40 resultados para multivariate regression tree
Resumo:
PURPOSE Open surgical management of unstable pelvic ring injuries has been discussed controversially compared to percutaneous techniques in terms of surgical site morbidity especially in older patients. Thus, we assessed the impact of age on the outcome following fixation of unstable pelvic ring injuries through the modified Stoppa approach. METHODS Out of a consecutive series of 92 patients eligible for the study, 63 patients (mean age 50 years, range 19-78) were evaluated [accuracy of reduction, complications, failures, Majeed-Score, Oswestry Disability Questionnaire (ODI), Mainz Pain Staging System (MPSS)] at a mean follow-up of 3.3 years (range 1.0-7.9). Logistic multivariate regression analysis was performed to assess the outcome in relation to increasing patient age and/or Injury Severity Score (ISS). RESULTS Out of 63 patients, in 36 an "anatomic" reduction was achieved. Ten postoperative complications occurred in eight patients. In five patients, failure of fixation was noted at the anterior and/or posterior pelvic ring. In 49 patients, an "excellent" or "good" Majeed-Score was obtained; the mean ODI was 14 % (range 0-76 %); 50 patients reported either no or only minor chronic pelvic pain (MPSS). Only an increasing ISS conferred an increased likelihood of the occurrence of a non-anatomical reduction, a "poor" or "fair" Majeed-Score, or an ODI >20 %. CONCLUSIONS Increasing age did not impact the analysed parameters. Open reduction and internal fixation of the anterior pelvic ring through a modified Stoppa approach in unstable pelvic ring injuries did not result in an unfavourable outcome with increasing age of patients.
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The purpose of this study was to determine the prevalence and possible etiological factors of erosive tooth wear and wedge-shaped defects in Swiss Army recruits and compare the findings with those of an analogous study conducted in 1996. In 2006, 621 recruits between 18 and 25 years of age (1996: 417 recruits; ages 19 to 25) were examined for erosive tooth wear and wedge-shaped defects. Additional data was acquired using a questionnaire about personal details, education, dentitions subjective condition, oral hygiene, eating and drinking habits, medications used, and general medical problems. In 2006, 60.1% of those examined exhibited occlusal erosive tooth wear not involving the dentin (1996: 82.0%) and 23.0% involving the dentin (1996: 30.7%). Vestibular erosive tooth wear without dentin involvement was seen in 7.7% in 2006 vs. 14.4% in 1996. Vestibular erosive tooth wear with dentin involvement was rare in both years (0.5%). Oral erosive tooth wear lacking exposed dentin was also rare in those years, although more teeth were affected in 2006 (2.1%) than in 1996 (0.7%). The examinations in 2006 found one or more initial wedge-shaped lesions in 8.5% of the recruits, while 20.4% of the study participants exhibited such in 1996. In 1996, 53% consumed acidic foods and beverages more than 5 times/day; in 2006, 83.9% did so. In neither study did multivariate regression analyses show any significant correlations between occurrence and location of erosive tooth wear and wedge-shaped defects and various other parameters, e.g., eating and hygiene habits, or dentin hyper-sensitivity. Despite a significant increase in consumption of acidic products between 1996 and 2006, the latter study found both fewer erosive tooth wear and fewer wedge-shaped defects (i.e., fewer non-carious lesions.).
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OBJECTIVE The aim of this study was to examine the prevalence of nutritional risk and its association with multiple adverse clinical outcomes in a large cohort of acutely ill medical inpatients from a Swiss tertiary care hospital. METHODS We prospectively followed consecutive adult medical inpatients for 30 d. Multivariate regression models were used to investigate the association of the initial Nutritional Risk Score (NRS 2002) with mortality, impairment in activities of daily living (Barthel Index <95 points), hospital length of stay, hospital readmission rates, and quality of life (QoL; adapted from EQ5 D); all parameters were measured at 30 d. RESULTS Of 3186 patients (mean age 71 y, 44.7% women), 887 (27.8%) were at risk for malnutrition with an NRS ≥3 points. We found strong associations (odds ratio/hazard ratio [OR/HR], 95% confidence interval [CI]) between nutritional risk and mortality (OR/HR, 7.82; 95% CI, 6.04-10.12), impaired Barthel Index (OR/HR, 2.56; 95% CI, 2.12-3.09), time to hospital discharge (OR/HR, 0.48; 95% CI, 0.43-0.52), hospital readmission (OR/HR, 1.46; 95% CI, 1.08-1.97), and all five dimensions of QoL measures. Associations remained significant after adjustment for sociodemographic characteristics, comorbidities, and medical diagnoses. Results were robust in subgroup analysis with evidence of effect modification (P for interaction < 0.05) based on age and main diagnosis groups. CONCLUSION Nutritional risk is significant in acutely ill medical inpatients and is associated with increased medical resource use, adverse clinical outcomes, and impairments in functional ability and QoL. Randomized trials are needed to evaluate evidence-based preventive and treatment strategies focusing on nutritional factors to improve outcomes in these high-risk patients.
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AIM To associate the dimension of the facial bone wall with clinical, radiological, and patient-centered outcomes at least 10 years after immediate implant placement with simultaneous guided bone regeneration in a retrospective study. MATERIAL AND METHODS Primary endpoint was the distance from the implant shoulder (IS) to the first bone-to-implant contact (IS-BIC10y ). Secondary endpoints included the facial bone thickness (BT10y ) 2, 4, and 6 mm apical to the IS, and the implant position. At baseline, the horizontal defect width (HDWBL ) from the implant surface to the alveolar wall was recorded. At recall, distance from the IS to the mucosal margin (IS-MM10y ), degree of soft tissue coverage of the mesial and distal aspects of the implants (PISm10y , PISd10y ; Papilla Index), pocket probing depth (PPD10y ), and patient-centered outcomes were determined. Width of the keratinized mucosa (KM), Full-Mouth Plaque and Bleeding Score (FMPS, FMBS) were available for both time points. RESULTS Of the 20 patients who underwent immediate implant placement with simultaneous guided bone regeneration and transmucosal healing, nine males and eight females with a median age of 62 years (42 min, 84 max) were followed up for a median period of 10.5 y (min 10.1 max 11.5). The 10-year implant survival rate was 100%. Multivariate regression analysis revealed a correlation of the IS-BIC10y , controlled for age and gender, with four parameters: HDWBL (P = 0.03), KMBL -10 (P = 0.02), BT10 4 mm (P = 0.01), and BT10 6 mm (P = 0.01). CONCLUSION Within the conditions of the present study, the horizontal defect width was the main indicator for the vertical dimension of the facial bone. The facial bone dimension was further associated with a reduction in the width of the keratinized mucosa and the dimension of the buccal bone.
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PURPOSE To identify the prevalence and progression of macular atrophy (MA) in neovascular age-related macular degeneration (AMD) patients under long-term anti-vascular endothelial growth factor (VEGF) therapy and to determine risk factors. METHOD This retrospective study included patients with neovascular AMD and ≥30 anti-VEGF injections. Macular atrophy (MA) was measured using near infrared and spectral-domain optical coherence tomography (SD-OCT). Yearly growth rate was estimated using square-root transformation to adjust for baseline area and allow for linearization of growth rate. Multiple regression with Akaike information criterion (AIC) as model selection criterion was used to estimate the influence of various parameters on MA area. RESULTS Forty-nine eyes (47 patients, mean age 77 ± 14) were included with a mean of 48 ± 13 intravitreal anti-VEGF injections (ranibizumab:37 ± 11, aflibercept:11 ± 6, mean number of injections/year 8 ± 2.1) over a mean treatment period of 6.2 ± 1.3 years (range 4-8.5). Mean best-corrected visual acuity improved from 57 ± 17 letters at baseline (= treatment start) to 60 ± 16 letters at last follow-up. The MA prevalence within and outside the choroidal neovascularization (CNV) border at initial measurement was 45% and increased to 74%. Mean MA area increased from 1.8 ± 2.7 mm(2) within and 0.5 ± 0.98 mm(2) outside the CNV boundary to 2.7 ± 3.4 mm(2) and 1.7 ± 1.8 mm(2) , respectively. Multivariate regression determined posterior vitreous detachment (PVD) and presence/development of intraretinal cysts (IRCs) as significant factors for total MA size (R(2) = 0.16, p = 0.02). Macular atrophy (MA) area outside the CNV border was best explained by the presence of reticular pseudodrusen (RPD) and IRC (R(2) = 0.24, p = 0.02). CONCLUSION A majority of patients show MA after long-term anti-VEGF treatment. Reticular pseudodrusen (RPD), IRC and PVD but not number of injections or treatment duration seem to be associated with the MA size.
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The development of coronary vasculopathy is the main determinant of long-term survival in cardiac transplantation. The identification of risk factors, therefore, seems necessary in order to identify possible treatment strategies. Ninety-five out of 397 patients, undergoing orthotopic cardiac transplantation from 10/1985 to 10/1992 were evaluated retrospectively on the basis of perioperative and postoperative variables including age, sex, diagnosis, previous operations, renal function, cholesterol levels, dosage of immunosuppressive drugs (cyclosporin A, azathioprine, steroids), incidence of rejection, treatment with calcium channel blockers at 3, 6, 12, and 18 months postoperatively. Coronary vasculopathy was assessed by annual angiography at 1 and 2 years postoperatively. After univariate analysis, data were evaluated by stepwise multiple logistic regression analysis. Coronary vasculopathy was assessed in 15 patients at 1 (16%), and in 23 patients (24%) at 2, years. On multivariate analysis, previous operations and the incidence of rejections were identified as significant risk factors (P < 0.05), whereas the underlying diagnosis had borderline significance (P = 0.058) for the development of graft coronary vasculopathy. In contrast, all other variables were not significant in our subset of patients investigated. We therefore conclude that the development of coronary vasculopathy in cardiac transplant patients mainly depends on the rejection process itself, aside from patient-dependent factors. Therapeutic measures, such as the administration of calcium channel blockers and regulation of lipid disorders, may therefore only reduce the progress of native atherosclerotic disease in the posttransplant setting.
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Histopathologic tumor regression grades (TRGs) after neoadjuvant chemotherapy predict survival in different cancers. In bladder cancer, corresponding studies have not been conducted. Fifty-six patients with advanced invasive urothelial bladder cancer received neoadjuvant chemotherapy before cystectomy and lymphadenectomy. TRGs were defined as follows: TRG1: complete tumor regression; TRG2: >50% tumor regression; TRG3: 50% or less tumor regression. Separate TRGs were assigned for primary tumors and corresponding lymph nodes. The prognostic impact of these 2 TRGs, the highest (dominant) TRG per patient, and competing tumor features reflecting tumor regression (ypT/ypN stage, maximum diameter of the residual tumor) were determined. Tumor characteristics in initial transurethral resection of the bladder specimens were tested for response prediction. The frequency of TRGs 1, 2, and 3 in the primary tumors were n=16, n=19, and n=21; corresponding data from the lymph nodes were n=31, n=9, and n=16. Interobserver agreement in determination of the TRG was strong (κ=0.8). Univariately, all evaluated parameters were significantly (P≤0.001) related to overall survival; however, the segregation of the Kaplan-Meier curves was best for the dominant TRG. In multivariate analysis, only dominant TRG predicted overall survival independently (P=0.035). In transurethral resection specimens of the chemotherapy-naive bladder cancer, the only tumor feature with significant (P<0.03) predictive value for therapy response was a high proliferation rate. In conclusion, among all parameters reflecting tumor regression, the dominant TRG was the only independent risk factor. A favorable chemotherapy response is associated with a high proliferation rate in the initial chemotherapy-naive bladder cancer. This feature might help personalize neoadjuvant chemotherapy.
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Objective: Processes occurring in the course of psychotherapy are characterized by the simple fact that they unfold in time and that the multiple factors engaged in change processes vary highly between individuals (idiographic phenomena). Previous research, however, has neglected the temporal perspective by its traditional focus on static phenomena, which were mainly assessed at the group level (nomothetic phenomena). To support a temporal approach, the authors introduce time-series panel analysis (TSPA), a statistical methodology explicitly focusing on the quantification of temporal, session-to-session aspects of change in psychotherapy. TSPA-models are initially built at the level of individuals and are subsequently aggregated at the group level, thus allowing the exploration of prototypical models. Method: TSPA is based on vector auto-regression (VAR), an extension of univariate auto-regression models to multivariate time-series data. The application of TSPA is demonstrated in a sample of 87 outpatient psychotherapy patients who were monitored by postsession questionnaires. Prototypical mechanisms of change were derived from the aggregation of individual multivariate models of psychotherapy process. In a 2nd step, the associations between mechanisms of change (TSPA) and pre- to postsymptom change were explored. Results: TSPA allowed a prototypical process pattern to be identified, where patient's alliance and self-efficacy were linked by a temporal feedback-loop. Furthermore, therapist's stability over time in both mastery and clarification interventions was positively associated with better outcomes. Conclusions: TSPA is a statistical tool that sheds new light on temporal mechanisms of change. Through this approach, clinicians may gain insight into prototypical patterns of change in psychotherapy.
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BACKGROUND Recently, histopathological tumour regression, prevalence of signet ring cells, and localisation were reported as prognostic factors in neoadjuvantly treated oesophagogastric (junctional and gastric) cancer. This exploratory retrospective study analyses independent prognostic factors within a large patient cohort after preoperative chemotherapy including clinical and histopathological factors. METHODS In all, 850 patients presenting with oesophagogastric cancer staged cT3/4 Nany cM0/x were treated with neoadjuvant chemotherapy followed by resection in two academic centres. Patient data were documented in a prospective database and retrospectively analysed. RESULTS Of all factors prognostic on univariate analysis, only clinical response, complications, ypTNM stage, and R category were independently prognostic (P<0.01) on multivariate analysis. Tumour localisation and signet ring cells were independently prognostic only when investigator-dependent clinical response evaluation was excluded from the multivariate model. Histopathological tumour regression correlates with tumour grading, Laurén classification, clinical response, ypT, ypN, and R categories but was not identified as an independent prognostic factor. Within R0-resected patients only surgical complications and ypTNM stage were independent prognostic factors. CONCLUSIONS Only established prognostic factors like ypTNM stage, R category, and complications were identified as independent prognostic factors in resected patients after neoadjuvant chemotherapy. In contrast, histopathological tumour regression was not found as an independent prognostic marker.
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PURPOSE To identify the influence of fixed prosthesis type on biologic and technical complication rates in the context of screw versus cement retention. Furthermore, a multivariate analysis was conducted to determine which factors, when considered together, influence the complication and failure rates of fixed implant-supported prostheses. MATERIALS AND METHODS Electronic searches of MEDLINE (PubMed), EMBASE, and the Cochrane Library were conducted. Selected inclusion and exclusion criteria were used to limit the search. Data were analyzed statistically with simple and multivariate random-effects Poisson regressions. RESULTS Seventy-three articles qualified for inclusion in the study. Screw-retained prostheses showed a tendency toward and significantly more technical complications than cemented prostheses with single crowns and fixed partial prostheses, respectively. Resin chipping and ceramic veneer chipping had high mean event rates, at 10.04 and 8.95 per 100 years, respectively, for full-arch screwed prostheses. For "all fixed prostheses" (prosthesis type not reported or not known), significantly fewer biologic and technical complications were seen with screw retention. Multivariate analysis revealed a significantly greater incidence of technical complications with cemented prostheses. Full-arch prostheses, cantilevered prostheses, and "all fixed prostheses" had significantly higher complication rates than single crowns. A significantly greater incidence of technical and biologic complications was seen with cemented prostheses. CONCLUSION Screw-retained fixed partial prostheses demonstrated a significantly higher rate of technical complications and screw-retained full-arch prostheses demonstrated a notably high rate of veneer chipping. When "all fixed prostheses" were considered, significantly higher rates of technical and biologic complications were seen for cement-retained prostheses. Multivariate Poisson regression analysis failed to show a significant difference between screw- and cement-retained prostheses with respect to the incidence of failure but demonstrated a higher rate of technical and biologic complications for cement-retained prostheses. The incidence of technical complications was more dependent upon prosthesis and retention type than prosthesis or abutment material.