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Risk assessment of pulmonary embolism by multivariate analysis.

A prospective study of 6,527 hospitalized patients was performed to evaluate the effectiveness of multivariate analysis of risk factors to correctly designate risk for pulmonary embolism. History of previous pulmonary embolism was the single most important factor. In patients without prior history, five factors emerged: inactivity, congestive heart failure, Doppler ultrasound evidence of deep-vein occlusion, female sex, and black race. Used together, these factors permitted a discrimination of risk such that 68.7% of pulmonary embolization was found to occur in 32.2% of the population designated as showing increased risk. Multivariate analysis of clinical factors improved assessment of risk, compared to the use of lower extremity findings alone, and proved to be useful in identifying individuals at increased risk for pulmonary embolism.

Analysis of Variance

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

[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

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

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

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

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

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

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

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

[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

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

[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

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

[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

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

Relationships among the symptoms of the elderly as revealed by multivariate analysis: a preliminary study.

One hundred and sixty-eight elderly subjects in a geriatric hospital and the adjoining nursing home were examined in a study of relationships among the items of Hasegawa's dementia scale. A three-dimensional model using multivariate analysis demonstrated the relationships among items. The results led to the identification of six clinical groups determined by the presence of stroke and the score on the dementia scale. Nonstroke subjects of middle intellectual level had disturbances of memory and orientation. This group fell into two categories during the course of a five-year follow-up study: severe dementia and intellectual deterioration. Retrospective multivariate analysis results suggested that features characteristic of the severe intellectual deterioration group were earlier disturbances of orientation and distant memory. This statistical method uses only objective clinical data in order to avoid subjective and, often, biased judgments.

Aged

Multivariate analysis of postoperative complications after esophageal resection.

To determine the contributing factors for eight postoperative complications after esophagectomy through a right thoracoabdominal approach, a multivariate analysis was carried out on preoperative and intraoperative variables in 141 patients with thoracic esophageal cancer. Although postoperative complications occurred in 125 patients, only 7 died of such complications. The multivariate analysis indicated that the retrosternal route was a significant factor predisposing to postoperative atelectasis. Age, preoperative arterial oxygen tension, and volume transfused were significant factors predisposing to postoperative hypoxemia, whereas age, routes other than the intrathoracic route, and volume transfused were significant factors predisposing to prolonged respiratory support. In addition, preoperative total serum bilirubin level and volume transfused were significant factors predisposing to postoperative hyperbilirubinemia; preoperative serum creatinine level was a significant contributing factor for postoperative renal insufficiency; and sex, antesternal route, and substituted colon were significant contributing factors for anastomotic leakage. There were no significant factors predisposing to postoperative pneumonia and liver dysfunction. These significant factors should be taken into consideration not only during perioperative management but also when choosing the operative procedures and extending the surgical indication for esophagectomy through a right thoracoabdominal approach.

Age Factors