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PubMed1997

Laboratory diagnosis of anemia and related diseases using multivariate analysis.

To establish a simple computer program for the laboratory diagnosis of anemia and related diseases, multivariate analyses were applied to the results of routine hematological laboratory tests obtained from 48 patients and 51 healthy volunteers. The patients studied were limited to those who had not been treated hematologically by the time of their first visit to our hospital, and their first data obtained in our laboratory were analyzed. Final diagnoses were aplastic anemia (AA) in 21, myelodysplastic syndrome (MDS) in 14, iron deficiency anemia (IDA) in 3, polycytemia vera (PV)in 3, and idiopathic thrombocytopenic purpura (ITP) in 7. Eight parameters, WBC, RBC, Hb, Ht, MCV, MCH, MCHC, and PLT, were transformed to normal distribution and then applied to principal component analysis to evaluate their independence. Very close relationships were observed between Ht and Hb, and between MCV and MCH. One each of these pairs was selected by discriminant analysis and two sets, RBC, MCH, Hb, PLT, and WBC, and RBC, MCV, Ht, PLT, and WBC, were obtained. Two canonical components gave good discrimination of these five diseases and also of normal subjects. When disease prediction was made using this analysis, 37 of 48 patients (77.1%) were predicted correctly, and furthermore, when two disease predictions were allowed, all patients were diagnosed properly. Some overlaps were observed in this two-dimensional coordinate system, especially of AA and MDS, and also with normal subjects. To improve the system further, the additional parameters of age and sex were added to construct a three-dimensional analysis which resulted in much clearer discrimination. The whole procedure described is being developed with subjects who are not taking medication. Subsequently, the general application of this analytical procedure should be limited to only those not on medications. In conclusion, this is in essence a demonstration project; however, this trial of laboratory diagnosis using routine hematological laboratory results appears to be promising. Further extension of the study by increasing numbers of patients and disorders studied, including secondary anemias, will allow the design of diagnostic software for use with personal computers at the sites of primary care.

Adult↗
PubMed2001

Risk factors associated with fetal losses in treated antiphospholipid syndrome pregnancies: a multivariate analysis.

PROBLEM: Pregnancies in women with antiphospholipid syndrome (APS) are associated with obstetric complications despite treatment. The present study analyzes risk factors and evaluates fetal outcome in a large sample of treated APS pregnancies. METHOD OF STUDY: Seventy-seven pregnancies in 56 women were included. Twelve selected variables potentially related to the outcome of treated pregnancies were analyzed in a multivariate logistic regression model. RESULTS: Treated women delivered 65 live infants at 24-41 weeks gestation (mean 36.7+/-0.5) but two neonatal deaths occurred. There were seven first-trimester miscarriages (9%) and five intrauterine fetal demises (6.5%). Thus, the probability of having a live baby under treatment was 82% (95% CI 71.3-89.6%), a figure significantly greater (P <0.001) than that observed before therapy (25.7%; 95% CI 18.7-33.7%). Variables related with fetal outcome in the multivariate model were: preconceptional use of aspirin and abnormal umbilical artery Doppler velocimetry at 23-26 weeks gestation. CONCLUSIONS: The present report shows that in treated APS pregnancies: i) aspirin treatment started preconceptionally is an independent and significant prognostic factor associated with favorable fetal outcome; and ii) abnormal velocity waveforms in the umbilical artery predict adverse outcome of pregnancy.

Abortion, Spontaneous↗
PubMed2005

Locomotor ecology of wild orangutans (Pongo pygmaeus abelii) in the Gunung Leuser Ecosystem, Sumatra, Indonesia: a multivariate analysis using log-linear modelling.

The large body mass and exclusively arboreal lifestyle of Sumatran orangutans identify them as a key species in understanding the dynamic between primates and their environment. Increased knowledge of primate locomotor ecology, coupled with recent developments in the standardization of positional mode classifications (Hunt et al. [1996] Primates 37:363-387), opened the way for sophisticated multivariate statistical approaches, clarifying complex associations between multiple influences on locomotion. In this study we present a log-linear modelling approach used to identify key associations between orangutan locomotion, canopy level, support use, and contextual behavior. Log-linear modelling is particularly appropriate because it is designed for categorical data, provides a systematic method for testing alternative hypotheses regarding interactions between variables, and allows interactions to be ranked numerically in terms of relative importance. Support diameter and type were found to have the strongest associations with locomotor repertoire, suggesting that orangutans have evolved distinct locomotor modes to solve a variety of complex habitat problems. However, height in the canopy and contextual behavior do not directly influence locomotion: instead, their effect is modified by support type and support diameter, respectively. Contrary to classic predictions, age-sex category has only limited influence on orangutan support use and locomotion, perhaps reflecting the presence of arboreal pathways which individuals of all age-sex categories follow. Effects are primarily related to a tendency for adult, parous females to adopt a more cautious approach to locomotion than adult males and immature subjects.

Age Factors↗
PubMed1994

[Role of postoperative irradiation for carcinoma of the uterine cervix: multivariate analysis of prognostic factors and patterns of failure].

We retrospectively analyzed the patterns of recurrence in 48 patients who underwent postoperative irradiation following surgery for carcinoma of the uterine cervix. The end points of pelvic control, distant metastases and disease-free survival were analyzed for parameters including FIGO stage, nodal status, degree of stromal invasion, histology and tumor size. Univariate and multivariate analyses showed that some prognostic parameters had little influence on pelvic control rate, but had a marked impact on the incidence of distant metastases and disease-free survival rate. These results suggest that postoperative irradiation improves pelvic control rate, but has little therapeutic benefit in preventing distant metastases or improving survival rate. In conclusion, we should give more consideration to adjuvant systemic therapy in addition to postoperative irradiation for high-risk patients.

Adult↗
PubMed1998

Risk factors for treatment-related death in elderly patients with aggressive non-Hodgkin's lymphoma: results of a multivariate analysis.

PURPOSE: It has been suggested that age is associated with chemotherapy-related death in patients with non-Hodgkin's lymphoma (NHL) treated with doxorubicin-containing chemotherapy. The purpose of this study was to evaluate the relative influence of increasing age and other clinical parameters on the occurrence of treatment-related death in elderly patients with intermediate- or high-grade NHL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy. METHODS: A retrospective study of patients 60 years of age or older with intermediate- or high-grade NHL treated with CHOP chemotherapy in a single cancer center. The following variables were recorded: age (60 to 69, 70 to 79, and 80 to 94 years), histology (Working Formulation [WF] D, E, F, G, and H), Ann Arbor stage, B symptoms, extranodal involvement, bulky disease (> 7 cm), performance status (Eastern Cooperative Oncology Group [ECOG] scale), International Prognostic Index (IPI score), serum lactate dehydrogenase (LDH) level and doxorubicin relative dose-intensity (RDI). The relationship between these features and treatment-related death was assessed in univariate and multivariate logistic regression analysis. RESULTS: From 1982 to 1991, 267 consecutive patients were treated. Median age was 70 years (range, 60 to 94 years). There were 35 toxic deaths. Sixty-three percent of the deaths occurred after the first cycle. Infection accounted for 82% of the toxic deaths. In the univariate analysis, the features associated with an increased risk of toxic death were ECOG performance status 2 to 4 (relative risk [RR], 7.82), B symptoms (RR, 3.38), diffuse large-cell histology (RR, 3.06), bulky disease (RR, 2.58), serum levels of LDH (RR, 2.53), and IPI score (RR, 2.46). The age groups did not show significance. In the regression model, performance status 2 to 4 was the only independent predictor of treatment-related death (RR, 3.52; 95% confidence interval [CI], 2.98 to 4.06). CONCLUSION: Our results show that in elderly patients with NHL treated with doxorubicin-based chemotherapy the risk for treatment-related death is associated with poor performance status rather than with increasing chronologic age.

Age Factors↗
PubMed1989

Two regression models and a scoring system for predicting survival and planning treatment in myelodysplastic syndromes: a multivariate analysis of prognostic factors in 370 patients.

Therapy planning in patients with myelodysplastic syndromes (MDSs) is complicated by its high prognostic heterogeneity. Forty-one patient and disease characteristics at onset of 370 patients with MDS were analyzed to identify significant prognostic factors for survival and transformation to acute myeloblastic leukemia (AML), and to develop and validate a regression model for predicting survival. Multivariate regression analysis showed that the total bone marrow percentage of blast cells, age, platelet count, WBC count, and hemoglobin level were the characteristics more significantly associated with survival in the overall series. The bone marrow percentage of type I blast cells was the most important factor predicting transformation into AML. Proportional hazards regression analysis in a randomly selected training sample of 240 patients demonstrated that the combination of total bone marrow percentage of blast cells, platelet count, and age had the strongest predictive relation to survival length. The resulting regression models, continuous and categorized, were validated in the remaining test sample of 130 patients by demonstrating its capability of segregating patients into low-, intermediate-, and high-risk groups, with distinctively different survival curves (P less than .0001). A scoring system derived from the categorized model also had a great prognostic value (P less than .0001). These regression models and the simpler scoring system may be accurately used for decision-making regarding therapy in MDS patients.

Female↗
PubMed1998

Complications of intra-aortic balloon counterpulsation. The role of catheter size and duration of support in a multivariate analysis of risk.

AIMS: The aim of this study was to assess the risk of intra-aortic balloon counterpulsation and to identify clinical and procedural variables that would predict complications. METHODS AND RESULTS: We analysed 381 consecutive patients who were treated between 1977 and 1995 at our catheterization laboratory and/or medical intensive care unit. The complications considered relevant were limb ischaemia requiring catheter removal, vascular injury, bleeding requiring transfusion, embolic events, and infection. In eight patients the balloon could not be inserted. The rate of complications for the remaining 373 patients was 12.9%. Between 1977 and 1980, surgical insertion was performed using a 12 French catheter with a complication rate of 30.4% (seven of 23 patients). Percutaneous implantation, performed after 1981, had an overall complication rate of 11.7% (41 of 350 patients). Using thinner catheters for percutaneous placement was associated with a reduction in the rate of complications, from 20.7% (17 of 82 patients) for 12 French catheters to 9.9% (10 of 101 patients) for 10.5 French catheters (P = 0.04), and 8.4% (14 of 167 patients) for 9.5 French catheters (P = 0.006). Multivariate logistic regression analysis identified duration of counterpulsation > 48 h (odds ratio 3.6), catheter size (odds ratio 3.4 for 12 French catheters), peripheral vascular disease (odds ratio 2.7), and shock (odds ratio 2.0) as independent risk factors for counterpulsation-associated complications. When considering 9.5 French catheters only (167 patients, all after 1992), the sole remaining independent risk factor was duration of counterpulsation > 48 h (odds ratio 3.8). Those patients with 9.5 French catheters in whom counterpulsation did not exceed 48 h had a low complication rate of 3.9%. CONCLUSION: The rate of percutaneous intra-aortic balloon counterpulsation complications was thus significantly reduced by employing thinner catheters. It was at an acceptable level for 9.5 French catheters, where a long duration of counterpulsation emerged as the most significant factor associated with complications. Whether using even thinner catheters in combination with a sheathless implantation technique further minimizes the risk of counterpulsation remains to be seen.

Aged↗
PubMed2003

Secondary patellar resurfacing in total knee arthroplasty: results of multivariate analysis in two case-matched groups.

Although patellofemoral symptoms after patellar-retaining knee arthroplasty are common, no evidence has been published in the literature on the potential benefit from patellar resurfacing at a later stage. This study evaluates the effect of secondary (delayed) patellar resurfacing using comparisons between 2 case-matched groups of patients with primary and secondary patellar resurfacing. Furthermore, multivariate statistical methods were applied to study factors that may influence the final outcome. Our results suggest that although significant clinical improvement was seen after delayed patella resurfacing, the outcome of secondary patellar resurfacing is inferior to that expected for a similar group of patients with primary resurfacing. Furthermore, the timing (delay period) of the secondary resurfacing procedure appears to negatively affect the final outcome. This suggests that secondary patellar resurfacing, when indicated, should be considered at an early stage.

Aged↗
PubMed2002

HLA matching for simultaneous pancreas-kidney transplantation in the United States: a multivariable analysis of the UNOS data.

BACKGROUND: As the incidence of diabetic nephropathy increases, especially in minority populations, more simultaneous pancreas-kidney (SPK) transplants are being performed both in the United States and worldwide. The role of matching on SPK outcomes and organ allocation remains controversial. The purpose of this analysis was to determine the influence of HLA matching using currently employed criteria on 5-year SPK graft survival. METHODS: We performed an analysis of all 3,316 SPK transplants performed in the United States reported to the United Network for Organ Sharing (UNOS) between December 31, 1988 and December 31, 1994. Kaplan-Meier unadjusted 1- and 5-year graft survival with log rank comparisons and Cox multivariable regression models that adjusted for 12 confounding variables were used to analyze the influence of HLA matching on outcomes. RESULTS: Despite low-grade HLA or DR matching or high levels of common reactive groups (CREG) mismatching, 1- and 5-year allograft survival rates were 90% and 78% for kidney, and 85% and 75% for pancreas transplantation. CONCLUSIONS: SPK transplantation is associated with excellent outcomes independent of the level of HLA matching. These data support the hypothesis that SPK transplants need not be allocated based on matching criteria, thus minimizing organ ischemia time and promoting a more racially equitable allocation for SPKs in the US today.

Adult↗
PubMed1990

Prognostic factors of nasopharyngeal carcinoma: a multivariate analysis.

Between 1979 and 1985, 561 patients with nasopharyngeal carcinoma were reviewed to determine prognostic factors that may influence survival. Sex (p = 0.294) and histopathology (p = 0.677) had no correlation to the actuarial survival, whereas the site of cervical metastasis (p = 0.001) and the radiation doses to the nasopharynx and regional lymph nodes (p = 0.03) were both significant when one used univariate analyses. Cox's multivariate regression model revealed that the presence rather than the site of distant metastases was the single most important independent factor influencing the treatment outcome (p less than 0.0001). The addition of chemotherapy, on the other hand, did not show a survival benefit even when one took available confounding factors into account. There are, however, survival advantages associated with: (a) young age (less than or equal to 40 years), (b) asymptomatic status, (c) Stage I or II lesions, and (d) biopsy via nasopharynx instead of neck nodes. These favorable prognostic factors may be used for therapeutic guidance and end-result reporting.

Adolescent↗