John Kalbfleisch - Academia.edu (original) (raw)

Papers by John Kalbfleisch

Academic Emergency Medicine, 2013

We propose a nonparametric bivariate time-varying coefficient model for longitudinal measurements... more We propose a nonparametric bivariate time-varying coefficient model for longitudinal measurements with the occurrence of a terminal event that is subject to right censoring. The time-varying coefficients capture the longitudinal trajectories of covariate effects along with both the followup time and the residual lifetime. The proposed model extends the parametric conditional approach given terminal event time in recent literature, and thus avoids potential model misspecification. We consider a kernel smoothing method for estimating regression coefficients in our model and use cross-validation for bandwidth selection, applying undersmoothing in the final analysis to eliminate the asymptotic bias of the kernel estimator. We show that the kernel estimates are asymptotically normal under mild regularity conditions, and provide an easily computable sandwich variance estimator. We conduct extensive simulations that show desirable performance of the proposed approach, and apply the method ...

— Kidney transplantation has emerged as the treatment for the most serious forms of kidney diseas... more — Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease, but the supply of kidneys from deceased donors cannot meet the fastgrowing demand. Recently, Kidney Paired Donation (KPD) program, a modality which enables willing but incompatible live donor-candidate pairs to swap donors, offers a promising solution for closing the gap between kidney supply and demand. Most of current KPD programs focus mainly on organ allocations strategies achieving the maximum number of transplants or matches. However, patients ’ quality of life after transplants can be more important for kidney candidates. In this paper, we propose a novel algorithmic platform to optimize cross-matches with the maximum benefits for donor-candidate pairs. Utilizing the power of integer programming, our platform implements a recently proposed method that takes probabilistic-based utility as the objective function, so that the overall expected utility, instead of the number of matc...

Stroke, Feb 1, 2012

Background/Purpose: Increased time to tPA treatment is associated with worse outcomes. Thus, iden... more Background/Purpose: Increased time to tPA treatment is associated with worse outcomes. Thus, identifying modifiable treatment delays may improve stroke outcomes. We hypothesized that pre-thrombolytic anti-hypertensive treatment (AHT) may prolong door to treatment time (DTT). Methods: Secondary data analysis of consecutive tPA-treated patients at 24 randomly selected Michigan community hospitals in the INSTINCT trial. DTT among stroke patients who received pre-thrombolytic AHT were compared to those that did not receive pre-thrombolytic AHT. We then calculated a propensity score for the probability of receiving pre-thrombolytic AHT using a logistic regression model with covariates including demographics, stroke risk factors, antiplatelet or beta blocker as home medication, stroke severity (NIHSS), onset to door time, admission glucose, pretreatment systolic and diastolic blood pressure, EMS usage and location at time of stroke. A paired t-test was then performed to compare the DTT between the propensity matched groups. A separate generalized estimating equations (GEE) approach was also used to estimate the differences between patients receiving pre-thrombolytic AHT and those that did not while accounting for within hospital clustering. Results: A total of 557 patients were included in INSTINCT, however onset, arrival or treatment times were not able to be determined in 23, leaving 534 patients for this analysis. The unmatched cohort consisted of 95 stroke patients who received pre-thrombolytic AHT and 439 stroke patients who did not receive AHT from 2007-2010 ( table ). In the unmatched cohort, patients who received pre-thrombolytic AHT had a longer DTT (mean increase 9 minutes; 95% confidence interval (CI) 2-16 minutes) than patients who did not receive pre-thrombolytic AHT. After propensity matching (table), patients who received pre-thrombolytic AHT had a longer DTT (mean increase 10.4 minutes, 95% CI 1.9 - 18.8) than patients who did not receive pre-thrombolytic AHT. This effect persisted and its magnitude was not altered by accounting for clustering within hospitals. Conclusion: Pre-thrombolytic AHT is associated with modest delays in DTT. This represents a feasible target for physician educational interventions and quality improvement initiatives. Further research evaluating optimum hypertension management pre-thrombolytic treatment is warranted.

Stroke, Feb 1, 2012

Background and purpose Protocol deviations (PDs) before and immediately after IV thrombolysis for... more Background and purpose Protocol deviations (PDs) before and immediately after IV thrombolysis for acute ischemic stroke are common. Patient and hospital factors associated with PDs are not well described. We aimed to determine which patient or hospital factors were associated with pre- and post-treatment PDs in a cohort of community treated thrombolysis patients. Methods The INSTINCT (Increasing Stroke Treatment through Interventional Behavior Change Tactics) study was a multicenter, cluster-randomized controlled trial in 24 Michigan community hospitals evaluating the efficacy of a barrier assessment and educational intervention to increase appropriate tPA use. PDs were defined based on 2007 AHA guidelines with the addition of the 3-4.5 hour treatment window, for which the ECASS III criteria were applied. PDs were categorized as pre-treatment (Pre-PDs), post-treatment (Post-PDs) or both. Multi-level logistic regression models were fitted to determine whether patient and hospital variables were associated with Pre-PDs or Post-PDs. The models included all variables specified a priori to be potentially clinically relevant; Pre-PD was included as a covariate in the model for Post-PD. Results During the study, 557 patients (mean age 70; 52% male; median NIHSS 12) were treated with IV tPA. PDs occurred in 233 (42%) patients: 26% had only Post-PDs, 7% had only Pre-PDs, and 9% had both. The most common PDs included failure to treat post-treatment hypertension (131, 24%), antiplatelet agent within 24 hours of treatment (61, 11%), pre-treatment blood pressure over 185/110 (39, 7%), anticoagulant agent within 24 hours of treatment (31, 6%), and treatment outside the time window (29, 5%). Symptomatic intracranial hemorrhage (SICH) was observed in 7.3% of patients with PDs and 6.5% of patients without any PD. In-hospital case fatality was 12% with and 10% without a PD. The differences in SICH and case fatality were not statistically significant. In the fully adjusted model, older age was significantly associated with Pre-PDs ( Table ). When Post-PDs were evaluated with adjustment for Pre-PDs, age was not associated with PDs; however, Pre-PDs were associated with Post-PDs. Conclusion Older age was associated with increased odds of Pre-PDs in Michigan community hospitals. Pre-PDs were associated with Post-PDs. SICH and in-hospital case fatality were not associated with PDs; however, the low number of such events limited our ability to detect a difference. Stroke severity and hospital factors were not associated with PDs.

Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease,... more Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease, but the supply of kidneys from deceased donors cannot meet the fastgrowing demand. Recently, Kidney Paired Donation (KPD) program, a modality which enables willing but incompatible live donor-candidate pairs to swap donors, offers a promising solution for closing the gap between kidney supply and demand. Most of current KPD programs focus mainly on organ allocations strategies achieving the maximum number of transplants or matches. However, patients’ quality of life after transplants can be more important for kidney candidates. In this paper, we propose a novel algorithmic platform to optimize cross-matches with the maximum benefits for donor-candidate pairs. Utilizing the power of integer programming, our platform implements a recently proposed method that takes probabilistic-based utility as the objective function, so that the overall expected utility, instead of the number of matches...

Randomization was a key contribution of Sir Ronald Fisher to the conduct of scientific investigat... more Randomization was a key contribution of Sir Ronald Fisher to the conduct of scientific investigations. Along with the protective aspects of randomization, Fisher also noted that the distribution induced by randomization can form the basis of inference. Indeed, in some instances, the randomization test and related procedures seem to be the only tools available for inference. Several authors have noted the advisability of randomizing again if, in a particular instance, the observed randomization leads to an unacceptable degree of imbalance in important factors between two treatment groups. We develop further methods initially proposed in Morgan and Rubin (2012) and Xu and Kalbfleisch (2011) on the systematic use of rerandomization. In particular, we combine optimal matching with rerandomization, which retains efficiency gains and improves robustness. The approach is potentially useful in cluster randomized trials. Extensions of the methods to multiple armed trials are also considered ...

BACKGROUND A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients w... more BACKGROUND A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients with asthma. Our goal was to evaluate factors associated with habitual snoring and OSA risk in these patients. METHODS Patients with asthma were surveyed at specialty clinics with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) and questions about the frequency of asthma symptoms (National Asthma Education and Prevention Program guidelines), followed by medical record review. SA-SDQ scores >or= 36 for men and >or= 32 for women defined high OSA risk. Logistic regression was used to model associations with habitual snoring and high OSA risk. RESULTS Among 244 patients, 37% snored habitually and 40% demonstrated high OSA risk. Independent predictors of habitual snoring included gastroesophageal reflux disease (GERD) [odds ratio (OR), 2.19; 95% confidence interval (CI), 1.19 to 4.02] and use of an inhaled corticosteroid (ICS) [OR, 2.66; 95% CI, 1.05 to 6.72]. High OS...

In clinical and observational studies, recurrent event data (e.g. hospitalization) with a termina... more In clinical and observational studies, recurrent event data (e.g. hospitalization) with a terminal event (e.g. death) are often encountered. In many instances, the terminal event is strongly correlated with the recurrent event process. In this ar- ticle, we propose a semiparametric method to jointly model the recurrent and terminal event processes. The dependence,is modeled,by a shared gamma,frailty that is

In this paper, we develop a weighted permutation (WP) method to construct con- fidence intervals ... more In this paper, we develop a weighted permutation (WP) method to construct con- fidence intervals for regression parameters in relative risk regression models. The WP method,is a generalized permutation approach. It constructs a resampled his- tory which mimics the observed history for individuals under study. Inference pro- cedures are based on studentized score statistics that are insensitive to the forms of the relative risk function. This makes the WP method,appealing in the general framework,of the relative risk regression model. First order accuracy of the WP method,is established using the counting process approach with a partial likeli- hood filtration. A simulation study indicates that the method,typically improves accuracy over asymptotic confidence intervals. Permutation Methods in Relative Risk Regression Models By Wenyu Jiang Biometric Research Branch,

Canadian Journal of Statistics, 1998

Canadian Journal of Statistics, 2014

Journal of immunology (Baltimore, Md. : 1950), Jan 5, 2015

Cardiac dysfunction is a major consequence of sepsis/septic shock and contributes to the high mor... more Cardiac dysfunction is a major consequence of sepsis/septic shock and contributes to the high mortality of sepsis. Innate and inflammatory responses mediated by TLRs play a critical role in sepsis-induced cardiac dysfunction. MicroRNA-146 (miR-146) was first identified as a negative regulator in innate immune and inflammatory responses induced by LPS. This study examined whether miR-146a will have a protective effect on sepsis-induced cardiac dysfunction. Lentivirus-expressing miR-146a (LmiR-146a) or lentivirus-expressing scrambled miR (LmiR-control) was delivered into the myocardium via the right carotid artery. Seven days after transfection, mice were subjected to cecal ligation and puncture (CLP). Untransfected mice were also subjected to CLP-induced sepsis. Cardiac function was examined by echocardiography before and 6 h after CLP. In vitro studies showed that increased miR-146a levels suppress LPS-induced IκBα phosphorylation and inflammatory cytokine production in both H9C2 ca...

Journal of the American Society of Nephrology : JASN, Jan 16, 2015

Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysi... more Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysis facilities with the national average, and are currently adjusted for race. However, whether the adjustment for race obscures or clarifies disparities in quality of care for minority groups is unknown. Cox model-based SMRs were computed with and without adjustment for patient race for 5920 facilities in the United States during 2010. The study population included virtually all patients treated with dialysis during this period. Without race adjustment, facilities with higher proportions of black patients had better survival outcomes; facilities with the highest percentage of black patients (top 10%) had overall mortality rates approximately 7% lower than expected. After adjusting for within-facility racial differences, facilities with higher proportions of black patients had poorer survival outcomes among black and non-black patients; facilities with the highest percentage of black patie...

Infection control and hospital epidemiology, Jan 16, 2015

OBJECTIVE To observe patient care across hemodialysis facilities enrolled in the National Opportu... more OBJECTIVE To observe patient care across hemodialysis facilities enrolled in the National Opportunity to Improve Infection Control in ESRD (end-stage renal disease) (NOTICE) project in order to evaluate adherence to evidence-based practices aimed at prevention of infection. SETTING AND PARTICIPANTS Thirty-four hemodialysis facilities were randomly selected from among 772 facilities in 4 end-stage renal disease participating networks. Facility selection was stratified on dialysis organization affiliation, size, socioeconomic status, and urban/rural status. MEASUREMENTS Trained infection control evaluators used an infection control worksheet to observe 73 distinct infection control practices at the hemodialysis facilities, from October 1, 2011, through January 31, 2012. RESULTS There was considerable variation in infection control practices across enrolled facilities. Overall adherence to recommended practices was 68% (range, 45%-92%) across all facilities. Overall adherence to expect...

Lecture Notes in Statistics, 1989

Academic Emergency Medicine, 2013

We propose a nonparametric bivariate time-varying coefficient model for longitudinal measurements... more We propose a nonparametric bivariate time-varying coefficient model for longitudinal measurements with the occurrence of a terminal event that is subject to right censoring. The time-varying coefficients capture the longitudinal trajectories of covariate effects along with both the followup time and the residual lifetime. The proposed model extends the parametric conditional approach given terminal event time in recent literature, and thus avoids potential model misspecification. We consider a kernel smoothing method for estimating regression coefficients in our model and use cross-validation for bandwidth selection, applying undersmoothing in the final analysis to eliminate the asymptotic bias of the kernel estimator. We show that the kernel estimates are asymptotically normal under mild regularity conditions, and provide an easily computable sandwich variance estimator. We conduct extensive simulations that show desirable performance of the proposed approach, and apply the method ...

— Kidney transplantation has emerged as the treatment for the most serious forms of kidney diseas... more — Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease, but the supply of kidneys from deceased donors cannot meet the fastgrowing demand. Recently, Kidney Paired Donation (KPD) program, a modality which enables willing but incompatible live donor-candidate pairs to swap donors, offers a promising solution for closing the gap between kidney supply and demand. Most of current KPD programs focus mainly on organ allocations strategies achieving the maximum number of transplants or matches. However, patients ’ quality of life after transplants can be more important for kidney candidates. In this paper, we propose a novel algorithmic platform to optimize cross-matches with the maximum benefits for donor-candidate pairs. Utilizing the power of integer programming, our platform implements a recently proposed method that takes probabilistic-based utility as the objective function, so that the overall expected utility, instead of the number of matc...

Stroke, Feb 1, 2012

Background/Purpose: Increased time to tPA treatment is associated with worse outcomes. Thus, iden... more Background/Purpose: Increased time to tPA treatment is associated with worse outcomes. Thus, identifying modifiable treatment delays may improve stroke outcomes. We hypothesized that pre-thrombolytic anti-hypertensive treatment (AHT) may prolong door to treatment time (DTT). Methods: Secondary data analysis of consecutive tPA-treated patients at 24 randomly selected Michigan community hospitals in the INSTINCT trial. DTT among stroke patients who received pre-thrombolytic AHT were compared to those that did not receive pre-thrombolytic AHT. We then calculated a propensity score for the probability of receiving pre-thrombolytic AHT using a logistic regression model with covariates including demographics, stroke risk factors, antiplatelet or beta blocker as home medication, stroke severity (NIHSS), onset to door time, admission glucose, pretreatment systolic and diastolic blood pressure, EMS usage and location at time of stroke. A paired t-test was then performed to compare the DTT between the propensity matched groups. A separate generalized estimating equations (GEE) approach was also used to estimate the differences between patients receiving pre-thrombolytic AHT and those that did not while accounting for within hospital clustering. Results: A total of 557 patients were included in INSTINCT, however onset, arrival or treatment times were not able to be determined in 23, leaving 534 patients for this analysis. The unmatched cohort consisted of 95 stroke patients who received pre-thrombolytic AHT and 439 stroke patients who did not receive AHT from 2007-2010 ( table ). In the unmatched cohort, patients who received pre-thrombolytic AHT had a longer DTT (mean increase 9 minutes; 95% confidence interval (CI) 2-16 minutes) than patients who did not receive pre-thrombolytic AHT. After propensity matching (table), patients who received pre-thrombolytic AHT had a longer DTT (mean increase 10.4 minutes, 95% CI 1.9 - 18.8) than patients who did not receive pre-thrombolytic AHT. This effect persisted and its magnitude was not altered by accounting for clustering within hospitals. Conclusion: Pre-thrombolytic AHT is associated with modest delays in DTT. This represents a feasible target for physician educational interventions and quality improvement initiatives. Further research evaluating optimum hypertension management pre-thrombolytic treatment is warranted.

Stroke, Feb 1, 2012

Background and purpose Protocol deviations (PDs) before and immediately after IV thrombolysis for... more Background and purpose Protocol deviations (PDs) before and immediately after IV thrombolysis for acute ischemic stroke are common. Patient and hospital factors associated with PDs are not well described. We aimed to determine which patient or hospital factors were associated with pre- and post-treatment PDs in a cohort of community treated thrombolysis patients. Methods The INSTINCT (Increasing Stroke Treatment through Interventional Behavior Change Tactics) study was a multicenter, cluster-randomized controlled trial in 24 Michigan community hospitals evaluating the efficacy of a barrier assessment and educational intervention to increase appropriate tPA use. PDs were defined based on 2007 AHA guidelines with the addition of the 3-4.5 hour treatment window, for which the ECASS III criteria were applied. PDs were categorized as pre-treatment (Pre-PDs), post-treatment (Post-PDs) or both. Multi-level logistic regression models were fitted to determine whether patient and hospital variables were associated with Pre-PDs or Post-PDs. The models included all variables specified a priori to be potentially clinically relevant; Pre-PD was included as a covariate in the model for Post-PD. Results During the study, 557 patients (mean age 70; 52% male; median NIHSS 12) were treated with IV tPA. PDs occurred in 233 (42%) patients: 26% had only Post-PDs, 7% had only Pre-PDs, and 9% had both. The most common PDs included failure to treat post-treatment hypertension (131, 24%), antiplatelet agent within 24 hours of treatment (61, 11%), pre-treatment blood pressure over 185/110 (39, 7%), anticoagulant agent within 24 hours of treatment (31, 6%), and treatment outside the time window (29, 5%). Symptomatic intracranial hemorrhage (SICH) was observed in 7.3% of patients with PDs and 6.5% of patients without any PD. In-hospital case fatality was 12% with and 10% without a PD. The differences in SICH and case fatality were not statistically significant. In the fully adjusted model, older age was significantly associated with Pre-PDs ( Table ). When Post-PDs were evaluated with adjustment for Pre-PDs, age was not associated with PDs; however, Pre-PDs were associated with Post-PDs. Conclusion Older age was associated with increased odds of Pre-PDs in Michigan community hospitals. Pre-PDs were associated with Post-PDs. SICH and in-hospital case fatality were not associated with PDs; however, the low number of such events limited our ability to detect a difference. Stroke severity and hospital factors were not associated with PDs.

Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease,... more Kidney transplantation has emerged as the treatment for the most serious forms of kidney disease, but the supply of kidneys from deceased donors cannot meet the fastgrowing demand. Recently, Kidney Paired Donation (KPD) program, a modality which enables willing but incompatible live donor-candidate pairs to swap donors, offers a promising solution for closing the gap between kidney supply and demand. Most of current KPD programs focus mainly on organ allocations strategies achieving the maximum number of transplants or matches. However, patients’ quality of life after transplants can be more important for kidney candidates. In this paper, we propose a novel algorithmic platform to optimize cross-matches with the maximum benefits for donor-candidate pairs. Utilizing the power of integer programming, our platform implements a recently proposed method that takes probabilistic-based utility as the objective function, so that the overall expected utility, instead of the number of matches...

Randomization was a key contribution of Sir Ronald Fisher to the conduct of scientific investigat... more Randomization was a key contribution of Sir Ronald Fisher to the conduct of scientific investigations. Along with the protective aspects of randomization, Fisher also noted that the distribution induced by randomization can form the basis of inference. Indeed, in some instances, the randomization test and related procedures seem to be the only tools available for inference. Several authors have noted the advisability of randomizing again if, in a particular instance, the observed randomization leads to an unacceptable degree of imbalance in important factors between two treatment groups. We develop further methods initially proposed in Morgan and Rubin (2012) and Xu and Kalbfleisch (2011) on the systematic use of rerandomization. In particular, we combine optimal matching with rerandomization, which retains efficiency gains and improves robustness. The approach is potentially useful in cluster randomized trials. Extensions of the methods to multiple armed trials are also considered ...

BACKGROUND A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients w... more BACKGROUND A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients with asthma. Our goal was to evaluate factors associated with habitual snoring and OSA risk in these patients. METHODS Patients with asthma were surveyed at specialty clinics with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) and questions about the frequency of asthma symptoms (National Asthma Education and Prevention Program guidelines), followed by medical record review. SA-SDQ scores >or= 36 for men and >or= 32 for women defined high OSA risk. Logistic regression was used to model associations with habitual snoring and high OSA risk. RESULTS Among 244 patients, 37% snored habitually and 40% demonstrated high OSA risk. Independent predictors of habitual snoring included gastroesophageal reflux disease (GERD) [odds ratio (OR), 2.19; 95% confidence interval (CI), 1.19 to 4.02] and use of an inhaled corticosteroid (ICS) [OR, 2.66; 95% CI, 1.05 to 6.72]. High OS...

In clinical and observational studies, recurrent event data (e.g. hospitalization) with a termina... more In clinical and observational studies, recurrent event data (e.g. hospitalization) with a terminal event (e.g. death) are often encountered. In many instances, the terminal event is strongly correlated with the recurrent event process. In this ar- ticle, we propose a semiparametric method to jointly model the recurrent and terminal event processes. The dependence,is modeled,by a shared gamma,frailty that is

In this paper, we develop a weighted permutation (WP) method to construct con- fidence intervals ... more In this paper, we develop a weighted permutation (WP) method to construct con- fidence intervals for regression parameters in relative risk regression models. The WP method,is a generalized permutation approach. It constructs a resampled his- tory which mimics the observed history for individuals under study. Inference pro- cedures are based on studentized score statistics that are insensitive to the forms of the relative risk function. This makes the WP method,appealing in the general framework,of the relative risk regression model. First order accuracy of the WP method,is established using the counting process approach with a partial likeli- hood filtration. A simulation study indicates that the method,typically improves accuracy over asymptotic confidence intervals. Permutation Methods in Relative Risk Regression Models By Wenyu Jiang Biometric Research Branch,

Canadian Journal of Statistics, 1998

Canadian Journal of Statistics, 2014

Journal of immunology (Baltimore, Md. : 1950), Jan 5, 2015

Cardiac dysfunction is a major consequence of sepsis/septic shock and contributes to the high mor... more Cardiac dysfunction is a major consequence of sepsis/septic shock and contributes to the high mortality of sepsis. Innate and inflammatory responses mediated by TLRs play a critical role in sepsis-induced cardiac dysfunction. MicroRNA-146 (miR-146) was first identified as a negative regulator in innate immune and inflammatory responses induced by LPS. This study examined whether miR-146a will have a protective effect on sepsis-induced cardiac dysfunction. Lentivirus-expressing miR-146a (LmiR-146a) or lentivirus-expressing scrambled miR (LmiR-control) was delivered into the myocardium via the right carotid artery. Seven days after transfection, mice were subjected to cecal ligation and puncture (CLP). Untransfected mice were also subjected to CLP-induced sepsis. Cardiac function was examined by echocardiography before and 6 h after CLP. In vitro studies showed that increased miR-146a levels suppress LPS-induced IκBα phosphorylation and inflammatory cytokine production in both H9C2 ca...

Journal of the American Society of Nephrology : JASN, Jan 16, 2015

Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysi... more Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysis facilities with the national average, and are currently adjusted for race. However, whether the adjustment for race obscures or clarifies disparities in quality of care for minority groups is unknown. Cox model-based SMRs were computed with and without adjustment for patient race for 5920 facilities in the United States during 2010. The study population included virtually all patients treated with dialysis during this period. Without race adjustment, facilities with higher proportions of black patients had better survival outcomes; facilities with the highest percentage of black patients (top 10%) had overall mortality rates approximately 7% lower than expected. After adjusting for within-facility racial differences, facilities with higher proportions of black patients had poorer survival outcomes among black and non-black patients; facilities with the highest percentage of black patie...

Infection control and hospital epidemiology, Jan 16, 2015

OBJECTIVE To observe patient care across hemodialysis facilities enrolled in the National Opportu... more OBJECTIVE To observe patient care across hemodialysis facilities enrolled in the National Opportunity to Improve Infection Control in ESRD (end-stage renal disease) (NOTICE) project in order to evaluate adherence to evidence-based practices aimed at prevention of infection. SETTING AND PARTICIPANTS Thirty-four hemodialysis facilities were randomly selected from among 772 facilities in 4 end-stage renal disease participating networks. Facility selection was stratified on dialysis organization affiliation, size, socioeconomic status, and urban/rural status. MEASUREMENTS Trained infection control evaluators used an infection control worksheet to observe 73 distinct infection control practices at the hemodialysis facilities, from October 1, 2011, through January 31, 2012. RESULTS There was considerable variation in infection control practices across enrolled facilities. Overall adherence to recommended practices was 68% (range, 45%-92%) across all facilities. Overall adherence to expect...

Lecture Notes in Statistics, 1989