Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “association testing”

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 325 records · Page 18Linked to original sources

Intellectual ability correlates of the Marlowe-Crowne Social Desirability Scale.

The hypothesis that the Marlowe-Crowne Scale would be negatively related to a variety of intellectual ability measures was investigated in a sample of college students. As predicted, MC scores were negatively correlated with measures of intelligence (Quick Test), associational ability (Remote Associates Test), and academic achievement (course grades). These results suggest that the vulnerable self-esteem and defensiveness traditionally ascribed to high versus low MC scorers may at least in part, reflect a history of poorer performance in intellectual and academically related activities.

Journal Article↗

[Early syphilis].

Given the transmission of Treponema pallidum during human sexual contact, syphilis now occurs in France only in sexually high-risk, disadvantaged populations. The English-language terminology of "early syphilis" has progressively replaced that of "primary" and "secondary" in French usage. Induration of the chancre and the papular nature of secondary skin rashes remain the best criteria for clinical diagnosis. Serological tests associate test specific for treponematoses (Treponema pallidum haemagglutination assay, TPHA) and a nonspecific screening test (Venereal diseases research laboratory, VDRL) to confirm clinically suspected disease. Routine use of long-acting penicillin (benzathine penicillin) is consistently effective. The continuing risk of active syphilis in a pregnant woman and the possibility of severe syphilis in HIV patients require vigilance.

Disease Outbreaks↗

Mortality and morbidity of members of the British Nuclear Tests Veterans Association and the New Zealand Nuclear Tests Veterans Association and their families.

More than 20,000 British servicemen--many of them on their National Service, few of them volunteering for the tests, and most in their early twenties, some still boy soldiers in their teens--were required to 'participate' in the United Kingdom nuclear tests in Australia and Christmas Island in the 1950s and 1960s. 528 members of the New Zealand Navy were also present for one series of tests. There was also a Fijian Army contingent, which has been variously numbered between 100 and 500 men. An estimated 16,000 Australian servicemen and civilians were also involved in the tests at Maralinga and other sites. The men performed a wide range of duties, from highly technical preparations for the detonations to catering and clerical jobs. But whatever their role, they were all required to witness the detonations as part of their 'indoctrination' for the possibility of nuclear war. Most of them were required to line up on the beach, with their backs to the detonations and their hands over their eyes for the first minute or so. They were then allowed to turn around and look at the awesome sight as the mushroom cloud plumed thousands of feet into the air. Very few wore more than shorts and sandals during their time at the tests; only those who were thought to be at risk from radiation injury were issued with protective clothing and radiation dose badges. The UK government was sure that the troops, most of whom were standing within 20 km of the detonations and some of whom were present for 25 nuclear bomb blasts in as many weeks on Christmas Island, were not irradiated. The Ministry of Defence still routinely issues a document to nuclear veterans who feel that their illnesses were caused by the radiation they encountered when they were young men which states: The background [radiation] dose received by civilians and members of HM Forces serving at or off Christmas Island in the years 1956 to 1964 was only about 35% of that which they would have received on average had they remained, for that period of their lives, in the United Kingdom--that is, some 100 microsieverts per calendar month less at Christmas Island than in the United Kingdom. This sanguine view of the health burden borne by nuclear veterans and their families is not borne out by the data reported in this study of the health outcomes of the 2,500 men (2,200 UK, 238 New Zealand and 62 Fijian) on whom data are available to the present researcher. Thirty per cent of the men in this sample have already died, mostly in their fifties. Two-thirds of them died from cancers that are pensionable in the United States as presumptively radiogenic among nuclear veterans. About one in seven of the men in the sample of 1,014 who responded to the questionnaire circulated in late 1997 did not father any children after they returned from the weapons tests. Among the nearly 5,000 children and grandchildren of this group of more than a thousand veterans, there are 26 cases of spina bifida alone--more than five times the usual rate for live births in the UK. Nearly half the health problems among the offspring of the nuclear weapons tests veterans reported in this study consist of the same dermatological, musculoskeletal and gastrointestinal conditions from which many of the men have also suffered. Among the 2,261 children of 1,041 veterans, more than 200 skeletal abnormalities were reported, including more than 30 cases of short stature and 18 spinal problems, mostly curvature and scoliosis. More than 100 skin conditions were reported, mostly eczema and dermatitis, in many cases described as congenital. Over 50 of the children are already suffering from arthritis and similar conditions, although they are only now entering their thirties. Hip deformities were reported for 19 children and kneecap deformities for 14. More than 100 of the veterans' children reported reproductive difficulties; 24 women reported problems with their ovaries. This pattern of morbidity was repeated in the grandchildren, tho

Adolescent↗

Economic costs associated with two testing strategies for screening feeder calves for persistent infection with bovine viral diarrhea virus.

OBJECTIVE: To develop partial budgets of the economic costs of 2 test strategies for screening cattle for persistent infection with bovine viral diarrhea virus (BVDV). DESIGN: Partial budget analysis. ANIMALS: 938 calves arriving at 2 stocker operations. PROCEDURE: Calves were tested to determine prevalence of persistent BVDV infection. Test strategies that were evaluated included a single-test strategy consisting of immunohistochemical staining of skin biopsy specimens from all animals and a 2-test strategy consisting of polymerase chain reaction (PCR) assaying of pooled blood samples followed by immunohistochemical staining of skin biopsy specimens from animals in pools for which assay results were positive. Break-even costs (i.e., cost of persistent BVDV infection per animal necessary to justify whole-herd diagnostic testing) associated with each test strategy were calculated as a function of disease prevalence and test cost. RESULTS: Apparent prevalence of persistent BVDV infection was 0.32%. Sensitivity and specificity of the PCR assay for pooled samples were 100% and 89.7%, respectively. Regardless of the prevalence of persistent BVDV infection, the break-even cost for the 2-test strategy was lower than the break-even cost for the single-test strategy. However, the economic advantage was greatest when prevalence was low. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that using a 2-test strategy to screen cattle for persistent BVDV infection, whereby the first test involves PCR assaying of pooled samples and the second involves immunohistochemical testing only of those animals represented in pooled samples with positive assay results, will reduce the cost of screening incoming feedlot cattle, compared with immunohistochemical testing of all animals.

Animals↗

Qualitative semi-parametric test for genetic associations in case-control designs under structured populations.

Recently, statistical methods have been proposed using genomic markers to control for population stratification in genetic association studies. However, these methods either have unacceptable low power when population stratification becomes strong or cannot control for population stratification well under admixture population models. In this paper, we propose a semiparametric association test to detect genetic association between a candidate marker and a qualitative trait of interest in case-control designs. The performance of the test is compared to other existing methods through simulations. The results show that our method gives correct type I error rate both under discrete population models and admixture population models, and our method is robust to the extent of the population stratification. In most of the cases we considered, our method has higher power and, in some cases, substantially higher power than that of existing methods.

Case-Control Studies↗

Pedigree disequilibrium test (PDT) replicates association and linkage between DRD4 and ADHD in multigenerational and extended pedigrees from a genetic isolate.

Association/linkage between dopamine D4 receptor (DRD4) polymorphisms and attention-deficit/hyperactivity disorder (ADHD) has been suggested by case-control- and nuclear-family-based studies. Here, we present a candidate gene analysis for DRD4 using 14 extended and multigenerational families segregating ADHD derived from the 'Paisa' community of Antioquia, Colombia, a genetic isolate. Two DRD4 polymorphisms (a 120 bp tandem duplication at the promoter and a 48 bp-VNTR at exon 3), reported associated to ADHD, were genotyped. Parametric and non-parametric linkage analyses, and a family-based association test (FBAT), the pedigree disequilibrium test (PDT), were applied to search for evidence of association/linkage. Two-point LOD scores were significantly negative, with values ranging from -3.21 (P=0.011158) to -7.66 (P=0.000091 at theta=0). Non-parametrical analysis resulted in nonsignificant evidence for linkage. The PDT showed a moderate trend toward significance of association/linkage between the 7-repeat (7R) allele at the 48 bp VNTR and ADHD (P=0.0578). Furthermore, the haplotype analysis shows a significant association/linkage of the 7R-240 bp haplotype (P=0.0467) with ADHD. Results suggest that either a moderate DRD4 genetic effect, or linkage disequilibrium of DRD4 with an ADHD disease locus in the vicinity or the linkage to a phenotypic component of the ADHD spectrum could be underlying this association/linkage. These results provide further evidence for the association of ADHD to genetic variation in or near to DRD4 and replicate the previously reported association between ADHD and the 7R allele.

Alleles↗

Temporal stability of the implicit association test-anxiety.

The Implicit Association Test-Anxiety (IAT-Anxiety; Egloff & Schmukle, 2002) provides an indirect assessment of anxiety by measuring associations of self (vs. other) with anxiety-related (vs. calmness-related) words. In 3 studies (using 3 independent samples), we examined the temporal stability of the IAT-Anxiety. In Study 1, 65 participants responded twice to the IAT-Anxiety with a time lag of 1 week. The test-retest correlation was .58. In Study 2 (N = 39), we extended the time interval between test and retest to 1 month and this yielded a stability coefficient of .62. In Study 3 (N = 36), we examined the long-term stability (time lag: 1 year) of the IAT-Anxiety and this showed a correlation of .47. We discuss implications of these results for the assessment of personality dispositions with the IAT.

Adult↗

Sampling, sample preparation, and analytical variability associated with testing wheat for deoxynivalenol.

The variability associated with testing wheat for deoxynivalenol (DON) was measured using a 0.454 kg sample, Romer mill, 25 g comminuted subsample, and the Romer Fluoroquant analytical method. The total variability was partitioned into sampling, sample preparation, and analytical variability components. Each variance component was a function of the DON concentration and equations were developed to predict each variance component using regression techniques. The effect of sample size, subsample size, and number of aliquots on reducing the variability of the DON test procedure was also determined. For the test procedure, the coefficient of variation (CV) associated with testing wheat at 5 ppm was 13.4%. The CVs associated with sampling, sample preparation, and analysis were 6.3, 10.0, and 6.3%, respectively. For the sample variation, a 0.454 kg sample was used; for the sample preparation variation, a Romer mill and a 25 g subsample were used; for the analytical variation, the Romer Fluoroquant method was used. The CVs associated with testing wheat are relatively small compared to the CV associated with testing other commodities for other mycotoxins, such as aflatoxin in peanuts. Even when the small sample size of 0.454 kg was used, the sampling variation was not the largest source of error as found in other mycotoxin test procedures.

Algorithms↗

Who has Pap tests? Variables associated with the use of Pap tests in absence of screening programmes.

Characteristics associated with the use of Pap tests were studied in a random sample of 581 women 18-69 years old; residents of Turin, Italy. There has been no organized screening programme in the area. (Tests possibly related to symptoms were not considered). Data were analysed by multiple logistic regression. Some 48% of women had never had a smear. The prevalence of women ever undergoing a Pap test was higher in middle-aged, married and more educated women (p less than 0.001 in all these cases). We found a linear trend (p less than 0.05) related to time since last visit to the family physician. A number of 'preventive' behavioural practices (physical exercise, no alcohol consumption) and experience of early diagnostic procedures for cancer e.g. BSE and mammography, were also associated with ever having had a Pap smear. The prevalence of ever-tested women was significantly lower among lifetime non-smokers than among ex-smokers and current smokers who planned to stop smoking but not lower than in current smokers who did not plan to stop. Results were similar when having had a test within the last three years was taken as the outcome. These results may be useful in planning screening strategies and educational programmes designed to improve attendance in an organized screening programme.

Adolescent↗

Test of association between haplotypes and phenotypes in case-control studies: examination of validity of the application of an algorithm for samples from cohort or clinical trials to case-control samples using simulated and real data.

The use of haplotype information in case-control studies is an area of focus for the research on the association between phenotypes and genetic polymorphisms. We examined the validity of the application of the likelihood-based algorithm, which was originally developed to analyze the data from cohort studies or clinical trials, to the data from case-control studies. This algorithm was implemented in a computer program called PENHAPLO. In this program, haplotype frequencies and penetrances are estimated using the expectation-maximization algorithm, and the haplotype-phenotype association is tested using the generalized likelihood ratio. We show that this algorithm was useful not only for cohort studies but also for case-control studies. Simulations under the null hypothesis (no association between haplotypes and phenotypes) have shown that the type I error rates were accurately estimated. The simulations under alternative hypotheses showed that PENHAPLO is a robust method for the analysis of the data from case-control studies even when the haplotypes were not in HWE, although real penetrances cannot be estimated. The power of PENHAPLO was higher than that of other methods using the likelihood-ratio test for the comparison of haplotype frequencies. Results of the analysis of real data indicated that a significant association between haplotypes in the SAA1 gene and AA-amyloidosis phenotype was observed in patients with rheumatoid arthritis, thereby suggesting the validity of the application of PENHAPLO for case-control data.

Algorithms↗

Four clinical tests of sacroiliac joint dysfunction: the association of test results with innominate torsion among patients with and without low back pain.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the association between innominate torsion (asymmetric anteroposterior positioning of the pelvic innominates) and Gillet, standing forward flexion, sitting forward flexion, and supine-to-sit tests. SUBJECTS: A sample of 21- to 50-year-old patients with low back pain (n=150) and a comparison group of patients with upper-extremity impairments (n=138) were recruited from outpatient physical therapy facilities. METHODS: The association of single and combined test results with innominate torsion (calculated from pelvic landmark data) and with presence or absence of low back pain were estimated via odds ratios, sensitivities, specificities, and predictive values. RESULTS: Individual test sensitivities were low (8%-44%), as were negative predictive values (28%-38%), for identifying the presence of innominate torsion. Combining tests and controlling for sex, age group, leg-length difference, or iliac crest level did not improve performance characteristics. The associations of test results with low back pain were weak, with the exception of the Gillet test (odds ratio=4.57). CONCLUSION AND DISCUSSION: The data do not support the value of these tests in identifying innominate torsion, although the use of these tests for identifying other phenomena (eg, sacroiliac joint hypomobility) cannot be ruled out. Further exploration of the association of Gillet test results with low back pain is warranted.

Adult↗

How do homozygous parents affect TDT as a test for association?

The traditional transmission disequilibrium test (TDT) (Spielman et al., 1993) is a powerful test for association only in the presence of linkage. Since allele transmissions from homozygous parents do not carry any information on linkage, the TDT statistic uses data only on heterozygous parents. However, homozygous parents carry information on association between alleles at a marker locus and a disease locus. In this article, we explore whether inclusion of homozygous parents increases the power to detect association. The resultant test statistic follows a chi(2) distribution with 2 degrees of freedom. Monte-Carlo simulations are included to compare the performance of this test with the traditional TDT under different disease models.

Alleles↗

Two tests of association for a susceptibility locus for families of variable size: an example using two sampling strategies.

A two-stage approach was used to analyze Problem 2 simulated data from Genetic Analysis Workshop 11. In the first stage, we tested for linkage with the Haseman-Elston test in SIBPAL. Markers that were significant in the first stage were followed up with two types of association tests. These association tests differ in the type of family information used: 1) parental transmissions to affected children or 2) differences in marker allele frequencies between affected and unaffected siblings. We also explored how the conclusions changed when different sampling strategies were used. Of particular interest was whether the entire data set should be used to test for both linkage and association or whether the data set should be halved to allow for replication of the initial association results.

Environment↗

[Removal of harmful admixtures from a surrogate atmospheric condensate of a closed habitat with the help of a cultivated bacterial association].

Tested was an idea to eliminate six harmful admixtures reside in a surrogate of atmospheric condensate of closed habitats by a cultivated bacterial association. The purpose was to select members of the bacterial associations that would assimilate acetone, acetic acid, ethanol, ethyl acetate, methylamine and ammonia as free, so immobilized on insoluble cellular polyvinylformal. The resulted association of three bacterial species showed the ability to transform into end products a six-component surrogate of atmospheric condensate. Methylopila capsulata VKM V-1606 metabolized methylamine, Paracoccus denitrificans VKM V-1324--acetone. Pseudomonas esterophilus VKM V-1736 D was found to act as an ethyl acetate destructor decomposing the admixture to ethanol and acidic acid which were oxidized also by this species to carbon dioxide and water. Each of these bacterial strains in the test association metabolized ammonia as a source of nitric nutrition.

Acetaldehyde↗

Validating the utility of the Spanish version of the American Diabetes Association Risk Test.

The American Diabetes Association (ADA) Risk Test, often used for decisions to blood glucose screen or not, lacks studies reporting the reliability or validity for the Spanish version of the tool. The objective of this study is to further validate the utility of the Spanish version of the ADA's Risk Test for Latino Populations. A convenience sample of 316 Latinos participated in this study. A positive but weak statistical correlation was found between blood glucose and the Risk Test score (.138), suggesting low reliability and validity of the Spanish version of the instrument. Two internal consistency estimates of reliability techniques were computed for the Risk Test for diabetes scale items, indicating low reliability.

Adult↗

Association analysis of mitochondrial DNA heteroplasmic variants: Methods and application.

We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust identification and association testing of heteroplasmy. Our simulation studies demonstrated that gene-based tests maintained an appropriate type I error rate at &#x3b1;&#x202f;=&#x202f;0.001. Notably, when 5&#x202f;% or more heteroplasmic variants within a target region were linked to an outcome, burden-extension tests (including the adaptive burden test, variable threshold burden test, and z-score weighting burden test) outperformed the sequence kernel association test (SKAT) and the original burden test. Applying this framework, we conducted association analyses on whole-blood derived heteroplasmy in 17,507 individuals of African and European ancestries (31&#x202f;% of African Ancestry, mean age of 62, with 58&#x202f;% women) with whole genome sequencing data. We performed both cohort- and ancestry-specific association analyses, followed by meta-analysis on both pooled samples and within each ancestry group. Our results suggest that mtDNA-encoded genes/regions are likely to exhibit varying rates in somatic aging, with the notably strong associations observed between heteroplasmy in the RNR1 and RNR2 genes (p&#x202f;<&#x202f;0.001) and advance aging by the Original Burden test. In contrast, SKAT identified significant associations (p&#x202f;<&#x202f;0.001) between diabetes and the aggregated effects of heteroplasmy in several protein-coding genes. Further research is warranted to validate these findings. In summary, our proposed statistical framework represents a valuable tool for facilitating association testing of heteroplasmy with disease traits in large human populations.

Humans↗

Obesity and prostate cancer screening among African-American and Caucasian men.

BACKGROUND: Differential prostate-specific antigen (PSA) testing practices according to obesity-related comorbid conditions may contribute to inconsistent results in studies of obesity and prostate cancer. We investigated the relationship between obesity and PSA testing, and evaluated the role of prior diagnoses and disease screening on PSA testing patterns. METHODS: Men, 40 and 79 years old and without prior prostate cancer were recruited from 25 health centers in the Southern US (n = 11,558, 85% African-American). An extensive in-person interview measured medical and other characteristics of study participants, including PSA test histories, weight, height, demographics, and disease history. Odds ratios (OR) and (95% confidence intervals) from logistic regression summarized the body mass index (BMI) and PSA test association while adjusting for socio-economic status (SES). RESULTS: BMI between 25 and 40 was significantly associated with recent PSA testing (past 12 months) (OR(25.0-29.9) = 1.23 (1.09, 1.39); OR(30-34.9) = 1.36 (1.18, 1.57); OR(35.0-39.9) = 1.44 (1.18, 1.76); OR(> or =40) = 1.15 (0.87, 1.51)). Prior severe disease diagnoses, such as heart disease, did not influence the obesity and PSA test association. However, adjustment for prior high blood pressure or high cholesterol diagnoses reduced the BMI-PSA testing associations. Physician PSA test recommendations were not associated with BMI, and results did not appreciably vary by race. CONCLUSIONS: Overweight and obese men were preferentially PSA tested within the past 12 months. BMI was not associated with physician screening recommendations. Data suggest that clinical diagnoses related to obesity increase clinical encounters that lead to preferential selection of obese men for prostate cancer diagnosis. This detection effect may bias epidemiologic investigations of obesity and prostate cancer incidence.

Adult↗

Power comparison of various sibship tests of association.

There are several tests available for use with family studies to test if there is significant evidence of association with a particular disease gene locus, especially of HLA. We have used large simulations to compare the powers of tests using criteria N, R, T, PR, WP and some new tests involving both affecteds and unaffecteds in a sibship. It was found that tests using both affected and unaffected siblings were often more powerful.

Genetic Diseases, Inborn↗