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Results for “multivariate analysis”

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PubMed1994

A multivariate analysis of repeated measures: linkage of the albinism gene (Tyr) to a QTL influencing ethanol-induced anesthesia in laboratory mice.

We propose the use of multivariate analysis of variance in order to address linkage relationships between a genetic marker and a phenotype that is specified by multiple variables. Moreover, enhanced power of a linkage model that simultaneously accounts for environmental factors is demonstrated in the present study. This strategy was used to establish linkage of a quantitative trait locus influencing ethanol-induced anesthesia to the albinism gene (Tyr) in mouse. This approach, which can be implemented immediately with most statistical packages, provides the extreme flexibility of multivariate analysis of variance for analyzing complex questions of linkage regarding either animal or human research paradigms.

Albinism↗

PubMed1996

Risk factors for central nervous system involvement in non-Hodgkins-lymphoma--a multivariate analysis.

A consecutive cohort of patients with NHL was examined to identify the factors predictive of CNS-involvement with Cox's proportional hazards model in a multivariate analysis. Twenty-seven cases of CNS-involvement were found among 498 patients with NHL. Only 3 of 96 patients with low-grade lymphomas had CNS involvement, all occurring after transformation into high-grade lymphoma. In univariate analysis of 402 patients with intermediate or high-grade lymphoma, lymphoblastic histology (including Burkitt's lymphoma), age <35 years, B-symptoms, stage IV disease, testis involvement and bone marrow involvement were found to be statistically significant risk factors. Lymphoblastic histology was found to be strongly correlated to age younger than 35 years. In the multivariate analysis only lymphoblastic histology, stage IV disease and B-symptoms were found to be significantly associated with CNS involvement. It is concluded that CNS prophylaxis should be considered in all patients with lymphoblastic histology and in patients with stage IV B lymphomas other than those of low-grade types.

Actuarial Analysis↗

PubMedDate not supplied

Differential diagnosis of Krukenberg tumors using multivariate analysis.

AIMS AND BACKGROUND: Krukenberg tumors are ovarian metastases from a gastroenteric malignancy in 90% of cases. At present, diagnostic imaging techniques (US, CT, MRI) do not provide any reliable diagnostic criteria to differentiate these metastases from ovarian primaries. We tried to use multivariate analysis to distinguish malignant ovarian primaries from Krukenberg tumors based on their differential natural history. PATIENTS AND METHODS: We retrospectively compared the CT findings of Krukenberg tumors (47 patients, 79 masses, only from gastroenteric malignancy) with CT findings of primary epithelial ovarian cancers (46 patients, 67 masses). We compared the same independent variables in the two groups: age, morphology, margins, carcinomatosis, bilateral versus unilateral involvement, ascites, lymph node involvement, metastases on the basis of multivariate analysis. RESULTS: According to the best fitted model, clear-cut margins (OR: 3.75; 95% CI: 1.14-9.72) and the presence of carcinomatosis (OR: 4.21; 95% CI: 1.51-11.72) were the strongest predictors of a diagnosis of Krukenberg tumor. In contrast, the presence of ascites was more likely to be a protective factor (OR: 0.22; 95% CI: 0.08-0.62). CONCLUSIONS: We can try to make a differential diagnosis between a metastatic lesion from the gastroenteric tract and a primary adnexal lesion based on the multivariate statistical analysis of intraperitoneal spread of the different types of cancer rather than on morphologic findings at CT.

Adolescent↗

PubMed1989

Prognostic value of histologic grade nuclear components of Scarff-Bloom-Richardson (SBR). An improved score modification based on a multivariate analysis of 1262 invasive ductal breast carcinomas.

We did a multivariate analysis of 1262 patients with operable, invasive ductal breast carcinoma to assess the prognostic value of the Scarff-Bloom-Richardson (SBR) histologic grading system. Nodal metastasis and SBR were the two most important factors for metastasis-free survival (MFS), P = 10-9 and P = 10-5, respectively, for total study time. In patients who were node negative, the SBR and International Union Against Cancer (UICC) stages were the most important for MFS (P = 4 X 10-4 and P = 0.03). In order to try to improve the SBR prognostic value, we first studied the three components of the SBR separately: ductoglandular differentiation proved the least predictive and nuclear pleomorphism and mitotic index the most predictive. A rearrangement of the two nuclear scores alone produced higher risk values and better risk separation of patient subpopulations than SBR, and eliminated the SBR from the multivariate model. This rearrangement, modified SBR (MSBR), defined five new risk subgroups with statistically different risk ratios for MFS (P = 3 X 10-8). SBR grade II (55% of patients) was separated into three MSBR groups significantly different according to MFS (P = 0.008). In the patients who were node negative, MSBR replaced the SBR and was the most important factor for prediction of relapse of MFS (P less than 0.00001). The MSBR is more accurate and predictive than the standard SBR grade and is particularly useful when the nodal status of the patient is negative or unknown.

Adult↗

PubMedDate not supplied

[Multivariate analysis of aminoacyl-tRNA synthetase activities of liver and hepatomas (author's transl)].

Data on the aminoacyl-tRNA synthetase activities in normal liver and in three transplantable rat hepatomas, viz Yoshida's AH 130 and Morris's 5123C and 7793, were studied by means of factor analysis, a powerful technique of multivariate analysis particularly suitable foridentifying factors which theoretically may account for the pattern of interrelations between several variables. The analysis has been performed on 51 patterns of enzyme activities, covering 17 out of the 20 aminoacyl-tRNA synthetases; 80% on average of the total variability of the 17 enzyme activities may be accounted for by the first 4 factors extracted. The enzymes seem to fall into different groups, depending on their relationship with the factors thus identified. The results suggest that enzymes belonging to the same group share a common control mechanism, and are independent of the enzymes belonging to different groups, both in normal liver and in hepatomas.

Amino Acyl-tRNA Synthetases↗

PubMed1995

[Multivariate analysis of spinal automatism in neurological diseases].

We investigated the relationship between spinal automatism (SA) and other neurological signs and symptoms (pyramidal, extrapyramidal, cerebellar, autonomic) by multivariate analysis in cervical spondylotic myelopathy (CSM) 112 cases, amyotrophic lateral sclerosis (ALS) 121 cases, and multiple system atrophy (MSA) 115 cases (olivo-ponto-cerebellar atrophy (OPCA) 55 cases, Shy-Drager syndrome (SDS) 42 cases, striato-nigral degeneration (SND) 18 cases). SA elicitation maneuver we used was pinprick stimulation at the dorsal pedal skin, and all cases showed twitched or phasic triple flexion pattern. As SA was elicited in 19 cases in CSM (17.0%), 23 cases (19.0%) in ALS, 36 cases (31.3%) in MSA, SA was more elicited in MSA than in ALS and CSM (p < 0.05, p < 0.01 by chi-squared test). In MSA, SA tended to be elicited more likely in SDS (21 cases, 50.0%) and in SND (8 cases, 44.4%) than in OPCA (7 cases, 12.7%) (p < 0.01 by chi-squared test). In MSA, the longer the duration of the disease became, the more SA was elicited, but not in ALS and CSM. Multivariate analysis (quantification method type II) showed that clinical signs as a statistical contribution factor for SA elicitation ranked Babinski's sign, micturition disturbance in ALS and CSM and Babinski's sign, orthostatic hypotension in MSA in order: In all 3 diseases, Babinski's sign and autonomic disturbance ranked higher. This conclusion suggested that SA was not always related to the pyramidal tract damage and was associated with the damage of small myelinated fibers in and/or around the pyramidal tract.

Adult↗

PubMed1995

A multivariate analysis of childhood abdominal pain in Trinidad.

This is a multivariate analysis of the data recorded in assessing 1158 consecutive admissions presenting to a children's surgical ward with acute abdominal pain. There were 56 binary variables available for entry into the analysis. A statistical software package was used to perform a stepwise discriminant analysis on the data. The program selected 18 variables as having discriminating power in assigning patients to the six diagnostic groups. In order of discriminating power these were, mainly, a positive urine culture, the bowel history, the findings on rectal examination, the location of abdominal tenderness, the presence of a mass, and the white cell count. Lesser discriminating potential was assigned to the presence of dehydration; fluid levels on erect abdominal films, a rise in temperature, an increased pulse rate, the presence of urinary symptoms, and the general appearance of the child. Use of these data led to an overall correct classification of 80.7% of cases. It is concluded that these variables should be included in the assessment of children with acute abdominal pain.

Abdomen, Acute↗

PubMed1988

Multivariate analysis for histologic prognostic factors in soft tissue sarcomas.

To investigate histologic prognostic factors in soft tissue sarcomas (STS), multivariate analysis was performed on 236 patients with complete clinical information. These included 141 males and 95 females with an age range from 1 to 85 years (median, 47.6 years). Histologically, malignant fibrous histiocytoma (33.5%) was the most common type followed by synovial sarcoma (11%), liposarcoma (10%), rhabdomyosarcoma (7%), and leiomyosarcoma (7%). Monofactorial analysis revealed that sex, depth, location, histologic grade, cellularity, frequency of mitosis, and necrosis were significant prognostic factors. By multivariate analysis, only frequency of mitosis and depth of tumors were proved to be of prognostic significance. The prognostic importance of the frequency of mitosis as shown in previous and the present studies indicates that further investigation of the cell proliferation in patients with STS is required.

Age Factors↗

PubMed1990

Prognostic risk factors for graft failure following pancreas transplantation: results of multivariate analysis of data from the International Pancreas Transplant Registry.

A multivariate analysis of prognostic factors for graft failure was performed on patients in the International Pancreas Transplant Registry. The analysis was restricted to the period January 1978 to June 1987 and included 764 patients. All patients had at least 1 year of follow-up. The following variables were studied: transplant year, continent (N. America, Europe, others), type of donor (cadaver, living related mismatched, living related HLA-identical), donor mismatch at the HLA A, B loci, donor mismatch at the DR loci, preservation time, kidney association (pancreas transplant alone, simultaneous pancreas and kidney transplant, pancreas after kidney transplant), whole versus segmental pancreatic transplant, graft duct management technique (polymer injection, enteric drainage, stomach drainage, bladder drainage), and immunosuppression. By stepwise, logistic regression analysis, we found that the following factors were predictive for 1-year graft function: donor mismatch at the DR loci (P = 0.0003), kidney association (P less than 0.0001), type of donor (P = 0.04), and immunosuppression (P = 0.0002). For donor mismatch at the DR loci, we found an odds ratio for success of 2.2 for 0 versus 2 mismatches. The odds for success were 2.9 for simultaneous pancreas and kidney transplant versus pancreas transplant alone. The best results--79% 1-year graft survival--were obtained for the combination of 0 mismatches at the DR loci, pancreas after kidney transplant, living related HLA-identical donor, and the immunosuppressive regimen consisting of cyclosporin, azathioprine, and prednisone. Patients receiving a pancreas transplant alone with 0 mismatches at the DR loci, living related HLA-identical donor, and triple immunosuppressive regimen had a predicted 1-year graft survival of 71%.

Graft Rejection↗

PubMed1992

Hypothyroidism following radiotherapy for head and neck cancer: multivariate analysis of risk factors.

The incidence of hypothyroidism following radiotherapy for head and neck cancer is 10-45% in several series. In order to identify possible risk factors a multivariate analysis was performed in 221 patients previously treated with either radiotherapy alone or combined with surgery or chemotherapy. Diagnostic procedures included: total T3 and T4, free T4 and TSH measured by radioimmunoassay, and thyroid scintigraphy. The absolute rate of hypothyroidism was 41.17% (subclinical 26.24%, clinical 14.93%). No thyroid nodules were detected in any patient. By multivariate analysis, risk factors that significantly influenced a higher incidence of hypofunction were: high radiation dose (p = 0.000), combination of radiotherapy and cervical surgery (p = 0.003), time from therapy (p = 0.022) and no shielding of midline (p = 0.026).

Cobalt Radioisotopes↗

PubMed2003

Improved accuracy in estimation of left ventricular function parameters from QGS software with Tc-99m tetrofosmin gated-SPECT: a multivariate analysis.

UNLABELLED: The purpose of this study was to verify whether the accuracy of left ventricular parameters related to left ventricular function from gated-SPECT improved or not, using multivariate analysis. METHODS: Ninety-six patients with cardiovascular diseases were studied. Gated-SPECT with the QGS software and left ventriculography (LVG) were performed to obtain left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV). Then, multivariate analyses were performed to determine empirical formulas for predicting these parameters. The calculated values of left ventricular parameters were compared with those obtained directly from the QGS software and LVG. RESULTS: Multivariate analyses were able to improve accuracy in estimation of LVEF, EDV and ESV. Statistically significant improvement was seen in LVEF (from r = 0.6965 to r = 0.8093, p < 0.05). Although not statistically significant, improvements in correlation coefficients were seen in EDV (from r = 0.7199 to r = 0.7595, p = 0.2750) and ESV (from r = 0.5694 to r = 0.5871, p = 0.4281). CONCLUSION: The empirical equations with multivariate analysis improved the accuracy in estimating LVEF from gated-SPECT with the QGS software.

Adolescent↗

PubMed1997

[Multivariate analysis of the problems of long-term levodopa therapy in Parkinson's disease].

We investigated clinical features of adverse reactions to long-term levodopa therapy by the multivariate analysis. Dyskinesia, wearing off effect, on-off effect, mental symptoms, and frozen gait were noted in 29 (11.2%), 78 (30.0%), 17 (6.5%), 45 (17.7%), and 52 (20.0%), respectively, of 260 patients with Parkinson's disease to whom levodopa had been administered for over one year. In the statistical investigation by the multivariate analysis (quantification method type II), the age of initial levodopa therapy, the duration from the onset to the initiation of levodopa therapy, and the duration of levodopa therapy were not closely related to the development of any adverse reaction, while Hoehn & Yahr's stage and the dosage of levodopa had the most significant influence on the development of adverse reactions. Furthermore, concomitant use of amantadine hydrochloride produced an inhibitory effect on the development of dyskinesia. We conclude that early institution of levodopa therapy in Parkinson's disease may not be an important risk factor of adverse reactions.

Adult↗

PubMed2003

Factors affecting mortality in generalized postoperative peritonitis: multivariate analysis in 96 patients.

Mortality of generalized postoperative peritonitis remains high at 22% to 55%. The aim of the present study was to identify prognostic factors by means of univariate and multivariate analysis in a consecutive series of 96 patients. Mortality was 30%. Inability to clear the abdominal infection or to control the septic source, older age, and unconsciousness were significant factors related to mortality in the multivariate analysis. Failure to control the peritoneal infection (15%) was always fatal and correlated with failed septic source control, high Acute Physiology and Chronic Health Evaluation (APACHE) II score, and male gender. Failure to control the septic source (8%) also was always fatal and correlated with high APACHE II score and therapeutic delay. In patients with immediate source control, residual peritonitis occurred in 9% after purulent or biliary peritonitis and in 41% after fecal peritonitis ( p = 0.002). In patients without immediate control of the septic source, delayed control was still achieved in 100% after a planned relaparotomy (PR) strategy versus 43% after an on-demand relaparotomy (ODR) strategy ( p = 0.018). In the same patients, mortality was 0% in the PR group versus 64% in the ODR group ( p = 0.007). Early relaparotomy is related to improved septic source control. After relaparotomy for generalized postoperative peritonitis, a PR strategy is indicated whenever source control is uncertain. It also might decrease mortality in fecal peritonitis. An ODR approach is adequate for purulent and biliary peritonitis with safe septic source control.

Adolescent↗

PubMed1980

Evaluation by multivariate analysis of changes in systolic time intervals during exercise in the supine and upright positions.

In this study multivariate analysis was adopted to establish how simultaneous changes in heart rate (HR), blood pressure (BP) and work load (W) can affect systolic time intervals (STI). Thus, 13 normal volunteers underwent two consecutive exercise stress tests in the supine and upright position on a bicycle ergometer. By multivariate analysis it was shown that, while in the supine position left ventricular ejection time (LVET) is influenced by HR and W (LVET) = 330.6 - 0.76 HR - 0.41 W, F = 224, P is less than 0.001), in the upright position LVET changes are due only to HR variations (LVET = 309 - 0.88 HR, P is less than 0.001). Pre-ejection period (PEP) in both positions is related to HR and W, but this latter has a non-linear influence (supine: PEP = 110.9 - 0.15 HR -0.34 W + 0.0012 W(2), F = 56.4, P is less than 0.001; upright: PEP = 119 - 0.16 HR - 0.5 W + 0.0025 W(2), F = 86.7, P is less than 0.001). Finally, PEP/LVET ratio is correlated both in the supine and upright position with maximal BP, HR and W; however, the influence of HR and BP is different in the two positions (supine: PEP/LVET = 0.259 + 0.00047 BP + 0.00068 HR - 0.00167 W + 0.000013 W(2), F = 5.68, P is less than 0.01; upright: PEP/LVET = 0.201 + 0.0011 HR - 0.00371 W + 0.00016 W(2), F = 4.79, P is less than 0.01).

Adolescent↗

PubMedDate not supplied

Clinical stage I and II endometrial carcinoma: multivariate analysis of prognostic factors.

In 221 patients with FIGO stage I and II endometrial carcinoma, the impact on survival of age at diagnosis, menopausal status, FIGO stage, myometrial invasion, tumor grade and histology was evaluated by univariate and multivariate analysis. At a median follow-up of 50 months (range 45-210), 42 patients had died, and therefore overall survival was 81% (179/221). Univariate analysis showed that age, menopausal status and histology did not influence survival, whereas FIGO stage, myometrial invasion and tumor grade were important prognostic factors. Multivariate analysis showed that tumor grade had a significant and independent impact on survival and confirmed that FIGO stage is the most important parameter influencing survival.

Actuarial Analysis↗

PubMed1999

[Statistical analysis of localized non-Hodgkin's lymphomas of the head and neck--multivariate analysis of prognostic factors and evaluation of therapeutic modalities].

Prognostic factors and treatment outcome of 48 patients with Stage I (29) or II (19) non-Hodgkin's lymphoma of the head and neck were analyzed retrospectively. There were 26 males and 22 females, aged from 15 to 89 years old, with an average age of 57. The primary lesion was located in Waldeyer's ring in 25 patients, the nasal cavity and paranasal sinuses in 13, cervical lymph nodes in 8, and others in 2. Histologically, 2 had low grade lymphoma, 42 had intermediate grade disease, and 1 had high grade disease. The patients were treated with radiation alone (5 patients), chemotherapy according to a cyclophosphamide, doxorubicin, vincristine, prednisone- (CHOP) regimen (8 patients), or a combination of both treatments (35 patients). In univariate analyses, an unfavorable prognosis was associated with age > or = 60, Stage I disease, and extralymphatic lesion. Multivariate analysis showed that an extralymphatic lesion was a significant independent risk factor for death (p = 0.0093). The overall five-year survival rate was 73.5%. Differences in the treatment was not reflected in the outcome. Our results suggest that a combination of chemotherapy (CHOP) and radiation is an appropriate treatment for lymphatic stage I and II non-Hodgkin's lymphoma of the head and neck. However, more intensive therapy is necessary for patients with extralymphatic head and neck NHL.

Adolescent↗

PubMed1991

Multivariate analysis to simplify the differential diagnosis of broad complex tachycardia.

Univariate analysis has identified several criteria that aid the differential diagnosis of broad complex tachycardia. In this study of 102 consecutive patients multivariate analysis was performed to identify which of 15 clinical and 11 electrocardiographic variables were independent predictors of ventricular tachycardia. These were shown to be a history of myocardial infarction, the QRS waveforms in leads aVF and V1, and a change in axis from sinus rhythm to tachycardia of more than 40 degrees. If none of the criteria was met, the diagnosis was almost certainly supraventricular tachycardia. If one criterion was met the diagnosis was probably supraventricular tachycardia. If two criteria were met then the diagnosis was probably ventricular tachycardia. If three or four criteria were met, the diagnosis was almost certainly ventricular tachycardia. The predictive accuracy was 93%. This was increased to 95% by including two other criteria--definite independent P wave activity and ventricular extrasystoles with the same QRS configuration as that in tachycardia. These criteria were not included in the multivariate analysis because though they were 100% specific they were seldom seen. These four criteria can be used as simple rules in determining the origin of a broad complex tachycardia.

Diagnosis, Differential↗

PubMed1988

Applications of multivariate analysis in diagnostic cytology.

Three multivariate methods for structure simplification (cluster analysis, principal component analysis and factor analysis) and three multivariate methods for prediction (discriminant analysis, analysis of variance and regression analysis) are discussed and contrasted, along with basic descriptive statistics for multivariate data. These methods are only a subset of the multivariate methods currently in use, but include those that have thus far been applied in diagnostic cytology. Multivariate analyses provide a basis for describing and analyzing large complex data sets and, with the enormous amounts of data becoming available, their applications in many areas of diagnostic cytology must surely increase.

Cytological Techniques↗