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PubMed1996

Compression sonography in patients with indeterminate or low-probability lung scans: lack of usefulness in the absence of both symptoms of deep-vein thrombosis and thromboembolic risk factors.

OBJECTIVE: We sought to determine whether compression sonography could be eliminated in the evaluation of patients who lacked both thromboembolic risk factors and symptoms of deep-vein thrombosis and who had an indeterminate or low-probability lung scan. MATERIALS AND METHODS: The medical records of 155 consecutive patients who underwent bilateral lower-extremity sonography after an indeterminate or low-probability lung scan were reviewed. The presence of thromboembolic risk factors and deep-vein thrombosis symptoms and the result of sonography were recorded. Patients were divided into two groups: group 1 consisted of patients with either thromboembolic risk factors or deep-vein thrombosis symptoms, and group 2 consisted of patients without thromboembolic risk factors and without deep-vein thrombosis symptoms. The incidences of deep-vein thrombosis in groups 1 and 2 were compared by use of a two-tailed Fisher's exact test. RESULTS: Thromboembolic risk factors or deep-vein thrombosis symptoms were found in 109 of 155 patients (70%) (group 1). Deep-vein thrombosis was found in nine of 108 patients (8%) in group 1. Both thromboembolic risk factors and deep-vein thrombosis symptoms were absent in 47 of 155 patients (30%) (group 2). Deep-vein thrombosis was found in none of 47 patients (95% confidence interval, 0-8%) in group 2. The difference in the incidences of deep-vein thrombosis in groups 1 and 2 approached statistical significance (p = .0579). The negative predictive value of the absence of both thromboembolic risk factors and deep-vein thrombosis symptoms in excluding deep-vein thrombosis was 100% (95% confidence interval, 93-100%). CONCLUSION: If both symptoms of deep-vein thrombosis and thromboembolic risk factors are absent, the usefulness of lower-extremity sonography in detecting deep-vein thrombosis in patients with an indeterminate or low-probability lung scan is low. The manner in which these findings may be used to modify individual practice patterns will undoubtedly depend on the rate of detection of deep-vein thrombosis at a given institution.

Algorithms↗

PubMed1982

Stimulus-presentation probability influences newborns' head orientation to sound.

Although newborn infants are capable of turning their heads toward laterally-presented sounds, the incidence of such responding varies across studies. Previous work suggests that as the probability of a laterally-presented sound increases head-turning performance improves. To test this "lateral-stimulus-presentation probability" hypothesis, we presented 30 alert newborns with a rattle sound from a lateral source on either 1/4, 2/4, or 3/4 of all sound trials. On remaining sound trials the rattle came from a loudspeaker located above the infant's head. For 12 infants all lateral trials were presented consecutively; these trials were spaced across the session for the other infants. The likelihood of correct head turning increased linearly as the lateral-stimulus-presentation probability increased. The distribution of lateral trials did not influence the incidence of correct head turning.

Acoustic Stimulation↗

PubMed1995

Composite probability modelling of increasing resolution where diagnostic covariates are unmeasurable for some subjects.

When predictive covariates for a dichotomous outcome dependent variable are undetectable or unmeasurable for some subjects, a fact in itself that may be of considerable prognostic importance, traditionally such subjects' data are dropped from multiple logistic regression analyses. An alternative analytical algorithm is offered here for such situations. First, a series of multiple logistic regressions are applied to the complete data where covariates are initially coded as dichotomous, e.g., detectable or nondetectable. Then, a second series of logistic regressions are fitted for those subjects for whom a covariate is detectable and measurable with the fully resolved measure as the covariate. Ultimately, all individual model-specific predicted probabilities of the outcome for a subject are combined into a single probability through the proposed "Composite Probability Modelling of Increased Resolution" (CPMIR). When such an analysis was applied to discriminate 133 patients with acoustic tumours from a sample of 133 patients with cochlear disease, using a latency measure of the auditory brainstem response evoked potential as the predictive covariate, CPMIR yielded a superior model chi square to any component model, used the full cohort of patients, and produced the largest area under the ROC curve. This algorithm is offered as a general statistical modelling device.

Adult↗

PubMed2000

Comparison of forced-choice and subjective probability scales measuring behavioral intentions.

Three surveys compared the accuracy of predictions based on forced-choice and subjective probability scales. The latter produced significantly more accurate election predictions and significantly reduced the percentage of undecided, or "Don't Know" responses, compared to forced-choice scales in all three surveys. Analysis indicates subjective probability scales decrease sampling error and confirms there is an inherent source of error in traditional forced-choice questions about voting intentions not attributable to sampling error. The results are discussed with respect to (1) sampling and measurement errors in forced-choice and subjective probability scales measuring behavioral intentions, (2) their practical application, and (3) cognitive theory, especially support theory.

Adolescent↗

PubMed1976

[Relationship between perception of facial expression by schizophrenic patients and disorders in their assessment of probability].

The author proposes a method of studying some traits of mimic perception where an oral report is avoided. The essence of the method is in a distribution by the examine of a series of photographs of the same face into such groups so as to have similar facial expressions. The experiments demonstrated that such distributions are mainly performed on a direct intuitive level. The examinee is given several series of photographs of different faces. In an evaluation of the results the probability of different combinations attained in a group of normals are being considered. The author compared a group of schizophrenic patients (60 cases) and a group of normals (100 cases). The patients significantly more frequently (p less than 0.001) give combinations of photographs with a low probability 0.01-0.05. The preliminary data indicate that this trait correlates with the severity of the clinical picture. Among the normals 7% of the examined individuals gave a stable high amount of answers with a low probability. This group of individuals detected characterological peculiarities reflected in the questionnaire. It may be assumed that this trait in the evaluation of mimics is due to a constitutional and morbid process.

Affective Symptoms↗

PubMed2000

Deployment and the probability of spousal aggression by U.S. Army soldiers.

OBJECTIVE: To determine the relationship between length of soldier deployment and self-reports of moderate and severe spousal violence. METHODS: The Conflict Tactics Scale was used to measure self-reports of behaviors exhibited in marital conflict. Surveys were administered to a 15% random sample of 26,835 deployed and nondeployed married active duty U.S. Army men and women in the 50 United States during the period 1990 to 1994. Multinomial logistic regression and ordered probit analysis were used to estimate the probabilities of moderate and severe violence by length of deployment. RESULTS: After controlling for demographic variables, the probability of severe aggression was significantly greater for soldiers who had deployed in the past year compared with soldiers who had not deployed. CONCLUSIONS: Deployment contributes a significant but small increase to the probability of self-reported spousal aggression during a 1-year period. Although deployment is a military operation, similar effects may be observed in certain civilian occupations.

Adult↗

PubMed1999

Variations in the survival probabilities of the PVC-protected red mangrove propagules: testing the encased replanting technique.

The EcoEléctrica Mangrove Planting Project, a five-year voluntary effort, has the purpose of testing a recently developed mangrove planting technique at the EcoEléctrica site in Peñuelas, Puerto Rico. The goal of the project is to provide empirical validation to promote or improve the technique to be used in recovering mangrove ecosystems in Puerto Rico and United States. The research presented herein analyzed the information collected on the first two years of the project. The proportions of remaining casings and seeds per study zone were compared using the chi-square distribution. Zone 1 had the least pipes lost while Zone 4 had the most (p < 0.05). Forty-three percent of the seeds in Zone 1 remained in the casing, while 26% remained in Zone 2 (p = 0.03). Median growth rates of seeds per study zone showed that Zone 1 had the highest median growth rates. Survival analysis described the survival experience of the seeds, and differences in survival probabilities were compared with the log-rank test. Zone 1 seeds had a better survival experience compared to Zones 2, 3 and 4 (p < 0.0001). Survival probabilities for being free of spots were over 60% during the whole study period. No significant differences were observed in the survival experience with the use-or-no use of casing extensions (p = 0.40), and the use-or-no use of nursed seeds (p = 0.26). Differences in survival probabilities might be attributed to variations in wave energy, depth or substrate conditions. This hypothesis will be evaluated in the second phase of the study.

Conservation of Natural Resources↗

PubMed2000

Combining registration-system and survey data to estimate birth probabilities.

With the widespread availability of event-history data, demographers have increasingly eschewed registration-system data in favor of survey data. We propose instead using survey and registration-system data in combination, via a constrained maximum-likelihood framework for demographic hazard modeling. As an application, we combine panel survey data and birth registration data to estimate annual birth probabilities by parity. The general fertility rate obtained from registration-system data constrains the weighted sum of parity-specific birth probabilities. The variances about the parity-specific birth probabilities are halved when registration-system data are used to constrain the estimates. Other demographic applications are discussed.

Adolescent↗

PubMedDate not supplied

Probable Alzheimer's disease: gender-related issues.

Probable Alzheimer's disease is diagnosed by exclusion when no other disorder--such as stroke, brain infection, or vitamin deficiency--can be found to account for specific cognitive change. Although probable Alzheimer's disease affects both men and women, studies in many different populations show that between 1.5 and 3 times as many women as men suffer from probable Alzheimer's disease. For women with the disease, one needs to consider behavioral and cognitive problems, therapeutic issues, and other gender-related risks. Additionally, social, psychological, and emotional variables play a role in the female caregiver's burden.

Alzheimer Disease↗

PubMed2001

[A patient with probable dementia with Lewy bodies, who showed improvement of dementia and parkinsonism by the administratim of donepezil].

We present a 73-year-old man with probable dementia with Lewy bodies(DLB). At 65 years of age, he gradually developed bradykinesia, gait disturbance and mild amnesia. At 71 years of age, he noted resting tremor in bilateral hands, and amnesia and disorientation were exacerbated. He was diagnosed as having parkinsonism and took L-dopa/carbidopa at 100 mg/day. Since he developed hallucination and abnormal behavior 2 days after the initiation of the drug, he stopped taking L-dopa and was admitted to our hospital. A neurological examination on admission revealed moderate amnesia, disorientation, finger agnosia, constitutional apraxia, mask-like face, cogwheel rigidity, resting tremor in bilateral hands, and bradykinesia. Brain MRI showed mild brain atrophy, and single photon emission computerized tomography(SPECT) showed diffuse moderate hypoperfusion in bilateral cerebral cortex. As he had fluctuating cognitive dysfunction and parkinsonism, he was diagnosed to have probable DLB. As his dementia was exacerbated by trihexyphenidyl, an anti-cholinergic agent, at 2 mg/day, we treated him with donepezil, an anti-choline esterase agent, at 3-5 mg/day. His parkinsonism, including rigidity and bradykinesia, was markedly improved his dementia, consisting of amnesia and disorientation. Electroencephalography (EEG) improved in the organization of the dominant rhythm. The SPECT improved in the blood perfusion of the bilateral frontal lobe as well as cognitive function and parkinsonism were maintained by donepezil for 6 months after discharge. A therapeutic efficacy of donepezil for DLB has recently been reported. It is notable that donepezil was beneficial not only for cognitive dysfunction but also for parkinsonism in the present case with probable DLB.

Aged↗

PubMed2002

Inverse relationship between release probability and readily releasable vesicles in depressing and facilitating synapses.

We tested the hypothesis that the probability of vesicular exocytosis at synapses is positively correlated with the pools of readily releasable synaptic vesicles, as shown for mammalian neurons grown in tissue culture. We compared synapses of two identified glutamatergic neurons: phasic (high-output, depressing) and tonic (low-output, facilitating) crustacean motor neurons, which differ 100- to 1000-fold in quantal content. Estimates of vesicles available for exocytosis were made from depletion during forced release and from electron microscopic observation of vesicles docked at synaptic membranes near active zones. Both measurements showed a significantly larger pool of readily releasable vesicles in facilitating synapses, despite their much lower quantal output during stimulation. Thus, the probability for release of docked vesicles is very much lower at facilitating synapses, and the presence of more docked vesicles does not predict higher synaptic release probability in these paired excitatory neurons.

Action Potentials↗

PubMed2003

Motor axonal injury and amyotrophic lateral sclerosis: risk assessment using a reverse probability analysis technique.

A relationship between antecedent trauma and amyotrophic lateral sclerosis (ALS) has been clinically suspected for over a century. Nine cases of ALS that occurred over a 14-year period in young U.S. men (age range, 28-43 years) following trauma that produced motor axonal injury that antedated (range, 5-42 months) the onset of ALS have been reported by a single neurologist. After estimating the number of cases of ALS in 28- to 43-year-old American men that would be expected to occur over a 14-year period, a reverse probability analysis technique was used to determine the expected incidence rates of motor axonal injury in a ideally matched control population that would give probabilities of 0.05, 0.01, and 0.001 of observing nine or more instances of motor axonal injury occurring during the previous 5 to 42 months. This analysis was repeated assuming that this one neurologist had only reported 50 and 10% of all instances of ALS that occurred during this 14-year period in American men ages 28 to 43 years who had experienced trauma that produced motor axonal injury that occurred 5 to 42 months before the onset of ALS. Reverse probability analysis is a technique that can be used in performing risk assessments.

Adult↗

PubMed2003

Effect of hemostatic risk factors on the individual probability of thrombosis during pregnancy and the puerperium.

In a retrospective study of 190 women with a first history of venous thromboembolism during pregnancy and the puerperium and 190 age-matched women with at least one prior pregnancy and no history of venous thromboembolism, the individual probability of thrombosis was determined. Assuming an overall risk of 1 in 1500 pregnancies, the probability of pregnancy-related thrombosis in carriers of homozygous factor V Leiden was 1 in 80 (odds ratio 20.6, p=0.005) and among carriers of combined heterozygous factor V Leiden and heterozygous G20210A mutation in the prothrombin gene 1 in 20 (odds ratio 88, p<0.001). The probability of thrombosis per pregnancy among women with elevated levels of factor VIII:C (>172 % activity) was 1 in 385 (odds ratio 4.5, p<0.001) and among those with increased levels of von Willebrand factor antigen (>190 %) 1 in 435 (odds ratio 4.0, p=0.002), independent of elevated factor VIII:C levels. The high prevalence of combined and homozygous defects of hemostatic components (21.6%) in patients as compared with normal women (0.86%) supports the concept that venous thromboembolism is a multicausal disorder.

3' Untranslated Regions↗

PubMed2003

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients: part I. Differences due to the acquisition of HIV-infection.

OBJECTIVE: Due to side effects, such as hyperlipidaemia and insulin resistance, there is an increasing concern that antiretroviral drugs lead to an epidemic of cardiovascular diseases in HIV-infected patients. The present study characterizes the cardiovascular risk profile of HIV-infected individuals, due to the acquisition of HIV-infection. METHODS: Cardiovascular risk factors of 309 HIV-infected adults (HIV-acquisition: 59.2% by homosexual contact (group 1), 28.5% by heterosexual contact (group 2), 9.1% by intravenous drug abuse (group 3) and 3.2% by blood transfusion (group 4)) were analysed. Overall 10-years probability for cardiovascular events was analysed by the Framingham algorithm. RESULTS: Tobacco use was more common in group 1 subjects compared with group 2 subjects (67% vs. 52%; p<0.05). Additionally, group 1 subjects exhibited elevated total cholesterol (5.6 +/- 0.1 mmol/L vs. 4.8 +/- 0.3), LDL-cholesterol (3.6 +/- 0.1 mmol/L vs. 2.8 +/- 0.2) and triglyceride concentrations (3.2 +/- 0.3 mmol/L vs. 1.7 +/- 0.2) compared with group 3 (all p<0.05). No significant differences between the groups were detected in glucose metabolism. The overall 10-years probability for cardiovascular events was significantly higher in group 1 compared with group 2 and group 3 (12.2 +/- 0.8% vs. 6.6 +/- 0.9% and 7.9 +/- 1.6%, p<0.05). CONCLUSIONS: The cardiovascular risk profile differs between subgroups of HIV-infected individuals, leading to significant higher probability of cardiovascular events in group 1 subjects. The risk of premature atherosclerosis by HIV-infected individuals and therapeutic options remains to be established.

Adult↗

PubMed2002

[Investigation on the transition probability of the aluminum resonant double lines].

In order to obtain the aluminum resonant double lines, Al I 396.15 nm and Al I 394.40 nm, we have recorded the time-resolved spectra of the plasma induced by Nd:YAG laser ablating metal aluminum in Ar, under the Ar ambient pressure 10 kPa, at 0.1 mm in front of the target, with laser pulse energy 145 mJ/pulse. Relative intensities of the double lines were acquired by integrating the area under the double lines, respectively. According to the ratio of the intensities of the double lines, the ratio of transition probability of the double lines was deduced, and contrasted with the theoretical value. As the result, we found they tally with each other exactly. Limited to our experimental condition, we could only estimate approximately the ratio of transition probability of the double lines. Further experiments were needed for precise measurements of respective transition probability of the double lines.

English Abstract↗

PubMed2004

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients. Part II: gender differences.

OBJECTIVE: Due to the side effects of antiretroviral therapy and long term survival there is an increasing concern of an elevated rate of cardiovascular diseases in HIV-infected patients. The present study analysed the cardiovascular risk profile and the probability of cardiovascular events in HIV-infected patients, due to differences of gender. METHODS: Cardiovascular risk factors of 309 HIV-infected adults, including 240 males were analysed. Overall 10-years probability for cardiovascular events was evaluated by the Framingham algorithm. RESULTS: Gender differences were detected in cardiovascular risk factors such as lipid values, blood pressure and the rate of smoking. Tobacco use was much more common in HIV-infected males compared with HIV-infected females (67.5% vs. 49.3%; p<0.001). Although no significant difference was noticed in total cholesterol (5.49 +/- 0.09 vs. 5.53 +/- 0.19 mmol/L, p = 0.84), the HDL-cholesterol concentration was significantly lower (1.09 +/- 0.03 vs. 1.36 +/- 0.06 mmol/L, p < 0.001) and the triglyceride concentration higher (3.01 +/- 0.21 vs. 2.06 +/- 0.26 mmol/L, p = 0.02) in HIV-infected males compared to HIV-infected females. Additionally, systolic blood pressure was higher in HIV-infected males compared with HIV-infected females (123.1 +/- 1.1 vs. 115.4 +/- 2.1 mmHg, p < 0.01). No significant differences were detected in HbA1c concentrations between both groups (5.15 +/- 0.07 vs. 5.31 +/- 0.11, p = 0.26). The overall 10-years probability for cardiovascular events was 8.7% (median) in HIV-infected males and 1.7% in HIV-infected females (p < 0.0001). CONCLUSIONS: In the present study, we observed gender differences in the cardiovascular risk profile of HIV-infected individuals. The risk of premature atherosclerosis and associated cardiovascular events was significantly higher in HIV-infected males.

Adult↗

PubMed2004

Short report: detection probability of arbovirus infection in mosquito populations.

An important component of arbovirus surveillance is monitoring the vector for presence of the pathogen. Intervention and preventive programs need early detection of arboviral activity in mosquito populations. In this report, we examine the factors affecting the probability of detection of mosquito infections. Since arbovirus infection rates in mosquito populations are very low, observations of zero-infected mosquito samples are common. Using statistical models, we describe methods to estimate the probability of detection and upper bounds of confidence intervals of mosquito infection rates as measures of confidence for observations of zero infection. Our results show that detection of low levels of mosquito infections requires large samples (greater than 1,600 individuals) for a high probability (0.8) of detection. Due to focal transmission of arboviruses, grouping samples over different sampling sites and times is often inappropriate for detection of mosquito infection. We emphasize sample size as a key determinant in detection of mosquito infections and recommend intensified entomologic surveys at sentinel sites to detect arboviral activity.

Animals↗

PubMed2006

Predictive probability of serum prostate-specific antigen for prostate cancer: an approach using Bayes rule.

This article introduces the use of Bayes probability rule to calculate age and serum prostate-specific antigen (PSA)-specific positive predictive values (PPVs) for prostate cancer. The PPV is the conditional probability of having prostate cancer, given a value of PSA and a particular age group. The formulation uses values of sensitivity obtained from previously reported studies of more than 2,700 men with prostate cancer, and it uses values of specificity obtained from previously reported studies of more than 99,000 men without prostate cancer. The formulation also introduces the use of a population-based and age-specific probability of prostate cancer, and for this it relies on the National Cancer Institute-sponsored Surveillance, Epidemiology and End Results data. The Bayes PPV suggests that in younger men, cut points defining an elevated PSA level should be raised rather than lowered. The Bayes formulation also provides estimates of the PPV for narrow intervals of PSA, and these tabulated results may provide useful guidelines for the implications of serum PSA levels at specific age groups.

Adenocarcinoma↗