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SPECIAL ARTICLES

PULMONARY TUBERCULOSIS IN

INDUSTRY

INCIDENCE AND AFTER-HISTORY

AN ANALYSIS OF 3755 CASES

BY H. H. BASHFORD, M.D., M.R.C.P. Lond.CHIEF MEDICAL OFFICER TO THE POST OFFICE ; AND

W. L. SCOTT, M.C., M.D. Glasg.SECOND MEDICAL OFFICER TO THE POST OFFICE

IT cannot be claimed that the Post Office is repre-sentative of industry at large, but it is numericallythe largest employer of labour in this country, witha total staff of some 185,000 men and 55,000 women.It also embraces a great variety of employments,outdoor and indoor, manual, technical, and clerical.Its experience, therefore, in the incidence of pul-monary tuberculosis, and in the after-history of curedor arrested cases that have returned to duty, mayperhaps be of some general interest. As regardsincidence rates, those to be quoted are in respect ofthe established staff of about 121,000 men and35,000 women, all of whom have been subjected beforeestablishment to a very thorough medical examina-tion. But, on the other hand, they have all beenbetween the ages of 16 and 60, which embraces theperiod of life during which pulmonary tuberculosisis most likely to manifest itself, whereas incidencerates reported for the community at large must bebased upon a population including very large numbersof persons below and above these ages, in which theoccurrence of pulmonary tuberculosis is relativelyuncommon, and must therefore, to a considerableextent, be diluted by these. Between the years1914 and 1935, the incidence rate of pulmonarytuberculosis in the established staff of the PostOffice has in some years been less and in some frac-

tionally higher than that reported for the whole

population of England and Wales. The tendency,however, in common with recent general experience,has been in the direction of a steady decrease ; andthe incidence rate for the year 1935-namely, 1-04 per1000 employees-was the lowest in Post Office records.As regards the rate of incidence amongst Post

Office workers in London and those in the provinces,the average rate of incidence for the years 1920 to1935 inclusive was 1-55 per 1000 employees forLondon, as compared with 1-43 per 1000 for the

provinces. As between men and women workers,the average rate of incidence for the years 1920 to1935 inclusive was 1-54 per 1000 of male workersand 1.24 per 1000 of female workers. Over the sameperiod, the average rate of incidence amongst manual,mainly outdoor workers, was 1-92 per 1000 in Londonand 1.56 per 1000 in the provinces, as compared with1.21 per 1000 for non-manual indoor workers inLondon and 1-06 for non-manual indoor workersin the provinces. It will thus be seen that the highestrate of incidence has been amongst manual, mainlyoutdoor, workers in London and the lowest amongstnon-manual indoor workers in the provinces, the

comparative advantage in the case of the latter

group being 0-86 per 1000 employees.

TABLE L-Age-distribution of 1848 cases returning towork in the years 1914 to 1926 inclusive

Four cases occurred in earlier years whose ages could not betraced.

Unfortunately, accurate statistics of the numericalcomposition of the whole Post Office staff for theobserved years, in age-groups, are not available ;and therefore percentage incidence rates in age-groups cannot be given. For what it is worth,however, Table I. has been constructed.

TABLE II.-ANNUAL WASTAGE FOR FIRST TEN YEARS AFTER RESUMPTION OF WORK

A= Retired, or died of pulmonary tuberculosis. B= Retired, or died of other causes. C == Retired for non-health reasons.

I m 1- I I , -

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Turning to the after-history, in ordinary workingconditions, of cured or arrested cases of pulmonarytuberculosis, it should, perhaps, first be made clearthat, as long as there is a reasonable prospect ofrecovery to render regular and efficient service, thePost Office has been prepared to allow very prolongedperiods of sick absence, frequently exceeding a yearin duration. It has been found, however, during thelast twenty-two years, that the percentage of casesof pulmonary tuberculosis able to return to workhas remained fairly constantly at not more than 50.Thus, of a group of 3755 cases occurring in the years1914 to 1926 inclusive, the number resuming dutywas 1848: the after-history of this group duringthe first ten years following resumption of work isshown in Table II.

It will be seen that of this group of 1848 casesthere had been-ignoring retirements for othercauses-a further wastage by the end of ten yearsof 775 cases due to recurrent pulmonary tuberculosis,and 110 cases due to other forms of ill-health-i.e.,a total wastage due to ill-health during the ensuingten years after resumption of work of about 48 percent.-an approximately 44 per cent. wastage havingoccurred during the first six years after resumption,and of the survivors, another 16-6 per cent. wastageduring the next four years.

It is usual in the Post Office, on resumption afterpulmonary tuberculosis, to arrange, whenever pos-sible, for a period, often prolonged for several years,of regular indoor duty. And, although the climaticfactor, per se and in most cases, is regarded as con-siderably less important than those of personalrégime and immediate domestic environment, trans-fers are not infrequently arranged to country or

seaside places. Nevertheless experience has shown thatthe subsequent wastage due to recurrent pulmonarytuberculosis or other ill-health is somewhat higherin the manual, mainly outdoor, classes (male) thanin the others. Thus, out of a group of 950 suchworkers, returning cured or arrested in the years1914 to 1926 inclusive, there had been a wastageof 578, or roughly 60 per cent., as the result of recur-rent pulmonary tuberculosis or other ill-health, bythe end of ten years. Out of a group of 542 lightmanual or clerical indoor workers (male) returningcured or arrested in the same period, there had beena wastage for these causes of 272, or roughly 50 percent.As regards the industrial survival rate amongst

women workers returning cured or arrested, the

relatively large number of subsequent resignations,not specifically attributed to ill-health-and many,no doubt, for marriage and domestic reasons-tendsto invalidate any conclusions. Of a group of 231such cases returning to work in the years 1914-26inclusive, 65 had either died or retired from recurrentpulmonary tuberculosis, and 17 from other .forms ofill-health by the end of ten years, 82 of the groupbeing still in the Service at the end of that time.

Given industrial survival after ten years, however,the further outlook would appear to become lessunfavourable ; and in a group of ten-years’ survivors,whom it was possible to observe for another fiveyears, there was a wastage, by the end of that period,of not more than about 14 per cent., 39 of the subse-quent deaths or retirements having been due torecurrent pulmonary tuberculosis and 28 to othercauses.

CONCLUSIONS

On the general basis, therefore, of a group of3755 cases of pulmonary tuberculosis occurring

during a period of thirteen years and observed fornot less than ten, and in some cases for more thantwenty, subsequent years, it can be stated :-

1. That of those who incur pulmonary tuberculosis,not more than 50 per cent. are able to return to

work, even after prolonged periods of treatment.2. That of those who return there has been a

further wastage of about 48 per cent., as a result ofrecurrent pulmonary tuberculosis or other forms ofill-health, by the end of ten years, the heaviest

wastage having occurred in the first six years.3. That in respect of the incidence amongst them

of pulmonary tuberculosis, light manual or clericalindoor workers would appear to have a slight advan-tage over manual, mainly outdoor workers, and a10 per cent. advantage in respect of subsequentsurvival in industry after resumption of duty. Itmust be remembered, however, in respect of thePost Office, that the years observed have covered aperiod in which its largest mainly outdoor group,namely postmen, has included from between 30 to40 per cent. of war-disabled men, a considerablylarger proportion than in any other single group.

4. That of cured and arrested cases who survivea period of ten years, the wastage due to recurrentpulmonary tuberculosis or other forms of ill-healthat the end of a further five years is reduced to about14 per cent.

We should like to record our thanks to all those whohave assisted in the collection and preparation of theabove figures, and particularly to Mr. A. W. Scott of themedical branch of the Post Office.

MEDICINE AND THE LAW

Heart Disease and Sudden Strain

A WORKMEN’S compensation case, illustrating a nowestablished principle, came before the Court of Appealat the end of October (Hilton v. Billington and

Newton). Mrs. Hilton’s husband had been employedas a lorry-driver. He strained himself last Februaryin frequently cranking up a heavy lorry which had achoked carburettor. Severe pain followed, and alsoan attack of influenza. After ten days’ absence herecovered and went back to work, but he died onApril 27th. Post-mortem examination showed theheart to be in a diseased condition, so that a suddenstrain might have caused death at any time. Whenthe application came before the Hanley county court,one doctor said that death was directly due to thestrain of cranking up the lorry. Hilton’s own

doctor gave the following evidence of the conditionwhen the patient was about to resume work:" Apparently well recovered when he came to mysurgery, but heart irregular, heaving impulse." Thedeputy county court judge said that the heart strainmight have caused death, but it was one of severalpossible causes and it had not been proved to bethe effective cause. The Court of Appeal now saysthat the county court misunderstood the doctor’sevidence. The doctor’s evidence meant that Hiltonhad recovered from the influenza but not from theheart disease ; the county court judge went wrong inthinking that the evidence meant that Hilton hadrecovered from the strain. Lord Justice Slesserpointed out that there was no evidence of the toxiceffect of influenza on the patient’s heart; the countycourt judge had overlooked the continuity of thepain up to the time of death. The medical evidenceshowed that the workman was continuously ill from