistically significant differences in absenteeism between study and control subjects, the evidence indicates that the economic losses incurred by the hypertensives are not due entirely to increased absenteeism. Thus, two possible reasons for these losses are that the hypertensives worked less overtime or that they were given fewer promotions. The hypertensives may have been unwilling to work long hours because they had been told by their physicians or had decided for themselves that they should “take it easy”. They may have decided to forego promotions for the same reason or alternatively, they may have been passed over for promotion because their supervisors considered them to be less healthy than normotensive employees. In addition to these problems, which could have arisen because the hypertensives were conscious of their disease, participation in the research project may have influenced their earning potential because the assessments that were part of the study may have changed their attitudes toward their jobs and/or their supervisors’ attitudes toward them. However, it should be pointed out that direct contact with study personnel occurred only intermittently during a 2 year period in 1973-I 975 and not at all throughout the remaining 3 years of follow-up. Although a greater proportion of study subjects felt they had been passed over for promotion, lack of data about actual promotions in the plant and the small number of men who felt that they had been denied promotion do not allow us to draw any firm conclusions about the impact of hypertension on job promotions. For hypertensives who are not compliant with treatment. there is evidence that increased absenteeism also contributes to income loss. Individuals who are disinclined to take their

Labelling

Among

Hypertensive

Employees

423

medication may react differently to the knowledge that they are hypertensive and it may be possible to identify such individuals at screening, or early on in the course of their medical management. If so, techniques should be developed which help these people cope better with the diagnosis and treatment of their disease. Our findings in a heavy industry in Canada may well not be generalizable to other settings or hypertensive populations and we hope that other investigators will explore this matter in different circumstances. If similar economic losses are documented elsewhere, then further studies would be desirable to determine the reasons and remedies for this problem. In any event, it would be inappropriate to conclude from our findings that the identification and appropriate treatment of hypertensive individuals should be curtailed. REFERENCES I. 2. 3. 4. 5. 6. I. 8.

Haynes RB. Sackett DL, Taylor DW, et al: Absenteeism from work following the detection and labelling of hypertensives. N ‘EnpI J Med 299: 741-744. 1978 Alderman MH, Charlion ME, Melchar LA. Labelling and absenteeism: the Massachusetts Mutual experience. Clin Invest Med 4: 165-171, 1981 Harris 1, and Associates Inc: The Public and High Blood Pressure: A Survey (DHEW Publication No. [NIH] 74-356). Washington, DC: Government Printing Office, 1973 Monk M: Blood pressure awareness and psychological well-being in the U.S. Health and Nutrition Examination Survey. Clin Invest Med 4: 183-189, 1981 Soghikian K, Fallick-Hunkeler EM, Ury HK, Fischer AA: The effect of high blood pressure treatment awareness on emotional well-being. Clin Invest Med 4: 191-196, 1981 Taylor DW, Haynes RB, Sackett DL, Gibson ES: Longterm followup of absenteeism among working men following the detection and treatment of their hypertension. Clin Invest Med 4: 173-177. 1981 Mossey jMvl: Psychological consequences of labeiiing in hypertension. Clin Invest Med 4: 201-207, 1981 Sackett DL. Haynes RB, Gibson ES, et al: Randomized clinical trial of strategies for improving medication compliance in hypertension. Lancet I: 120551207. 1975