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Disability absenteeism of industrial workers with myocardial infarcts
Disability with
absenteeism
myocardial
of industrial
workers
infarcts
Neil1 K. Weaver, M.D.* Baton Rouge, La.
mhe physician who wishes to rehabiliA tate patients who have recovered satisfactorily after myocardial infarction must recognize a number of deterrents. Among these are fear that the individual will have another attack for which the employer may be held liable, and concern that the cardiac employee cannot work effectively, and that he will experience high and costly sickness absenteeism. The administration of compensation benefits for workers who experience subsequent attacks is a complex process which often involves courts, commissions, and customs wherein the testimony and opinions of the individual practitioner of cardiology seemingly carry little weight. For removal of this obstacle to cardiac rehabilitation, legal and socioeconomic reforms would seem to take precedence over strictly medical advances. On the other hand, the effectiveness on the job of cardiac workers who are placed in a suitable assignment has been demonstrated so widely and overwhelmingly that the productivity of such employees is no longer of major concern. In this study, data which pertain to the absenteeism experience of industrial workers with proved myocardial infarcts are presented. Such information, which heretofore has received scant attention, may be helpful to From
the Medical Department. Baton Rouge Company, Baton Rouge, La. Received for publication March 9, 1961. *Associate Professor of Clinical Medicine and Orleans, La.
457
physicians situations alike.
in discussing with patients
return-to-work and employers
Method The 100 subjects whose records form the basis of this report were selected from current or recent lists of permanently partially disabled employees identified in the total population of 7,500 workers of a large oil refinery and petro-chemical plant. The two criteria required for inclusion in the study were: (1) the worker must have a diagnosis of healed myocardial infarction established beyond reasonable doubt, after which, (2) he must have resumed work for a period of at least a year. (Data collected on subjects whose period of work was 6 to 12 months did not differ significantly from the findings to be presented; however, subjects with less than a year of work experience after infarction were excluded in order to avoid the possible criticism that the period of observation at work was too short.) All have been effective workers on the job, since they were included in an organized program for the selective placement of handicapped workers which entailed periodic review by both physician and supervisor.’ The average age of the study group was 50 years, as compared to 45 years for the entire worker population. Refinery,
Occupational
Manufacturing
Medicine,
Division
Tulane
of the Humble
University
School
Oil and
of Medicine,
Refining
New
4.58
Weaver
Complete information as to the number of absences from work due to disability-, the duration of each absence, and the clinical reason for each absence was collected for each of the 100 subjects. The survey period began with the patient’s return to work after an initial myocardial infarction and ended June 30, 1960. Seven subjects in the study group became totall). and permanently incapacitated for work, and 3 died. For these individuals the survey period ended on the last day on which they worked. Some patients experienced subsequent infarcts and again resumed work for a year or more. The periods of absence from the job due to later attacks are included in the analysis. Only five infarcts in this series were “silent” or unrecognized in the acute stage. These were discovered, usuall\. at routine periodic examination, when stable electrocardiographic patterns typical of healed infarction were found on indivicluals whose previous tracings lvere normal. Such findings were not associated with periods of disability. The absenteeism experience of the 100 workers with proved myocardial infarcts is compared with data for the whole refiner! population, derived in a similar manner for those years in which most of the cardiac cases were analyzed. Each period of allsence is measured in calendar days, and rates are calculated according to the procedure recommended by the American Medical Association Committee on Medical Care for Industrial Workers.? Other matters concerned with heart disease and employment have been excluded as irrelevant to the study of absenteeism. Results The 100 subjects of this study had an average of 4.7 years (range: 1 to 17 years) at work after the initial episode of myocardial infarction. Thus, 470 man-)-ears of \vork experience are included in the survey. Ten workers subsequently developed a second infarct, and 2 patients had a third. In all, 112 infarctions were recognized in the subjects during the study. Disability absenteeism rates for the cardiac workers are compared with rates for all refinery workers in Table I. The worker with a healed infarct was absent 10.0
Am. Hcort .I. October, 1961
calendar davs annually because of sickness or injury- (disability rate), as compared to an average of 9.9 days for all refinery workers. The annual number of absences per employee (frequency rate) for the cardiac group was 1.2, and for all workers, 1.1. The average duration of absence (severity rate) was 8.3 days for the study group, and 8.9 days for the whole worker population. Only 2.7 of the 10 days of absence each year by the cardiac worker were the result of cardiovascular disease. The major types of cardiovascular disabilities occurring in the 100 subjects are shown in Table II. Chest pain due to angina, coronar!. insufficiency, or myocardial infarctioil ;1ccounted for two to three times as man)-da).s of disability as did either myocardial failure or other conditions (arrh\-thmias, strokes, hypertension, peripheral vascular disease, and time away from the job for observation and regulation of medication). The frequency rate for cardiovascular absences was 0.16, and the severity rate was 17 days. Analysis of absenteeism by age group (Table III) reveals variation in cnrdiovascular absences from 2.2 days per \-ear for the SO-54 age group to 4.7 clays for the 4.5-49 age group. The increase in noncardiovascular absences in workers in the 60-64 age group was caused by a number of prolonged periods of disability involving operations. Table IV compares the absenteeism experience of salaried employees and wage earners. The salaried group was composed of 16 supervisory and technical and 26 clerical workers, 42 in number, with an observed work experience of 210 man-years. The wage earners consisted of 39 skilled and 19 unskilled employees, a total of 58 with 260 man-years at work after infarction. Cardiovascular absences for the salaried workers averaged 1 day per worker annually, as compared to 4 days for the wage earner. AAl1 types of disabilities for the salaried employee amounted to 6.7 days )-earl>-, about half the number of days (12.7) lost bJ- the wage employee. Corresponding disability rates for these groups in the entire population were 6.1 and 11.6. In addition to disability and frequency rates, the duration of absence for an episode of acute mvocartlial infarction is
Disability
Table I. Disability
All
with
refinery
healed workers
Disability rate (deys/entployee/yr.)
group
infarcts
(100
(7,500
causes of disability
Cause of absence
All
employees)
i~+arcts
450
I
8.3
9.9
1.1
8.9
for work
in 100 employees with healed infarcts Frequency rate (absences/enrployee/yr.)
1.5 0. 5 0.7 2.7
cardiovascular
Table I I I. Absenteeism
Severity rate (days/absence)
1.2
Disability rate (days/employee/yr.)
etc.)
Frequency rate (absences/employee/yr.)
10.0
employees)
Table II. Cardiovasczhlar
Chest pain Myocardial failure Other (arrhythmias,
with myocurdiai
absenteeism experience
Employee
\XTorkers
absenteeism of workers
Severity rate (days/absence)
0.07 0.02 0.07
21 2.5 10
0.16
17
experience by age group Disability
Age group (Y7.1
Nun&be7 of workers
4044 4539 SO-54 5.5-59 60-64
13 14 18 31 24
of
Number infarcts
Work experience (man-years)
rate (days/employee/yr.I
_ Curdiovascular
Table IV. Absenteeism
14 16 18 36 28
52 63 97 136 122
Total
2.3 4.7 2.2 2.8 3.4
5.6 5.2 4.2 5.4 13.9
7.9 9.9 6.4 8.2 17.3
of salaried employees and wage earners
T 100 Workers
with
healed
myocardial
infarcts
,411 re$nery
workers
Disability rate (days/employee/yr.j Employee
?PUP
-1 Cardiovascular
Frequency rate (absencesjemployeejyr.)
Other1 I Total
Cardiooascularl
I
Average lost with
days acute
infarcts Other
Total
Disability rate (dayslentployeelyr.)
Salaried (42 workers)
1.0
S.7
6.7
0.12
1.06
1.18
93
6.1
Wage (58 workers)
4.1
8.6
12.7
0.18
1.08
1.26
109
11.6
460
Am. Heart J. October, 1961
Weaver
shown. This was 93 days for the salaried worker and 109 days for the wage earner; the combined average was 102 days. Discussion
These data suggest that patients with myocardial infarction who are able to return to work in a suitable assignment do not have high disability absenteeism. The 100 subjects, with a total observed experience of 470 man-years, on resuming work after an infarction averaged only 10.0 calendar days of disability annually. In comparison, the average for all refinery workers was 9.9 days. The survey group also had surprisingly low frequency rates for disability absences-O.16 for cardiovascular causes and 1.2 for all causes. These findings are in general agreement with other reports on absenteeism of fulltime workers with heart disease of various etiologies. One hundred and eighty-nine workers followed by the Work Classification Unit, Adult Cardiac Clinic of the Third (New York University) Medical Division, Bellevue Hospital, lost an average of approximately 9 days per year.3 Greer4 reported an average absenteeigm of 13.3 days annually for 45 industrial workers with arteriosclerotic heart disease, compared with 11.3 days for all employees. Neither report described details of the derivation of data upon which conclusions were based. Wyshak, Snegireff and Law5 studied absenteeism of workers with various types of heart disease or diabetes in 17 manufacturing plants,5 and found that employees with coronary heart disease were able to work with little more disability than persons free of heart disease; cardiac workers placed in “light” jobs lost less time than “production” workers. A previous study from this department also revealed a generally good prognosis for patients who returned to work after cardiovascular absences.6 Nearly 88 per cent of those who resumed work either continued on the job or retired for nonmedical reasons. In the course of the 3-year observation period, approximately 6 per cent died and another 6 per cent retired for medical reasons. This analysis, based on a large number of cardiovascular absences of all types, differs from the present one
which is based on the experience of patientemployees with a specific type of heart disease. It may appear surprising that the employees of this study who had established heart disease of a serious nature did not lose more time from the job because of disability than did the average worker. It is possible that such employees, having recovered satisfactorily from a life-threatening illness to resume a productive job in industry, are highly motivated to stay on the job and avoid unnecessary absences. Even though higher job motivation may be contributory to the lower absenteeism experience of salaried workers as compared to wage earners, other important factors are the generally better work environment and less physically demanding assignments available to the “white collar” worker. It deserves re-emphasis that disability absenteeism is affected by many factors, nonmedical as well as medical.’ For example, it has long been recognized that some periods of apparent “disabilit\,” bear a strong relationship to the availability and duration of disability payments. None of the workers who were surveyed was involved in a compensation suit. All were covered by a company benefit plan which provided, in general, full pay for the first 12 weeks of disability, and one-half pay for an additional 40 weeks. Such n plan offers sufficient economic security to generally deter efforts to work when actually disabled, and joint follow-up of each absentee by full-time company physicians and the personal physician tended to minimize unnecessary and unduly prolonged periods of absence. Summary
Disability absenteeism of 100 subjects who resumed industrial work for an ohserved 470 man-years after myocardial infarction is reviewed. They experienced 10.0 calendar days of disability per person annually, whereas the average for all workers ill the same plant was 9.9 days. Only 2.7 da\-s of absence each year were due to cardiovascular conditions. The cardiac employee had, on the average, 1.2 periods of disability yearly, as compared to 1.1 absence per worker for the whole refinery population. Analysis of absenteeism by age
Volume Number
62 4
Disability
absenfeeism of workers
group revealed no significant trend in the patients studied. Salaried cardiac workers had one fourth as many days of absence for cardiovascular reasons, and one half as many days of disability for all reasons, as did wage earners. The absenteeism experience of workers with healed myocardial infarcts who resumed work in a suitable job assignment did not differ significantly from that of the whole plant population. REFERENCES 1. Weaver, cardiacs 2. American Medical
N. Ii.: The selective placement of in industry, Postgrad. Med. 24:4, 1958. Medical Association Committee on Care for Industrial Workers: Pre-
with myocardial
in.arcts
461
liminary guide for measuring work absence due to illness and injury, J.A.M.A. 168:1230, 1958. 3. Staff of the Work Classification Unit, Adult Cardiac Clinic, Bellevue Hospital: An occupational analysis of 580 cardiac clinic patients, Circulation 3:289, 1951. 4. Greer, W. E.: Experience in selective placement and follow-up on cardiacs. 1~ Rosenbaum, F. F., and Belknap, E. L., editors: Work and the heart, New York, 1959, Paul B. Hoeber, chapter 43, p. 383. 5. Wyshak, G., Snegireff, L. S., and Law, A. F.: Work experience of persons with cardiovascular disease or diabetes, J. Chron. Dis. 1052.5, 1959. 6. Thorpe, J. J., and Weaver, N. IX.: Effective return to work of the cardiac employee, A.M.A. Arch. Indust. Health 18:168, 1959. 7. WTade, L. J.: Why people won’t work, Texas J. Med. 54:496, 1958.
absenteeism
myocardial
of industrial
workers
infarcts
Neil1 K. Weaver, M.D.* Baton Rouge, La.
mhe physician who wishes to rehabiliA tate patients who have recovered satisfactorily after myocardial infarction must recognize a number of deterrents. Among these are fear that the individual will have another attack for which the employer may be held liable, and concern that the cardiac employee cannot work effectively, and that he will experience high and costly sickness absenteeism. The administration of compensation benefits for workers who experience subsequent attacks is a complex process which often involves courts, commissions, and customs wherein the testimony and opinions of the individual practitioner of cardiology seemingly carry little weight. For removal of this obstacle to cardiac rehabilitation, legal and socioeconomic reforms would seem to take precedence over strictly medical advances. On the other hand, the effectiveness on the job of cardiac workers who are placed in a suitable assignment has been demonstrated so widely and overwhelmingly that the productivity of such employees is no longer of major concern. In this study, data which pertain to the absenteeism experience of industrial workers with proved myocardial infarcts are presented. Such information, which heretofore has received scant attention, may be helpful to From
the Medical Department. Baton Rouge Company, Baton Rouge, La. Received for publication March 9, 1961. *Associate Professor of Clinical Medicine and Orleans, La.
457
physicians situations alike.
in discussing with patients
return-to-work and employers
Method The 100 subjects whose records form the basis of this report were selected from current or recent lists of permanently partially disabled employees identified in the total population of 7,500 workers of a large oil refinery and petro-chemical plant. The two criteria required for inclusion in the study were: (1) the worker must have a diagnosis of healed myocardial infarction established beyond reasonable doubt, after which, (2) he must have resumed work for a period of at least a year. (Data collected on subjects whose period of work was 6 to 12 months did not differ significantly from the findings to be presented; however, subjects with less than a year of work experience after infarction were excluded in order to avoid the possible criticism that the period of observation at work was too short.) All have been effective workers on the job, since they were included in an organized program for the selective placement of handicapped workers which entailed periodic review by both physician and supervisor.’ The average age of the study group was 50 years, as compared to 45 years for the entire worker population. Refinery,
Occupational
Manufacturing
Medicine,
Division
Tulane
of the Humble
University
School
Oil and
of Medicine,
Refining
New
4.58
Weaver
Complete information as to the number of absences from work due to disability-, the duration of each absence, and the clinical reason for each absence was collected for each of the 100 subjects. The survey period began with the patient’s return to work after an initial myocardial infarction and ended June 30, 1960. Seven subjects in the study group became totall). and permanently incapacitated for work, and 3 died. For these individuals the survey period ended on the last day on which they worked. Some patients experienced subsequent infarcts and again resumed work for a year or more. The periods of absence from the job due to later attacks are included in the analysis. Only five infarcts in this series were “silent” or unrecognized in the acute stage. These were discovered, usuall\. at routine periodic examination, when stable electrocardiographic patterns typical of healed infarction were found on indivicluals whose previous tracings lvere normal. Such findings were not associated with periods of disability. The absenteeism experience of the 100 workers with proved myocardial infarcts is compared with data for the whole refiner! population, derived in a similar manner for those years in which most of the cardiac cases were analyzed. Each period of allsence is measured in calendar days, and rates are calculated according to the procedure recommended by the American Medical Association Committee on Medical Care for Industrial Workers.? Other matters concerned with heart disease and employment have been excluded as irrelevant to the study of absenteeism. Results The 100 subjects of this study had an average of 4.7 years (range: 1 to 17 years) at work after the initial episode of myocardial infarction. Thus, 470 man-)-ears of \vork experience are included in the survey. Ten workers subsequently developed a second infarct, and 2 patients had a third. In all, 112 infarctions were recognized in the subjects during the study. Disability absenteeism rates for the cardiac workers are compared with rates for all refinery workers in Table I. The worker with a healed infarct was absent 10.0
Am. Hcort .I. October, 1961
calendar davs annually because of sickness or injury- (disability rate), as compared to an average of 9.9 days for all refinery workers. The annual number of absences per employee (frequency rate) for the cardiac group was 1.2, and for all workers, 1.1. The average duration of absence (severity rate) was 8.3 days for the study group, and 8.9 days for the whole worker population. Only 2.7 of the 10 days of absence each year by the cardiac worker were the result of cardiovascular disease. The major types of cardiovascular disabilities occurring in the 100 subjects are shown in Table II. Chest pain due to angina, coronar!. insufficiency, or myocardial infarctioil ;1ccounted for two to three times as man)-da).s of disability as did either myocardial failure or other conditions (arrh\-thmias, strokes, hypertension, peripheral vascular disease, and time away from the job for observation and regulation of medication). The frequency rate for cardiovascular absences was 0.16, and the severity rate was 17 days. Analysis of absenteeism by age group (Table III) reveals variation in cnrdiovascular absences from 2.2 days per \-ear for the SO-54 age group to 4.7 clays for the 4.5-49 age group. The increase in noncardiovascular absences in workers in the 60-64 age group was caused by a number of prolonged periods of disability involving operations. Table IV compares the absenteeism experience of salaried employees and wage earners. The salaried group was composed of 16 supervisory and technical and 26 clerical workers, 42 in number, with an observed work experience of 210 man-years. The wage earners consisted of 39 skilled and 19 unskilled employees, a total of 58 with 260 man-years at work after infarction. Cardiovascular absences for the salaried workers averaged 1 day per worker annually, as compared to 4 days for the wage earner. AAl1 types of disabilities for the salaried employee amounted to 6.7 days )-earl>-, about half the number of days (12.7) lost bJ- the wage employee. Corresponding disability rates for these groups in the entire population were 6.1 and 11.6. In addition to disability and frequency rates, the duration of absence for an episode of acute mvocartlial infarction is
Disability
Table I. Disability
All
with
refinery
healed workers
Disability rate (deys/entployee/yr.)
group
infarcts
(100
(7,500
causes of disability
Cause of absence
All
employees)
i~+arcts
450
I
8.3
9.9
1.1
8.9
for work
in 100 employees with healed infarcts Frequency rate (absences/enrployee/yr.)
1.5 0. 5 0.7 2.7
cardiovascular
Table I I I. Absenteeism
Severity rate (days/absence)
1.2
Disability rate (days/employee/yr.)
etc.)
Frequency rate (absences/employee/yr.)
10.0
employees)
Table II. Cardiovasczhlar
Chest pain Myocardial failure Other (arrhythmias,
with myocurdiai
absenteeism experience
Employee
\XTorkers
absenteeism of workers
Severity rate (days/absence)
0.07 0.02 0.07
21 2.5 10
0.16
17
experience by age group Disability
Age group (Y7.1
Nun&be7 of workers
4044 4539 SO-54 5.5-59 60-64
13 14 18 31 24
of
Number infarcts
Work experience (man-years)
rate (days/employee/yr.I
_ Curdiovascular
Table IV. Absenteeism
14 16 18 36 28
52 63 97 136 122
Total
2.3 4.7 2.2 2.8 3.4
5.6 5.2 4.2 5.4 13.9
7.9 9.9 6.4 8.2 17.3
of salaried employees and wage earners
T 100 Workers
with
healed
myocardial
infarcts
,411 re$nery
workers
Disability rate (days/employee/yr.j Employee
?PUP
-1 Cardiovascular
Frequency rate (absencesjemployeejyr.)
Other1 I Total
Cardiooascularl
I
Average lost with
days acute
infarcts Other
Total
Disability rate (dayslentployeelyr.)
Salaried (42 workers)
1.0
S.7
6.7
0.12
1.06
1.18
93
6.1
Wage (58 workers)
4.1
8.6
12.7
0.18
1.08
1.26
109
11.6
460
Am. Heart J. October, 1961
Weaver
shown. This was 93 days for the salaried worker and 109 days for the wage earner; the combined average was 102 days. Discussion
These data suggest that patients with myocardial infarction who are able to return to work in a suitable assignment do not have high disability absenteeism. The 100 subjects, with a total observed experience of 470 man-years, on resuming work after an infarction averaged only 10.0 calendar days of disability annually. In comparison, the average for all refinery workers was 9.9 days. The survey group also had surprisingly low frequency rates for disability absences-O.16 for cardiovascular causes and 1.2 for all causes. These findings are in general agreement with other reports on absenteeism of fulltime workers with heart disease of various etiologies. One hundred and eighty-nine workers followed by the Work Classification Unit, Adult Cardiac Clinic of the Third (New York University) Medical Division, Bellevue Hospital, lost an average of approximately 9 days per year.3 Greer4 reported an average absenteeigm of 13.3 days annually for 45 industrial workers with arteriosclerotic heart disease, compared with 11.3 days for all employees. Neither report described details of the derivation of data upon which conclusions were based. Wyshak, Snegireff and Law5 studied absenteeism of workers with various types of heart disease or diabetes in 17 manufacturing plants,5 and found that employees with coronary heart disease were able to work with little more disability than persons free of heart disease; cardiac workers placed in “light” jobs lost less time than “production” workers. A previous study from this department also revealed a generally good prognosis for patients who returned to work after cardiovascular absences.6 Nearly 88 per cent of those who resumed work either continued on the job or retired for nonmedical reasons. In the course of the 3-year observation period, approximately 6 per cent died and another 6 per cent retired for medical reasons. This analysis, based on a large number of cardiovascular absences of all types, differs from the present one
which is based on the experience of patientemployees with a specific type of heart disease. It may appear surprising that the employees of this study who had established heart disease of a serious nature did not lose more time from the job because of disability than did the average worker. It is possible that such employees, having recovered satisfactorily from a life-threatening illness to resume a productive job in industry, are highly motivated to stay on the job and avoid unnecessary absences. Even though higher job motivation may be contributory to the lower absenteeism experience of salaried workers as compared to wage earners, other important factors are the generally better work environment and less physically demanding assignments available to the “white collar” worker. It deserves re-emphasis that disability absenteeism is affected by many factors, nonmedical as well as medical.’ For example, it has long been recognized that some periods of apparent “disabilit\,” bear a strong relationship to the availability and duration of disability payments. None of the workers who were surveyed was involved in a compensation suit. All were covered by a company benefit plan which provided, in general, full pay for the first 12 weeks of disability, and one-half pay for an additional 40 weeks. Such n plan offers sufficient economic security to generally deter efforts to work when actually disabled, and joint follow-up of each absentee by full-time company physicians and the personal physician tended to minimize unnecessary and unduly prolonged periods of absence. Summary
Disability absenteeism of 100 subjects who resumed industrial work for an ohserved 470 man-years after myocardial infarction is reviewed. They experienced 10.0 calendar days of disability per person annually, whereas the average for all workers ill the same plant was 9.9 days. Only 2.7 da\-s of absence each year were due to cardiovascular conditions. The cardiac employee had, on the average, 1.2 periods of disability yearly, as compared to 1.1 absence per worker for the whole refinery population. Analysis of absenteeism by age
Volume Number
62 4
Disability
absenfeeism of workers
group revealed no significant trend in the patients studied. Salaried cardiac workers had one fourth as many days of absence for cardiovascular reasons, and one half as many days of disability for all reasons, as did wage earners. The absenteeism experience of workers with healed myocardial infarcts who resumed work in a suitable job assignment did not differ significantly from that of the whole plant population. REFERENCES 1. Weaver, cardiacs 2. American Medical
N. Ii.: The selective placement of in industry, Postgrad. Med. 24:4, 1958. Medical Association Committee on Care for Industrial Workers: Pre-
with myocardial
in.arcts
461
liminary guide for measuring work absence due to illness and injury, J.A.M.A. 168:1230, 1958. 3. Staff of the Work Classification Unit, Adult Cardiac Clinic, Bellevue Hospital: An occupational analysis of 580 cardiac clinic patients, Circulation 3:289, 1951. 4. Greer, W. E.: Experience in selective placement and follow-up on cardiacs. 1~ Rosenbaum, F. F., and Belknap, E. L., editors: Work and the heart, New York, 1959, Paul B. Hoeber, chapter 43, p. 383. 5. Wyshak, G., Snegireff, L. S., and Law, A. F.: Work experience of persons with cardiovascular disease or diabetes, J. Chron. Dis. 1052.5, 1959. 6. Thorpe, J. J., and Weaver, N. IX.: Effective return to work of the cardiac employee, A.M.A. Arch. Indust. Health 18:168, 1959. 7. WTade, L. J.: Why people won’t work, Texas J. Med. 54:496, 1958.