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PubMed1987

Detection of neutrophilocytes and NO2-producing bacteria in urine by dipstick BM-test-9.

A prospective study compared the detection of leucocytes and bacteria in urine with the dipstick test (presence of esterases in granulocytes and nitrite) to chamber counting of urine, microscopic examination of the urinary sediment, and urine culture. Examined were 174 urine specimens. The dipstick esterase test and the sediment count were almost equally sensitive in detecting leucocyturia. Using chamber count and a cut-off point of 10 or more leucocytes per cubic millimeter as denoting significant leucocyturia, the esterase test gave a predictive value for negative test (PV neg) of 75% and a predictive value for positive test (PV pos) of 96%. PV neg of the dipstick nitrite test was 78% and PV pos 100% in detecting bacteriuria (10(5) bacteria per milliliter). Combining the esterase test with the nitrite test did not increase PV neg. Our result was that the dipstick test seems to be a simple screening procedure for leucocyturia and bacteriuria. The test is suggested to replace the time-consuming microscopic examinations of urine for leucocytes. When the nitrite test is positive, routine urine culture may be omitted.

Adolescent↗
PubMedDate not supplied

[Clinical significance and predictive value of laboratory tests in thrombosis associated with antiphospolipid antibodies].

Antiphospholipid antibodies are a wide ranging, heterogeneous family of autoantibodies, formerly believed to be directed to anionic phospholipids. Recent research, however, has confirmed that they are directed to plasma proteins bound to suitable (phospholipid) anionic surfaces. The most well-known and best characterized antigens are beta 2-glycoprotein I, recognized by anticardiolipin antibodies, and prothrombin, recognized by most lupus anticoagulants. Lupus anticoagulants are generally identified on the basis of their capacity to prolong the phospholipid-dependent coagulation tests. Two types of lupus anticoagulants, anticardiolipin-type A, and antiprothrombin antibodies, whose presence is associated with different coagulation profiles, have been identified. Anticardiolipin-type A and antiprothrombin antibodies may be detected also by specific immunoassays. The capacity of several methodologies to detect antiphospholipid antibodies reflects chiefly their immunological and functional heterogeneity. Since most of the laboratory methods have not yet been standardized, the results of studies on the clinical relevance of antiphospholipid antibodies must be analyzed with caution. The association between antiphospholipid antibodies with peculiar clinical manifestations such as venous and arterial thrombosis, recurrent miscarriage, and thrombocytopenia, characterizes the so-called "antiphospholipid syndrome". Retrospective and cross-sectional studies have confirmed the role of anticardiolipin antibodies and lupus anticoagulants as risk factors for both venous and arterial thrombosis, the most common clinical manifestations of the antiphospholipid syndrome. Prospective studies performed in different patient populations have confirmed the association between anticardiolipin antibodies and lupus anticoagulants with venous, and possibly, arterial thrombosis, although information on the predictive value of the various laboratory tests with respect to thrombosis is still limited. It is hoped that the development and standardization of assays that selectively identify antiphospholipid antibodies associated with increased risk of thrombosis will lead to therapeutic strategies able to prevent thromboembolic complications of the antiphospholipid syndrome.

Adult↗
PubMed1981

Predictive value of early testing of auditory localization for language development.

This pilot study attempted to determine whether atypical localization to voice during the first year of life could be predictive of later delayed language development. 22 children who had been tested at six to nine months of age and found to have normal hearing were retrospectively divided into "atypical' and 'normal' groups. They were then evaluated for language development at four years of age. The atypical group had significantly lower scores on two of the four measures of language competence, but the results must be interpreted with caution because of the small number of children in the study.

Auditory Perception↗
PubMed1989

Prediction of normal values in pulmonary function testing.

Appropriate use of reference equations for predicting normal values is important for maximizing the clinical and research usefulness of pulmonary function testing. Because of the diversity of clinical and research uses of pulmonary function testing, predictive equations derived from different populations may be needed for specific applications. Similarly, different limits of normalcy other than the traditional 95 per cent confidence limits may be more appropriate for some applications. Unanswered questions remain about the effects of race and altitude on predicted values for many pulmonary function parameters. In order to establish confidence that the predictive equations, lower limits of normalcy, and testing methodology are appropriate for specific patient populations, it is suggested that each clinical laboratory obtain PFT measurements on 10 to 20 individuals considered free of disease and representative of their patient population and compare these results with the prediction equations selected for use. Although the testing of such a small sample of normal subjects will not assist in the selection of optimal equations if the differences between equations are minor, it will detect grossly inappropriate predictive values and limits of normalcy as well as identify problems with testing methodology.

Humans↗
PubMed2006

Comparison of predictive values of two diagnostic tests from the same sample of subjects using weighted least squares.

Screening and diagnostic tests are important in disease prevention or control. The predictive values of positive and negative (PPV and NPV) test results are two of four operational characteristics of a screening test. We review an existing method based on the generalized estimating equation (GEE) methodology for comparing predictive values from the same sample of subjects and propose two Wald test statistics derived from the weighted least squares (WLS) method for the analysis of categorical data. Using these results, we propose sample size calculation formulae for this problem. Simulation studies are conducted to compare the performances of the two Wald test statistics (one based on the difference of two PPVs or NPVs, another based on the logarithm of the ratio of two PPVs or NPVs) and the score/Wald test statistic derived from GEE. We recommend using the difference-based WLS approach.

Angiography↗
PubMed1985

[Exercise test coupled with thallium-201 myocardial scintigraphy after a primary posterior wall infarct. Apropos of 123 patients subjected to coronarography].

The following investigations were performed in 123 patients (118 men and 5 women) with an average age of 51 +/- 6 years, between the 3rd and 6 week after primary posterior infarction, a standard exercise stress test on a bicycle ergometer coupled with Thallium 201 myocardial scintigraphy, followed by coronary angiography in the following 15 days. The object of these investigations was to detect severe stenosis (greater than 70%) of the left anterior descending artery and 50% stenosis of the left main stem. Thirteen investigations could not be interpreted because of a submaximal exercise stress test which did not attain 85% of the theoretical maximal heart rate. The sensitivity of exercise stress testing was 73% and that of myocardial scintigraphy 71%. On the other hand, the specificity of scintigraphy was 94% compared to 68% for exercise stress testing. The predictive value of a positive scintigraphy was 88% compared to 47% for stress testing. However, the predictive value of a negative test was similar with both techniques (87% for exercise stress testing, 90% for scintigraphy). When all the positive results were considered, the sensitivity was 93% but the specificity only 66%. The simplest and most rational way of exploiting the information provided by these investigations is to combine the results: when they are concordant they indicate the true diagnosis in 90% of cases. Discordant results pose a more difficult problem with myocardial scintigraphy being the more reliable: its positive predictive value was 71% when exercise stress testing was negative; its negative predictive value was 87% when exercise stress testing was positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

Promoting breastfeeding in Bolivia: do social networks add to the predictive value of traditional socioeconomic characteristics?

This study tested whether the prediction of health-related knowledge (correct breastfeeding practices in this case) could be improved by including information about the composition of an individual's personal network above and beyond that predicted by his/her socioeconomic or demographic characteristics. Few studies have tested the predictive value of social networks, especially for population-based studies, despite an increased use of social networks in the past few years in several fields of health research, especially in research relating to prevention of HIV/AIDS and design of HIV/AIDS programmes. Promotion of breastfeeding practices that enhance child survival is important in Bolivia because of high infant morbidity and mortality in the country. Data on a cross-sectional urban probability sample of 2,354 women and men aged 15-49 years were collected from seven urban areas in Bolivia. Model building and the log likelihood ratio criteria were used for assessing the significance of variables in a logistic model. Results showed that the network variables added significantly (p < 0.05 for knowledge of breastfeeding only with no other liquids and for knowledge of breastfeeding only with no solids p < 0.01) to the predictive power of the socioeconomic variables. These results may also hold for other health research areas, increasingly using social network analysis, such as that of HIV/AIDS.

Adolescent↗
PubMed1992

MR imaging and HMPAO scintigraphy in conjunction with balloon test occlusion: value in predicting sequelae after permanent carotid occlusion.

OBJECTIVE: Permanent occlusion of the internal carotid artery may be required for en bloc resection of a neck tumor or to treat certain aneurysms. The risk of ischemic infarct is usually assessed with carotid balloon test occlusion and concurrent distal arterial pressure measurement. However, up to 20% of patients who tolerate the test occlusion have delayed neurologic sequelae. We propose enhanced MR imaging and hexamethylpropyleneamine oxime (HMPAO) scintigraphy to detect subclinical signs of ischemia and hypoperfusion as adjuncts to the balloon test occlusion to identify patients at risk for delayed sequelae. SUBJECTS AND METHODS: We prospectively examined 12 patients referred for balloon test occlusion of the carotid artery. Serial measurements of distal occluded internal carotid pressure were recorded. 99mTc-HMPAO was injected IV after 2 min of asymptomatic test occlusion, and single-photon emission computed tomographic (SPECT) data acquisition was done 1-6 hr later. Contrast-enhanced MR imaging was performed 1-8 hr after completion of the 30-min test occlusion. Signs of decreased perfusion or ischemia on these tests were compared with the mean distal arterial pressure and neurologic status of the patient during test occlusion. RESULTS: Seven (58%) of 12 patients had abnormal findings on HMPAO scintigraphy or contrast-enhanced MR imaging. Only one patient had neurologic deficits that corresponded to abnormal MR enhancement. The other 11 patients (92%) remained asymptomatic during the 30-min test occlusion. Of these 11 asymptomatic patients, five (45%) had areas of decreased perfusion on scintigraphy and three (27%) had abnormal MR contrast enhancement suggesting residual focal ischemia as a result of the test occlusion. Mean arterial pressures in the distal occluded artery did not correlate well with the imaging results. CONCLUSION: HMPAO scintigraphy can show clinically silent areas of decreased perfusion, while enhanced MR shows signs of acute ischemia (i.e., significant hypoperfusion) associated with asymptomatic balloon test occlusion. Theoretically, such patients would be at increased risk for permanent sequelae after permanent carotid occlusion.

Adult↗
PubMed1985

Nutritional regulation of host resistance and predictive value of immunologic tests in assessment of outcome.

In this review, the authors describe the current information on nutrition modulation of immunity, enumerate the various immunologic tests that are potentially useful in nutritional assessment, examine the reliability of tests predicting disease and complications, and discuss how immunologic evaluation may help in the decision process regarding nutritional support.

Antigen-Antibody Complex↗
PubMed1989

A destabilization theory on health impairments by night- and shift work--some tests about its predictive value.

270 blue collar workers (181 shift and 89 day workers) of an Austrian oil refinery were investigated in 1976/77. 125 of them (60% of those still employed) were reinvestigated in 1981/82 (91 shift and 34 day workers). Subjects were interviewed about family situation, working conditions, sleep quality, risk factors and health problems. These informations were used for a partial test of our destabilization hypothesis, which states that a dynamic equilibrium between the degree of adaptation to the working sphere, the social sphere and the recreation sphere is a necessary condition for the preservation of health and that shift work, by its direct impact on all these activity spheres, tends to disturb the equilibrium, thus leading either directly or by increasing risk factors to diminished wellbeing and health impairment. It could be demonstrated that the causal structures of the formation of health problems differ considerably between shift and day workers in the predicted way. Furthermore, it was shown that shift and day workers differ with respect to the amount of destabilization and that within shift workers the degree of destabilization is a useful predictor of health impairment.

Adaptation, Physiological↗
PubMed2001

Negative predictive value of human papillomavirus test following conization of the cervix uteri.

OBJECTIVE: The goal of this study was to determine/evaluate the negative predictive value of human papillomavirus (HPV) testing following conization of cervix uteri. METHODS: A prospective analysis was undertaken on 79 cone biopsies of women with high-grade lesions (cervical intraepithelial neoplasia (CIN) III). HPV testing was performed on cervical smears before and after conization. We correlated the margin status (defined as positive cone margin or endocervical curettage status) and positive conization HPV status with the residual disease in a hysterectomy specimen. A Digene II kit was used to perform HPV testing. HPV detection was done by Hybrid Capture assay. RESULTS: Of the 79 patients, 47(59.5%) had positive margins after conization. HPV testing was positive in 37 cases (78.7%) and negative in 10 cases (21.3%). Residual disease was found in 31 of 47 (66%) postconization hysterectomy specimens. No residual lesions were found in HPV-negative cases. Of the 32 cases with negative margins following conization, HPV testing was negative in 25 cases (78%) and was positive in 7 cases (22%). Among these 25 cases with negative HPV tests, no residual lesion was detected, and in 7 HPV-positive cases, only one residual lesion was found. CONCLUSION: HPV testing is potentially an effective tool in predicting residual dysplasia after conization and could potentially assist in the decision between hysterectomy and conservative follow-up in women with CIN III.

Cervix Uteri↗
PubMed1985

Suprapubic sonographic detection of prostate carcinoma.

Between January 1 and March 31, 1983, 103 patients scheduled for prostatic surgery were blindly evaluated preoperatively by suprapubic real time sonography. Prospectively, the sensitivity was 72.7%, specificity 72.2%, predictive value of positive test 51.6% and predictive value of negative 86.7% for the detection of prostatic carcinoma. Retrospective analysis increased the sensitivity to 86% and when clinical information was utilized, only one carcinoma escaped detection. Unfortunately, both prostatic inflammation and occasionally benign prostatic hypertrophy may simulate carcinoma sonographically, thus producing a significant number of false positives. No ultrasonically detectable characteristics could be found which unequivocally separate carcinomas from inflammation and hypertrophy. For this reason routine suprapubic screening does not seem warranted.

Carcinoma↗
PubMed2003

Neuropsychological prediction of conversion to dementia from questionable dementia: statistically significant but not yet clinically useful.

BACKGROUND: Verbal memory impairment, one of the earliest signs of Alzheimer's disease (AD), may help identify people with cognitive impairment, insufficient for a diagnosis of dementia (questionable dementia: QD), at risk of developing AD. Other cognitive parameters have been found that may indicate which people with QD will go on to develop dementia. Nevertheless, some researchers have reported only partial success in differentiating between mild AD and age related cognitive impairment. OBJECTIVES: To discover if there are early, pre-clinical cognitive markers that could help identify patients attending our memory clinic who were at risk of developing dementia. METHODS: Multidisciplinary assessment of a consecutive sample of 195 patients with QD seen in a National Health Service hospital outpatient clinic; 135 seen for a mean follow up of 24.5 months. RESULTS: Conversion rate to dementia was 27.4% (37 of 135). A diagnosis of probable or possible AD was made in 15.6% (21 of 135) of cases. Despite statistically significant differences in some cognitive tasks between those who did and those who did not go on to dement, Cox regression analyses failed to improve prediction rates markedly above base rates and were unstable. CONCLUSION: A large number of studies claim good prediction of conversion to dementia using cognitive test scores. Although this study produced similarly good sensitivity and specificity values, proper consideration of the statistical analyses and their clinical significance suggested that these prediction methods are currently too imprecise for clinical use. Use of cognitive indicators combined with neuroradiological, neuropathological, and genetic factors for predicting conversion to dementia might prove more reliable but may be beyond the scope of many geriatric services.

Aged↗
PubMed2001

Value of combinations of pancreatic function tests to predict mild or moderate chronic pancreatitis.

UNLABELLED: Pancreatic function tests share an insufficient accuracy concerning the detection of mild or moderate forms of chronic pancreatitis. It was evaluated here whether by combination of different assays the prediction or exclusion of chronic pancreatitis could be improved. METHODS: 62 patients with chronic abdominal pain and suspected chronic pancreatitis underwent an endoscopic retrograde pancreaticography. The duct alterations were classified according to the Cambridge criteria. In all individuals the pancreolauryl test in serum (PLT-S) and urine (PLT-U) was performed and elastase 1-immunoreactivity (E) as well as chymotrypsin (Chy) activity in stool were measured. Sensitivities, specificities, receiver-operator-curves as well as cut-off points at optimal accuracies were calculated for each single assay and all test combinations. Cut offs were optimized by a mathematical model to achieve highest accuracies. RESULTS: In 30 patients the pancreatic duct was normal and in 32 patients alterations of the duct system were found. These were classified as mild in 10 patients, as moderate in 8 patients and as severe in 14 patients. In those with mild and moderate disease all pancreatic function tests showed sensitivities/specificities of 60-65% and 65-70%, respectively. Only in severe chronic pancreatitis elastase was superior to the other tests. Combinations of function tests did not lead to improved accuracy. After mathematical optimization the accuracy (sensitivity 80%, specificity 80%) was best for the combination of PLT-S (cut off 4.7 micrograms/ml) and E (cut off 500 micrograms/g). Both parameters had to be below these newly defined cut offs to diagnose chronic pancreatitis. CONCLUSIONS: The accuracy of pancreatic function tests may be improved by use of altered cut offs and a combination of serum pancreolauryl test and elastase. These newly defined cut offs will have to be evaluated in a much larger study.

Adult↗
PubMed1989

Laboratory aid in the diagnosis of acute appendicitis. A blinded, prospective trial concerning diagnostic value of leukocyte count, neutrophil differential count, and C-reactive protein.

The diagnostic value of C-reactive protein (CRP), total white blood cell (WBC) count, total neutrophil count, and neutrophil differential count were evaluated in a prospective blinded study of 204 patients submitted with the tentative diagnosis of acute appendicitis. The laboratory tests were performed on blood samples obtained at the time of admission, and the results were stored until the patients were discharged. One hundred patients were operated on: 59 had appendicitis, 3 had other surgically correctable diseases, and 38 had a superfluous exploration. All 104 nonoperated patients recovered spontaneously. The sensitivity, specificity, and predictive values of single tests and test combinations were calculated at different cutoff levels. Using standard reference intervals, WBC count demonstrated the best sensitivity (83 percent) and predictive value of a negative result (88 percent). Combining the tests by an "or" rule enhanced the sensitivity to 100 percent, employing WBC count or CRP or neutrophil percentage above the reference range (triple test), but at the expense of the predictive value of a positive test (37 percent). It was concluded that both single tests and combined tests are of limited value in predicting acute appendicitis. However, the same triple test combination proved a predictive value of a negative result at 100 percent (95 percent confidence limits 92 to 100 percent), indicating that acute appendicitis is unlikely when these tests are simultaneously negative. The triple test combination was valid in 32 percent of the patients who were free from appendicitis. In the study group, 10 of the patients (25 percent) who had a superfluous exploration had a negative triple test, and they might have avoided surgery if it had been used. Therefore, the triple test is recommended as a help in reducing the significant rate of negative laparotomies in patients suspected of having acute appendicitis.

Acute Disease↗