MULTIPHASIC SCREENING

1434 well-woman " clinic in a general practice, run by a doctor with some ancillary help and limited to a few specific tests; the main yields were anaemias and a few cases of cervical and breast cancer. The Rotherham report,5,6 by contrast, refers to a large battery of tests offered to a much larger population, but this clinic was kept open for only a short period of time as a campaign ". Investigations included examinations for cancer of the breast and cervix, haematology, glycosuria, glaucoma, hearing and vision defects, blood-pressure, and respiratory function. Substantial experience of large-scale large-battery testing on a continued basis comes mainly from the United States. Again, the backgrounds vary-some systems being based upon health insurance, others within an industrial setting. Collings et al.11 used a self-administered health

described

Screening for Disease* MULTIPHASIC SCREENING E. G. KNOx Health Services Research

Centre, Department of Social Medicine, University ofBirmingham

THE

"multiphasic screening" (M.P.s.) first in the Cumulative Index Medicus in 1968, but it was used in titles to papers 25 years ago 1-3 The term was presumably in conversational usage even before this, but the origins of this rather curious " term are obscure. Despite the reference to phases " there is no critical sequence or conditional stages or branches in the process, and the term is usually considered to be synonymous with " multiple screening ". Where specific connotations have been applied, they have usually been expressed in other terms. For example, Breslow3 included the restriction " performed by technicians under medical direction " within his definition, and the Multiphasic Health Services Screening Committee of the National Health and Medical Research Council of Australia (N.H.M.R.C.A.)4 adopted a definition which included a battery of tests " with minimal involvement of medical practitioners". This is not, however, a universally accepted constraint. Donaldson and Howe1l5 and Girt et a1.,6 describing an experiment in Rotherham which would have met these terms, referred simply to " multiple screening " or " multiple health screening ". Moreover, in many programmes it is clearly intended that the procedures be carried out by doctors or under direct medical supervision or after (rather than before) a consultation with a doctor.’ In some studies, mainly European, the procedure seems to be equated with a "periodic health check-up " with some supplementary investigations, rather than as a substitute for or prelude to such a check-up. Special benefits are sometimes claimed for multiple tests in the sense that the whole is said to represent more than the sum of the parts, and emphasis is laid upon the combinatorial quality of the information obtained-e.g., the simultaneous availability of electroterm

appeared

cardiogram

(E.c.G.),

blood-pressure, serum-lipids,

and smoking history. The multiple aspect is also associated with the notion of serial testing, and with the suggestion that a baseline reading (E.C.G., bloodpressure, intraocular tension, and so on) might facilitate the interpretation of later readings. By and large, however, the combinatorial aspect seems to have proved theoretical rather than practical, and the main benefits are convenience to the patient and to his doctor, and economy. SIZE

OF

THE

MULTIPLE

SCREEN

The contents and contexts of multiple screening vary from simple combinations of a few tests to very large batteries. Breslow 10 quoted a definition used by the U.S. President’s Commission on the Health Needs of the Nation which required only " the application of two or more screening tests in combination ". In Britain, Wookey7 has *

A

reprint of this series will be available Nov. 2, p. 1092.

early in 1975 (see Lancet,

a

"

"

questionary, urinalysis, serum chemistry, hsematology, E.c.G., chest X-ray, blood-pressure, anthropometry, hearing

spirometry, and tonometry in an industrial setting. Yedida et al.,12 working among Californian cannery workers, used a similar series of tests, except for the omission of the hearing test and the addition of cervical cytology, breast palpation, and a serological test for syphilis. The Kaiser Permanente scheme in California provides and vision tests,

similar extended series of tests in the context of a healthThe Varmland scheme in central insurance plan 13 Sweden offered a similar battery of tests to a whole adult population,14 while the Shepherd Foundation scheme, in Australia, provides a similar extended series of tests.’ Flagle 15 has compiled a composite " typicallist of tests obtained from various schemes, and, in addition to those already mentioned, includes achilleometry, dental examination, dental X-ray, skin-fold thickness, psychometrics, retinal photography, temperature, and thermography. Additional components suggested or implemented in these or other schemes have included mammography, proctoscopy, and sigmoidoscopy,l3.16 and different schemes differ in the range of urinary, hsematological, and serological tests, and in other details. For example, the Shepherd Foundation scheme tests six audiometric frequencies in each ear, in addition to tests for visual acuity and tonometry, and maps the visual fields. .P.s. is much more common in the United States than in Britain, where the only permanent large-scale clinic is the one set up by the British United Provident Association in 1970. Howe 17 provided a partial register American schemes, but thought that it included only of the larger ones and that there could in fact be several thousand in various parts of the country. The larger schemes alone served about 750,000 Americans in 1970. Howe suggests ,a dichotomy between small and very large systems. This arises from the technicalities and the costs of data processing. Large schemes require computer processing; but computers lead to economic disaster, he thinks, unless the throughput is around 15,000 examinations per annum or more. This has opened up a gap between schemes too large to be run without a computer and those too small to be run with one. a

BENEFITS

The benefits of multiphasic screening-or any other health-care scheme-can only be evaluated in terms of set objectives. Unfortunately, the objectives have been stated in a variety of different ways, or sometimes omitted altogether. Lucas et all conducted an inquiry of 67 M.P.S. programmes, and the responses relating to objectives were grouped into three classes -namely, (a) enhancement of the patient data-base available to the physician, (b) health maintenance

1435

population served, and (c) the attempt’ to more people into the health-care system. of these objectives can be regarded the second Only as a true health-care objective in a primary sense, lending itself to evaluation in terms of improved mortality or morbidity rates or the well-being of the participants. Only 4% of the programmes studied were prepared to characterise their objectives in these terms, and this reluctance is reflected in the paucity of reported results stated in terms of changed health status. Indeed, until very recently, no serious attempts

where the global efficacy of M.P.S. is have been demonstrated, and although can be regarded as a small marginal addition to an existing M.P.S. scheme, this does not excuse us from evaluating it. Detailed information of this kind is the necessary basis for modifying M.P.S. programmes as opposed to simply extending them. Most tests incur errors and carry hazards, and a group of bad tests put together can make a very bad test indeed.

of the

required

even

introduce

believed each test

to

do this had been made. Three major randomised control trials have been reported-two of them in plan only, without results, and the other in Yugoslavia .20 Howone in Britain 1& Kaiser the Permanente scheme has been ever, of papers by Collen and his a series in reported colleagues.11,21-23 This investigation was based upon random allocation of over 5000 persons to each of two groups and their follow-up over a period of seven It was impossible to maintain equivalent years. follow-up techniques in both sets of patients, and there was some subsequent drift in the relative sizes of the groups, but their social structures remained comparable. Comparisons after seven years showed no remarkable differences with respect to the prevalence of major disabilities or chronic conditions. There was an excess of partial disability in controls as opposed to screened, but this assessment was based upon a questionary completed by patients and might have been related to differing self-appreciations induced by the differing levels of medical contact rather than to disabilities which might have been confirmed objectively. The relative excess among controls of demands upon doctor and hospital services can also be interpreted ambiguously, either as attitudinal or objective indices. Mortalities after seven years showed a small but not necessarily negligible difference, 35-6 per 1000 enrolled in the screened group and -39-2 per 1000 in the controls. Singled out for special comparison was a group of "potentially postponable" causes of death, defined on the basis of medical opinion before the results of the survey were known and including carcinoma of large bowel, rectum, breast, cervix, uterus, kidney, and prostate, and deaths from hypertension, hypertensive cardiovascular disease, and intracranial haemorrhage. There were 19 such deaths in the screened group compared with 41 in the controls, a difference which can be considered statistically significant. However, not all these conditions were the subject of screening procedures designed to detect them, and Collen and his colleagues did not declare how many were in fact detected by screening. Until further information becomes available, we must take it that the demonstrable primary health benefits of M.P.S. are quite small and that, although they are probably real, even this is open to some doubt. The main lesson from these studies may be that for purposes of evaluation the health objectives of multiphasic screening are probably best identified with the individual components. Each of them requires a separate validation exercise in terms such as those suggested by Whitby 24 or in the Nuffield Provincial Hospitals Trust study.2S This will be

COSTS

to

Most workers would

probably agree that M.P.S. amounts essentially to an administrative arrangement and that its justification as a scheme (over and above the justification of its components) is to be made in terms of economics and administrative mechanics. A full examination would a detailed analysis of costs, and a comparison with those which would have been incurred if the test were carried out separately or in smaller groups. Against this would have to be set some measure of the inefficiencies of combining into one regimen a series of tests, each of which must have a different optimal pattern of delivery in terms of age distribution and frequency. No approach to so comprehensive an assessment is available. However, a number of cost estimates have been provided, using a variety of different methods. Collenet al.,26 referring to the Kaiser Permanente scheme, estimated the costs at $21(8) per full examination. Collings et all estimated their costs at about$30(C12). The Shepherd Foundation scheme charges a fee of$A50(33). The various programmes investiged by Lucas et aI,18 charged fees ranging from$15(f6) to over$60(E25). Mackintosh 27 complained that lack of uniformity in costing methods, including various treatments of amortisations and development costs, made it difficult to interpret published results. In his own scheme he estimated costs at$70(29) per full examination for men and$93( £ 39) for women. None has specifically computed the savings which might accrue from carrying out the tests together as opposed to separately, nor have the costs of subsequent medical consultations and treatment and the attendance costs incurred by patients been included. Estimates of the demand for medical care which screening stimulated and the later demand which screening would have forestalled do not Desirable objectives would seem to have been available. clearly be formulated differently in the contexts of In Britain, for example, different health-care systems. stimulated demand would be seen mainly as an additional cost and forestalled demand as a saving. By contrast, the third class of objective listed by Lucas et al.18 in an American setting was specifically evangelical. Indeed, in a consideration of cost effectiveness Lucas et al. characterise M.p.s. as a " successful business venture ". They are not alone in this approach, and objectives recognised by Howe 17 are also frankly commercial, or, as described by Flagle, tactical The results of some studies, and implicitly the objectives, have been defined in terms of yields ". For example, Yedida et al.12 found one or more abnormalities in about 40% of Californian seasonal workers, using a mobile clinic. Soghikian and Collen 16 said that 70 % of their examinations (i.e., attendances) resulted in a diagnosis of some kind. Neither of these groups stated how many of the abnormalities were already known to

require

"

"

the patient or his physician and how many were newly discovered. The difficulties of follow-up do not seem to have permitted this, and Soghikian, in a reported discussion following his paper,16 admitted that he could not answer this particular point. Nor do there seem to be any valid statistics of results expressed in terms

1436 of actual referrals

kept, subsequent diagnoses confirmed rejected, prescribed, or (beyond the Kaiser Permanente results already discussed) morbidity or mortality prevented. Occasionally, the costs of M.P.S. have been expressed in relation to yields. For example, or

Yedida

new

et

aJ.l2 estimated

at$90(38)

costs et al.28 were

CONCLUSION

.

There is little in the way of reported concrete investigation of the attitudes, expectations, and satisfactions afforded by M.P.s. to those attending the clinics. Cutler et a113 gave some factual information about attendance-rates; about a quarter of their control group presented for M.P.s. spontaneously while two-thirds of their study group could be induced to attend through letter-writing and telephone calls. Soghikian and Collen 16 investigated attendance patterns and came to the conclusion that M.P.s. was an eminently acceptable procedure to patients, but did not go beyond this. They declared, furthermore, that the further validation of M.P.s. would depend upon " its demonstrated value to the medical pro-

fessian " (my italics). Perhaps these expressions of purpose, and the economic studies already quoted, do indeed suggest the limits of the objectives appropriate for evaluating a procedure which has been defined explicitly in administrative terms by many of its practitioners and proponents, or implicitly so through their lack of interest in primary health objectives. Acceptance of administrative and economic objectives would at least make it clear that there is an absolute additional requirement that every individual component of a multiphasic screening scheme must be made the subject of a separate and rigorous examination following the assignment of genuine health-care objectives. The admirable and difficult investigations of pooled outcomes referred to above are unlikely to supply a completely satisfactory substitute. In the meantime we seem to have little option but to adhere, though perhaps with diminishing enthusiasm, to the view expressed by the N.H.M.R.C.A.4: " multiphasic health screening procedures appear to be of little value in medical practice at the present time, particularly in respect of individuals who are apparently well and who are not in hospital ". REFERENCES 1. Canelo, C. K.,

ALAN BAILEY Research

Department, B.U.P.A. Medical Centre, London N1

per referral

Collen able to cost the a physician. components of their programme separately in this manner and the estimates ranged from$1’53(JM)’65) per positive audiogram to$408(170) per positive mammogram. Tonometry was another high cost test at$275(115) per positive. Abnormal chest X-rays at$2’40(S1) per positive, hypertension at$2’66(S1’11), bacteriuria at$6’03(2’50), abnormal E.c.G. at$10(4), and a positive test for syphilis at$10’65(S4-27) gave better value. Mackintosh’s 27 estimates, computed in an alternative manner, ranged from about$15( £ 6.25) for abnormal vision to$11,870(3000) for positive cervical cytology.

to

BIOCHEMISTRY OF WELL POPULATIONS

treatments

Bissell, D. M., Abrams, H., Breslow, L. Calif. Med. 1949, 71, 1. 2. Chapman, A. L. Publ. Hlth Rep., Wash. 1949, 64, 1311. 3. Breslow, L. Am. J. publ. Hlth, 1950, 40, 274.

SINCE the last war, clinical biochemistry has been growing in importance, and automation has made multiple blood analysis more economic. Applying a number of tests in a situation where only one was requested by the clinician has often been diagnostically helpful, and has also revealed some unsuspected clinical conditions.1,2 In the same period screening centres have evolved where a battery of tests, including biochemical ones, are done in the hope that certain diseases may be detected in their early stages and thereby prevented. These are the so-called "well people " clinics; those attending them are active and in full-time employment (the clinics are often supported by industry) and they are unaware that anything is physically wrong with them. At the B.U.P.A.

Medical Centre almost all attendances are referrals because of symptoms are very rare.

routine;

VARMLAND

In the early 1960s G. and I. Jungner undertook a massive study of about 90,000 adults living in the Varmland county of Sweden.3 A screening programme was offered on a voluntary basis, and the response-rate was 76%. In addition to a brief medical history, measurements of height, weight, and blood-pressure, urinalysis, chest X-ray, and blood-tests (see table) were

Multiphasic Health Screening Services Committee of the National Health and Medical Research Council of Australia. Multiphasic Health Screening Services. Canberra, 1972. 5. Donaldson, R. J., Howell, J. M. Br. med. J. 1965, ii, 1034. 6. Girt, J. L., Hooper, L. A., Abel, R. A. Rep. publ. Hlth med. Subj. 1969, no. 121. 7. Wookey, B. E. P. Br. med. J. 1971, i, 396. 8. Percy-Robb, I. W., Cruickshank, D., Lamont, L., Whitby, L. G. 4.

ibid. p. 596. 9. Duras, F. P. ibid. 1972, iii, 232. 10. Breslow, L. Prev. Med. 1973, 2, 177. 11. Collings, G. H., Fitzpatrick, M. M., Levy, B., Walsh, J. M.J. occup. Med. 1972, 14, 434. 12. Yedida, A., Bunow, M. A., Muldavin, M. ibid. 1969, 11, 601. 13. Cutler, J. L., Ramcharan, S., Feldman, R., Siegelaub, A. B., Campbell, B., Friedman, G. D., Dales, L. G., Collen, M. F. Prev. Med. 1973, 2, 197. 14. The Värmland Survey (translated by Greta Sargeant). Socialstyrelsen Redovisar, Stockholm, 1971. 15. Flagle, C. D. Meth. Inform. Med. 1971, 10, 201. 16. Soghikian, K., Collen, F. B. Bull. N.Y. Acad. Med. 1969, 45, 1366. 17. Howe, H. F. J. Am. med. Ass. 1972, 219, 885. 18. Lucas, F. V., Bender, M., Mark, F. D., Thorner, R. M., Webb, D. R. Adv. med. Eng. 1973, 3, 199. 19. Trevelyan, H. Prev. Med. 1973, 1, 278. 20. Thorner, R. M., Djordjevic, D., Vuckmanovic, C., Pesic, B., Culafic, B., Mark, F. ibid. 1973, 2, 295. 21. Ramcharan, S., Cutler, J. L., Feldman, R., Siegelaub, A. B., Campbell, B., Friedman, G. D., Dales, L. G., Collen, M. F. ibid. p. 207. 22. Dales, L. G., Friedman, G. D., Ramcharan, S., Siegelaub, A. B., Campbell, B. A., Feldman, R., Collen, M. F. ibid. p. 221. 23. Collen, M. F., Dales, L. G., Friedman, G. D., Flagle, C. D., Feldman, R., Siegelaub, A. B. ibid. p. 236. 24. Whitby, L. G. Lancet, 1974, ii, 819. 25. McKeown, T. (editor). Screening in Medical Care. London, 1968. 26. Collen, M. F., Kidd, P. H., Feldman, R., Cutler, J. L. New Engl.J. Med. 1969, 280, 1043. 27. Mackintosh, D. Publ. Hlth Rep., Wash. 1970, 85, 685. 28. Collen, M. F., Feldman, R., Siegelaub, A., Crawford, D. New Engl. J. Med. 1970, 283, 459.