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Results for “Multivariate response regression”

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PubMed1995

The emergency contraceptive pill: a survey of knowledge and attitudes among students at Princeton University.

OBJECTIVE: Our purpose was to measure and analyze knowledge and attitudes about emergency contraceptive pills. The hypothesis we tested was that more accurate knowledge about the regimen would be associated with favorable attitudes towards its use. STUDY DESIGN: We conducted a random sample telephone survey and a series of focus group discussions at Princeton University (results for 11 focus groups are presented elsewhere) A total of 550 undergraduate and graduate students were selected randomly for participation in the survey, and the response rate was 82%. The study's primary outcome measure was attitudes toward the emergency contraceptive pill as a method of fertility control. We used multivariate regression analysis with ordered logit models to test the hypothesized association between knowledge and attitudes. RESULTS: Basic awareness and approval of the emergency contraceptive pill were widespread, yet students lacked detailed knowledge, which did contribute to health and ethical misgivings about the regimen. Students with accurate information, especially those students who knew that the therapy is a large dose of regular oral contraceptives and that side effects are generally minor, were significantly more likely than others to report favorable attitudes. Many students confused the pills dispensed by the university health services (Oral, Wyeth-Ayerst, Philadelphia) with the abortifacient RU 486. Students noted discussion of the method is rare, and many wanted to know more about it. Statistical results are reported with a 95% confidence level. CONCLUSIONS: Educational efforts should offer specific information about the composition of emergency contraceptive pills, the side effects, and how the regimen works.

Abortifacient Agents, Steroidal↗

PubMed2002

Interferon and amantadine in naive chronic hepatitis C: a double-blind, randomized, placebo-controlled trial.

Recent controlled trials on the efficacy of an amantadine/interferon combination in treatment-naive patients with chronic hepatitis C yielded contradictory results. We therefore conducted a large, double-blind, placebo-controlled, multicenter trial in naive patients with chronic hepatitis C: 246 patients were randomized to receive interferon alfa-2a (6 MIU sc thrice weekly for 20 weeks, then 3 MIU sc thrice weekly) and either amantadine sulphate (2 x 100 mg p.o. QD) or placebo. Treatment continued for a total of 52 weeks, if HCV-RNA in serum polymerase chain reaction (PCR) had fallen below detection limit (1,000 copies/mL) at treatment week 10, and stopped otherwise. All patients were followed for 24 weeks off therapy. After 10 weeks of treatment, 66/121 patients treated with amantadine (55%) and 78/125 treated with placebo (62%) had lost HCV-RNA (n.s.). After 24 weeks of follow-up, 25 patients in the amantadine (21%) and 17 (14%) in the placebo group remained HCV-RNA negative (n.s.). During therapy, virologic breakthroughs occurred less often in the amantadine than in the placebo group [14 (12%) vs. 27 (22%) patients; P =.04]. Multivariate logistic regression analysis revealed genotype, viremia level, age, and amantadine therapy [risk ratio 0.4 (95%CI 0.2-1.0), P =.05] as predictors of sustained virologic response. Adverse events and impact of therapy on quality of life were similar in amantadine and placebo treated patients. Compared with current standard treatment (interferon/ribavirin), the interferon/amantadine combination was not cost-effective. In conclusion, amantadine does not add to a clinically relevant extent to the treatment of naive patients with chronic hepatitis C.

Adult↗

PubMed2000

Incidence and associated factors of neutralizing anti-interferon antibodies among chronic hepatitis C patients treated with interferon in Taiwan.

BACKGROUND: The administration of interferon (IFN) could be complicated by the development of neutralizing anti-interferon antibodies (NA). This study evaluates the frequency and associated factors of NA among chronic hepatitis C patients treated with different IFNs. METHODS: Ninety-five chronic hepatitis C patients were randomized to be treated with recombinant IFN-alpha2a (n = 28), IFN-alpha2b (n = 39) or lymphoblastoid IFN-alpha1 (n = 28) given intramuscularly, 3-6 million units, thrice weekly for 24 weeks. Serum samples collected before, during and after the cessation of treatment were checked for NA. RESULTS: Three patients were withdrawn from treatment. All patients were negative for NA before treatment and 13 (14%) patients developed neutralizing antibodies. Of the 26 patients treated with IFN-alpha2a, 6 (23.1%) developed NA. whereas NA were detected in only 6 (15.4%) of 39 and 1 (3.7%) of 27 patients treated with IFN-alpha2b and IFN-alphanl, respectively. Age, gender, HCV genotype, ALT level, IFN total dose and liver histology were not associated with the development of NA. By using multivariate logistic regression it was shown that pretreatment HCV RNA level and IFN preparation were the two major factors related to the production of NA. The response of treatment was related to pretreatment viremia but not to the presence of NA. CONCLUSIONS: The frequency of development of NA among Taiwanese patients with chronic hepatitis C might be related to different IFN preparations and pretreatment HCV RNA level. The response of treatment was related to pretreatment HCV RNA level but not to the presence of NA.

Adult↗

PubMed2005

Anxiety disorders associated with suicidal ideation and suicide attempts in the National Comorbidity Survey.

This study examined the relationship between anxiety disorders and suicidal ideation or suicide attempts in a nationally representative sample (N = 5877; age, 15-54; response rate, 82.4%). A modified version of the Composite International Diagnostic Interview was used to make DSM-III-R mental disorder diagnoses. Two multivariate logistic regression analyses were performed with suicidal ideation (N = 754) and suicide attempts (N = 259) as dependent variables. In each regression, the independent variables entered were lifetime social phobia, panic disorder, agoraphobia, generalized anxiety disorder, simple phobia, and posttraumatic stress disorder (PTSD). Covariates in the analyses were sociodemographics, lifetime mood disorders, substance use disorders, nonaffective psychosis, antisocial personality disorder, and presence of three or more lifetime DSM-III-R diagnoses. PTSD was significantly associated with suicidal ideation (adjusted odds ratio = 2.79; p < 0.01) and suicide attempts (adjusted odds ratio = 2.67; p < 0.01). None of the other anxiety disorders were significantly associated with suicidal ideation or attempts. The robust association between PTSD and suicide attempts has important implications for psychiatric assessment of suicidal behavior. Future research is required to investigate the mechanisms underlying the relationship between PTSD and suicidal behavior.

Adolescent↗

PubMed1997

Recombinant interferon-alpha-2a for treatment of chronic hepatitis C: results of a multicenter randomized controlled dose study.

To compare the efficacy of low and relatively high dosages of recombinant interferon (IFN)-alpha-2a in Japanese patients with chronic hepatitis C, as well as to characterize the type of patients who will respond well to a low-dosage treatment, 88 patients with histologically proven chronic hepatitis C were randomly assigned to two treatment groups; one treated with IFN-alpha-2a 6 MU daily for 2 weeks followed by 6 MU three times weekly for 22 weeks (6-MU group), and another given the same initial treatment followed by 3 MU three times weekly for 22 weeks (3-MU group). The rate of sustained normalization of ALT 6 months after the cessation of treatment was 33% in the 3-MU group and 40% in the 6-MU group (p = 0.64). In addition, there was no difference in elimination of serum HCV-RNA 6 months after the cessation of treatment between the 3-MU group (26%) and 6-MU group (29%). Multivariate stepwise regression analysis revealed that serum HCV-RNA level (p = 0.0035) and platelet count (p = 0.0009) were independent variables useful in predicting a sustained response of ALT. The sustained response rate of ALT in patients with a serum HCV-RNA level less than 10(5) copies/ml and serum platelet level above 15 x 10(4)/microliter was 71%, whereas that in patients with a serum HCV-RNA level above 10(5) copies/ml and serum platelet level less than 15 x 10(4)/microliter was 12%. These results indicate that a high rate of sustained response to IFN therapy can be expected in chronic hepatitis C patients with a low serum level of HCV-RNA and a high level of platelets, even if treated with a low dose of IFN.

Antiviral Agents↗

PubMed2005

Preliminary evaluation of whole-blood gamma interferon release for clinical assessment of cellular immunity in patients with active coccidioidomycosis.

Assessment of the cellular immune response in coccidioidomycosis has epidemiologic and prognostic importance. Measurement of delayed-type hypersensitivity to skin testing has been used in the past to determine cellular immunity in coccidioidomycosis. However, no skin tests are currently available in the United States. Assay of gamma interferon (IFN-gamma) release in whole blood in response to incubation with antigen has been used to assess cellular immunity in tuberculosis. We used a similar assay using the coccidioidal antigen preparation T27K to measure the in vitro cellular immune responses among a cohort of 69 subjects with active coccidioidomycosis. IFN-gamma release was bimodal, with concentrations above and below 5 IU/ml. Using multivariate logistic regression, underlying disease and disseminated or chronic pulmonary coccidioidomycosis was significantly associated with the release of IFN-gamma at a concentration of <5 IU/ml (P = 0.02 or 0.05, respectively). In addition, the release IFN-gamma concentration was <5 IU/ml in all subjects with a clinical severity score of > or =6 (P = 0.02). The release IFN-gamma concentration correlated with expression of CD69 on T lymphocytes in an in vitro assay using T27K as the antigen (Spearman's rho = 0.59; P < 0.01). These results suggest that the IFN-gamma release assay with T27K as the antigen may be a useful clinical test for assessing cellular immunity in patients with active coccidioidomycosis.

Antigens, CD↗

PubMed1997

Aging and severity of hypertension attenuate endothelium-dependent renal vascular relaxation in humans.

Endothelial dysfunction may be related to cardiovascular risk factors, such as aging, hypertension, and atherosclerosis. We investigated whether aging and hypertension independently alter endothelial function in the renal circulation in humans in the absence of abnormalities in lipid and glucose metabolism. L-Arginine (500 mg/kg over 30 minutes) was intravenously administered to 33 patients with essential hypertension and 35 normotensive subjects. The L-arginine-induced increases in renal plasma flow (10.1+/-0.8% versus 15.8+/-0.9%, P<.05) and plasma cGMP (53+/-4% versus 82+/-5%, P<.05) were significantly smaller in patients with essential hypertension than in the normotensive subjects. Multivariate stepwise regression analysis showed that age (P<.0002) and the mean blood pressure (P<.0001) were independently and negatively correlated with the renal plasma flow response to L-arginine. Age (P<.002), mean blood pressure (P<.0001), and male sex (P<.05) were independently correlated with the L-arginine-induced increase in plasma cGMP. The peak change in plasma cGMP was significantly correlated with the L-arginine-induced increase in renal plasma flow (r=.63, P<.001). These findings suggest that aging and hypertension may independently impair endothelium-dependent renovascular dilation and that this effect may be caused at least in part by a decrease in nitric oxide production.

Adult↗

PubMed1998

Profile of a clinical practice: Thresholds for surgery and surgical outcomes for patients with primary hyperparathyroidism: a national survey of endocrine surgeons.

A 1991 NIH Consensus Development Conference statement provided recommendations for the management of patients with asymptomatic and minimally symptomatic primary hyperparathyroidism (primary HPT), but adherence to these guidelines has not been documented. We conducted a cross-sectional survey of North American members of the American Association of Endocrine Surgeons inquiring about surgeon and primary HPT patient characteristics, thresholds for surgery, and clinical outcomes. Multivariate regression was used to assess the relationship of physician characteristics to practice patterns and outcomes. Of 190 surgeons surveyed, 147 (77%) responded; 109 provided complete responses (57%). These surgeons spend 66% of their time in patient care and perform an average of 33 (range, 1-130) parathyroidectomies/yr. More than 72% of primary HPT patients who underwent surgery were asymptomatic or minimally symptomatic. High volume surgeons (>50 cases/yr) had significantly lower thresholds for surgery with respect to abnormalities in preoperative creatinine clearance, bone densitometry changes, and levels of intact PTH and urinary calcium compared to their low volume colleagues (1-15 cases/yr). Overall reported surgical cure rates were 95.2% after primary operation and 82.7% after reoperation. Compared to high volume surgeons, low volume endocrine surgeons had significantly higher complication rates after primary operation (1.9% vs. 1.0% respectively; P < 0.01) and reoperation (3.8% vs. 1.5%; P < 0.001) as well as higher in-hospital mortality rates (1.0% vs. 0.04%; P < 0.05). Endocrine surgeons operate on a large number of asymptomatic or minimally symptomatic primary HPT patients. Even among a group of highly experienced surgeons who typically see patients after referral from endocrinologists, clinical outcomes and criteria for surgery vary widely and appear to be associated with surgeon experience. Their criteria for surgery diverge from NIH guidelines. These results implore the endocrine community to examine the evidential basis for decisions made in the management of primary HPT.

Female↗

PubMed1996

Cellular ions in NIDDM: relation of calcium to hyperglycemia and cardiac mass.

OBJECTIVE: To investigate the role of hyperglycemia in mediating the clinical association of NIDDM with hypertension and left ventricular dysfunction and hypertrophy. RESEARCH DESIGN AND METHODS: Since hyperglycemia elevates cytosolic free calcium (Cai) both in myocardial and vascular smooth muscle cells, we utilized nuclear magnetic resonance (NMR) spectroscopy to measure erythrocyte Cai levels and compared them with serum ionized calcium (Caio), glucose, and insulin values before and following an oral glucose tolerance test (OGTT) and with previously obtained cardiac structural indexes in normotensive and hypertensive NIDDM (n = 32) and normal control subjects (n = 35). RESULTS: Compared with control subjects, normotensive NIDDM subjects had higher Cai (31.5 +/- 2.3 vs. 24.3 +/- 1.9 nmol/l, P = 0.05), lower intracellular free magnesium (Mgi) (200 +/- 10 vs. 225 +/- 7 mumol/l, P = 0.05), and greater posterior wall thickness (0.98 +/- 0.04 vs. 0.86 +/- 0.03 cm, P = 0.05). Hypertensive NIDDM subjects exhibited a further increase in Cai (43.1 +/- 4.4 nmol/l, P = 0.05 vs. control subjects) and left ventricular mass (LVM) (201.5 +/- 12.2 vs. 155.8 +/- 7.7 g, P = 0.05 vs. control subjects). For all subjects, significant relationships were observed between Cai and fasting blood glucose (r = 0.510, P < 0.01), HbAic (r = 0.389, P < 0.05), and the glycemic response to OGTT (the area under the curve [AUC] for glucose; r = 0.519, P < 0.01) and to systolic (r = 0.504, P < 0.01) and diastolic (r = 0.624, P < 0.01) blood pressure. Left ventricular mass index (LVMI) was related to fasting glucose levels (r = 0.406, P < 0.01) and the AUC for glucose (r = 0.380, P < 0.01), but not to fasting insulin or insulin responses to an OGTT. The LVMI was best related to Cai (r = 0.516, P < 0.01), while being inversely related to Caio (r = -0.486, P < 0.01). Multivariate regression indicated the contribution of glucose to LVMI was independent of age, BMI, insulin, and blood pressure but demonstrated a significant interaction with Cai. CONCLUSIONS: Altogether, these data suggest that glucose-related excess Cai is a fundamental lesion in diabetes that contributes to the elevated blood pressure and cardiac mass in this disease.

Blood Glucose↗

PubMed2004

Genomic-wide cDNA microarray screening to correlate gene expression profile with chemoresistance in patients with advanced lung cancer.

We conducted a study using cDNA microarray analysis to determine whether expression levels of genes in tumors were correlated with tumor response to chemotherapy. Between September 2000 and December 2001, 47 patients were registered in the study. Eighteen patients had small cell lung cancer (SCLC), and others had non-small cell lung cancer (NSCLC). All patients except three received platinum-based chemotherapy. Sixteen of the 18 patients with SCLC (89%) and 13 of the 29 patients with NSCLC (45%) responded to chemotherapy, respectively. Transbroncheal biopsy specimens of tumors were obtained before chemotherapy. The expression levels of 1176 genes in tumor specimens were analyzed using the Atlas Human Cancer 1.2 Array. When we analyzed the data for correlations between gene expression levels and tumor response to chemotherapy, there was a significant increase in the expression of nine genes in non-responders compared with responders to chemotherapy (p< 0.01). Multivariate regression analysis revealed that allogenic inflammatory factor, HLA-DR antigen associated invariant subunit and MHC class II HLA-DR-beta precursor were independent chemo-resistant factors (p<0.0001). When we analyzed the differences in gene expression levels between patients with SCLC and NSCLC, expression levels of one or more resistant genes were increased in comparison with the mean expression of control house keeping genes in five of 18 SCLC patients and 19 of 29 NSCLC patients, respectively (p=0.012). In conclusion, some chemo-resistant genes were detected in the tumor tissue of lung cancer patients using cDNA microarray analysis. A prospective study is required to confirm whether expression levels of these genes reflect chemosensitivity.

Adult↗

PubMed2005

Internal consistency reliability is a poor predictor of responsiveness.

BACKGROUND: Whether responsiveness represents a measurement property of health-related quality of life (HRQL) instruments that is distinct from reliability and validity is an issue of debate. We addressed the claims of a recent study, which suggested that investigators could rely on internal consistency to reflect instrument responsiveness. METHODS: 516 patients with chronic obstructive pulmonary disease or knee injury participating in four longitudinal studies completed generic and disease-specific HRQL questionnaires before and after an intervention that impacted on HRQL. We used Pearson correlation coefficients and linear regression to assess the relationship between internal consistency reliability (expressed as Cronbach's alpha), instrument type (generic and disease-specific) and responsiveness (expressed as the standardised response mean, SRM). RESULTS: Mean Cronbach's alpha was 0.83 (SD 0.08) and mean SRM was 0.59 (SD 0.33). The correlation between Cronbach's alpha and SRMs was 0.10 (95% CI -0.12 to 0.32) across all studies. Cronbach's alpha alone did not explain variability in SRMs (p = 0.59, r2 = 0.01) whereas the type of instrument was a strong predictor of the SRM (p = 0.012, r2 = 0.37). In multivariable models applied to individual studies Cronbach's alpha consistently failed to predict SRMs (regression coefficients between -0.45 and 1.58, p-values between 0.15 and 0.98) whereas the type of instrument did predict SRMs (regression coefficients between -0.25 to -0.59, p-values between <0.01 and 0.05). CONCLUSION: Investigators must look to data other than internal consistency reliability to select a responsive instrument for use as an outcome in clinical trials.

Clinical Trials as Topic↗

PubMedDate not supplied

Pediatrician practices regarding referral to early intervention services: is an established diagnosis important?

OBJECTIVE: Early intervention (EI) programs provide services to children with developmental conditions, regardless of whether such children have an underlying medical diagnosis. We aim to (1) Determine the proportion of general pediatricians who believe an established diagnosis is important when considering EI referral; and (2) Determine whether this perception is associated with lower reported likelihood of referral. METHODS: Mailed survey to random sample of pediatricians. We used multivariable logistic regression to study the association between the perception that a medical diagnosis is important when referring to EI, and the reported likelihood of EI referral for children with common developmental conditions. RESULTS: Response rate was 55% (894 of 1617). A total of 64% of respondents considered an established diagnosis important for EI referral. Likelihood of referral for delayed speech was lower among those who considered a diagnosis important than among those who did not (77% vs 87%; P = .02). Similar patterns held for global delay (91% vs 97%; P = .02), loss of developmental milestones (80% vs 88%; P = .03), and parental concern for inappropriate development (45% vs 60%; P = .002). In multivariable models, perception of the importance of an established diagnosis was associated with lower likelihood of referral for children with delayed speech (adjusted odds ratio [aOR] 0.48; 95% confidence interval [CI] 0.26-0.87) and for parental concern for inappropriate development (aOR 0.46; 95% CI 0.30-0.72). CONCLUSIONS: A majority of general pediatricians believe that an established diagnosis is important when considering EI referral. This perception is associated with decreased reported referral for children with speech delay and those whose parents express concern for inappropriate development.

Attitude of Health Personnel↗

PubMed2005

A pilot case-control study of gamma-radiation sensitivity and risk of papillary thyroid cancer.

In vitro gamma-radiation-induced chromatid breaks per cell (b/c) in lymphocytes may be associated with risk of papillary thyroid cancer (PTC). This pilot case-control study involved 106 patients with thyroid disease (57 with PTC and 49 with benign thyroid disease) and 105 cancer-free matched controls. Multivariate logistic regression analyses identified that an elevated gamma-radiation-induced b/c value was a risk factor for PTC (adjusted odds ratio = 4.54; 95% CI, 2.07-9.95), and a dose-response relationship was evident when the b/c values were categorized into tertiles. High levels of chromatid breaks induced by gamma-radiation may constitute an independent risk factor for PTC, but further study is needed.

Adolescent↗

PubMed1987

Predicting the pharmacodynamics of heparin: a clinical evaluation of the Hepcon System 4.

The magnitude of the anticoagulation response to heparin (heparin responsiveness) varies substantially from patient to patient. Identifying extremes of sensitivity and resistance prior to intravenous administration of heparin would facilitate anticoagulation for cardiopulmonary bypass (CPB). The performance of the Hepcon System 4 (HemoTec, Inc, Englewood, CO), an instrument designed for that purpose, was tested. Using nonheparinized blood samples from 157 patients scheduled for surgery requiring CPB, this device performed activated coagulation times (ACT) with three different concentrations of in vitro heparin. After determining each patient's in vitro heparin response, the heparin dose predicted to produce ACT values of 480 seconds (group 1, N = 77) or 600 seconds (group 2, N = 80) was administered. Five minutes later each patient's ACT was determined with the Hemochron method (International Technidyne, Inc, Edison, NJ). Simultaneously, several other variables that might predict heparin responsiveness were investigated. When compared with the observed ACT, the Hepcon System 4 inadequately predicted the response. There was considerable scatter in this comparison, but most frequently the in vitro method substantially underestimated the in vivo heparin dose requirement. Heparin responsiveness decreased significantly with high platelet counts and advanced age, but was unaffected by the initial hematocrit, ACT, partial thromboplastin time, or preoperative heparin therapy. Previous investigations have not identified a relationship between advanced age and reduced heparin responsiveness. Combining the Hepcon heparin dose-response in vitro method with the other parameters evaluated, stepwise regression could only account for 39% of the observed variability in heparin responsiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1998

[Prognostic factors in low-grade lymphoma].

PURPOSE: Prognostic factors in low grade non-Hodgkin's lymphoma (LGL) are not well established. The aim of this study is to investigate prognostic factors on LGL treated in our institution during the last decade. PATIENTS AND METHODS: The study was carried out on 70 cases of newly diagnosed LGL, most treated with CVP or clorambucil and prednisone. The median follow-up was 37 months (1-132). Variables reported as prognostic factors in previous series were subjected to bivariate and multivariate analysis. RESULTS: Relevant clinical features were: Ann Arbor III-IV stage 74%, ECOG > or = 2-17%, bone marrow involvement 60% and large tumor burden according to MD Anderson criteria 21%. Complete response (CR) was achieved in 50% and partial response in 29%. In bivariate analysis factors related with poor CR were B symptoms, large tumor burden, high LDH and more than one extranodal site involvement. Logistic regression showed that large tumor burden (p = 0.02; OR = 0.07) and B symptoms (p = 0.07; OR = 0.14) were the best prognostic factors of poor CR. Five year global survival (GS) was 55%, with a median of 76 months. In univariate analysis factors related with GS were ECOG > or = 2, B symptoms, bulky, large tumor burden, retroperitoneo involvement and absence of CR. In multivariate analysis the only factor related with poor GS was large tumor burden (p < 0.00001; RR = 5.93). When therapeutic response was included in the model, absence of CR (p = 0.008; RR = 3.40) and large tumour burden (p = 0.005; RR = 3.86) were the factors selected. CONCLUSIONS: In LGL tumor burden was the most important prognostic variable. Tumor response showed less importance than in high grade lymphomas.

Adult↗

PubMed1994

Salvage therapy for multiple myeloma: the University of Arkansas experience.

OBJECTIVE: To summarize a spectrum of salvage regimens for multiple myeloma (MM) developed during the past decade. DESIGN: We reviewed the experience at the University of Arkansas in the management of patients with MM who failed to achieve remission ("primary unresponsive") or had a relapse despite myelosuppressive doses of chemotherapy ("resistant relapse"). MATERIAL AND METHODS: Results with use of the various chemotherapeutic protocols are presented, and multivariate regression analysis was applied to determine the independent contributions of certain factors toward event-free and overall survival. RESULTS: The VAD regimen (vincristine sulfate, Adriamycin [doxorubicin hydrochloride], and dexamethasone) yielded responses in 29% of previously unresponsive and 46% of relapsed cases of MM, in comparison with 25% and 21%, respectively, with use of dexamethasone only. Responses occurred more frequently when tumor cell RNA content was high, tumor burden was low, and duration of drug resistance was less than 1 year. The duration of survival in patients who received high doses of melphalan was decreased in those with increased serum levels of lactate dehydrogenase. EDAP (etoposide, dexamethasone, ara-C, and cisplatin) produced 75% or more tumor cytoreduction in 8 of 20 patients. Overall in patients with an increasing number of adverse factors, response rates and survival decreased progressively with less intensive therapy but were unaffected when more intensive therapy was used. In the multivariate analysis, the most important features for extended survival were a low beta 2-microglobulin level before transplantation and application of two bone marrow transplants within 6 months. CONCLUSION: Variables relative to the patient's overall medical condition, prior treatment, characteristics of MM at diagnosis, and response history should be carefully assessed to determine a plan for salvage therapy that will maximize the opportunity for sustained remission and survival.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Classification and prognostic evaluation in multiple myeloma. A retrospective study of relationship of survivals and responses to chemotherapy to immunological types, 20 single prognostic factors, 15 clinical staging systems, and 6 morphological classifications.

In a group of 136 completely followed up patients with multiple myeloma, the prognostic significance of the immunological myeloma types, of 20 different single prognostic factors, of 15 clinical staging systems, and of 6 morphological classifications was retrospectively investigated by means of the calculation of mean survivals, survival curves, and responses to chemotherapy. A univariate analysis was employed in order to correlate each prognostic parameter at presentation with the survival in the whole group; a multivariate analysis according to the Cox's hazards regression model was used in order to select the most powerful prognostic variables. The patients were grouped according to the myeloma immunological types, to the mean value of each single prognostic factor, and to each stage of the clinical and morphological systems. Causes of death were also related to immunological multiple myeloma types. All single variables, except age and serum calcium, presented a significant relationship with the survival, even if at different significance levels. Cox's regression model selected among them, serum levels of beta 2-microglobulin, percentage of bone marrow plasma cells, hemoglobinemia, lytic bone lesions, and Bence-Jones proteinuria as the most significant factors related to survival. Each clinical and morphological staging system divided groups of patients with significant differences in mean survivals, or in survival curves, or in response to therapy. Multiple myeloma type IgA and micromolecular, with Bence-Jones proteinuria, and type lambda were associated with a poor prognosis, with low therapeutical response, and with the development of fatal renal failure. All these parameters, together with new prognostic factors, are useful in the prognostic evaluation, and, when applied in different steps of the diagnosis and the therapy, allow of studying the clinical course of multiple myeloma under different perspectives, in order to have a more complete picture of the disease and of the single patient.

Adult↗

PubMed2003

Bayesian analysis of a multivariate null intercept errors-in-variables regression model.

Longitudinal data are of great interest in analysis of clinical trials. In many practical situations the covariate can not be measured precisely and a natural alternative model is the errors-in-variables regression models. In this paper we study a null intercept errors-in-variables regression model with a structure of dependency between the response variables within the same group. We apply the model to real data presented in Hadgu and Koch (Hadgu, A., Koch, G. (1999). Application of generalized estimating equations to a dental randomized clinical trial. J. Biopharmaceutical Statistics 9(1):161-178). In that study volunteers with preexisting dental plaque were randomized to two experimental mouth rinses (A and B) or a control mouth rinse with double blinding. The dental plaque index was measured for each subject in the beginning of the study and at two follow-up times, which leads to the presence of an interclass correlation. We propose the use of a Bayesian approach to model a multivariate null intercept errors-in-variables regression model to the longitudinal data. The proposed Bayesian approach accommodates the correlated measurements and incorporates the restriction that the slopes must lie in the (0, 1) interval. A Gibbs sampler is used to perform the computations.

Bayes Theorem↗