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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

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

Papillary thyroid carcinoma: a multivariate analysis of prognostic factors including an evaluation of the p-TNM staging system.

OBJECTIVE: To analyse the prognostic factors in papillary thyroid carcinoma, and in particular to evaluate the accuracy of the pathological tumour, nodes, metastases (p-TNM) staging. DESIGN: Retrospective univariate and multivariate analysis. SETTING: University hospital in Norway. SUBJECTS: 167 patients who were operated on for papillary thyroid carcinoma between 1971 and 1985. Main outcome measures--Death of papillary thyroid carcinoma, and length of recurrence free survival. RESULTS: Male sex, increasing age, larger tumours, and spread of growth beyond the thyroid all independently increased the risk of dying of papillary thyroid carcinoma, whereas the period of recurrence free survival was influenced only by the presence of regional metastases and the patient's age. The age related p-TNM staging is suitable for predicting the likelihood of death, but is less accurate in the prediction of recurrence free survival. The age of 45 years is too low to be useful in predicting survival, especially in women. CONCLUSION: The identification of sex in the multivariate analysis as a strong independent predictor of death of papillary thyroid cancer suggests that the prognostic value of the age related p-TNM staging system could be improved if sex was adjusted for, and if a different age was used for men and women.

Adult

Radiotherapy in T1 laryngeal cancer: prognostic factors for locoregional control and survival, uni- and multivariate analysis.

From 1975 through 1985, 194 patients with T1 glottic, 37 patients with T1 supraglottic, and 3 patients with T1 subglottic cancer were treated with radiotherapy. Local control and ultimate locoregional control (after salvage surgery) was 91% and 97% for T1 glottic, 84% and 81% for T1 supraglottic, and 2/3 and 3/3, respectively for subglottic tumors. In uni- and multivariate analysis local control for glottic tumors was associated with extension of the tumor on the vocal cord (entire length of vocal cord vs others, p = 0.01) and continuation of smoking after therapy (yes/no, p = 0.03). No prognostic factor for local control was found in supraglottic tumors. However, regional control and survival were impaired by N stage (N0 vs N+, p less than 0.0005), local recurrence (yes/no, p less than 0.0005), and extension of the tumor (one supraglottic subsite vs more than one, p less than 0.05). Mild late complications were seen in 13% of patients without salvage therapy. Following univariate analysis, field size, fraction size (greater than 2 Gy), maximum tumor dose (greater than 70 Gy), age, post-treatment biopsy, and tumor site were associated with complication rate. Following multivariate analysis, site, fraction size, maximum tumor dose, and continuation of smoking after therapy were independent prognostic factors for mild late complications (mostly arytenoid edema).

Adult

Impact of neck dissection on survival in well-differentiated thyroid cancer: a multivariate analysis of 218 cases.

The management of cervical lymph node metastases in well-differentiated carcinoma of the thyroid has been highly controversial. In the Department of Surgery (II), Kanazawa University Hospital, the surgical management of cervical lymph node metastases in curable well-differentiated carcinoma of the thyroid has been changed from a conservative approach to an aggressive one since 1973. In order to determine whether an aggressive approach for cervical lymph node metastases is adequate, a retrospective multivariate analysis was carried out of 218 cases of well-differentiated thyroid cancer. The patients have been followed up from 5 to 30 years. Multivariate analysis was conducted following Cox's model. As for the results, the aggressive management of cervical lymph node metastases appeared to have an impact on survival. Furthermore, age and sex were confirmed to be important prognostic factors and a partial lobectomy was confirmed to be inadequate as a type of thyroidectomy.

Adenocarcinoma

[Effective evaluation of combination chemotherapy in stage I-II of non-Hodgkin's lymphoma--a comparison of treatment with multivariate analysis].

Sixty-one patients with non-Hodgkin's lymphoma (Stage I and II) were treated solely with radiotherapy or in combination with chemotherapy. A multivariate analysis was used to identify the prognostic factors that significantly affected the treatment outcome. The variables examined included: stage of disease, according to the Ann Arbor classification, sex, age, pathological criteria, according to the LSG, the presence or absence of systemic symptoms, the sites of disease involvement, the LDH, the bulk of the disease, and the combination chemotherapy. Variables achieving a p-value in the 0 to 0.10 range with a multivariate analysis for the overall survival were the stage of disease, the sites of the disease involvement, the bulk of the disease, and the combination chemotherapy. Finally, the overall survival was affected by bulk of the disease (p less than 0.01) and the combination chemotherapy (p less than 0.01). The 5-year survival rates were 84.4% for stage I and 50.7% for stage II. The survival rates were 47.5% for radiotherapy treatment alone and 75.3% for combination chemotherapy. It thus was concluded that combination chemotherapy was effective for treatment of stages I and II of non-Hodgkin's lymphoma.

Adolescent

Selection of patients for programmed ventricular stimulation: a clinical decision-making model based on multivariate analysis of clinical variables.

OBJECTIVE: This study was conducted to assess the utility of clinical variables in predicting the inducibility of sustained ventricular arrhythmias in a heterogeneous group of patients undergoing programmed ventricular stimulation. METHODS: Variables were considered in a simulated chronologic order to determine the incremental information added by the signal-averaged electrocardiogram (ECG) and left ventricular ejection fraction. All patients undergoing baseline programmed ventricular stimulation for induction of ventricular tachyarrhythmia during a 30-month period were included in the study. Fourteen historical, ECG, signal-averaged ECG and left ventricular wall motion variables were evaluated for their ability in predicting inducibility of a sustained ventricular arrhythmia, a "positive" event, at programmed ventricular stimulation. RESULTS: On univariate analysis of the clinical variables, comparison between patients with positive or negative results showed significant differences in 10 of the 14 clinical variables: major cardiac diagnosis, history of ventricular tachycardia, myocardial infarction by history or ECG, all five signal-averaged ECG variables, left ventricular ejection fraction and presence of left ventricular aneurysm. On multivariate analysis, five independent variables were determined to be important: history of ventricular tachycardia, historical or ECG evidence of myocardial infarction, history of loss of consciousness, filtered QRS duration on the signal-averaged ECG and left ventricular ejection fraction. However, with sequential multivariate analysis, a model based only on historical and conventional ECG data was found to do as well as a model that included signal-averaged ECG and left ventricular ejection fraction data. CONCLUSIONS: Routinely available noninvasive historical, ECG, signal-averaged ECG and left ventricular wall motion variables can be used to accurately predict the outcome of programmed ventricular stimulation. The majority of the predictive power was obtained with the routine model, using only historical and ECG data. The signal-averaged ECG and left ventricular wall motion analysis added no significant incremental information.

Aged

[Gastric adenocarcinoma surgically treated. A multivariate analysis of prognostic factors].

One hundred and twelve curatively resected gastric adenocarcinomas were studied retrospectively to appreciate the survival factors. Twenty different criteria (clinic, histologic and therapeutic parameters) were assessed using univariate and then multivariate analysis (semi parametric regression (COX's) model). Only three criteria were very important according to the multivariate analysis: 1) invasion of neighboring organs (p less than 0.006) with a relative risk score (RRS) of 4.26; 2) intravascular or intralymphatic tumor embols outside the tumor (p less than 0.004; RRS = 2.11); 3) invaded distal nodes (located at the origin of the vessels (p less than 0.04; RRS = 1.88). A prognosis index was described according to these results. A repartition of the patients in three prognostic groups according to these 3 criteria was proposed. Future, trials should consider these three different prognostic groups.

Adenocarcinoma

[A multivariate analysis of prognostic factors of spinocerebellar degenerations].

To clarify the factors relating to the prognosis of spinocerebellar degenerations (SCD), we performed a follow-up study on the survival of patients with Friedreich disease, familial spastic paraparasis, sporadic olivopontocerebellar atrophy (OPCA), hereditary OPCA of Menzel type, sporadic late cortical cerebellar atrophy (LCCA), cerebellar atrophy of Holmes type, Shy-Drager syndrome, striatonigral degeneration, dentatorubropallidoluysian atrophy, or Joseph disease. One hundred and forty-eight patients admitted to the Nagoya University Hospital during the period of 1976 to 1990 were dealt with. They had been followed-up for 15 years at longest through the medical records, or through the direct informations from the patients or their family members or both. In order to find factors influencing the survival of the patients, Kaplan-Meier method was used as the 1st step to construct the survival curve for each factor. These were calculated by generalized Wilcoxon test. Employing Cox's proportional hazard model, a multivariate analysis was then performed based on the factors which were shown significant in the 1st step. The multivariate analysis showed that the following four factors are related to the prognosis of SCD patients, i.e., lack of hereditary trait, existence of orthostatic hypotension, lack of walking disorder at onset, and lack of nystagmus on admission. Of these factors, the lack of hereditary trait had the most intimate relation to their poor prognosis. Therefore, these four factors are statistically informative to predict prognosis of each patient with SCD.

Adolescent

Multivariate analysis of the histopathologic prognostic factors of cervical cancer in patients undergoing radical hysterectomy.

Three hundred forty-five patients with invasive carcinoma of the uterine cervix, Stages Ib (211 patients) and II (134 patients), underwent radical hysterectomy and pelvic lymphadenectomy. The influence of histologic factors including histologic subtype, maximum depth of cervical stromal invasion, degree of stromal invasion, longitudinal tumor diameter, lymph-vascular space invasion, corpus invasion, parametrial invasion, vaginal invasion, and pelvic lymph node (PLN) metastases on survival were examined by multivariate analysis. Univariate analysis revealed that all the variables except corpus invasion and vaginal invasion were significant in survival (P less than 0.05). Among these variables, however, PLN metastases, histologic subtype, and longitudinal tumor diameter were identified as independent and significant prognostic factors by multivariate analysis using Cox regression models. The prognostic index (PI), defined by the model (an indicator of the patient's place in the prognostic spectrum), was able to divide the patients into three prognostic groups. The key factors in the definition of these groups were (1) squamous cell carcinoma, small tumor diameter, and no PLN metastases for the good prognostic group and (2) PLN metastasis in two or more node groups, adenocarcinoma with one positive PLN group, or squamous cell carcinoma with one PLN group and large diameter for the poor prognostic group. These prognostic findings could predict the prognosis more precisely than that of clinical staging.

Adult