Confirmatory factor analytic models of the WAIS-R for neuropsychiatric patients

Five multifactor models, in both orthogonal and oblique versions, and a single-factor model of the WAIS-R's factor pattern were examined by confirmatory maximum likelihood factor analyses of a data matrix constructed from the results for 90 neuropsychiatric patients. None of the models fits the data matrix in an absolute sense, even though all of the models represented an improvement over a null statistical model. For the multifactor models, the best results were obtained by oblique solutions, in which the degree of correlation between the factors varied from .71 to .93. The single-factor model fit nearly as well as, and in some instances better than, many of the multifactor models. The best-fitting model, viz., a three-factor oblique one, was only marginally better in its fit than two of the three two-factor models or the competing three-factor model.     

Prevalence of leptospirosis in various risk groups

Two hundred and twenty seven patients were included in the study. The test group included 55 patients of pyrexia of unknown origin (PUO), 42 veterinary workers, 38 hepatitis patients and 25 village farmers. The control group comprised of 27 Syphilis controls and 40 healthy controls. Of the total study entrants, 186 were tested for Leptospira antibodies by IgM ELISA and 41 by microscopic agglutination test (MAT). ELISA results of 45 patients were further tested by MAT for comparative evaluation. Out of 160 patients of the test group 56(35.0%) were positive for Leptospira antibodies. The positivity was 18(32.73%) amongst PUO patients, 15(35.71%) of the farm workers, 15(39.47%) of hepatitis patients and 8(32.0%) farmers. Leptospira antibodies were not detected in any of the controls. The antibody positivity was seen in 33(32.04%) of the 103 urban patients and 23(40.35%) of 57 rural patients. Out of 56 Leptospira cases, in 39(69.64%) history of animal contact was present. The common clinical features in these patients included fever in 51(91.07%), myalgia 48(85.71%), headache 42(75.0%), Anorexia 31(55.35%), Jaundice 24(42.86%) and nausea/vomiting in 21(37.5%). Of the 45 ELISA results compared with that of MAT, there was 86.67% agreement between the tests.     

Effects of prior testing with the WAIS-R NI on subsequent retest with the WAIS-R.

Seven subtests from the Wechsler Adult Intelligence Scale, Revised as a Neuropsychological Instrument (WAIS-R NI) were administered to 20 nonreferred university students. The same participants were administered the corresponding subtests from the WAIS-R 3 to 4 weeks later. Data concerning amount and consistency of change in 'scaled scores' were compared to those reported by Wechsler (1981) for test-retest with the WAIS-R. Performance on standard items was also compared to performance on multiple choice items from the WAIS-R NI. Gains observed in subtest 'scaled scores' at retest were comparable to those reported by Wechsler (1981). A substantial minority of participants obtained lower scores on some multiple choice items than they did on corresponding standard items. Implications and limitations of the current data, and the pressing need for comprehensive normative data for the WAIS-R NI are discussed.     

Prevalence of precipitins in groups at risk of developing hypersensitivity pneumonitis

A study was made of the prevalence of serum precipitins to Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, and pigeon serum in population groups suspected to be at high risk for the development of hypersensitivity pneumonitis. Pigeon breeders' sera contained precipitins mainly to pigeon serum (38%) and A. fumigatus (18%). Occupants of homes in which forced air heating systems were investigated for the presence of microorganisms reacted mostly with M. faeni (13%) and A. fumigatus (8%). Individuals from environments where several cases of hypersensitivity pneumonitis were discovered reacted largely with M. faeni (28%) and T. vulgaris (21%). Sera supplied by physicians from patients with respiratory symptoms reacted primarily to A. fumigatus (24%) and to a lesser extent to M. faeni (16%) and T. vulgaris (9%). The results indicate that the prevalence of precipitins to the tested antigens is not uniform and may be influenced by the environment. Furthermore, the prevalence of precipitins in groups at risk is greater than previously reported for the normal population.     

Inter-subtest scatter in the WAIS-R standardization sample

To be able to evaluate the possible diagnostic significance of the magnitude of subtest-to-subtest scatter on the Wechsler Adult Intelligence Scale—Revised (WAIS-R), it is important to know the frequency of various levels of scatter in the general population. To provide this information, the magnitude of scatter across all 11 subtests, and across the subtests of the Verbal and Performance scales, was computed for each of the 1,880 individuals used in the WAIS-R standardization. The range (difference between highest and lowest subtest scaled scores) was found to be an effective measure of scatter when compared with other, more complex indices. Scaled score scatter, which ranged from 2 to 16 points on the Full Scale, averaged 6.7 points for the Full Scale and 4.7 points each for the Verbal and Performance scales. Scatter had little relationship to age, sex, race, and years of education completed. However, the average amount of scatter increased substantially with IQ level. Normative tables for interpreting scatter are provided, and implications of these findings for the practitioner, especially in neuropsychology, are discussed.     

Clinical utility of a WAIS-R short form

ζ Investigated the validity of the Vocabulary-Block Design subtest combination as an estimate of the WAIS-R Full Scale IQ in a sample of 30 psychiatric patients. The correlation between the short form IQ and the WAIS-R Full Scale IQ was highly significant, r(28) = 0.87, p <0.001. A pairwise t-test computed between the mean IQs for the standard and short form was nonsignificant, t(29) <1. One-half of the Ss showed changes in intelligence classification when the short form was used. The short form should not be used when precise IQ estimates are required. However, the short form appears useful as a screening device to discriminate between patients with normal and subnormal intelligence. With respect to the detection of normal vs. subnormal intelligence. the short form achieved a correct classification rate of 87%.     

Test-retest stability of the WAIS-R in a clinical sample

This study assessed WAIS-R test-retest stability for a sample of 21 psychiatric and neurological patients. The test-retest interval ranged from 2 weeks to 144 weeks, with a mean of 38 weeks. Subtest stability coefficients were highly significant; only Similarities, r(19) = .45, p less than .05, fell below a correlation of .74. The Verbal, Performance, and Full Scale IQs yielded highly significant stability coefficients (.79, .88, and .86). Nevertheless, the range of gain or loss for any single individual was comparatively large. On the Full Scale IQ, 18 of 21 (86%) subjects showed changes of 3 points or more, and 8 of 21 (38%) actually changed IQ classifications. Gain or loss in total score was unrelated to initial level of brightness on the Full Scale, age at initial testing, or days between examinations. Conversely, gain or loss on the Full Scale was associated strongly with years of education, r(19) = .55, p less than .01. When the sample was divided into brain-damaged and psychiatric subgroups, the difference in retest gain on the Full Scale IQ was nonsignificant.     

Prevalence of hepatitis C virus infection in different groups of selected populations

The objective of this study to determine the prevalence of hepatitis C virus at Caltagirone (CT) among blood donors, health care workers, drug users, hemodialysis patients and thalassaemics. The identification of risk factors for HCV infection and liver function in HCV correlate hepatitis. Anti-hepatitis C virus antibodies were detected in 0.64% of blood donors, in 68.44% of drug users, in 58.55% hemodialysis patients and in 67.50% of thalassaemics. Drug abuse, haemodialysis, blood transfusions are the major risk factors for hepatitis C.     

Stability of WAIS-R scatter indices in the elderly.

The test-retest reliability and clinical stability of WAIS-R VIQ-PIQ differences, inter, and intrasubtest scatter were investigated in a sample of 61 normal persons 75 years and older. The test-retest coefficient was.76 for VIQ-PIQ discrepancy, ranged from.05 to.56 for the intersubtest scatter range, and from.08 to.43 for intrasubtest scatter. In terms of clinical stability, 56% of subjects maintained a similar magnitude and direction of meaningful VIQ-PIQ differences from test to retest. Classification of subtest strengths and weakness from test to retest was generally poor with an average disagreement of 52% from the first to the second assessment. Intrasubtest scatter also displayed poor clinical stability with 25-50% of subjects demonstrating meaningful changes on retest.     

Autoantibodies in neuropsychiatric lupus

The American College of Rheumatology presented a consensus document in 1999 proposing the classification of 19 different syndromes defined by neurological and psychiatric manifestations of systemic lupus erythematosus (SLE). The detection of autoantibodies in patient's serum or cerebrospinal fluid has not been used as diagnostic markers for the proposed neuropsychiatric lupus classifications as their disease associations remain highly contentious. Autoantibodies detected in the serum and/or cerebrospinal fluid, that have been reported to segregate with patients presenting with neuropsychiatric lupus include: (1) anti-neuronal antibodies, (2) brain-lymphocyte cross-reactive antibodies, (3) anti-ribosomal P antibodies, (4) anti-phospholipid antibodies and (5) anti-ganglioside antibodies. Tests for anti-neuronal, anti-brain-lymphocyte cross-reactive and anti-ganglioside antibodies remain highly specialized whereas tests for ribosomal P antibodies and for antiphospholipid antibodies are currently routinely available in most diagnostic laboratories. Anti-ribosomal antibodies segregate with SLE. Antiphospholipid P antibodies are markers for the antiphospholipid syndrome. This syndrome may be associated with another disease, commonly SLE. In this setting, neuropsychiatric manifestations in SLE may arise as a consequence of thrombotic episodes involving the cerebral vasculature. There is a pressing need for antibodies to ribosomal P and to phospholipids to be standardized for routine diagnostic application. We conclude that the search for specific antibody marker(s) that can be applied for the routine laboratory diagnosis for neuropsychiatric lupus remains elusive.     

Reliability of the WAIS-R with psychiatric inpatients.

WAIS-R subtest and composite scale reliabilities, standard errors of measurement, and standard errors of estimate were determined for a sample of psychiatric inpatients (N = 100). For Digit Span and Digit Symbol, test-retest stability coefficients were obtained; split-half reliability coefficients were calculated for all other subtests. With the exception of Object Assembly (rxx = .38), all subtest and composite scale reliability coefficients were large and acceptable. Based on the standard error of measure, the most reliable WAIS-R subtests were Digit Symbol (.77), Information (1.04), and Picture Completion (1.07). Reliability coefficients for the psychiatric inpatient sample were, in general, comparable to those values reported for the standardization group (Wechsler, 1981). Significant differences were obtained only on the Object Assembly and Vocabulary subtests.     

Prevalence of HBV infection among different HIV-risk groups in Hai Phong, Vietnam

Hepatitis B virus (HBV) infection in Hai Phong, northern Vietnam, was characterized by analyzing the prevalence and genotype distribution of HBV as well as co-infection with human immunodeficiency virus type 1 (HIV-1) among five different risk groups for HIV infection. Plasma samples were collected from intravenous drug users (n=760, anti-HIV-1 antibody positive rate: 35.9%), female sex workers (FSWs; n=91, 23.1%), seafarers (n=94, 0%), pregnant women (n=200, 0.5%), and blood donors (n=210, 2.9%) in 2007 [Ishizaki et al. (2009): AIDS Res Hum Retroviruses 25:175-182]. Samples were screened for the hepatitis B surface antigen (HBsAg) and anti-HBs antibody and analyzed genetically. The cumulative HBV incidence rate (HBsAg+anti-HBs) was 53.2% (10.7+42.5%) in intravenous drug users, 51.6% (11.0+40.6%) in FSWs, 54.3% (9.6+44.7%) in seafarers, 50.5% (12.5+38.0%) in pregnant women, and 51.0% (18.1+32.9%) in blood donors; there was no significant difference among these groups. Of 163 HBsAg-positive samples, 113 could be analyzed genetically. Phylogenetic analysis, based on the preS1 region, revealed genotype B4 was most prevalent (90/113; 79.6%), followed by C1 (17.7%), I1 (1.8%), and B2 (0.9%). There was no significant difference in HBV genotype distribution among different HIV infection-risk groups. The prevalence of HBsAg was 10.3% (31/301) in HIV-1-infected individuals and 12.5% (132/1,054) in non-HIV-1-infected individuals, which was not significant. In addition, no significant difference in HBV genotype distribution was observed between HBV/HIV-1 coinfected and HBV mono-infected groups. These results suggest that, although HBV and HIV-1 share modes of transmission, major transmission routes of HBV have been different from those of HIV-1 in Hai Phong, Vietnam.     

Intellectual loss in Alzheimer's dementia and WAIS-R intrasubtest scatter

Patterns of intrasubtest scatter in the WAIS-R protocols of patients (n = 32) with Alzheimer's disease were compared to those of normal elderly controls (n = 32). The Alzheimer's patients showed more randomly dispersed item failures on some subtests, but normal controls showed more intrasubtest variability on other measures. Rates of correct diagnostic classification based on scatter measures were only slightly better than chance despite the presence of prominent anomia, memory impairment, construction apraxia, and significant decline from premorbid intellectual level in demented patients. In contrast, demographically based estimates of intellectual loss produced accurate diagnostic classification in 81% of the cases. The incremental validity of qualitative scatter analysis in the evaluation of suspected Alzheimer's disease appears to be minimal.     

WAIS-R intersubtest scatter in patients with dementia of Alzheimer's type

This study explored the relationship between three indices of intersubtest scatter and level of cognitive deterioration in a sample of 104 patients with dementia of Alzheimer's type, who ranged in age between 52 and 84 years. Scatter was highly related to education and premorbid level of functioning. Advancement of dementia was shown to be associated with decrease in scatter, which suggests caution in interpretation of high magnitude of intersubtest scatter as an indication of brain dysfunction. Easy-to-calculate range of scatter proved to be adequate measure of scatter. Calculation of more complex indices, such as PVI, provides only minimal incremental gain.     

Prevalence of herpes simplex virus type 2 antibodies in selected population groups in Italy

The estimated prevalence of herpes simplex virus type-2 specific antibodies was less then 0.1 % in a national sample of 1,169 healthy young males, 4.8 % among 411 health care workers and 55 % among 397 homosexuals. These viral infections seem to pose a health problem for risk groups such as homosexuals but not for the general population.     

Prevalence of HIV antibodies in groups at risk in Zürich,Switzerland

Summary The prevalence of HIV antibodies in various groups at risk was studied in 1,546 persons in Zürich. The prevalence was 17% (39/236) in homosexual men, 7% (13/180) in bisexual men, and 45% (14/31) and 42% (22/53) in female and male intranvenous drug abusers, respectively. Heterosexual transmission appeared to be the route of infection in four seropositive persons (two women and two men) who had no homosexual contacts and were not drug abusers (4/1050).Abbreviations HIV Human immune deficiency virus - HTLV III Human T-cell lymphotropic virus type III - IVDA Intravenous drug abusers - LAV Lymphadenopathy-associated virus     

Critique of a Doppelt-type short form of the WAIS-R

The purpose of this article is to correct a number of errors in a study by Reynolds, Willson, and Clark (1983). The short form that they proposed, which consists of Information and Arithmetic from the Verbal Scale and Picture Completion and Block Design from the Performance Scale, is shown to be more reliable and more valid than they realized. A corrected table is presented for converting the sums of age-scaled scores on their short form to estimated Full Scale IQs.