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314 useless. A MacConkey’s medium which supports the growth of the staphylococcus will give proteus as discrete grey colonies, large red Escherichia coli colonies, smaller pink staphylococci, and little red Streptococcus facalis. Regrettably the 0.5% of hasmolytic streptococci may be missed, unless they prove to be Str. facalis after all ! The loss of one night, required for incubation, is of little importance for a screening test to select cases for antibiotic treatment to prevent the development of pyelo- nephritis. It is when the bacteriologist is studying pus from an acute infection, where tissue destruction is con- tinuing, minute by minute, that his micro-gardening techniques are painfully slow. It is for this reason that those attempting to apply chemical methods to bacterio- logy should have every encouragement. E. BOWERS. Corbett Hospital, Stourbridge. J. H. M. PINKERTON G. L. GIBSON J. K. HOUSTON. Department of Midwifery and Gynaecology, Queen’s University of Belfast. SIR,-We agree with Dr. Kincaid-Smith and her co-workers (July 11) that the triphenyl-tatrazolium- chloride (T.T.C.) test 1 is a reliable method for screening urine for significant bacteriuria. In the Royal Maternity Hospital, Belfast, the method has been used for the past six months to screen the urine of all antenatal patients at intervals during pregnancy. Our results in 976 consecutive tests show: Bacteriuria (all organisms)-105 per ml. 90, T.T.C. test posi- tive 85 (94%). Bacteriuria (gram-negative bacilli)-105 per ml. 72, T.T.C. test positive 72 (100%). We need to know more about the chain of events reputed to follow significant bacteriuria during pregnancy. The use of the T.T.c. test enables sufficiently large numbers of patients to be studied so that a reasoned conclusion may be reached on the value of routine antenatal bacteriolosv. WECHSLER TEST P. J. MITTLER. Department of Psychology, Birkbeck College, London, W.C.1. SIR,-Dr. Heaton-Ward (July 18) suspects that the Wechsler adult intelligence scale is not valid, because it gives higher I.Q.s than the Binet scale, and because its results are contrary to his clinical experience. But is it not equally possible that the Binet test is lacking in validity ? There is a wealth of evidence 3 that the Binet test is unsuit- able for adults, and particularly for adults suspected of mental subnormality. It has never been standardised on adults. It fails to make any allowance for the age of the patient-hence the greater discrepancy between Binet and W.A.LS. i.Q.s found in older people. It penalises the " subcultural " or verbally deprived person because of its high verbal loading, especially after the seven-year level, which is a critical borderline area in subnormality assessments. It has many grave technical imperfections of standardisation, norms, scoring and theory. All these are fully documented in the literature. This is not to argue that all is wrong with the Binet, and that the Wechsler is a perfect test. But psychologists working on subnormality are virtually unanimous in their preference for the Wechsler test. The British Psychological Society’s Working Party on Subnormality 4 conducted a survey from which it was quite evident that the W.A.I.S. was the preferred instrument for use with adults, though the Binet still has a place in the assess- ment of children, and may have to be used with adult imbeciles, for lack of a better test. 1. Simmons, N. A., Williams, J. D. Lancet, 1962, i, 1377. 2. Chard, T., Cole, P. G. ibid. 1963, ii, 326. 3. Clarke, A. M., Clarke, A. D. B. Mental Deficiency: The Changing Outlook. London, 1958. 4. Bull. Brit. Psychol. Soc. 1963, 16, 53. Castell, J., Mittler, P. Brit. J. Psychiat. (in the press). The inadequacies of the Binet test in subnormality work have been so frequently catalogued-and psychologists are by now almost without exception convinced on this point-that it comes as something of a surprise to find Dr. Heaton-Ward objecting at this stage to the Wechsler on the grounds given in his letter. While he is not alone in finding individual instances where the result of a test is contrary to his clinical judgment, the balance of the scientific evidence is against him. Incidentally, it would be interesting to know where Dr. Heaton-Ward places the upper limit of subnormality of intelligence, since he regards an I.Q. of 75 as " definitely within the subnormal range ". The British Psychological Society, as a result of its survey of 1000 adult admissions to hospitals for the subnormal,2 has recommended that the upper limit of sub- normality of intelligence should be set at i.Q. 70, corresponding to a score two standard deviations below the mean; the l.Q. range 70- 85 (-2 to -1 s.D.) should be regarded as borderline subnormal, and I.Q.s below 55 (-3 s.D.s) as severely sub- normal. These recommendations are comparable to those used by the American Association on Mental Deficiency.5 Dr. Heaton-Ward is right to emphasise the need, since the Mental Health Act came into force, to demonstrate subnormality of intelligence before a person can be classi- fied as mentally subnormal. It seems all the more import- ant, therefore, to ensure that the tests used conform to the highest available standards. OLD PEOPLE AT HOME SIR,-Dr. Williamson and his colleagues (May 23) paint a gloomy picture of the amount of disease, among old people, that is unknown to their general practitioners. They state that probably the " degree of unawareness of morbidity among doctors in the country as a whole is not less than that recorded ". To see how far this sweeping condemnation is applicable to South-West London, I ANALYSIS OF ALL 223 PATIENTS OVER 65 YEARS OLD IN A SOUTH-WEST- LONDON GENERAL PRACTICE analysed the condition of all my patients over the age of I 65 in my general practice. This practice is in a part of London where most of the houses are 50-100 years old, and nearly all are occupied by several families. Patients who had not been seen recently, some 50 in all, were visited for the purpose of this communication. Only 1 patient with a major unknown disability was found. She was deaf and required a hearing aid. The accompanying table shows the findings (there is overlap between the groups). These findings suggest that the social services are more 5. Heber, R. F. Amer. J. ment. Defic. 1961, 65, 499.
Transcript of WECHSLER TEST
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useless. A MacConkey’s medium which supports the growth ofthe staphylococcus will give proteus as discrete grey colonies,large red Escherichia coli colonies, smaller pink staphylococci,and little red Streptococcus facalis. Regrettably the 0.5% ofhasmolytic streptococci may be missed, unless they prove to beStr. facalis after all !The loss of one night, required for incubation, is of
little importance for a screening test to select cases forantibiotic treatment to prevent the development of pyelo-nephritis. It is when the bacteriologist is studying pusfrom an acute infection, where tissue destruction is con-tinuing, minute by minute, that his micro-gardeningtechniques are painfully slow. It is for this reason thatthose attempting to apply chemical methods to bacterio-logy should have every encouragement.
E. BOWERS.Corbett Hospital,
Stourbridge.
J. H. M. PINKERTONG. L. GIBSON
J. K. HOUSTON.Department of Midwifery and
Gynaecology,Queen’s University of Belfast.
SIR,-We agree with Dr. Kincaid-Smith and herco-workers (July 11) that the triphenyl-tatrazolium-chloride (T.T.C.) test 1 is a reliable method for screeningurine for significant bacteriuria.
In the Royal Maternity Hospital, Belfast, the methodhas been used for the past six months to screen the urineof all antenatal patients at intervals during pregnancy.Our results in 976 consecutive tests show:
Bacteriuria (all organisms)-105 per ml. 90, T.T.C. test posi-tive 85 (94%).
Bacteriuria (gram-negative bacilli)-105 per ml. 72, T.T.C.
test positive 72 (100%).We need to know more about the chain of events
reputed to follow significant bacteriuria during pregnancy.The use of the T.T.c. test enables sufficiently largenumbers of patients to be studied so that a reasonedconclusion may be reached on the value of routineantenatal bacteriolosv.
WECHSLER TEST
P. J. MITTLER.Department of Psychology,
Birkbeck College,London, W.C.1.
SIR,-Dr. Heaton-Ward (July 18) suspects that theWechsler adult intelligence scale is not valid, because itgives higher I.Q.s than the Binet scale, and because itsresults are contrary to his clinical experience. But is it notequally possible that the Binet test is lacking in validity ?There is a wealth of evidence 3 that the Binet test is unsuit-
able for adults, and particularly for adults suspected of mentalsubnormality. It has never been standardised on adults. Itfails to make any allowance for the age of the patient-hencethe greater discrepancy between Binet and W.A.LS. i.Q.s foundin older people. It penalises the " subcultural " or verballydeprived person because of its high verbal loading, especiallyafter the seven-year level, which is a critical borderline area insubnormality assessments. It has many grave technical
imperfections of standardisation, norms, scoring and theory.All these are fully documented in the literature.
This is not to argue that all is wrong with the Binet, and thatthe Wechsler is a perfect test. But psychologists working onsubnormality are virtually unanimous in their preference for theWechsler test. The British Psychological Society’s WorkingParty on Subnormality 4 conducted a survey from which it wasquite evident that the W.A.I.S. was the preferred instrument foruse with adults, though the Binet still has a place in the assess-ment of children, and may have to be used with adult imbeciles,for lack of a better test.
1. Simmons, N. A., Williams, J. D. Lancet, 1962, i, 1377.2. Chard, T., Cole, P. G. ibid. 1963, ii, 326.3. Clarke, A. M., Clarke, A. D. B. Mental Deficiency: The Changing
Outlook. London, 1958.4. Bull. Brit. Psychol. Soc. 1963, 16, 53. Castell, J., Mittler, P. Brit. J.
Psychiat. (in the press).
The inadequacies of the Binet test in subnormality work havebeen so frequently catalogued-and psychologists are by nowalmost without exception convinced on this point-that itcomes as something of a surprise to find Dr. Heaton-Wardobjecting at this stage to the Wechsler on the grounds given inhis letter. While he is not alone in finding individual instanceswhere the result of a test is contrary to his clinical judgment, thebalance of the scientific evidence is against him.
Incidentally, it would be interesting to know where Dr.Heaton-Ward places the upper limit of subnormality of
intelligence, since he regards an I.Q. of 75 as " definitely within
the subnormal range ". The British Psychological Society, as aresult of its survey of 1000 adult admissions to hospitals for thesubnormal,2 has recommended that the upper limit of sub-normality of intelligence should be set at i.Q. 70, correspondingto a score two standard deviations below the mean; the l.Q.range 70- 85 (-2 to -1 s.D.) should be regarded as borderlinesubnormal, and I.Q.s below 55 (-3 s.D.s) as severely sub-normal. These recommendations are comparable to those usedby the American Association on Mental Deficiency.5
Dr. Heaton-Ward is right to emphasise the need, sincethe Mental Health Act came into force, to demonstratesubnormality of intelligence before a person can be classi-fied as mentally subnormal. It seems all the more import-ant, therefore, to ensure that the tests used conform to thehighest available standards.
OLD PEOPLE AT HOME
SIR,-Dr. Williamson and his colleagues (May 23) painta gloomy picture of the amount of disease, among oldpeople, that is unknown to their general practitioners.They state that probably the " degree of unawareness ofmorbidity among doctors in the country as a whole is notless than that recorded ". To see how far this sweepingcondemnation is applicable to South-West London, I
ANALYSIS OF ALL 223 PATIENTS OVER 65 YEARS OLD IN A SOUTH-WEST-LONDON GENERAL PRACTICE
analysed the condition of all my patients over the age of I65 in my general practice.
This practice is in a part of London where most of the housesare 50-100 years old, and nearly all are occupied by severalfamilies.
Patients who had not been seen recently, some 50 in all,were visited for the purpose of this communication. Only 1
patient with a major unknown disability was found. She wasdeaf and required a hearing aid.The accompanying table shows the findings (there is overlap
between the groups).
These findings suggest that the social services are more5. Heber, R. F. Amer. J. ment. Defic. 1961, 65, 499.
