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Results for “multivariate analysis”

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PubMedDate not supplied

[Early prognosis in chronic subdural hematomas. Multivariate analysis of 137 cases].

INTRODUCTION: In the literature there is evidence relating different factors such as age and preoperative clinical condition with prognosis in patients treated surgically for chronic subdural haematoma. OBJECTIVE: To clarify and quantify the magnitude of the factors which determine early prognosis (during hospital admission) of these patients. PATIENTS AND METHODS: We made a prospective study of 137 patients who had been operated on in our centre and found the relationship between different clinical and therapeutic variables with the clinical course and morbidity-mortality by means of multivariate and survival analysis. RESULTS: A high Markwalder functional score (3-4) is an independent factor of poor prognosis (OR = 13.15; CI 95% 6.1-28.4; p = 0.01), as is the presence of a coexisting coagulopathy (OR = 27.2; CI 95% 9.3-79.5; p = 0.01). Advanced age tended to increase the risk (OR = 1.104) but did not reach statistical significance (p = 0.0654). A multivariate logistic model, which included the functional score and presence of coagulopathy, correctly classified 94.7% of the cases studied. Analysis of survival showed two groups with different early mortality as a function of the Markwalder score (high: 3-4 and low: 0-1-2), which could be differentiated statistically (Log-Rank chi squared test: 3.95; p = 0.0468). CONCLUSIONS: The preoperative clinical state classified by functional scores and the presence of underlying coagulopathy are the main prognostic factors in chronic subdural haematoma during hospital admission. Advanced age is probably not in itself an independent factor for bad prognosis.

Aged↗

PubMed2006

Multivariate analysis of temporal descriptions of open-field behavior in wild-derived mouse strains.

The open-field test is a commonly used apparatus in many behavioral studies. However, in most studies, temporal changes of details of behavior have been ignored. We thus examined open-field behavior as measured by both conventional indices and 12 ethograms supported by detailed temporal observation. To obtain a broader understanding, we used genetically diverse mouse strains: 10 wild-derived mouse strains (PGN2, BFM/2, HMI, CAST/Ei, NJL, BLG2, CHD, SWN, KJR, MSM), one strain derived from the so-called fancy mouse (JFI), and one standard laboratory strain, C57BL/6. Conventional measurements revealed a variety of relationships: some strains did not show the hypothesized association between high ambulation, longer stay in the central area, and low defecation. Our ethological approach revealed that some behaviors, such as freezing and jumping, were not observed in C57BL/6 but were seen in some wild-derived strains. Principal component analysis which included temporal information indicated that these strains had varied temporal patterns of habituation to novelty.

Animals↗

PubMed1998

Multivariate analysis of objective vocal function.

No standard and valid multidimensional index of objective voice function has been developed that integrates the information generated from the multiple objective parameters of voice function. The goals of this research were 1) to identify important objective voice parameters and 2) to create a multidimensional voice function index by combining relevant parameters. We evaluated 97 dysphonic patients and 35 normal volunteers on 14 objective voice parameters. Three multidimensional voice indices were created and evaluated: 1) nonweighted univariate index, 2) weighted odds ratio index, and 3) weighted multivariate regression index. The univariate index required all 14 parameters, while the odds ratio and logistic regression models required only 4 parameters (frequency range, airflow at lips, maximum phonation time, and subglottic pressure). The chi2 values for the 3 models were 37.8, 37.6, and 46.0, respectively. All 3 indices were able to satisfactorily classify voice function as normal or abnormal. However, the regression index performed best.

Confidence Intervals↗

PubMed1997

The current status of postoperative complications and risk factors after a pulmonary resection for primary lung cancer. A multivariate analysis.

OBJECTIVE: The purpose of the present study is to identify the current postoperative complications after a pulmonary resection for primary lung cancer and the associated risk factors. METHODS: From 1988 to 1992, 291 patients with primary lung cancer, excluding T4 diseases, consecutively underwent a pulmonary resection at our institute. The observed postoperative complications were divided into non-life-threatening ones (simple arrhythmia, atelectasis, liver dysfunction, etc.) and life-threatening ones (respiratory failure, pyothorax, pneumonia, bronchopleural fistula, cardiac failure, cerebral infarction, myocardial infarction, etc.). Using logistic regression procedures, both univariate and multivariate analyses of the association between various perioperative factors and the incidence of postoperative complications were performed. RESULTS: Non-life-threatening complications occurred in 60 patients (20.6%) while life-threatening ones occurred in 36 (12.4%), and resulted in five in-hospital deaths (1.75%). Multivariate analyses showed that an age of 70 or older, a combined resection, an abnormality on preoperative ECG, and diffusing capacity of carbon monoxide (%DLco) below 70 were all independently associated with an increased non-life-threatening morbidity. On the other hand, an age of 70 or older, the need for a pneumonectomy, and a %DLco below 70 were also independently predominant risk factors for life-threatening morbidity. CONCLUSION: The risk factors for life-threatening morbidity therefore did not completely correspond to those for non-life-threatening morbidity. Since the mortality was quite low, even risk factors for life-threatening morbidity were not solely considered to be a contraindication for a major pulmonary resection.

Adult↗

PubMedDate not supplied

Preliminary criteria for primary fibromyalgia syndrome (PFS): multivariate analysis of a consecutive series of PFS, other pain patients, and normal subjects.

Primary fibromyalgia syndrome (PFS) is a common form of nonarticular rheumatism with chronic and generalized musculoskeletal aching and stiffness, accompanied by tender points at characteristic sites in the absence of an underlying condition. No satisfactory criteria for its diagnosis, based on appropriate controlled studies, have yet been proposed. We undertook such a study which included a consecutive series of clinically diagnosed PFS and compared them with 3 control groups--mild rheumatoid arthritis, localized fibromyalgia secondary to trauma and normal controls. Multivariate statistical analysis plus clinical judgement identified 6 historical features and 7 pairs of tender points that best discriminated PFS from the control groups. The criteria, derived from a combination of these historical features and tender points, provided greater than 90% sensitivity and specificity. In an independent and consecutive sample of 45 PFS patients, the criteria yielded a sensitivity of 89%. The present study indicates that a combination of historical features and TP's will likely provide effective PFS criteria.

Adult↗

PubMed2001

Locus of control and health behaviour revisited: a multivariate analysis of young adults from 18 countries.

The inconsistent and small associations between health locus of control and health behaviour found in previous studies may be due to the use of small samples, and an overreliance on correlations as measures of association. We assessed relationships between internal powerful others and chance health locus of control, health values, and ten health-related behaviours (physical exercise, smoking, alcohol consumption, breakfast, tooth-brushing, seat belt use, and consumption of fruit, fat, fibre and salt) in 4358 female and 2757 male university students from 18 European countries. Multivariate logistic modelling, assessing the odds of engaging in healthy behaviour with graded changes in locus of control, identified substantial associations. For five behaviours, the odds of healthy behaviour were more than 40% greater among individuals in the highest vs. lowest quartile of internal locus of control after adjustment for sex, age, health value and other locus of control scales. High chance locus scores were associated with more than 20% reductions in the likelihood of healthy options for six behaviours, while powerful others scores showed more variable associations with healthy actions. Inclusion of health value within the analyses did not change the nature of the relationships observed between variables. Associations between health locus of control and health behaviour are of a similar magnitude to other psychosocial factors when appropriate statistical tests are employed.

Adolescent↗

PubMed2004

A multivariate analysis of dysfunctional elimination syndrome, and its relationships with gender, urinary tract infection and vesicoureteral reflux in children.

PURPOSE: We explored and quantified the relationships between dysfunctional elimination syndrome (DES), and gender, urinary tract infection (UTI) and vesicoureteral reflux (VUR) in children. MATERIALS AND METHODS: Data on 2,759 pediatric patients treated at a referral practice who underwent renal sonography and voiding cystourethrography were summarized. The patients were children with VUR or normal genitourinary anatomy who presented with UTI or dysfunctional voiding and children screened for genitourinary problems such as hematuria, sibling reflux or bedwetting. A multivariate logistic regression approach was used to model and quantify the associations between DES and other pediatric urology factors. RESULTS: Of the girls 36.0% with unilateral VUR had DES, while 36.1% with bilateral VUR had DES. The corresponding rates for boys were 20.5% and 21.2%. The higher rate of DES in girls was independent of UTI and VUR status. While UTI was not associated with DES in boys or girls without VUR, in patients with VUR and UTI the risk of DES almost doubled (OR 1.97). Reflux alone without UTI was negatively associated with DES in boys (OR 0.50, 95% CI 0.34, 0.73) and girls (OR 0.26, 95% CI 0.19, 0.36). CONCLUSIONS: Girls had a significantly higher rate of DES than boys in all UTI and VUR subgroups in the current data. UTI significantly impacts the DES occurrence in patients with VUR. No statistically significant difference was detected in the DES rate between the unilateral and bilateral VUR groups, and the reflux group as a whole did not seem to have a higher rate of DES in boys or girls.

Child↗

PubMed1998

Tricyclic antidepressant and selective serotonin reuptake inhibitors antidepressant selection and health care costs in the naturalistic setting: a multivariate analysis.

BACKGROUND: Providers and payers have an interest in the total health care costs following the initiation of antidepressant treatment in the real world of clinical practice. Analyses of these costs can help evaluate the economic consequences of patient management decisions associated with initial antidepressant selection. OBJECTIVE: The purpose of this study was to assess the 1-year total direct health care costs for patients initiating therapy with one of the available tricyclic antidepressants (TCAs) or one of the three most often prescribed selective serotonin reuptake inhibitors (SSRIs) - paroxetine, sertraline, or fluoxetine. METHOD: A two-stage multivariate econometric model and data from fee-for-service private insurance claims between 1990 and 1994 were used to estimate the total direct health care costs following initial antidepressant drug selection for 2693 patients with a 'new' episode of antidepressant treatment. After controlling for both observed and unobserved characteristics, the 1-year total direct health care costs were found to be (1) statistically significantly lower for patients initiating therapy on fluoxetine than for patients initiating therapy on a TCA; (2) statistically significantly lower for patients who initiated therapy on fluoxetine than for patients initiating therapy on sertraline. CONCLUSIONS: Broadly considered, the findings in this study suggest that total direct health care costs differ across initial antidepressant selection after controlling for both observed and unobserved characteristics.

1-Naphthylamine↗

PubMed2003

Analgesic efficacy of flupirtine in primary care of patients with osteoporosis related pain. A multivariate analysis.

OBJECTIVE: Although chronic pain in elderly patients with osteoporosis is extremely common it has rarely been addressed in pharmacotherapy studies. The efficacy and tolerability of flupirtine (CAS 56995-20-1, Trancopal Dolo) up to 600 mg/day was investigated under daily practice conditions. DESIGN: This was an open-label, multicentre, prospective, observational phase IV study on 869 patients performed in 290 practices (mainly orthopedists) throughout Germany. MAIN OUTCOME MEASURE: Decrease in pain scores on a visual analogue scale (VAS, from 0 = none to 10 = maximum) after an average 3-week therapy, and evaluation of adverse events. Multivariate analyses were performed to identify factors associated with the efficacy of pain reduction. RESULTS: 81% of patients were female; the mean age of all patients was 67 years, and the mean body mass index was 25.7 kg/m2. 81% of patients had reduced bone density, 30% had a family history of osteoporosis, and 32% had previous bone fractures. The mean daily flupirtine dose was 270 +/- 12 mg. The mean baseline pain VAS scores were 7.1 (low back pain), 5.8 (neck pain), 5.6 (shoulder-arm pain), and 6.6 (other pain). Mean pain reduction at the end of flupirtine treatment was 43% for low back pain, 44% for neck pain, 40% for shoulder-arm pain, and 40% for other pain (all reductions p < 0.05 vs. baseline). Rates of pain reduction at the various sites were closely correlated, and the efficacy of pain reduction was independent of age. The pain reduction was more pronounced in patients with recent onset of pain and with higher pain intensity at entry. Tolerability of treatment was excellent with only 2.4% of patients reporting adverse events and only 12 patients (1.4%) withdrawing from the trial. CONCLUSION: This trial performed under daily practice conditions in a large unselected sample of patients confirms the efficacy and safety of flupirtine in the treatment of chronic pain in patients with osteoporosis, independent of the age of the patient.

Aged↗

PubMed2001

Multivariate analysis of risk factors for neck metastases in surgically treated parotid carcinomas.

OBJECTIVE: To analyze risk factors for neck metastases in patients with parotid carcinomas. DESIGN: Cohort of patients followed up from 1 to 366.2 months at a single institution. SETTING: Referral center, private or institutional practice, hospitalized care. PATIENTS: A total of 145 patients with parotid carcinomas with complete clinical and pathological information. The histological diagnosis was reviewed according to the World Health Organization classification for salivary gland tumors. INTERVENTION: Patients were treated by surgery alone (62 cases) or with postoperative radiotherapy (83 cases). A neck dissection was performed in 80 patients. MAIN OUTCOME MEASURE: Rates of neck lymph node metastasis. Univariate and multivariate analyses were carried out using logistic regression evaluating the significance of demographic, clinical, and pathological data. RESULTS: The following variables were significantly associated to the risk of lymph node metastasis by univariate analysis: histological type (P<.001), T stage (P<.001), desmoplasia (P = .001), facial palsy (P = .02), perineural invasion (P = .01), extraparotid tumor extension (P = .02), and necrosis (P = .003). By multivariate analysis, histological type (P<.001), T stage (P = .03), and desmoplasia (P = .006) had the highest correlation with lymph node metastasis. CONCLUSION: The significant risk factors for neck metastasis in parotid carcinoma were histological type (ie, adenocarcinoma, undifferentiated carcinoma, high-grade mucoepidermoid carcinoma, squamous cell carcinoma, and salivary duct carcinoma), T stage (T3 and T4), and desmoplasia (severe).

Adenocarcinoma↗

PubMed1994

Increased erythrocyte aggregation in insulin-dependent diabetes mellitus and its relationship to plasma factors: a multivariate analysis.

Red blood cell aggregation in vitro (kinetics and shear resistance) was studied in 13 healthy controls and 13 type I (insulin-dependent) diabetic patients free of severe degenerative complications who were matched for age, sex, and body mass index. Measurements were performed with a device that analyzes the laser light backscattered by a blood suspension. Both the velocity of rouleau formation and the cohesion of the rouleau network were significantly increased in diabetic patients. Plasma viscosity and whole-blood viscosity measured at low shear rate (0.95 s-1) were also significantly elevated in the diabetic group. Multivariate analyses of the whole population sample and the diabetic patients confirmed the influence of plasma proteins on the kinetics of aggregation. Fibrinogen levels, which were close to normal, affected mainly the shear resistance of the aggregates. Triglyceride and apolipoprotein (apo) B levels and indexes of metabolic control or protein glycation (fasting blood glucose and fructosamine) also appeared to influence markedly both the kinetics of rouleau formation and the cohesion of the rouleau networks. These rheological abnormalities occurred in diabetic patients before the appearance of any severe degenerative complications. We suggest that these rheological abnormalities are linked to plasma or erythrocyte factors, and are not due to angiopathy.

Adult↗

PubMed1999

Predictors of home care readiness for managed care: a multivariate analysis.

As home care agencies change from cost-based reimbursement to the managed care risk paradigm, many lack experience with organizational resources and functions needed to successfully operate in the managed care environment. This survey assessed the level of "readiness" for managed care reported by 162 randomly selected home care agencies in three mid-western states. Managed care readiness was measured by a 32-item mailed questionnaire addressing clinical, financial, operational, and informational systems within each agency. Higher levels of readiness were significantly related to the perception of being ready, proprietary auspices, and moderate agency size in a multivariate regression model. Agencies with these characteristics appear to be well positioned as home care moves into the managed care environment.

Aged↗

PubMed1992

Genetic differences in psychomotor performance decrement after alcohol: a multivariate analysis.

We reanalyzed data on the decline in performance on a battery of psychomotor tests, after a standard dose of ethanol (0.75 g/kg body weight), of 206 same-sex twin pairs. Principal components analysis identified two orthogonal factors. The first factor was strongly associated with increased body sway, self-rated intoxication and unwillingness to drive, and reported low average weekly alcohol consumption, but showed a very weak association with blood alcohol concentration. The second factor had high loadings on tests assessing psychomotor coordination, was strongly associated with blood alcohol concentration, but was unrelated to willingness to drive or self-rated intoxication. Multivariate genetic analysis indicated independent genetic and environmental determination of differences in sensitivity to the effects of alcohol on these two factors.

Adolescent↗

PubMed2005

Supracricoid partial laryngectomy in the treatment of laryngeal cancer: univariate and multivariate analysis of prognostic factors.

OBJECTIVES: To evaluate the oncological results of supracricoid partial laryngectomy as a treatment for selected glottic and supraglottic cancer in a large series of patients who had undergone uniform treatment over a 16-year period and to determine the different prognostic factors that may influence local control and survival. DESIGN: Retrospective clinical study. SETTING: Academic tertiary referral medical center. PATIENTS: The study population comprised 253 consecutive patients (234 men and 19 women) with glottic and supraglottic squamous cell carcinoma. The mean age was 58 years for men and 59.2 years for women. INTERVENTION: Supracricoid partial laryngectomy: 180 patients had undergone cricohyoidopexy and 73 had undergone cricohyoidoepiglottopexy. MAIN OUTCOME MEASURES: Local control and overall survival. Potential prognostic factors for local control and survival were evaluated with univariate and multivariate models. RESULTS: The 3-, 5-, 10-, and 16-year overall survival rates in this group of 253 patients were 85.8%, 79.1%, 57.6%, and 57.6%, respectively. With regard to local control, univariate and multivariate analyses showed that a positive resection margin was the only important predictor of local control and that a dysplastic lesion at the margin of resection is just as aggressive as the presence of invasive carcinoma. When considering the prognostic factors influencing survival, univariate analysis showed that the tumor category, lymph node category, tumor stage, and recurrence all had a significant influence on the survival rate. Multivariate analysis showed that the most important predictor of survival was recurrence. CONCLUSIONS: Supracricoid partial laryngectomy is a valid choice in the treatment of selected glottic and supraglottic cancer while maintaining laryngeal functions and achieving a high rate of local control. T category, N category, tumor stage, positive resection margins, and recurrence are the most important predictors of oncological outcome.

Carcinoma, Squamous Cell↗

PubMed2005

Multivariate analysis of selected metals in tannery effluents and related soil.

Effluent and relevant soil samples from 38 tanning units housed in Kasur, Pakistan, were obtained for metal analysis by flame atomic absorption spectrophotometric method. The levels of 12 metals, Na, Ca, K, Mg, Fe, Mn, Cr, Co, Cd, Ni, Pb and Zn were determined in the two media. The data were evaluated towards metal distribution and metal-to-metal correlations. The study evidenced enhanced levels of Cr (391, 16.7 mg/L) and Na (25,519, 9369 mg/L) in tannery effluents and relevant soil samples, respectively. The effluent versus soil trace metal content relationship confirmed that the effluent Cr was strongly correlated with soil Cr. For metal source identification the techniques of principal component analysis, and cluster analysis were applied. The principal component analysis yielded two factors for effluents: factor 1 (49.6% variance) showed significant loading for Ca, Fe, Mn, Cr, Cd, Ni, Pb and Zn, referring to a tanning related source for these metals, and factor 2 (12.6% variance) with higher loadings of Na, K, Mg and Co, was associated with the processes during the skin/hide treatment. Similarly, two factors with a cumulative variance of 34.8% were obtained for soil samples: factor 1 manifested the contribution from Mg, Mn, Co, Cd, Ni and Pb, which though soil-based is basically effluent-derived, while factor 2 was found associated with Na, K, Ca, Cr and Zn which referred to a tannery-based source. The dendograms obtained from cluster analysis, also support the observed results. The study exhibits a gross pollution of soils with Cr at levels far exceeding the stipulated safe limit laid down for tannery effluents.

Environmental Monitoring↗

PubMed2002

Coping with complexity. multivariate analysis of tumor karyotypes.

Human cancers are characterized by chromosomal aberrations, and an increasing number of specific balanced rearrangements have been found among malignant hematologic disorders. Most solid tumors, however, exhibit a much more complex cytogenetic pattern. Although these chromosome changes show a nonrandom distribution, tumor-specific aberrations are uncommon, and the solid tumors often contain a large number of abnormalities and also display extensive cytogenetic variability. The high level of karyotypic complexity has made a systematic characterization of the chromosomal patterns difficult. In order to better understand the biological relevance of highly abnormal karyotypes in tumor cell populations, novel statistical strategies are needed. We have developed and adapted several methods that may be useful for the evaluation of general patterns of karyotypic complexity, including distribution analysis of cytogenetic imbalances, temporal analysis for time of occurrence of aberrations, and principal component analysis for reconstructing karyotypic pathways. By applying these methods on the chromosomal changes presently known, distinct subgroups have been identified among breast, kidney, bladder, colon, and brain tumors.

Aneuploidy↗

PubMed2006

Is a patient's self-reported health-related quality of life a prognostic factor for survival in non-small-cell lung cancer patients? A multivariate analysis of prognostic factors of EORTC study 08975.

BACKGROUND: The aim of this prognostic factor analysis was to investigate if a patient's self-reported health-related quality of life (HRQOL) provided independent prognostic information for survival in non-small cell lung cancer (NSCLC) patients. PATIENTS AND METHODS: Pretreatment HRQOL was measured in 391 advanced NSCLC patients using the EORTC QLQ-C30 and the EORTC Lung Cancer module (QLQ-LC13). The Cox proportional hazards regression model was used for both univariate and multivariate analyses of survival. In addition, a bootstrap validation technique was used to assess the stability of the outcomes. RESULTS: The final multivariate Cox regression model retained four parameters as independent prognostic factors for survival: male gender with a hazard ratio (HR) = 1.32 (95% CI 1.03-1.69; P = 0.03); performance status (0 to 1 versus 2) with HR = 1.63 (95% CI 1.04-2.54; P = 0.032); patient's self-reported score of pain with HR= 1.11 (95% CI 1.07-1.16; P < 0.001) and dysphagia with HR = 1.12 (95% CI 1.04-1.21; P = 0.003). A 10-point shift worse in the scale measuring pain and dysphagia translated into an 11% and 12% increased in the likelihood of death respectively. A risk group categorization was also developed. CONCLUSION: The results suggest that patients' self-reported HRQOL provide independent prognostic information for survival. This finding supports the collection of such data in routine clinical practice.

Adult↗

PubMed1991

The utilization of home help in Sweden: a multivariate analysis.

We estimated the effect of a variety of factors on the utilization of home help among the elderly in Sweden using a sample (N = 421) of people 75 years and older. A regression analysis singled out two factors as the most important: physical functioning (instrumental activities of daily living) and living alone. Calculations of attributable fractions substantiated this result. Implications for planning and allocating home help are discussed.

Aged↗