Kenneth B. Christopher

Dr. Kenneth B. Christopher

Brigham and Women's Hospital, Boston, Massachusetts, USA
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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 October 2014 in JAMA
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KAKarin Amrein
Karin Amrein
CSChristian Schnedl
Christian Schnedl
AHAlexander Holl
Alexander Holl
RRRegina Riedl
Regina Riedl
Kenneth B. ChristopherKenneth B. Christopher
Kenneth B. Christopher
HDHarald Dobnig
Harald Dobnig
Research from JAMA — Effect of High-Dose Vitamin D3 on Hospital Length of Stay in Critically Ill Patients With Vitamin D Deficiency — The VITdAL-ICU Randomized Clinical Trial

1 August 2011 in Critical Care Medicine
Verified
Journal Article
Closed access
HBHeidi S. Bazick
Heidi S. Bazick
DCDomingo Chang
Domingo Chang
KMKarthik Mbbs Mahadevappa
Karthik Mbbs Mahadevappa
FGFiona K. Gibbons
Fiona K. Gibbons
Kenneth B. ChristopherKenneth B. Christopher
Kenneth B. Christopher
Objective: Red cell distribution width is a predictor of mortality in the general population. The prevalence of increased red cell distribution width and its significance in the intensive care unit are unknown. The objective of this study was to investigate the association between red cell distribution width at the initiation of critical care and all cause mortality. Design: Multicenter observational study. Setting: Two tertiary academic hospitals in Boston, MA. Patients: A total of 51,413 patients, aged ≥18 yrs, who received critical care between 1997 and 2007. Interventions: None. Measurements and Main Results: The exposure of interest was red cell distribution width as a predictor of mortality in the general population. The prevalence of increased red cell distribution width and its significance in the intensive care unit are unknown and categorized a priori in quintiles as ≤13.3%, 13.3% to 14.0%, 14.0% to 14.7%, 14.7% to 15.8%, and >15.8%. Logistic regression examined death by days 30, 90, and 365 postcritical care initiation, inhospital mortality, and bloodstream infection. Adjusted odds ratios were estimated by multivariable logistic regression models. Adjustment included age, sex, race, Deyo–Charlson index, coronary artery bypass grafting, myocardial infarction, congestive heart failure, hematocrit, white blood cell count, mean corpuscular volume, blood urea nitrogen, red blood cell transfusion, sepsis, and creatinine. Red cell distribution width was a particularly strong predictor of all-cause mortality 30 days after critical care initiation with a significant risk gradient across red cell distribution width quintiles after multivariable adjustment: red cell distribution width 13.3% to 14.0% (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.08–1.30; p <.001); red cell distribution width 14.0% to 14.7% (OR, 1.28; 95% CI, 1.16–1.42; p <.001); red cell distribution width 14.7% to 15.8% (OR, 1.69; 95% CI, 1.52–1.86; p <.001); red cell distribution width >15.8% (OR, 2.61; 95% CI, 2.37–2.86; p <.001), all relative to patients with red cell distribution width ≤13.3%. Similar significant robust associations postmultivariable adjustments are seen with death by days 90 and 365 postcritical care initiation as well as inhospital mortality. In a subanalysis of patients with blood cultures drawn (n = 18,525), red cell distribution width at critical care initiation was associated with the risk of bloodstream infection and remained significant after multivariable adjustment. The adjusted risk of bloodstream infection was 1.40- and 1.44-fold higher in patients with red cell distribution width values in the 14.7% to 15.8% and >15.8% quintiles, respectively, compared with those with red cell distribution width ≤13.3%. Estimating the receiver operating characteristic area under the curve shows that red cell distribution width has moderate discriminative power for 30-day mortality (area under the curve = 0.67). Conclusion: Red cell distribution width is a robust predictor of the risk of all-cause patient mortality and bloodstream infection in the critically ill. Red cell distribution width is commonly measured, inexpensive, and widely available and may reflect overall inflammation, oxidative stress, or arterial underfilling in the critically ill.

1 April 2011 in Critical Care Medicine
Verified
Journal Article
Closed access
ABAndrea Braun
Andrea Braun
DCDomingo Chang
Domingo Chang
KMKarthik Mbbs Mahadevappa
Karthik Mbbs Mahadevappa
FGFiona K. Gibbons
Fiona K. Gibbons
YLYan Liu
Yan Liu
Kenneth B. ChristopherKenneth B. Christopher
Kenneth B. Christopher
Objective: We hypothesized that deficiency in 25-hydroxyvitamin D before hospital admission would be associated with all-cause mortality in the critically ill. Design: Multicenter observational study of patients treated in medical and surgical intensive care units. Setting: A total of 209 medical and surgical intensive care beds in two teaching hospitals in Boston, MA. Patients: A total of 2399 patients, age ≥18 yrs, in whom 25-hydroxyvitamin D was measured before hospitalization between 1998 and 2009. Interventions: None. Measurements and Main Results: Preadmission 25-hydroxyvitamin D was categorized as deficiency in 25-hydroxyvitamin D (≤15 ng/mL), insufficiency (16–29 ng/mL), and sufficiency (≥30 ng/mL). Logistic regression examined death by days 30, 90, and 365 post-intensive care unit admission, in-hospital mortality, and blood culture positivity. Adjusted odds ratios were estimated by multivariable logistic regression models. Preadmission 25-hydroxyvitamin D deficiency is predictive for short-term and long-term mortality. At 30 days following intensive care unit admission, patients with 25-hydroxyvitamin D deficiency have an odds ratio for mortality of 1.69 (95% confidence interval of 1.28–2.23, p < .0001) relative to patients with 25-hydroxyvitamin D sufficiency. 25-Hydroxyvitamin D deficiency remains a significant predictor of mortality at 30 days following intensive care unit admission following multivariable adjustment (adjusted odds ratio of 1.69, 95% confidence interval of 1.26–2.26, p < .0001). At 30 days following intensive care unit admission, patients with 25-hydroxyvitamin D insufficiency have an odds ratio of 1.32 (95% confidence interval of 1.02–1.72, p = .036) and an adjusted odds ratio of 1.36 (95% confidence interval of 1.03–1.79, p = .029) relative to patients with 25-hydroxyvitamin D sufficiency. Results were similar at 90 and 365 days following intensive care unit admission and for in-hospital mortality. In a subgroup analysis of patients who had blood cultures drawn (n = 1160), 25-hydroxyvitamin D deficiency was associated with increased risk of blood culture positivity. Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for blood culture positivity of 1.64 (95% confidence interval of 1.05–2.55, p = .03) relative to patients with 25-hydroxyvitamin D sufficiency, which remains significant following multivariable adjustment (odds ratio of 1.58, 95% confidence interval of 1.01–2.49, p = .048). Conclusion: Deficiency of 25-hydroxyvitamin D before hospital admission is a significant predictor of short- and long-term all-cause patient mortality and blood culture positivity in a critically ill patient population.

22 April 2015 in Thorax
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Journal Article
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RDR. C. A. Dancer
R. C. A. Dancer
DPDhruv Parekh
Dhruv Parekh
SLSian Lax
Sian Lax
VDVijay D'Souza
Vijay D'Souza
SZShengxing Zheng
Shengxing Zheng
DTdavid thhickett
david thhickett
Rationale Vitamin D deficiency has been implicated as a pathogenic factor in sepsis and intensive therapy unit mortality but has not been assessed as a risk factor for acute respiratory distress syndrome (ARDS). Causality of these associations has never been demonstrated. Objectives To determine if ARDS is associated with vitamin D deficiency in a clinical setting and to determine if vitamin D deficiency in experimental models of ARDS influences its severity. Methods Human, murine and in vitro primary alveolar epithelial cell work were included in this study. Findings Vitamin D deficiency (plasma 25(OH)D levels 600 genes. In a clinical setting, pharmacological repletion of vitamin D prior to oesophagectomy reduced the observed changes of in vivo measurements of alveolar capillary damage seen in deficient patients. Conclusions Vitamin D deficiency is common in people who develop ARDS. This deficiency of vitamin D appears to contribute to the development of the condition, and approaches to correct vitamin D deficiency in patients at risk of ARDS should be developed. Trial registration UKCRN ID 11994.

1 January 2012 in Critical Care Medicine
Verified
Journal Article
Closed access
ABAndrea B. Braun
Andrea B. Braun
FGFiona K. Gibbons
Fiona K. Gibbons
ALAugusto Litonjua
Augusto Litonjua
EGEdward MD Giovannucci
Edward MD Giovannucci
Kenneth B. ChristopherKenneth B. Christopher
Kenneth B. Christopher
Objective: We hypothesized that deficiency in 25-hydroxyvitamin D at critical care initiation would be associated with all-cause mortalities. Design: Two-center observational study. Setting: Two teaching hospitals in Boston, MA. Patients: The study included 1,325 patients, age ≥18 yrs, in whom 25-hydroxyvitamin D was measured 7 days before or after critical care initiation between 1998 and 2009. Measurements: 25-hydroxyvitamin D was categorized as deficiency in 25-hydroxyvitamin D (≤15 ng/mL), insufficiency (16–29 ng/mL), and sufficiency (≥30 ng/mL). Logistic regression examined death by days 30, 90, and 365 postcritical care initiation and in-hospital mortality. Adjusted odds ratios were estimated by multivariable logistic regression models. Interventions: None. Key Results: 25-hydroxyvitamin D deficiency is predictive for short-term and long-term mortality. Thirty days following critical care initiation, patients with 25-hydroxyvitamin D deficiency have an odds ratio for mortality of 1.85 (95% confidence interval 1.15–2.98; p = .01) relative to patients with 25-hydroxyvitamin D sufficiency. 25-hydroxyvitamin D deficiency remains a significant predictor of mortality at 30 days following critical care initiation following multivariable adjustment for age, gender, race, Deyo-Charlson index, sepsis, season, and surgical vs. medical patient type (adjusted odds ratio 1.94; 95% confidence interval 1.18–3.20; p = .01). Results were similarly significant at 90 and 365 days following critical care initiation and for in-hospital mortality. The association between vitamin D and mortality was not modified by sepsis, race, or neighborhood poverty rate, a proxy for socioeconomic status. Conclusion: Deficiency of 25-hydroxyvitamin D at the time of critical care initiation is a significant predictor of all-cause patient mortality in a critically ill patient population.

1 December 2015 in Critical Care Medicine
Verified
Journal Article
Closed access
KMKris M Mogensen
Kris M Mogensen
MRMalcolm K. Robinson
Malcolm K. Robinson
JCJonathan D. Casey
Jonathan D. Casey
NGNicole S. Gunasekera
Nicole S. Gunasekera
TMTakuhiro Moromizato
Takuhiro Moromizato
Kenneth B. ChristopherKenneth B. Christopher
Kenneth B. Christopher
The association between nutritional status and mortality in critically ill patients is unclear based on the current literature. To clarify this relation, we analyzed the association between nutrition and mortality in a large population of critically ill patients and hypothesized that mortality would be impacted by nutritional status. Retrospective observational study. Single academic medical center. Six thousand five hundred eighteen adults treated in medical and surgical ICUs between 2004 and 2011. None. All cohort patients received a formal, in-person, standardized evaluation by a registered dietitian. The exposure of interest, malnutrition, was categorized as nonspecific malnutrition, protein-energy malnutrition, or well nourished and determined by data related to anthropometric measurements, biochemical indicators, clinical signs of malnutrition, malnutrition risk factors, and metabolic stress. The primary outcome was all-cause 30-day mortality determined by the Social Security Death Master File. Associations between nutrition groups and mortality were estimated by bivariable and multivariable logistic regression models. Adjusted odds ratios were estimated with inclusion of covariate terms thought to plausibly interact with both nutrition status and mortality. We used propensity score matching on baseline characteristics to reduce residual confounding of the nutrition status category assignment. In the cohort, nonspecific malnutrition was present in 56%, protein-energy malnutrition was present in 12%, and 32% were well nourished. The 30-day and 90-day mortality rates for the cohort were 19.1% and 26.6%, respectively. Nutritional status is a significant predictor of 30-day mortality following adjustment for age, gender, race, medical versus surgical patient type, Deyo-Charlson index, acute organ failure, vasopressor use, and sepsis: nonspecific malnutrition 30-day mortality odds ratio, 1.17 (95% CI, 1.01-1.37); protein-energy malnutrition 30-day mortality odds ratio, 2.10 (95% CI, 1.70-2.59), all relative to patients without malnutrition. In the matched cohort, the adjusted odds of 30-day mortality in the group of propensity score-matched patients with protein-energy malnutrition was two-fold greater than that of patients without malnutrition. In a large population of critically ill adults, an association exists between nutrition status and mortality.