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Multivariate Cox Proportional Hazards Models (multivariate + cox_proportional_hazard_models)
Selected AbstractsFruit and vegetable consumption and lung cancer risk: Updated information from the European Prospective Investigation into Cancer and Nutrition (EPIC)INTERNATIONAL JOURNAL OF CANCER, Issue 5 2007Jakob Linseisen Abstract The association of fruit and vegetable consumption and lung cancer incidence was evaluated using the most recent data from the European Prospective Investigation into Cancer and Nutrition (EPIC), applying a refined statistical approach (calibration) to account for measurement error potentially introduced by using food frequency questionnaire data. Between 1992 and 2000, detailed information on diet and life-style of 478,590 individuals participating in EPIC was collected. During a median follow-up of 6.4 years, 1,126 lung cancer cases were observed. Multivariate Cox proportional hazard models were applied for statistical evaluation. In the whole study population, fruit consumption was significantly inversely associated with lung cancer risk while no association was found for vegetable consumption. In current smokers, however, lung cancer risk significantly decreased with higher vegetable consumption; this association became more pronounced after calibration, the hazard ratio (HR) being 0.78 (95% CI 0.62,0.98) per 100 g increase in daily vegetable consumption. In comparison, the HR per 100 g fruit was 0.92 (0.85,0.99) in the entire cohort and 0.90 (0.81,0.99) in smokers. Exclusion of cases diagnosed during the first 2 years of follow-up strengthened these associations, the HR being 0.71 (0.55,0.94) for vegetables (smokers) and 0.86 (0.78,0.95) for fruit (entire cohort). Cancer incidence decreased with higher consumption of apples and pears (entire cohort) as well as root vegetables (smokers). In addition to an overall inverse association with fruit intake, the results of this evaluation add evidence for a significant inverse association of vegetable consumption and lung cancer incidence in smokers. © 2007 Wiley-Liss, Inc. [source] Statin use in Type 2 diabetes mellitus is associated with a delay in starting insulinDIABETIC MEDICINE, Issue 9 2004A. Yee Abstract Aims It has been suggested that HMG Co-A reductase inhibitors (,statins') may reduce the risk of developing Type 2 diabetes mellitus. This study was designed to evaluate whether use of statins would also delay progression to insulin therapy. Methods This was a retrospective cohort study using Saskatchewan Health databases to identify subjects newly started on oral antidiabetic agents from 1991 to 1996. Subjects < 30 years of age or with previous lipid-lowering drug use were excluded. Medications known to influence glycaemic control, co-morbidity, and demographic data were collected. Statin exposure was defined as at least 1 year of use. Primary outcome was starting insulin treatment. Multivariate Cox proportional hazards models were used to examine the association between statin use and starting insulin. Results The final cohort included 10 996 new users of oral antidiabetic agents, of which 484 (4.4%) used statins. Mean age was 64 years and 55% were male. Mean duration of follow-up was 5.1 years; 11.1% (n = 1221) eventually started insulin treatment. Statin users were no less likely than non-users to start insulin treatment eventually (11.6% vs. 11.1%, P = 0.74). After multivariate adjustment, however, statin use was associated with a 10-month delay before newly treated diabetic subjects needed to start insulin treatment (adjusted hazard ratio 0.74; 95% confidence interval 0.56, 0.97, P = 0.028). Conclusion The use of statins is associated with a delay in starting insulin treatment in patients with Type 2 diabetes initially treated with oral antidiabetic agents. Whether this relationship exists for patients at high risk of developing diabetes should be examined in a randomized trial. [source] Coffee consumption and risk of rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 11 2003Elizabeth W. Karlson Objective Recent reports have suggested an association between consumption of coffee or decaffeinated coffee and the risk of rheumatoid arthritis (RA), although data are sparse and somewhat inconsistent. Furthermore, existing studies measured dietary exposures and potential confounders only at baseline and did not consider possible changes in diet or lifestyle over the followup period. We studied whether coffee, decaffeinated coffee, total coffee, tea, or overall caffeine consumption was associated with the risk of RA, using the Nurses' Health Study, a longitudinal cohort study of 121,701 women. Methods Information on beverage consumption was assessed with a food frequency questionnaire (FFQ) that was completed every 4 years, from baseline in 1980 through 1998. Among the 83,124 women who completed the FFQ at baseline, the diagnosis of incident RA (between 1980 and 2000) was confirmed in 480 women by a connective tissue disease screening questionnaire and medical record review for American College of Rheumatology criteria. Relationships between intake of various beverages and the risk of RA were assessed in age-adjusted models and in multivariate Cox proportional hazards models including the cumulative average intake of each beverage during the followup period, adjusted for numerous potential confounders. In addition, for direct comparisons with prior reports, multivariate analyses were repeated using only baseline beverage information. Results We did not find a significant association between decaffeinated coffee consumption of ,4 cups/day (compared with no decaffeinated coffee consumption) and subsequent risk of incident RA, in either an adjusted multivariate model (relative risk [RR] 1.1, 95% confidence interval [95% CI] 0.5,2.2) or a multivariate model using only baseline reports of decaffeinated coffee consumption (RR 1.0, 95% CI 0.6,1.7). Similarly, there was no relationship between cumulative caffeinated coffee consumption and RA risk (RR 1.1, 95% CI 0.8,1.6 for ,4 cups per day versus none) or between tea consumption and RA risk (RR 1.1, 95% CI 0.7,1.8 for >3 cups/day versus none). Total coffee and total caffeine consumption were also not associated with the risk of RA. Conclusion In this large, prospective study, we find little evidence of an association between coffee, decaffeinated coffee, or tea consumption and the risk of RA among women. [source] Interleukin-6 predicts recurrence and survival among head and neck cancer patients,CANCER, Issue 4 2008Sonia A. Duffy PhD Abstract BACKGROUND. Increased pretreatment serum interleukin (IL)-6 levels among patients with head and neck squamous cell carcinoma (HNSCC) have been shown to correlate with poor prognosis, but sample sizes in prior studies have been small and thus unable to control for other known prognostic variables. METHODS. A longitudinal, prospective cohort study determined the correlation between pretreatment serum IL-6 levels, and tumor recurrence and all-cause survival in a large population (N = 444) of previously untreated HNSCC patients. Control variables included age, sex, smoking, cancer site and stage, and comorbidities. Kaplan-Meier plots and univariate and multivariate Cox proportional hazards models were used to study the association between IL-6 levels, control variables, and time to recurrence and survival. RESULTS. The median serum IL-6 level was 13 pg/mL (range, 0-453). The 2-year recurrence rate was 35.2% (standard error, 2.67%). The 2-year death rate was 26.5% (standard error, 2.26%). Multivariate analyses showed that serum IL-6 levels independently predicted recurrence at significant levels [hazard ratio (HR) = 1.32; 95% confidence interval (CI), 1.11 to 1.58; P = .002] as did cancer site (oral/sinus). Serum IL-6 level was also a significant independent predictor of poor survival (HR = 1.22; 95% CI, 1.02 to 1.46; P = .03), as were older age, smoking, cancer site (oral/sinus), higher cancer stage, and comorbidities. CONCLUSIONS. Pretreatment serum IL-6 could be a valuable biomarker for predicting recurrence and overall survival among HNSCC patients. Using IL-6 as a biomarker for recurrence and survival may allow for earlier identification and treatment of disease relapse. Cancer 2008. © 2008 American Cancer Society. [source] | ||||||||||