COMPARISON OF COST OF PREPARING REAGENTS IN LABORATORY WITH COST OF USING COMMERCIAL KITS

COMPARISON OF COST OF PREPARING REAGENTS IN LABORATORY WITH COST OF USING COMMERCIAL KITS

1273 Hospital Practice COMPARISON OF COST OF PREPARING REAGENTS IN LABORATORY WITH COST OF USING COMMERCIAL KITS R. W. RICHARDSON Biochemistry Depar...

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1273

Hospital Practice COMPARISON OF COST OF PREPARING REAGENTS IN LABORATORY WITH COST OF USING COMMERCIAL KITS R. W. RICHARDSON

Biochemistry Department, Coventry and Warwickshire Hospital, Coventry CV1 4FH A comparison of the cost of laboratorymade reagents with that of commercial kits was made for three serum-enzyme estimations and three serum-hormone estimations. The cost of reagents in kit form could only be justified on economic grounds for serum aspartate transaminase, alanine transaminase, and lactic dehydrogenase if the laboratory performed less than about 35 tests per day. It is unlikely that the use of kits for serum tri-iodothyronine, thyroxine, and thyrotrophic hormone can be justified on economic grounds for any workload. It is estimated that between £2 million and £3 million is spent unnecessarily by the National Health Service each year to purchase commercially prepared reagents for the six tests studied.

Summary

INTRODUCTION

MANY

laboratories use ready-made reagents in kit form. Advocates of these reagents fresupplied claim that costs are low because of bulk preparquently ation and that kits are particularly suitable for use in the "small" laboratory. Little information is available on the validity of these statements and on the workload which might make such kits economic to use. The new management structure in the National Health Service has introduced methods of departmental budgeting in many clinical chemistry departments in the United Kingdom; the greater responsibility for financial matters now given to heads of scientific departments makes consideration of laboratory costs important. This paper attempts to compare the cost of commercially prepared

hospital

reagents with that of reagents prepared in the laboratory, for certain laboratory tests at different workloads.

METHODS

The

tests

studied

were

serum

aspartate transaminase

(A.S.A.T.), alanine transaminase (A.L.A.T.), lactic dehydrogenase (L.D.), thyroxine (T4), triiodothyronine (T3), and thyrotrophic hormone (T.S.H.). These were chosen because they are estimated regularly in my laboratory and reagent kits are frequently used for these assays in other laboratories. The time taken to prepare reagents was estimated by observing laboratory staff on various occasions between October 1976 and March 1977. Costs were based on price and salary levels on April 1, 1977. An allowance for value added tax was included if appropriate.

Cost

of "In House" Preparation of Reagents

Cost of chemicals was based on those found satisfactory in this laboratory. Labour costs involved in preparing solutions were based on a salary of a State-registered technician with two years’ experience, and included an amount for superannuation and national insurance and an estimate of the cost of supervision. It was assumed that staff work a 48-week year with a working week of 30 hours laboratory bench-time.

Cost

of Kits

No attempt was made to choose the cheapest kits. Kits were chosen because they were in use satisfactorily in a number of laboratories known to me. Allowance was included for a discount, if available, for quantity and regular delivery. Any small difference in cost of reagents between manufacturers for enzyme estimations was not sufficient to affect the conclusions. Considerable variations in cost can be found for various kits for estimation of thyroid hormone; reagents in kit form from two firms used in other laboratories cost about 30% more for thyroxine estimations than the figure given.

RESULTS

Enzyme Estimations Comparative costs for enzyme estimations are shown in the accompanying table. Reagent-preparation time COST OF REAGENTS OBTAINED AS COMMERCIAL KITS AND COST OF REAGENTS PREPARED IN LABORATORY FOR THREE SERUM-ENZYME ESTIMATIONS AT VARIOUS DAILY WORKLOADS

71. Purtilo, D. T., Cassel, C., Yang, J. P. S. ibid. 1974, 291, 736. 72. Moore, G. E., Gerner, R. E., Franklin, H. A. J. Am. Med. Ass. 1967, 199, 519. 73. Gerber, P., Monroe, J. H. J. natn. Cancer Inst. 1968, 40, 855. 74. Chang, R. S., Lewis, J. P., Abildgaard, C. F. New Engl. J. Med. 1973, 289, 1325. 75. Strauch, B., Andrews, L-L., Siegel, N., Miller, G. Lancet, 1974, i, 234. 76. Falk, L. A., Nigida, S., Deinhardt, F., Cooper, R. W., Hernandez-Camacho,

J. I. J. natn. Cancer Inst. 1973, 51, 1987. 77. Deinhardt, F. Br. J. Cancer 1975,31, suppl. 2, 140. 78. Nikoskelainen, J., Leikola, J., Klemola, E. Br. med. J. 1974, iv, 72. 79. Klemola, E., von Essen, R., Henle, G., Henle, W. J. infect. Dis. 1970, 121, 608. 80. Jordan, M. C., Rousseau, W. E., Stewart, J. A., Noble, G. R., Chin, T. D. Y. Ann. intern. Med. 1973, 79, 153. 81. Klein, G. in The Herpesviruses (edited by A. Kaplan); p. 521. London, 1973. 82. Henle, W., Henle, G. Cancer, 1974, 34, 1368. 83. Epstein, M. A. in Viruses and Human Cancer (edited by Y. Ito) (in the

press). Epstein, M. A. Proceedings of the 2nd Interrational Symposium on Etiology and Control of Nasopharyngeal Carcinoma (in the press). 35. Epstein, M. A. J. natn. Cancer Inst. 1976, 56, 697. 84.

aspartate transaminase. alanine transaminase. serum lactic dehydrogenase.

A. S.A.T.: serum

A.L.A.T.: serum L.D.:

Cost is given in pence as cost per test.

when reagents are prepared in the laboratory varies from 10 to 20 min per day according to enzyme and to work load. For laboratories with a workload of about 100 tubes per day, reagents bought in kit form cost about twice as much as reagents prepared in the labora-

1274

chased, thus adding

to the cost. It has been assumed that the development costs are similar for both procedures. Cost of in-house preparation of reagents for enzyme assays is probably less than the figure given as calculations are based on one enzyme onlybeing estimated in a laboratory. In laboratories estimating 2 or 3 of the enzymes the cost of preparing reagents is less as some reagents are common to more than 1 test. It is also possible to save laboratory time by making large quantities of stable reagents such as buffers. Costs for hormone assays assume that radio-labelled substances are used solely for one type of estimation. In practice, any excess labelled T3 can be used for the

T3 uptake test by some modification of the Hamolsky procedure using ’Sephadex’ for binding of hormone. ; ’

of costs for three serum-hormone estimations in relation to workload to justify preparation of reagents in the

Comparison

laboratory.

tory. The difference is approximately 2p per tube. It becomes more economical to prepare reagents in the laboratory than to purchase them in kit form when more than 30-35 estimations of each enzyme are made daily. Hormone Estimations

The accompanying figure shows that the difference in cost between reagents in kit form and reagents prepared in the laboratory for hormone estimations is substantial. Time required to prepare reagents in the laboratory varies from 30-40 min weekly for T3 estimations to 50-200 min weekly for T4 estimations, and 250-300 min weekly for T.s.H. estimations, depending on the number of batches prepared each week. Costs are based on the normal practice in radioimmunoassay of making estimations in duplicate. The figure given should be halved if precision is considered to be satisfactory when single estimations are performed. It is unlikely that the use of kits for the three hormone estimations studied can be justified on economic grounds for any workload.

DISCUSSION

Reliability of Calculated Cost of "In-House Preparation" ofreagents It is difficult to know if the cost of labour has been estimated satisfactorily. The figure used was about twice the basic hourly rate for the grade and any reasonable variation about this figure will not affect the conclusions. Development costs have not been included. Laboratory staff need to spend time developing methods; this time will vary according to the experience of the laboratory concerned and to how well the procedure has been established in other laboratories. Further development of in-house methods will continue as improvements are

constantly sought. Similarly, a laboratory introducing a kit will need to spend time validating the procedure. It is also likely that a number of kits will need to be pur-

Excess labelled sodium iodide can be used for other estimations such as that of follicle-stimulating hormone and luteinising hormone, thus reducing the cost.

Reliability of Calculated Cost of Kits The actual cost of kits may be greater than that calculated as the time for reconstituting kits is not considered and waste is not allowed for. Users have told me that about 10% of kits are not used for various reasons. Laboratories with large workloads can often negotiate prices for bulk purchase of reagents thus reducing costs by up to 20%, but this is not possible for laboratories with small workloads. No allowance for this has been made in the figures given. Many kits have antibody-coated tubes or resin for separating free and bound hormone. These may save laboratory bench-time by eliminating steps in the procedure and the effect of this needs to be included, but the effect is likely to be small, as a procedure which eliminates one pipetting would save only about lp in labour cost per tube. Any benefits of these techniques is in increased analytical precision rather than significant reductions in cost. Other Considerations Economic considerations are not the only ones to be considered when laboratory methods are chosen. The analytical precision and accuracy that can be achieved must be taken into account and an assay with a sameday result has an advantage over an assay taking several days. It will be generally agreed that staff of high quality are required for consistently good laboratory standards and the use of kits may be desirable in laboratories without suitable staff. Our recruiting and training of staff in the United Kingdom must be at fault if satisfactory standards cannot be achieved.

Laboratory Organisation The figures quoted show large differences in cost at high workloads and the implication for laboratory must be considered. The enzymes considered need to be estimated in most clinical chemistry laboratories as a same-day service is desirable. The workload for T4 is probably great enough to justify its estimation in most laboratories undertaking radioimmunoassay, particularly if the free thyroxine index is used as a screening test. The costs given suggest that it might be possible for T3 and T.s.H. to be estimated in selected laboratories but not necessarily in "specialist

organisation

1275 laboratories". Laboratory workers are often unaware of the ease with which reagents for radioimmunoassay can be prepared. No difficulties have been encountered in this laboratory although the staff had little previous experience. Antiserum is expensive and consideration might be given to supply on a regional basis with serum being prepared in laboratories with animal facilities.

CONCLUSION

A comparison of the cost of laboratory-prepared with commercially prepared reagents for three serum-enzyme

estimations and three serum-hormone estimations suggests that the purchase of reagents in kit form cannot be justified on economic grounds except for those laboratories estimating less than about 35 sera daily for each of the

serum

enzymes considered. If the workload in my

laboratory and in laboratories known to me in the West Midlands is typical, it can be estimated from the figures given in this paper that between 2 million and ;3 million is spent unnecessarily in the United Kingdom each year to purchase ready-prepared reagents for the six studied. The benefits of preparing reagents in the laboratory are not only economic. Staff acquire greater analytical expertise than when commercial kits are used. This leads to better investigation of analytical problems when they occur and helps to produce an ability and desire to improve methods. As a result greater advantage can be taken of the high level of training and qualifications now expected of hospital laboratory workers in the United

least 100 yards long and are almost entirely occupied by roulette wheels, baccarat tables, and one-armed bandits, with the registration desk secluded in some hole in the corner, indeed often almost extruded into a back street. The gambling tables run 24 hours a day, and even at 7 A.M. on a Sunday morning most are still operating, as is the well-patronised bar. Any customer who starts to win or "invest" heavily is immediately plied with free drinks; time passes rapidly and unnoticed since there are neither windows nor clocks in the gambling rooms. The local Chamber of Commerce or its equivalent puts out a bulletin advertising various escort services for both sexes, and one need only ring the appropriate number for the escort to appear promptly at the hotel room door. This service can be paid for with a credit card, though hotel rooms have to be paid for in advance, and the television set is chained to the wall. The city itself is gaudy; every motel, hotel and gambling casino is suffused with neon illuminations which are somewhat more impressive from a height of 30 000 feet than at ground level. It is difficult not to get the impression that the U.S. energy shortage would abate overnight were the Las Vegas neon signs turned off. Such was the site for the recent meeting of the American College of Chest Physicians. As expected the total number attending the meeting was up on last time, but there were also larger audiences at the scientific meetings. Clearly the choice of venue was justified. are at

tests

Kingdom.

Round the World

United States CHEST PHYSICIANS IN LAS VEGAS

The number of medical meetings and conventions continues increase, and while there are a few which are devoted almost entirely to science, most attempt to combine a modicum of business with an abundance of pleasure-needless to say as a tax-free expense. The size of attendance at such meetings is closely related to the availability of the second commodity, and as a result the choice of city in which to hold the meeting becomes of paramount importance. Currently, San Francisco, New Orleans, Toronto, Montreal, and Las Vegas are in vogue, and attract much larger audiences than do Memphis, Detroit, or Cleveland. Despite the fact that Nevada has turned down the Equal Rights Amendment and all the women’s organisatioris are trying to boycott Las Vegas, this city is probably still the number-one choice. Situated in a desert plain, and surrounded by bare mountains rising 6000-7000 feet, in the 1920s Las Vegas had only a few hundred inhabitants. Shortly afterwards, gambling was legalised, and now the city and its environs have a population of around 150 000, most of whom are employed in the gambling industry. Every weekend sees an influx of around 100 000 visitors, mainly from California; many of them camp out in caravans in order to save money for gambling. It is estimated that$1 million changes hands each Saturday and Sunday evening. Most of the hotel foyers to

United States THE CASSANDRAS OF SCIENCE

MANY writers have commented on the rise of anti-scientific attitudes among the public here, and have given various explanations-the disillusionments of the Vietnam war, ecological disasters, the monstrous cost of Government-sponsored research with seemingly little return, and so on. But one aspect not often mentioned is disillusionment both with the scientists who prophesy the doom and destruction of the world, and with those who proclaim the principles of the technological age. How often have we heard the loudly trumpeted stories of scientific break-throughs, of the cancer cure that is just round the corner? In recent years most of the braying has come from the scientific forecasters of disaster, either imminent or in the distant future. When these prophecies come from excited journalists or from the crude manipulators whose technique is to multiply small figures to give monstrous global statistics, they can be ignored. Unfortunately, we seem to be having more and more of these fantasies from scientists with reputable credentials. It is central to the creeds of all of these Cassandras that if things go on as they are, then only disaster can result-but that any changes that are made will also lead to disaster. Meteorological evidence leads to the miserable conclusion that a new ice age is upon us (though it has led others to the equally inexorable conclusion that the world is warming up, that the ice caps will melt and the major U.S. cities, except perhaps mile-high Denver, will be below water). If to combat the coming cold we heat with oil, we shall run out of oil in no time. If we use electricity, then we shall need nuclear reactors, which will inevitably cause large-scale nuclear disasters. If we heat with coal, the carbon dioxide produced will have a greenhouse effect, the ice caps will melt, and so on. If, on the other hand, the world warms up, we shall not of course need all this heat. But then we will all be getting skin cancers from ultraviolet radiation, and many other unpleasant things. All this makes for good banner headlines, and while it may cause consternation to some, others have become disgusted at the facile nature of such so-called "scientific" observations. The late Henry Miller used to cite the scientific study of the last century that led to the inexorable conclusion that New York City would soon be eight foot deep in horse manure. You can be assured, as a scientific fact, that this is not so.