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Results for “multivariate analysis”

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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↗

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↗

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↗

PubMed1989

Multivariate analysis of aminoglycoside levels in hemodialysis patients.

Multivariate discriminant analysis was performed on data for 50 consecutive hemodialysis patients who had received aminoglycoside treatment because of severe bacterial infections. The 10 of the 60 clinical parameters considered to be most important were survival of patients (28/50 patients), success of treatment (27/50 patients), acute or chronic renal failure (15 vs. 35), age (54 +/- 17 years), creatinine level (675 +/- 298 mumol/l), artificial ventilation (21/50 patients), need for catecholamines (19/50 patients), continuous arteriovenous hemofiltration (9/50 patients), duration of therapy (12 +/- 8 days) as well as aminoglycoside peak (7.5 +/- 2.7 mg/l) and trough levels (3.6 +/- 1.3 mg/l). The 4 of the 10 parameters investigated by multivariate analysis significantly contributing to survival of patients were clinical success of aminoglycoside treatment (p = 0.0001), no need for catecholamines (p = 0.0001), duration of dosage (p = 0.003) and aminoglycoside peak levels (p = 0.009).

Adolescent↗

PubMed1990

[Preoperative discrimination between benign and malignant ovarian tumors by multivariate analysis].

To obtain a precise preoperative diagnosis of benign and malignant ovarian tumors, multivariate analysis was performed using a combination of tumor markers, diagnostic imagings, clinical findings and epidemiological data. Twenty-eight factors were selected for a discriminant analysis, which included 10 factors for tumor markers, 8 for diagnostic imagings, 4 for clinical features and 6 for epidemiological data. On 235 patients (malignant: 100, benign: 135), the usefulness of the discriminant analysis was evaluated retrospectively. As a results, an accuracy of preoperative discrimination was 82% for a discriminant analysis of tumor markers alone, 91% for diagnostic imagings, 84% clinical findings and 65% for epidemiological data. Twenty-one factors were selected by chi-square test or T-test. When 21 factors were used, the sensitivity and the specificity for the diagnosis of malignant ovarian tumor were 98% and 88% respectively. The results indicate that the discriminant analysis is valuable for preoperative discrimination of patient with ovarian tumors.

Adolescent↗

PubMed1995

Multivariate analysis of prognostic factors in 75 patients with soft tissue sarcoma.

The results of 75 patients with soft-tissue sarcomas treated by the combination of local surgical excision plus postoperative radiotherapy are reported. Thirty-five tumors were situated in the extremities, 32 in the trunk, and eight in the head and neck. Twenty-eight tumors were high grade, 33 intermediate and 14 low grade. Sixty-two patients had complete resections (wide or marginal) and 13 incomplete resections (intralesional). Radiation was administered with a shrinking-field technique (median total dose, 64 Gy; range, 50-78). Twenty-five patients developed local recurrence (33%). The 5-year local control rate was 67%. On univariate analysis, a tumor site other than extremity (p < 0.05), unfavorable histology (p < 0.01), and incomplete resection (p < 0.01) were poor risk factors for local recurrence. When multivariate analysis were performed, only incomplete resection (relative risk (RR) 7.2) remained a poor risk factor. The 5-year overall survival rate was 50.5% for the entire group. Following a univariate analysis of host tumor and treatment-related factors, a tumor site other than extremity (p < 0.05), high tumor grade (p < 0.01) unfavorable histology (p < 0.05), and incomplete tumor resection (p < 0.01) were found to significantly increase the risk of further tumor death. Multivariate analysis found high tumor grade (RR 5.6), and incomplete resection (RR 7) to be independent poor risk factors for survival.

Adult↗

PubMed1992

The prognosis of medical coma in Ibadan: results of multivariate analysis.

During a recent prospective investigation of 116 children with medical coma in Ibadan, 52 (45%) survived intact, 23 (20%) developed residual neurological deficits and the remaining 41 (35%) died. This series is concerned with the use of multivariate analysis in predicting outcome of medical coma in an individual patient, based mostly on clinical information (27 variables) obtained within 12 hours of admission. Stepwise logistic regression analysis revealed that only 17 of the 27 variables have independent significance in predicting outcome. When discriminant analysis was performed on these 17 variables so as to obtain a classification function of outcome (survived intact, survived with deficits and dead), 92% of the cases were correctly classified. Eight children were, however, seriously misclassified. These were four intact survivors and four dead cases who were classified as dead and survived without neurological sequelae, respectively. These results suggest that multivariate analysis of clinical and laboratory information obtained in the comatose state can provide predictive information.

Adolescent↗

PubMed1989

[The prognosis of thrombocytopenic purpura using predictive criteria evaluation by multivariate analysis methods].

The development of predictive systems with the resources of multivariate analysis let us to do gradually a more objective medicine. In this study we correlate a set of characteristics observed in 39 patients with thrombocytopenic purpura during the first week of medical treatment against the score of severity of the whole purpuric disorder, evaluated a the 25 week of evolution. It was accomplished with a model of multiple logistic regression of successive steps which let us to get the weights of each one of the indicants in order to predict the severity of the whole hemorrhagic diathesis. Probably the more significative indicants of severity are intracranial bleeding, profuse nasal and vaginal bleeding, profuse petechial bleeding and the presence of hematomas.

Adolescent↗

PubMed1991

A multivariate analysis of risk factors for preeclampsia.

OBJECTIVE: --To determine, in a multivariate analysis, risk factors for preeclampsia that could be observed early in pregnancy and to establish whether these risk factors are different for nulliparas and multiparas. DESIGN: --A case-control study of preeclampsia. SETTING: --Women who gave birth at Northern California Kaiser Permanente Medical Centers in 1984 and 1985. PARTICIPANTS: --Preeclamptic cases (n = 139) were determined from discharge diagnosis of severe preeclampsia and by confirmation of blood pressures and proteinuria from medical records. Controls (n = 132) were randomly selected women who had no discharge diagnosis of any hypertensive disorder of pregnancy and who had no evidence of hypertension or proteinuria from medical record review. MAIN VARIABLES EXAMINED: --Medical records were abstracted for information regarding maternal age, race, previous pregnancy history, family medical history, socioeconomic status, employment during pregnancy, body mass, and smoking and alcohol consumption. RESULTS: --Multiple logistic regression analyses confirmed that case patients were more likely than control patients to be nulliparous (adjusted odds ratio [OR], 5.4; 95% confidence interval [Cl], 2.8 to 10.3) and that preeclampsia in a previous pregnancy greatly increased the risk in a subsequent one (adjusted OR, 10.8; 95% Cl, 1.2 to 29.1). However, regardless of parity, preeclamptic women were also more likely to be of high body mass (adjusted OR, 1.7; 95% Cl, 1.2 to 6.2), to work during pregnancy (adjusted OR, 2.1; 95% Cl, 1.1 to 4.4), and to have a family history of hypertension (adjusted OR, 1.7; 95% Cl, 0.92 to 3.2). Having a previous history of a spontaneous abortion was protective but only in multiparous women (adjusted OR for multiparas, 0.09; 95% Cl, 0.02 to 0.48). In contrast, being black was a significant risk for preeclampsia but only in nulliparous women (adjusted OR for nulliparas, 12.3; 95% Cl, 1.6 to 100.8). CONCLUSIONS: --There are a number of risk factors for preeclampsia that may be determined early in a woman's pregnancy. Multiparas and nulliparas share certain risk factors but not others. A cohort investigation is needed to determine the ability of these risk factors to predict who develops preeclampsia.

Adult↗

PubMed1986

[Prognostic evaluation of patients surviving acute myocardial infarct: univariate and multivariate analysis].

The relationship between 31 variables and survival after acute myocardial infarction was evaluated in 432 patients discharged from our Coronary Care Unit from 1975 to 1984. The patients were followed for 1 to 105 months and either univariate and multivariate analysis were performed. For end-point death the significant variables (p less than 0.05) selected by the univariate analysis were: age, diabetes, smoke, heart rate at recovery, supraventricular arrhythmias, cardiac failure and complex ventricular arrhythmias either during recovery, either after discharge and finally spontaneous angina after hospital discharge. Meanwhile, for the end-point cardiac death age, smoke and supraventricular arrhythmias were not yet significant while arterial pressure at recovery and effort angina after hospital discharge were. Multivariate analysis identified cardiac failure during recovery, diabetes, complex ventricular arrhythmias before and spontaneous angina after discharge as independent variables contributing to total mortality: effort angina was a further significant one relatively to cardiac death. Thus, our study points out the importance of multivariate survival analysis when evaluating the relationship between survival after discharge for the effect of other prognostic factors. Moreover, providing identification of high risk cohorts permits appropriate interventions designed to lessen risk.

Adult↗

PubMedDate not supplied

Multivariate analysis of risk factors influencing survival in 110 ethnic Chinese with papillary thyroid cancer.

Data from 110 Chinese patients presenting with papillary thyroid cancer to a single institution up to December 1985 have been analyzed to evaluate the possible risk factors affecting survival. There were 83 women and 27 men with an age range of 15 to 78 years (mean 45 years, median 42 years). The longest follow-up period is 39 years and the median 10 years. Cervical lymph node recurrence more than 6 months after surgery developed in 12 patients, of whom 1 died with a concomitant distant metastasis. "Thyroid bed" tumor recurrence, after apparently complete surgery, presented in 10 patients and resulted in 5 deaths. Distant metastases were identified in 17 patients with 7 deaths. Another 4 patients died from advanced local disease incompletely resectable on presentation. The following seven risk factors for survival were selected for multivariate analysis: age, sex, tumor size, histologic evidence of extrathyroidal spread, lymph node recurrence, neck recurrence, and distant metastases. Age, size, neck recurrence, and distant metastases were all significant on univariate analysis. Using Cox proportional hazards regression in the multivariate analysis of these seven factors, only age (p < 0.0001) was shown to be significant. Age over 40 years on first diagnosis was a highly significant indicator of high risk (p = 0.0003, log-rank).

Adolescent↗

PubMed1994

Affiliations among steroid receptors as revealed by multivariate analysis of steroid binding data.

To illustrate the informative value of descriptive multivariate analysis in biochemical screening, we have analyzed several data matrices relating to the binding of steroids to the estrogen, progestin, androgen, glucocorticoid and mineralocorticoid receptors in different organs and species. We first compared dendrograms of steroid hormone receptors, that were obtained by an automatic hierarchical classification analysis of the binding data, to published phylogenetic trees of nuclear receptors based on amino-acid sequence analysis. The former classification describes the affiliations among the receptors as given by the binding specificity of a population of 187 steroids in a traditional cytosol binding assay (an indirect comparison of ligand binding sites); the latter describes the affiliations among the receptors as given by a comparison of selected primary sequences involved in ligand-dependent regulation of transactivation and dimerization. A similar hierarchical classification was also performed on the binding data of 62 steroids to myometrium cytosol from different species in order to show to what extent the progesterone-binding proteins in these species are affiliated. Hierarchical clustering methods classify each type of variable (receptor or steroid) independently. In order to be able to correlate both types of variable (receptors and steroids) on single-display graphs, it is necessary to resort to correspondence factorial analysis (CFA). CFA ranks the information content within the experimental system, highlighting major correlations and disclosing secondary correlations by eliminating redundant information and background noise. This multivariate method, applied to the analysis of published data, illustrated the particular specificity of estrogen binding in human vagina and raised the question of the nature of the binding protein in this tissue. Our examples are based on small data tables that can and have been analyzed de visu. However, it is certain that such descriptive multivariate techniques are indispensable for the analysis of large data banks not only to define structure-activity relationships but to estimate the degrees of affiliation among the biological variables being measured. Knowledge of such affiliations will help to organize available information in a context where the complexity of the biological systems under study is becoming increasingly apparent.

Animals↗

PubMed1992

Multivariate analysis of dietary habits in 931 elderly Japanese males: smoking, food frequency and food preference.

To define the influence of smoking on dietary patterns and food preference in elderly Japanese, a mail survey was conducted on about 3000 subjects aged 65 years and older. A multivariate analysis of dietary frequency data regarding 15 food items on 931 male respondents suggested that frequency of intake of plant food, including vegetables and fruits, was lower in smokers than in nonsmokers. Another multivariate analysis of food preference data regarding 18 food items on the same subjects suggested that smoking decreased the desire for plant food.

Aged↗

PubMed1995

Valve repair improves the outcome of surgery for mitral regurgitation. A multivariate analysis.

BACKGROUND: Mitral valve repair has been suggested as providing a better postoperative outcome than valve replacement for mitral regurgitation, but this impression has been obscured by differences in baseline characteristics and has not been confirmed in multivariate analyses. METHODS AND RESULTS: The outcomes in 195 patients with valve repair and 214 with replacement for organic mitral regurgitation were compared using multivariate analysis. All patients had preoperative echocardiographic assessment of left ventricular function. Before surgery, patients with valve repair were less symptomatic than those with replacement (42% in New York Heart Association functional class I or II versus 24%, respectively; P = .001), had less atrial fibrillation (41% versus 53%; P = .017), and had a better ejection fraction (63 +/- 9% versus 60 +/- 12%, P = .016). After valve repair, compared with valve replacement, overall survival at 10 years was 68 +/- 6% versus 52 +/- 4% (P = .0004), overall operative mortality was 2.6% versus 10.3% (P = .002), operative mortality in patients under age 75 was 1.3% versus 5.7% (P = .036), and late survival (in operative survivors) at 10 years was 69 +/- 6% versus 58 +/- 5% (P = .018). Late survival after valve repair was not different from expected survival. After surgery, ejection fraction decreased significantly in both groups but was higher after valve repair (P = .001). Multivariate analysis indicated an independent beneficial effect of valve repair on overall survival (hazard ratio, 0.39; P = .00001), operative mortality (odds ratio, 0.27; P = .026), late survival (hazard ratio, 0.44; P = .001), and postoperative ejection fraction (P = .001). CONCLUSIONS: Valve repair significantly improves postoperative outcome in patients with mitral regurgitation and should be the preferred mode of surgical correction. The low operative mortality is an incentive for early surgery before ventricular dysfunction occurs.

Aged↗

PubMed1994

[Pathophysiology of infantile hydrocephalus: studies with multivariate analysis].

We investigated factors relating to intellectual outcome in 21 patients with infantile hydrocephalus. Every patient had received V-P shunt operation before, and was followed up for at least one year. The intellectual development was evaluated with multivariate analysis, and was found to be contributed independently by etiology of hydrocephalus, age at onset, association of epilepsy, and shunt troubles. Thus, those with congenital hydrocephalus, onset after the neonatal period, epilepsy or shunt troubles were related to poor intelligence, while those with acquired hydrocephalus, onset during the neonatal period, and without epilepsy were related to favorable outcome. Among the patients, early onset was correlated with early surgical intervention, which also may have been a determining factor. We also conducted multivariate analysis with the results of somatosensory evoked potentials (SEPs) and visual evoked potentials (VEPs) as objective variables. For both SEPs and VEPs, etiology was considered to be the most important, but other factors also contributed considerably, including CT scan findings, current developmental status, and association of congenital anomalies and epilepsy. Clinical pictures of patients with infantile hydrocephalus apparently are very complicated, being determined by multiple factors, but these cerebral evoked potentials are thought to be useful in the evaluation and follow-up of the patients with infantile hydrocephalus.

Evoked Potentials, Somatosensory↗