Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Predictive Value of Tests”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1996

The nonreactive nonstress test: predictive value for neonatal anemia in the isoimmunized pregnancy.

OBJECTIVE: To assess the value of the fetal nonstress test (NST) in predicting neonatal transfusion in pregnancies complicated by red cell isoimmunization. METHODS: We retrospectively reviewed the records of all patients evaluated for isoimmunization in pregnancy for the period January 1992 to December 1994. In addition to prenatal care, serial ultrasonography, and invasive testing when indicated, patients had NSTs two times per week. Nonstress tests were interpreted as either reactive or nonreactive using standard criteria. Results of the last NST before delivery were analyzed. Neonatal outcome data were obtained prospectively and by chart review. RESULTS: Sixty patients with isoimmunization were identified during the study period. Fifty-one patients (85%) had reactive NSTs until delivery, and nine (15%) had nonreactive NSTs that prompted delivery. Twelve of 51 (23.5%) patients with reactive NSTs and seven of nine (77.8%) patients with nonreactive NSTs required neonatal transfusion (P = .003, odds ratio 11.4 [95% confidence interval (CI) 1.7-120.2]). The mean (standard error of the mean; range) hematocrit (%) at birth was 38.9 (3.0; 21.3-52.0) in patients with reactive NSTs and 28.3 (3.8; 14.5-45.0) in those with nonreactive NSTs (P < .05). A nonreactive NST had a 77.8% positive predictive value (95% CI 49.0-100) in identifying the need for neonatal transfusion. CONCLUSION: These findings indicate that a nonreactive NST is predictive of subsequent neonatal transfusion in patients with isoimmunization. The antepartum fetal NST is a useful adjunct in the management of isoimmunized pregnancies.

Adult↗
PubMed1992

Results of the National Institute of Allergy and Infectious Diseases Collaborative Clinical Trial to test the predictive value of skin testing with major and minor penicillin derivatives in hospitalized adults.

BACKGROUND: A history (or lack thereof) of penicillin allergy is known to be unreliable in predicting reactions on subsequent administration of the drug. This study tests the usefulness of four penicillin allergen skin tests in the prediction of IgE-mediated reactions subsequent to administration of penicillin. METHODS: Eight centers cooperated in the National Institute of Allergy and Infectious Diseases trial of the predictive value of skin testing with major and minor penicillin derivatives. Hospitalized adults were tested with a major determinant (octa-benzylpenicilloyl-ocytalysine) and a minor determinant mixture and its components (potassium benzylpenicillin, benzylpenicilloate, and benzylpenicilloyl-N-propylamine). Patients then received a therapeutic course of penicillin and were observed, for 48 hours, for adverse reactions compatible with an IgE-mediated immediate or accelerated allergy. RESULTS: Among 726 history-positive patients, 566 with negative skin tests received penicillin and only seven (1.2%) had possibly IgE-mediated reactions. Among 600 history-negative patients, 568 with negative skin tests received penicillin and none had a reaction. Only nine of the 167 positive skin test reactors received a penicillin agent and then usually by cautious incremental dosing. Two (22%) of these nine patients had reactions compatible with IgE-mediated immediate or accelerated penicillin allergy; both were positive to the two determinants. CONCLUSIONS: These data corroborate previous data about the negative predictive value of negative skin tests to these materials. The reaction rate in skin test-positive patients was significantly higher than in those with negative skin tests, demonstrating the positive predictive value of positive tests to both major and minor determinants. The number of patients positive only to the major determinant or only to the minor determinant mix was too small to draw conclusions about the positive predictive value of either reagent alone.

Adult↗
PubMed1991

Counselling patients with HIV infection about laboratory tests with predictive values.

Laboratory tests, including CD4 counts, p24 antigen, raised levels of B2 microglobulin, neopterin and CMV antibodies, have been established as important predictive markers of disease progression in patients with HIV infection. As HIV antibody testing becomes more accepted in medical practice, counselling about these laboratory predictors of progression can help patients and doctors plan together the patients' care and treatment. Addressing patients' main concerns at each stage of investigation and illness may help them to plan ahead of crises, reduce stress, and enhance communication between patients and health care providers.

Adult↗
PubMed1988

Fetal acoustic stimulation testing. III. Predictive value of a reactive test.

The nonstress test (NST) is a helpful adjunct to the management of high-risk pregnancies. However, fetal sleep states may lead to falsely nonreactive tests. We assessed the usefulness of transabdominal acoustic stimulation of the fetus and demonstrated an approximately 50% reduction in the number of nonreactive tests and a shorter testing time. No change in the predictive reliability of a reactive test was observed. With regard to the intrapartum and neonatal outcome in women delivering within seven days of a reactive test, no difference between the incidence of meconium-stained amniotic fluid, depressed one- or five-minute Apgar scores or operative intervention for fetal distress could be identified. A reactive test evoked by acoustic stimulation is as reliable as the NST. It offers the additional benefits of reduced testing time and a lower incidence of nonreactive tests.

Acoustic Stimulation↗
PubMed1998

The uncertainty associated with the predictive value of test results.

The uncertainty associated with predictive value of test results was taken into consideration, as concerns both sampling error (related to the size of the statistical reference samples) and analytical imprecision (unavoidably involved by the measurement itself). A software package, developed for the statistical calculations, was used for the treatment of the results obtained for serum free thyroxin in euthyroid and dysthyroid subjects, assumed as an experimental model. Examples are shown for the obtainable functions predictive value vs. estimate and the related uncertainty regions. These data could help in comparing test results and, in particular, in preparing fully informative laboratory reports. The difficulties involved by an extensive application of the procedure are discussed.

Humans↗
PubMed1993

Normal tension glaucoma: the value of predictive tests.

Fifty-four normal tension glaucoma cases were studied to determine the value of several clinical tests for predicting the progression of the disease. Outflow facility, intraocular pressure (IOP) increase after water drinking, and diurnal changes in IOP were studied. Progression was determined on the basis of changes in visual sensitivity as measured on the Octopus 201. A minimum of four examinations of the central 30 degrees were conducted over a 3- to 7-year period. Progression of visual field defects was seen in 38.5% of eyes that had demonstrated some degree of abnormality in at least one of three clinical tests, while only 10.7% of those eyes that appeared normal on the basis of these tests showed such progression. The difference was significant (p < 0.04). These results suggest that the three clinical tests may be of value in detecting normal tension glaucoma eyes at risk for progression of visual field defects.

Adult↗
PubMed1980

Urinary tract infections in pediatric practice. A comparative study of three diagnostic tools: dip-slides, bacterioscopy and leucocyturia.

1,261 fresh urine specimens of patients of a pediatric office were examined by optical microscope and cultured on dip-slides (Urotube). 132 pathological bacteriurias, representing 95 certain episodes of UTI, served as reference material. The bacteriuria, leucocyturia and bacterioscopy were analysed by means of four validity tests: sensitivity test, predictive value of negative test, specificity test, and predictive value of positive test. The comparison shows that bacterioscopy is as valuable as dip-slides, provided that (a) only the clearly or highly positive bacterioscopies, or (b) the associated bacterioscopy and leucocyturia--but only double negative or double positive--be considered.

Bacteriuria↗
PubMed1990

Umbilical artery blood velocity waveform analysis in predicting the small-for-dates fetus.

Doppler umbilical artery blood velocity waveforms were recorded longitudinally in 78 randomly selected pregnancies. The waveform maximal (A) to minimal (B) Doppler shift frequency ratios were determined to provide a semi-quantitative measure of impedance to blood flow in the fetoplacental circulation. Fifty-eight of these pregnancies and their outcomes were normal. The A/B ratios from this normal group were used to derive a normal range of this index throughout the second half of pregnancy. A further 45 pregnancies, also randomly selected, were studied once within 2 weeks of delivery. Using those measurements, plus those from the longitudinal groups sampled within 2 weeks of delivery, the predictive values of the A/B ratio in detecting the small for gestational age fetus have been derived. The sensitivity of the umbilical artery A/B ratio in predicting a small for gestational age infant within 2 weeks of delivery was 58% with a specificity of 94%. The positive test predictive value was 69% with a negative test predictive value of 90%. These predictive values are lower than those previously published, probably because high-risk pregnancies were over-represented in earlier studies. Waveform analysis within 2 weeks of delivery did, however, appear to identify fetuses destined to develop a range of perinatal problems. Large prospective studies are needed before the predictive value of Doppler waveform analysis is clarified.

Blood Flow Velocity↗
PubMed1994

Performance of NycoCard:::U-Albumin and Micral-Test rapid methods for detecting microalbuminuria.

NycoCard:::U-Albumin and Micral-Test semiquantitative methods were evaluated against nephelometric measurements of nightly albumin excretion rates from 159 consecutive diabetic patients. Both methods can be safely applied for screening of intact renal function even at a strict prediction limit for incipient nephropathy of albumin excretion rate = 15 micrograms/min (standardised specimens collected at bed-rest), since the predictive values of negative tests were 95-100% for both tests. Predictive values of positive tests were 38% (NycoCard:::U-Albumin) and 44% (Micral-Test), if the designated value of 10 mg/l was used as the limit of positivity. By using 20 mg/l as the limit, the predictive values of positive tests were 62% (NycoCard:::U-Albumin) and 72% (Micral-Test), indicating the need for quantitative measurements in patients with positive screening results at both these limits.

Albuminuria↗
PubMed2005

Nitrate-stimulated tilt testing enhances the predictive value of the tilt test on the risk of recurrence in patients with suspected vasovagal syncope.

OBJECTIVE: Nitrate-stimulated tilt testing may be used to diagnose vasovagal syncope and to guide therapy. However, to date the predictive value of the test is undetermined. This study analyses the risk of recurrence of syncope in vasovagal patients on the basis of a nitrate-stimulated tilt result and other clinical factors. METHODS AND RESULTS: We used a combined passive and nitrate-stimulated tilt protocol. One year after the test a questionnaire, asking about recurrence of syncope and other demographic factors, was sent to 131 patients. Passive tilting was found not to be a useful predictor; recurrence rates after a positive and negative test were 26% and 30%, respectively, and non-significant. With the addition of sublingual nitrates the test became a significant predictor; recurrence rates were 34 (34%) with a positive and 4 (13%) with a negative tilt test (p = 0.031). Univariate analysis of the clinical factors revealed that gender and pre-test symptomatology were significant predictors of recurrence. Multivariate analysis revealed no additional relationships. CONCLUSION: In patients with suspected vasovagal syncope, a positive tilt test with sublingual nitrates together with the clinical factors gender and symptomatology, are predictors for recurrence of syncope during one year of follow-up. Without specific therapy the prognosis of vasovagal syncope is good.

Adult↗
PubMed2005

Defining response in clinical trials for obsessive-compulsive disorder: a signal detection analysis of the Yale-Brown obsessive compulsive scale.

OBJECTIVE: Many studies of the treatment of obsessive-compulsive disorder (OCD) have used percent reduction cutoffs on the Yale-Brown Obsessive Compulsive Scale (YBOCS) to classify patients as treatment responders. However, reduction criteria have varied from 20% to 50%, with studies of cognitive-behavioral therapy (CBT) using a more stringent criterion than studies of pharmacotherapy. The aim of this retrospective investigation was to determine optimal YBOCS reduction criteria for classifying patients as responders. METHOD: Data from 87 adult clinic and research outpatients meeting DSM-IV-TR criteria for OCD according to structured interview were examined, comparing the percent YBOCS reduction from pretreatment to posttreatment with 2 "gold standard" criteria from the Clinical Global Impressions (CGI) scale: much or very much improved and mild illness or better. Signal detection analyses were used to determine the sensitivity, specificity, predictive value of a positive test, predictive value of a negative test, and efficiency of various YBOCS reduction cutoffs. RESULTS: A YBOCS reduction cutoff of 30% was optimal for predicting improvement on the CGI. The 20% cutoff used by many pharmacologic studies resulted in a high number of false positives, whereas the 50% cutoff used by most CBT studies resulted in a high number of false negatives. For predicting mild illness or better at posttreatment, a YBOCS reduction cutoff of 40% to 50% was optimal. CONCLUSIONS: A YBOCS reduction criterion of 30% appears to be optimal for determining clinical improvement, whereas a 40% to 50% reduction criterion is appropriate for predicting mild illness at posttreatment. Future studies should employ a standard definition of treatment response in order to facilitate cross-study comparisons.

Adult↗
PubMedDate not supplied

Predictive value of testing random urine sample to detect microalbuminuria in diabetic subjects during outpatient visit.

The predictive value of random urine sample during outpatient visit to predict persistent microalbuminuria was studied in 76 Type 1, insulin-dependent diabetic subjects, 61 Type 2, non-insulin-dependent diabetic subjects, and 72 Type 2, insulin-treated diabetic subjects. Seventy-six patients attended outpatient clinic during morning, and 133 during afternoon. Microalbuminuria was suspected if Urinary Albumin Excretion (UAE) exceeded 20 mg/l. All patients were hospitalized within 6 months following outpatient visit, and persistent microalbuminuria was assessed then if UAE was between 30 and 300 mg/24 h on 2-3 occasions in 3 urines samples. Of these 209 subjects eighty-three were also screened with Microbumintest (Ames-Bayer), a semi-quantitative method. Among the 209 subjects, 71 were positive both for microalbuminuria during outpatient visit and a persistent microalbuminuria during hospitalization: sensitivity 91.0%, specificity 83.2%, concordance 86.1%, and positive predictive value 76.3% (chi-squared test: 191; p less than 10(-4)). Data were not different for subjects examined on morning, or on afternoon. Among the 83 subjects also screened with Microbumintest, 22 displayed both a positive reaction and a persistent microalbuminuria: sensitivity 76%, specificity 81%, concordance 80%, and positive predictive value 69% (chi-squared test: 126; p less than 10(-4)). Both types of screening appeared equally effective during outpatient visit. Hence, a persistent microalbuminuria can be predicted during an outpatient visit in a diabetic clinic.

Adult↗
PubMed1991

The value of tests predicting renovascular hypertension in patients with renal artery stenosis treated by angioplasty.

The aim of this study was to evaluate tests predicting renovascular hypertension. This was done by relating the results of renal vein renin tests, the captopril test, and renal scintigraphic tests to the blood pressure outcome 12 months after relief of renal artery stenosis by percutaneous transluminal renal angioplasty in 31 patients. Cure was seen in eight (26%). Improved blood pressure was obtained in 12 patients (39%), and in 11 patients (35%), the result for blood pressure was a failure. The accuracies of the two mathematical models used to analyze the renal vein renin assays were 44% and 60%. The captopril test showed a sensitivity of 36% and an accuracy of 43%. Renal captopril technetium Tc 99m-labeled pentetic acid scintigraphy gave a sensitivity of 60%. Stepwise logistic regression analysis of clinical variables in relation to blood pressure response revealed age as the only factor significantly related to blood pressure outcome. We conclude that the tests used are unfit for helping select patients for percutaneous transluminal renal angioplasty and that age may have an important influence on outcome.

Adolescent↗