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Publications (5)25.12 Total impact

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    ABSTRACT: Older literature suggested that the plasma sodium concentration is not individual - that it is neither intrinsic to an individual nor reproducible, longitudinally. We recently observed that plasma sodium concentration is heritable. Because demonstrable heritability requires individuality of the relevant phenotype, we hypothesized that plasma sodium concentration was substantially individual. In two large health plan-based cohorts, we demonstrated individuality of the plasma sodium concentration over a ten-year interval; intraclass correlation coefficient (ICC) averaged 0.4 - 0.5. Individuality of plasma sodium increased significantly with age. Plasma sodium individuality was equal to or only slightly less than that for plasma glucose, but was less than the individuality for creatinine. Individuality of plasma sodium was further confirmed by comparing the Pearson correlation coefficient for within-individual vs. between-individual pairs of sodium determinations, and via application of the agreement index. Furthermore, the distribution of all sodium determinations for all participants within a population was similar to the distribution for the mean sodium concentration for individuals within that population. Therefore, the near-normal distribution of plasma sodium measurements within a population is likely not attributable to assay-specific factors but rather to genuine and durable biological variability in osmotic set-point. In aggregate, these data strongly support the individuality of the plasma sodium concentration. They further indicate that serial plasma sodium values for any given individual tend to cluster around a patient-specific set-point, and that these set-points vary among individuals.
    AJP Renal Physiology 04/2014; · 4.42 Impact Factor
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    ABSTRACT: Among lung cancer patients, depression has been associated with increased mortality, although the mechanisms are unknown. We evaluated the association of depression with mortality and receipt of cancer therapies among depressed veterans with lung cancer. A retrospective, cohort study of lung cancer patients in the Veterans Affairs-Northwest Health Network from 1995 to 2010. Depression was defined by ICD-9 coding within 24 months before lung cancer diagnosis. Multivariable Cox proportional analysis and logistic regression were used. In total, 3869 lung cancer patients were evaluated; 14% had a diagnosis of depression. A diagnosis of depression was associated with increased mortality among all stage lung cancer patients (hazard ratio = 1.14, 95% confidence interval: 1.03-1.27, P = 0.01). Among early-stage (I and II) non-small cell lung cancer (NSCLC) patients, the hazard ratio was 1.37 (95% confidence interval: 1.12-1.68, P = 0.003). There was no association of depression diagnosis with surgery (odds ratio = 0.83, 95% confidence interval: 0.56-1.22, P = 0.34) among early-stage NSCLC patients. A depression diagnosis was not associated with mortality (hazard ratio = 1.02, 95% confidence interval: 0.89-1.16, P = 0.78) or chemotherapy (odds ratio = 1.07, 95% confidence interval: 0.83-1.39, P = 0.59) or radiation (odds ratio = 1.04, 95% confidence interval: 0.81-1.34, P = 0.75) receipt among advanced-stage (III and IV) NSCLC patients. Increased utilisation of health services for depression was associated with increased mortality among depressed patients. Depression is associated with increased mortality in lung cancer patients and this association is higher among those with increased measures of depression care utilisation. Differences in lung cancer treatment receipt are probably not responsible for the observed mortality differences between depressed and non-depressed patients. Clinicians should recognise the significant effect of depression on lung cancer survival.
    Clinical Oncology 09/2013; · 2.83 Impact Factor
  • American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California; 05/2012
  • American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California; 05/2012
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    ABSTRACT: Lung cancer is the leading cause of cancer-related mortality. Intensive care unit (ICU) use among patients with cancer is increasing, but data regarding ICU outcomes for patients with lung cancer are limited. We used the Surveillance, Epidemiology, and End Results (SEER) -Medicare registry (1992 to 2007) to conduct a retrospective cohort study of patients with lung cancer who were admitted to an ICU for reasons other than surgical resection of their tumor. We used logistic and Cox regression to evaluate associations of patient characteristics and hospital mortality and 6-month mortality, respectively. We calculated adjusted associations for mechanical ventilation receipt with hospital and 6-month mortality. Of the 49,373 patients with lung cancer admitted to an ICU for reasons other than surgical resection, 76% of patients survived the hospitalization, and 35% of patients were alive 6 months after discharge. Receipt of mechanical ventilation was associated with increased hospital mortality (adjusted odds ratio, 6.95; 95% CI, 6.89 to 7.01; P < .001), and only 15% of these patients were alive 6 months after discharge. Of all ICU patients with lung cancer, the percentage of patients who survived 6 months from discharge was 36% for patients diagnosed in 1992 and 32% for patients diagnosed in 2005, whereas it was 16% and 11% for patients who received mechanical ventilation, respectively. Most patients with lung cancer enrolled in Medicare who are admitted to an ICU die within 6 months of admission. To improve patient-centered care, these results should guide shared decision making between patients with lung cancer and their clinicians before an ICU admission.
    Journal of Clinical Oncology 04/2012; 30(14):1686-91. · 17.88 Impact Factor