Use of the Social Security Administration Death Master File for ascertainment of mortality status

Risk of SARS-CoV-2 infection and adverse outcomes among vaccinated patients with tuberculosis

OBJECTIVES

Limited data are available to assess breakthrough SARS-CoV-2 infections, medical utilization, and mortality in patients with tuberculosis (TB). The aim of this study was to examine the risk of COVID-19 and severe outcomes in patients with TB between January 2020 and March 2022.

STUDY DESIGN

US electronic medical records were used to identify TB and non-TB patients who completed the primary series of vaccination and had no prior COVID-19.

METHODS

Breakthrough infections and severe adverse outcomes, defined by the Centers for Disease Control and Prevention as hospitalization, need for mechanical ventilation and/or intensive care unit admission, or in-hospital mortality, following a positive SARS-CoV-2 polymerase chain reaction (PCR) test. Follow-up began 14 days after the primary vaccination series was completed and continued for 365 days.

RESULTS

The study included 15,541 TB and 15,541 non-TB patients. The risk of breakthrough infection was significantly higher in the TB group than in the non-TB group after controlling for age, sex, ethnicity, socioeconomic status, and lifestyles (adjusted HR, 1.444; 95 % CI, 1.321-1.579). Similar trends were observed in pre-specified subgroup analyses stratified by age, sex, and status of TB. Patients in the TB group had higher risks of emergency room visit and critical care admission [adjusted HRs, 1.244 (95 % CI, 1.175-1.316) and 1.404 (95 % CI, 1.182-1.668)].

CONCLUSIONS

Our study revealed a higher risk of COVID-19 breakthrough infections and adverse outcomes among patients with TB. Thus, besides priority COVID-19 vaccination, healthcare providers should continue vigilance for patients with TB.

Haematological setpoints are a stable and patient-specific deep phenotype

The complete blood count (CBC) is an important screening tool for healthy adults and a common test at periodic exams. However, results are usually interpreted relative to one-size-fits-all reference intervals1,2, undermining the precision medicine goal to tailor care for patients on the basis of their unique characteristics3,4. Here we study thousands of diverse patients at an academic medical centre and show that routine CBC indices fluctuate around stable values or setpoints5, and setpoints are patient-specific, with the typical healthy adult's nine CBC setpoints distinguishable as a group from those of 98% of other healthy adults, and setpoint differences persist for at least 20 years. Haematological setpoints reflect a deep physiologic phenotype enabling investigation of acquired and genetic determinants of haematological regulation and its variation among healthy adults. Setpoints in apparently healthy adults were associated with significant variation in clinical risk: absolute risk of some common diseases and morbidities varied by more than 2% (heart attack and stroke, diabetes, kidney disease, osteoporosis), and absolute risk of all-cause 10 year mortality varied by more than 5%. Setpoints also define patient-specific reference intervals and personalize the interpretation of subsequent test results. In retrospective analysis, setpoints improved sensitivity and specificity for evaluation of some common conditions including diabetes, kidney disease, thyroid dysfunction, iron deficiency and myeloproliferative neoplasms. This study shows CBC setpoints are sufficiently stable and patient-specific to help realize the promise of precision medicine for healthy adults.

CenSoc: Public Linked Administrative Mortality Records for Individual-level Research

In the United States, much has been learned about the determinants of longevity from survey data and aggregated tabulations. However, the lack of large-scale, individual-level administrative mortality records has proven to be a barrier to further progress. We introduce the CenSoc datasets, which link the complete-count 1940 U.S. Census to Social Security mortality records. These datasets-CenSoc-DMF (N = 4.7 million) and CenSoc-Numident (N = 7.0 million)-primarily cover deaths among individuals aged 65 and older. The size and richness of CenSoc allows investigators to make new discoveries into geographic, racial, and class-based disparities in old-age mortality in the United States. This article gives an overview of the technical steps taken to construct these datasets, validates them using external aggregate mortality data, and discusses best practices for working with these datasets. The CenSoc datasets are publicly available, enabling new avenues of research into the determinants of mortality disparities in the United States.

Assessment of the Social Security Administration Death Master File for Comparative Analysis Studies of Peripheral Vascular Devices

OBJECTIVES

The objective of this study was to assess the reliability the Social Security Administration Death Master File (SSADMF) for evaluating mortality in comparative peripheral vascular device studies.

METHODS

We leveraged 2 versions of an administrative claims data set that were identical except for the source of mortality data. The SSADMF was the primary source of mortality records in one version. The SSADMF was combined with mortality from Medicare beneficiary records in the other. Our study was set in the context of a comparative effectiveness analysis of recent Food and Drug Administration interest involving peripheral paclitaxel-coated devices. Mortality of patients with Medicare Advantage insurance coverage from 2015 to 2018 who underwent femoropopliteal artery revascularization with a drug-coated device (DCD) or non-DCD was assessed through 2019. Covariate differences between treatment groups were adjusted by inverse propensity treatment weighting. The hazard ratio of DCD to non-DCD mortality was estimated using Cox regression.

RESULTS

The cumulative incidences of mortality differed substantially between versions of the data. Nevertheless, we could not reject the null hypothesis that the hazard ratios of the SSADMF (1.05; 95% confidence interval 0.95-1.17) and the Master Beneficiary Summary File/SSADMF (1.03; 95% confidence interval 0.96-1.11) were the same (P = .63).

CONCLUSIONS

The SSADMF is a common source of mortality records in the United States that can be linked to real-world data sources but is known to underreport mortality rates. We find that the SSADMF provides a reliable source of all-cause mortality for a comparative study assessing the safety of peripheral vascular devices.

Unseen Burden of Injury: Post-Hospitalization Mortality in Geriatric Trauma Patients

BACKGROUND/OBJECTIVES

Older adults are at risk for adverse outcomes after trauma, but little is known about post-acute survival as state and national trauma registries collect only inpatient or 30-day outcomes. This study investigates long-term, out-of-hospital mortality in geriatric trauma patients.

METHODS

Level I Trauma Center registry data were matched to the US Social Security Death Index (SSDI) to determine long-term and out-of-hospital outcomes of older patients. Blunt trauma patients aged ≥65 were identified from 2009 to 2015 in an American College of Surgeons Level 1 Trauma Center registry, n = 6289 patients with an age range 65-105 years, mean age 78.5 ± 8.4 years. Dates of death were queried using social security numbers and unique patient identifiers. Demographics, injury, treatments, and outcomes were compared using descriptive and univariate statistics.

RESULTS

Of 6289 geriatric trauma patients, 505 (8.0%) died as an inpatient following trauma. Fall was the most common mechanism of injury (n = 4757, 76%) with mortality rate of 46.5% at long-term follow-up; motor vehicle crash (MVC) (n = 1212, 19%) had long-term mortality of 27.6%. Overall, 24.1% of patients died within 1 year of trauma. Only 8 of 488 patients who died between 1 and 6 months post-trauma were inpatient. Mortality rate varied by discharge location: 25.1% home, 36.4% acute rehabilitation, and 51.5% skilled nursing facility, P < .0001.

CONCLUSION

Inpatient and 30-day mortality rates in national outcome registries fail to fully capture the burden of trauma on older patients. Though 92% of geriatric trauma patients survived to discharge, almost one-quarter had died by 1 year following their injuries.

Initial Patterns of Prescription Opioid Supply and Risk of Mortality Among Insured Adults in the United States

OBJECTIVE

To examine the association between initial patterns of prescription opioid supply (POS) and risk of all-cause mortality among an insured opioid-naïve patient population in the United States (US).

METHODS

This retrospective observational cohort study used de-identified, administrative health care claims data from a large national insurer (Optum Clinformatics Data Mart) from 2010 to 2015. Participants included insured, cancer-free adults prescribed opioid analgesics. Prescription opioids received during the first 6 months of therapy were used to categorize initial patterns of POS as daily or nondaily. Cox regression was used to estimate the association of initial patterns of POS with all-cause mortality within one year of follow-up, adjusting for baseline covariates to control for confounding.

RESULTS

A total of 4,054,417 patients were included, of which 2.75% had incident daily POS; 54.8% were female; median age was 50 years; mean Charlson comorbidity index (CCI) was 0.21 (standard deviation = 0.77); and mean daily morphine milligram equivalent was 34.61 (95% confidence intervals: 34.59, 34.63). There were 2068 more deaths per 100,000 person-years among patients who were prescribed opioids daily than nondaily. After adjusting for baseline covariates, the hazard of all-cause mortality among patients with incident daily POS was nearly twice that among those prescribed nondaily (hazard ratio [HR] = 1.94; 95% confidence intervals: 1.84, 2.04).

CONCLUSIONS

Among insured adult patients with noncancer pain, incident chronic POS was associated with a significantly increased risk of all-cause mortality over at most 1 year of follow-up. Because these results may be susceptible to bias, more research is needed to establish causality.

Vital Status Ascertainment for a Historic Diverse Cohort of U.S. Women

BACKGROUND

Studies linking large pregnancy cohorts with mortality data can address critical questions about long-term implications of gravid health, yet relevant US data are scant. We examined the feasibility of linking the Collaborative Perinatal Project, a large multiracial U.S. cohort study of pregnant women (n = 48,197; 1959-1966), to death records.

METHODS

We abstracted essential National Death Index (NDI) (1979-2016) (n = 46,428). We performed a linkage to the Social Security Administration Death Master File through 2016 (n = 46,450). Genealogists manually searched vital status in 2016 for a random sample of women (n = 1,249). We conducted agreement analyses for women with abstracted data among the three sources. As proof of concept, we calculated adjusted associations between mortality and smoking and other sociodemographic factors using Cox proportional hazards regression.

RESULTS

We successfully abstracted identifying information for most of the cohort (97%). National Death Index identified the greatest proportion of participants deceased (35%), followed by genealogists (31%) and Death Master File (23%). Estimates of agreement (κ [95% confidence interval]) between National Death Index and Death Master File were lower (0.52 [0.51, 0.53]) than for National Death Index and genealogist (0.66 [0.61, 0.70]). As expected, compared with nonsmokers, smoking ≥1 pack per day was associated with elevated mortality for all vital sources and was strongest for National Death Index.

CONCLUSIONS

Linking this historic cohort with mortality records was feasible and agreed reasonably on vital status when compared with other data sources. Such linkage enables future examination of pregnancy conditions in relation to mortality in a diverse U.S. cohort.

Evaluation of Mortality Data From the Social Security Administration Death Master File for Clinical Research

Importance

Despite its documented undercapture of mortality data, the US Social Security Administration Death Master File (SSDMF) is still often used to provide mortality end points in retrospective clinical studies. Changes in death data reporting to SSDMF in 2011 may have further affected the reliability of mortality end points, with varying consequences over time and by state.

Objective

To evaluate the reliability of mortality rates in the SSDMF in a cohort of patients with atherosclerotic cardiovascular disease (ASCVD).

Design, Setting, and Participants

This observational analysis used the IBM MarketScan Medicare and commercial insurance databases linked to mortality information from the SSDMF. Adults with ASCVD who had a clinical encounter between January 1, 2012, and December 31, 2013, at least 2 years of follow-up, and from states with 1000 or more eligible adults with ASCVD were included in the study. Data analysis was conducted between April 18 and May 21, 2018.

Main Outcomes and Measures

Kaplan-Meier analyses were conducted to estimate state-level mortality rates for adults with ASCVD, stratified by database (commercial or Medicare). Constant hazards of mortality by state were tested, and individual state Kaplan-Meier curves for temporal changes were evaluated. For states in which the hazard of death was constant over time, mortality rates for adults with ASCVD were compared with state-level, age group-specific overall mortality rates in 2012, as reported by the National Center for Health Statistics (NCHS).

Results

This study of mortality data of 667 516 adults with ASCVD included 274 005 adults in the commercial insurance database cohort (171 959 male [62.8%] and median [interquartile range (IQR)] age of 58 [52-62] years) and 393 511 in the Medicare database cohort (245 366 male [62.4%] and median [IQR] age of 76 [70-83] years). Of the 41 states included, 11 states (26.8%) in the commercial cohort and 18 states (43.9%) in the Medicare cohort had a change in the hazard of death after 2012. Among states with constant hazard, state-level mortality rates using the SSDMF ranged widely, from 0.06 to 1.30 per 100 person-years (commercial cohort) and from 0.83 to 6.07 per 100 person-years (Medicare cohort). Variability between states in mortality estimates for adults with ASCVD using SSDMF data greatly exceeded variability in overall mortality from the NCHS. No correlation was found between NCHS mortality estimates and those from the SSDMF (ρ = 0.29 [P = .06] for age 55-64 years; ρ = 0.18 [P = .27] for age 65-74 years).

Conclusions and Relevance

The SSDMF appeared to markedly underestimate mortality rates, with variable undercapture among states and over time; this finding suggests that SSDMF data are not reliable and should not be used alone by researchers to estimate mortality rates.

The Hispanic Paradox in Patients With Liver Cirrhosis: Current Evidence From a Large Regional Retrospective Cohort Study

BACKGROUND

Despite lower socioeconomic status, Hispanics in the United States paradoxically maintain equal or higher average survival rates compared to non-Hispanic Whites (NHW).

METHODS

We used multivariable Cox regression to assess whether this "Hispanic paradox" applies to patients with liver cirrhosis using a retrospective cohort of twenty 121 patients in a Chicago-wide electronic health record database.

RESULTS

Our study population included 3279 (16%) Hispanics, 9150 (45%) NHW, 4432 (22%) African Americans, 529 (3%) Asians, and 2731 (14%) of other races/ethnic groups. Compared to Hispanics, NHW (hazard ratio [HR] 1.26; 95% confidence interval [CI], 1.16-1.37), African American (HR 1.26; 95% CI, 1.15-1.39), and other races/ethnic groups (HR 1.55; 95% CI, 1.40-1.71) had an increased risk of death despite adjustment for age, sex, insurance status, etiology of cirrhosis, and comorbidities. On stratified analyses, a mortality advantage for Hispanics compared to NHW was seen for alcohol cirrhosis (HR for NHW 1.35; 95% CI, 1.19-1.52), hepatitis B (HR for NHW 1.35; 95% CI, 0.98-1.87), hepatitis C (HR for NHW 1.21; 95% CI, 1.06-1.38), and nonalcoholic steatohepatitis (HR for NHW 1.14; 95% CI, 0.94-1.39). There was no advantage associated with Hispanic race over NHW in cases of hepatocellular carcinoma or cholestatic liver disease.

CONCLUSIONS

Hispanic patients with cirrhosis experience a survival advantage over many other racial groups despite adjustment for multiple covariates.

Implication of Ventricular Assist Devices in Extracorporeal Membranous Oxygenation Patients Listed for Heart Transplantation

The new allocation criteria classify patients on veno-arterial extracorporeal membranous oxygenation (VA-ECMO) as the highest priority for receiving orthotopic heart transplantation (OHT) especially if they are considered not candidates for ventricular assist devices. The outcomes of patients who receive ventricular assist devices (VADs) after being listed for heart transplantation with VA-ECMO is unknown. We analyzed 355 patients listed for OHT with VA-ECMO from the United Network for Organ Sharing database from 2006 to 2014. Univariate and multivariate Cox proportional-hazards models were used to determine the contribution of prognostic variables to the outcome. Thirty-three patients (9.3%) received VADs (15 dischargeable, 7 non-dischargeable VADs). The VAD and non-VAD groups had similar listing characteristics except that the VAD group were more likely to have non-ischemic cardiomyopathy (48.5% vs. 25.2%), and less likely to be obese (6.1% vs. 25.2%) or have a history of prior organ transplant (3% vs. 31.1%). Patients who underwent VAD implantation had more days on the list (median 189 vs. 14 days) compared to the non-VAD group. Amongst the patients who had VADs, (25/33) 75.5% patients were subsequently transplanted with similar post-transplant survival compared to the non-VAD group (72% vs. 60.5%; p = 0.276). Predictors of one-year post-transplant mortality included panel reactive antibodies (PRA) class I ≥ 20%, recipient smoking history, increased serum creatinine and total bilirubin. Therefore, a small proportion of patients listed for transplantation with VA ECMO undergo VAD implantation. Their waitlist survival is better than non-VAD group but with similar post-transplant survival.

Association of Primary Care Physician Supply With Population Mortality in the United States, 2005-2015

IMPORTANCE

Recent US health care reforms incentivize improved population health outcomes and primary care functions. It remains unclear how much improving primary care physician supply can improve population health, independent of other health care and socioeconomic factors.

OBJECTIVES

To identify primary care physician supply changes across US counties from 2005-2015 and associations between such changes and population mortality.

DESIGN, SETTING, AND PARTICIPANTS

This epidemiological study evaluated US population data and individual-level claims data linked to mortality from 2005 to 2015 against changes in primary care and specialist physician supply from 2005 to 2015. Data from 3142 US counties, 7144 primary care service areas, and 306 hospital referral regions were used to investigate the association of primary care physician supply with changes in life expectancy and cause-specific mortality after adjustment for health care, demographic, socioeconomic, and behavioral covariates. Analysis was performed from March to July 2018.

MAIN OUTCOMES AND MEASURES

Age-standardized life expectancy, cause-specific mortality, and restricted mean survival time.

RESULTS

Primary care physician supply increased from 196 014 physicians in 2005 to 204 419 in 2015. Owing to disproportionate losses of primary care physicians in some counties and population increases, the mean (SD) density of primary care physicians relative to population size decreased from 46.6 per 100 000 population (95% CI, 0.0-114.6 per 100 000 population) to 41.4 per 100 000 population (95% CI, 0.0-108.6 per 100 000 population), with greater losses in rural areas. In adjusted mixed-effects regressions, every 10 additional primary care physicians per 100 000 population was associated with a 51.5-day increase in life expectancy (95% CI, 29.5-73.5 days; 0.2% increase), whereas an increase in 10 specialist physicians per 100 000 population corresponded to a 19.2-day increase (95% CI, 7.0-31.3 days). A total of 10 additional primary care physicians per 100 000 population was associated with reduced cardiovascular, cancer, and respiratory mortality by 0.9% to 1.4%. Analyses at different geographic levels, using instrumental variable regressions, or at the individual level found similar benefits associated with primary care supply.

CONCLUSIONS AND RELEVANCE

Greater primary care physician supply was associated with lower mortality, but per capita supply decreased between 2005 and 2015. Programs to explicitly direct more resources to primary care physician supply may be important for population health.

Decreased Lean Psoas Cross-Sectional Area Is Associated With Increased 1-Year All-Cause Mortality in Male Elderly Orthopaedic Trauma Patients

OBJECTIVES

To investigate the association between lean psoas cross-sectional area (CSA) and 1-year all-cause mortality in elderly patients sustaining pelvic and long bone fractures.

DESIGN

Retrospective cohort.

SETTING

Level I trauma center.

PATIENTS

Elderly trauma patients admitted from 2007 to 2014.

METHODS

We reviewed demographic and clinical data, injury mechanism, fracture OTA/AO classification, and mortality. Axial computed tomography images were used to measure lean psoas CSA at the L3-L4 disk space. Cox proportional hazard regression analysis was used to estimate 1-year mortality association with psoas CSA in crude and adjusted for age, body mass index, Injury Severity Score, medical comorbidities, and discharge destination in total population and stratified by sex.

MAIN OUTCOME MEASUREMENT

One-year all-cause mortality defined as death within 12 months from date of hospitalization.

RESULTS

Five hundred fifty-eight patients (54% female, 46% male) were analyzed. The pelvis was most commonly fractured (37.81%). A statistically significant association was observed between decreased lean psoas CSA and 1-year mortality in total population {hazard ratio [HR] = 0.93 [95% confidence interval (CI) = 0.90-0.96], P < 0.0001}. Stratification by gender revealed a statistically significant mortality HR in male patients [HR = 0.89 (95% CI = 0.84-0.96), P = 0.002]. We did not find a statistically significant mortality HR in female patients [HR = 0.95 (95% CI = 0.89-1.01), P = 0.103].

CONCLUSIONS

In this cohort of elderly orthopaedic trauma patients, decreased lean psoas CSA was associated with increased 1-year all-cause mortality in total population and males. Further investigation of the association of sarcopenia with mortality in the elderly is warranted.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Benzodiazepines and risk of all cause mortality in adults: cohort study

Objectives To evaluate the risk of all cause mortality associated with initiating compared with not initiating benzodiazepines in adults, and to address potential treatment barriers and confounding related to the use of a non-active comparator group.Design Retrospective cohort study.Setting Large de-identified US commercial healthcare database (Optum Clinformatics Datamart).Participants 1:1 high dimensional propensity score matched cohort of benzodiazepine initiators, and randomly selected benzodiazepine non-initiators with a medical visit within 14 days of the start of benzodiazepine treatment (n=1 252 988), between July 2004 and December 2013. To address treatment barriers and confounding, patients were required to have filled one or more prescriptions for any medication in the 90 days and 91-180 days before the index date (ie, the date of starting benzodiazepine treatment for initiators and the date of the selected medical visit for benzodiazepine non-initiators) and the high dimensional propensity score was estimated on the basis of more than 300 covariates.Main outcome measure All cause mortality, determined by linkage with the Social Security Administration Death Master File.Results Over a six month follow-up period, 5061 and 4691 deaths occurred among high dimensional propensity score matched benzodiazepine initiators versus non-initiators (9.3 v 9.4 events per 1000 person years; hazard ratio 1.00, 95% confidence interval 0.96 to 1.04). A 4% (95% confidence interval 1% to 8%) to 9% (2% to 7%) increase in mortality risk was observed associated with the start of benzodiazepine treatment for follow-ups of 12 and 48 months and in subgroups of younger patients and patients initiating short acting agents. In secondary analyses comparing 1:1 high dimensional propensity score matched patients initiating benzodiazepines with an active comparator, ie, patients starting treatment with selective serotonin reuptake inhibitor antidepressants, benzodiazepine use was associated with a 9% (95% confidence interval 3% to 16%) increased risk.Conclusions This large population based cohort study suggests either no increase or at most a minor increase in risk of all cause mortality associated with benzodiazepine initiation. If a detrimental effect exists, it is likely to be much smaller than previously stated and to have uncertain clinical relevance. Residual confounding likely explains at least part of the small increase in mortality risk observed in selected analyses.

Nucleated red blood cells, critical illness survivors and postdischarge outcomes: a cohort study

Background

Little is known about risk factors associated with out-of-hospital outcomes in survivors of critical illness. We hypothesized that the presence of nucleated red blood cells in patients who survived critical care would be associated with adverse outcomes following hospital discharge.

Methods

We performed a two-center observational cohort study of patients treated in medical and surgical intensive care units in Boston, Massachusetts. All data were obtained from the Research Patient Data Registry at Partners HealthCare. We studied 2878 patients, age ≥ 18 years, who received critical care between 2011 and 2015 and survived hospitalization. The exposure of interest was nucleated red blood cells occurring from 2 days prior to 7 days after critical care initiation. The primary outcome was mortality in the 90 days following hospital discharge. Secondary outcome was unplanned 30-day hospital readmission. Adjusted odds ratios were estimated by multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both nucleated red blood cells and outcome. Adjustment included age, race (white versus nonwhite), gender, Deyo–Charlson Index, patient type (medical versus surgical), sepsis and acute organ failure.

Results

In patients who received critical care and survived hospitalization, the absolute risk of 90-day postdischarge mortality was 5.9%, 11.7%, 15.8% and 21.9% in patients with 0/μl, 1–100/μl, 101–200/μl and more than 200/μl nucleated red blood cells respectively. Nucleated red blood cells were a robust predictor of postdischarge mortality and remained so following multivariable adjustment. The fully adjusted odds of 90-day postdischarge mortality in patients with 1–100/μl, 101–200/μl and more than 200/μl nucleated red blood cells were 1.77 (95% CI, 1.23–2.54), 2.51 (95% CI, 1.36–4.62) and 3.72 (95% CI, 2.16–6.39) respectively, relative to patients without nucleated red blood cells. Further, the presence of nucleated red blood cells is a significant predictor of the odds of unplanned 30-day hospital readmission.

Conclusion

In critically ill patients who survive hospitalization, the presence of nucleated red blood cells is a robust predictor of postdischarge mortality and unplanned hospital readmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1724-z) contains supplementary material, which is available to authorized users.

Exploring Delirium's Heterogeneity: Association Between Arousal Subtypes at Initial Presentation and 6-Month Mortality in Older Emergency Department Patients

OBJECTIVES

To determine how delirium subtyped by level of arousal at initial presentation affects 6-month mortality.

DESIGN

This was a preplanned secondary analysis of two prospective cohort studies.

SETTING

Academic tertiary care emergency department (ED).

PARTICIPANTS

1,084 ED patients who were 65 years old or older.

MEASUREMENTS

At the time of enrollment, trained research personnel performed the Confusion Assessment Method for the Intensive Care Unit and the Richmond Agitation Sedation Score to determine delirium and level of arousal, respectively. Patients were categorized as having no delirium, delirium with normal arousal, delirium with decreased arousal, or delirium with increased arousal. Death was ascertained by medical record review and the Social Security Death Index. Cox proportional hazard regression was used to analyze the association between delirium arousal subtypes and 6-month mortality.

RESULTS

Delirium with normal arousal was the only subtype that was significantly associated with increased 6-month mortality (hazard ratio [HR]: 3.1, 95% confidence interval [CI]: 1.3-7.4) compared with the no delirium group after adjusting for confounders. The HRs for delirium with decreased and increased arousal were 1.4 (95% CI: 0.9-2.1) and 1.3 (95% CI: 0.3-5.4), respectively.

CONCLUSIONS

Delirious ED patients with normal arousal at initial presentation had a threefold increased hazard of death within 6 months compared with patients without delirium. There was a trend towards increased hazard of death in delirious ED patients with decreased arousal, but this relationship did not reach statistical significance. These data suggest that subtyping delirium by arousal may have prognostic value but requires confirmation with a larger study.

Do inferences about mortality rates and disparities vary by source of mortality information?

PURPOSE

Researchers who study mortality among survey participants have multiple options for obtaining information about which participants died (and when and how they died). Some use public record and commercial databases; others use the National Death Index; some use the Social Security Death Master File; and still others triangulate sources and use Internet searches and genealogic methods. We ask how inferences about mortality rates and disparities depend on the choice of source of mortality information.

METHODS

Using data on a large, nationally representative cohort of people who were first interviewed as high school sophomores in 1980 and for whom we have extensive identifying information, we describe mortality rates and disparities through about age 50 using four separate sources of mortality data. We rely on cross-tabular and multivariate logistic regression models.

RESULTS

These sources of mortality information often disagree about which of our panelists died by about age 50 and also about overall mortality rates. However, differences in mortality rates (i.e., by sex, race/ethnicity, education) are similar across of sources of mortality data.

CONCLUSION

Researchers' source of mortality information affects estimates of overall mortality rates but not estimates of differential mortality by sex, race and/or ethnicity, or education.

Incidence and Case Fatality at the County Level as Contributors to Geographic Disparities in Stroke Mortality

BACKGROUND

Is the high stroke mortality in the Southeastern parts of the United States driven by differences in stroke incidence or case-fatality? This question remains unanswered. Differences in incidence would underscore the need for stroke prevention, while differences in case fatality would call for improved stroke care.

METHODS

Quartiles of US counties were defined by stroke mortality, and this gradient was related with stroke incidence and stroke case fatality in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, where 1,317 incident stroke events (of which 242 were fatal) occurred among 29,650 participants.

RESULTS

There was a significant (p = 0.0025) gradient of fatal stroke events in REGARDS (quartile 4 vs. quartile 1 (Q4/Q1) hazard ratio 1.95, 95% CI 1.35-2.81), demonstrating the consistency of REGARDS with national mortality data. The gradient for incident stroke (fatal + nonfatal) was also significant (p = 0.0023; Q4/Q1 hazard ratio 1.29, 95% CI 1.10-1.52). The gradient for stroke case-fatality was marginally significant (p = 0.058), though the OR for Q4/Q1 (1.71, 95% CI 1.13-2.25) was large.

CONCLUSIONS

Both stroke incidence and case-fatality in REGARDS appear to be contributing, underscoring the need for strengthening both stroke prevention and acute stroke care in order to reduce the disparity.

Slow Gait Speed and Risk of Mortality or Hospital Readmission After Myocardial Infarction in the Translational Research Investigating Underlying Disparities in Recovery from Acute Myocardial Infarction: Patients' Health Status Registry

OBJECTIVES

To determine the prognostic value of slow gait in predicting outcomes 1 year after acute myocardial infarction (AMI).

DESIGN

Observational cohort with longitudinal follow-up.

SETTING

Twenty-four U.S. hospitals participating in the Translational Research Investigating Underlying disparities in recovery from acute Myocardial infarction: Patients' Health status Registry.

PARTICIPANTS

Older adults (≥65) with in-home gait assessment 1 month after AMI (N = 338).

MEASUREMENTS

Baseline characteristics and 1-year mortality or hospital readmission adjusted using Cox proportional hazards regression in older adults with slow (<0.8 m/s) versus preserved (≥0.8 m/s) gait speed.

RESULTS

Slow gait was present in 181 participants (53.6%). Those with slow gait were older, more likely to be female and nonwhite, and had a higher prevalence of heart failure and diabetes mellitus. They were also more likely to die or be readmitted to the hospital within 1 year than those with preserved gait (35.4% vs 18.5%, log-rank P = .006). This association remained significant after adjusting for age, sex, and race (slow vs preserved gait hazard ratio (HR) = 1.76, 95% confidence interval (CI)=1.08-2.87, P = .02) but was no longer significant after adding clinical factors (HR = 1.23, 95% CI=0.74-2.04, P = .43).

CONCLUSION

Slow gait, a marker of frailty, is common 1 month after AMI in older adults and is associated with nearly twice the risk of dying or hospital readmission at 1 year. Understanding its prognostic importance independent of comorbidities and whether routine testing of gait speed can improve care requires further investigation.

Improved survival in patients enrolled promptly into remote monitoring following cardiac implantable electronic device implantation

Purpose

Guidelines advocate remote monitoring (RM) in patients with a cardiac implantable electronic device (CIED). However, it is not known when RM should be initiated. We hypothesized that prompt initiation of RM (within 91 days of implant) is associated with improved survival compared to delayed initiation.

Methods

This retrospective, national, observational cohort study evaluated patients receiving new implants of market-released St. Jude Medical™ pacemakers (PM), implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy (CRT) devices. Patients were assigned to one of two groups: an “RM Prompt” group, in which RM was initiated within 91 days of implant; and an “RM Delayed” group, in which RM was initiated >91 days but ≤365 days of implant. The primary endpoint was all-cause mortality.

Results

The cohort included 106,027 patients followed for a mean of 2.6 ± 0.9 years. Overall, 47,014 (44 %) patients had a PM, 31,889 (30 %) patients had an ICD, 24,005 (23 %) patients had a CRT-D, and 3119 (3 %) patients had a CRT-P. Remote monitoring was initiated promptly (median 4 weeks [IQR 2, 8 weeks]) in 66,070 (62 %) patients; in the other 39,957 (38 %) patients, RM initiation was delayed (median 24 weeks [IQR 18, 34 weeks]). In comparison to delayed initiation, prompt initiation of RM was associated with a lower mortality rate (4023 vs. 4679 per 100,000 patient-years, p < 0.001) and greater adjusted survival (HR 1.18 [95 % CI 1.13–1.22], p < 0.001).

Conclusions

Our data, for the first time, show improved survival in patients enrolled promptly into RM following CIED implantation. This advantage was observed across all CIED device types.

Association between pre-hospital vitamin D status and hospital-acquired new-onset delirium

The goal of the present study was to determine whether pre-hospital 25-hydroxyvitamin D (25(OH)D) levels are associated with the risk of hospital-acquired new-onset delirium (HANOD). We performed a retrospective cohort study of 4508 adult inpatients at two teaching hospitals in Boston from 1993 to 2006. All patients had 25(OH)D levels measured before hospital admission. The main outcome measure was HANOD, defined as the onset of delirium during an acute care hospitalisation. Patients with a history of delirium or dementia, or those with a diagnosis of delirium or dementia upon acute care hospitalisation were excluded from the analysis. To test the association of pre-hospital 25(OH)D levels with HANOD, we constructed a multivariable logistic regression model to adjust for clinically relevant covariates. Among our patient cohort, the mean 25(OH)D level was 22 (sd 13) ng/ml and approximately 4% of patients met the criteria for HANOD. Following adjustment for age, sex, race (non-white v. white), patient type (medical v. surgical) and Deyo-Charlson Index, patients with 25(OH)D levels < 10, 10-19·9 and 20-29·9 ng/ml had higher odds of HANOD than patients with 25(OH)D levels ≥ 30 ng/ml: OR 2·15 (95% CI 1·32, 3·50), OR 1·54 (95% CI 0·98, 2·43) and OR 1·23 (95% CI, 0·76, 1·99), respectively. These data support the rationale for randomised, controlled trials to test the role of vitamin D supplementation in the prevention of HANOD.

Derivation and validation of the acute organ failure score to predict outcome in critically ill patients: a cohort study

OBJECTIVES

Prediction models for ICU mortality rely heavily on physiologic variables that may not be available in large retrospective studies. An alternative approach when physiologic variables are absent stratifies mortality risk by acute organ failure classification.

DESIGN

Retrospective cohort study.

SETTING

Two large teaching hospitals in Boston, MA.

SUBJECTS

Ninety-two thousand eight hundred eighty-six patients aged 18 years old or older admitted between November 3, 1997, and February 25, 2011, who received critical care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The derivation cohort consisted of 35,566 patients from Brigham and Women's Hospital, and the validation cohort comprised 57,320 patients from Massachusetts General Hospital. Acute organ failure was determined for each patient based on International Classification of Diseases, 9th Revision, Clinical Modification code combinations. The main outcome measure was 30-day mortality. A clinical prediction model was created based on a logistic regression model describing the risk of 30-day mortality as a function of age, medical versus surgical patient type, Deyo-Charlson index, sepsis, and type acute organ failure (respiratory, renal, hepatic, hematologic, metabolic, and neurologic) after ICU admission. We computed goodness-of fit statistics and c-statistics as measures of model calibration and 30-day mortality discrimination, respectively. Thirty-day mortality occurred in 5,228 of 35,566 patients (14.7%) assigned to the derivation cohort. The clinical prediction model was predictive for 30-day mortality. The c-statistic for the clinical prediction model was 0.7447 (95% CI, 0.74-0.75) in the derivation cohort and 0.7356 (95% CI, 0.73-0.74) in the validation cohort. For both the derivation and validation cohorts, the Hosmer-Lemeshow chi-square p values indicated good model fit. In a smaller cohort of 444 patients with Acute Physiologic and Chronic Health Evaluation II scores determined, differences in model discrimination of 30-day mortality between the clinical prediction model and Acute Physiologic and Chronic Health Evaluation II were not significant (chi-square=0.76; p=0.38).

CONCLUSIONS

An acute organ failure-based clinical prediction model shows good calibration and discrimination for 30-day mortality in the critically ill. The clinical prediction model compares favorably to Acute Physiologic and Chronic Health Evaluation II score in the prediction of 30-day mortality in the critically ill. This score may be useful for severity of illness risk adjustment in observational studies where physiologic data are unavailable.

Measuring Mortality Information in Clinical Data Warehouses

The ability to track and report long-term outcomes, especially mortality, is essential for advancing clinical research. The purpose of this study was to present a framework for assessing the quality of mortality information in clinical research databases. Using the clinical data warehouse (CDW) at Columbia University Medical Center as a case study, we measured: 1) agreement in vital status between our institution's patient registration system and the U.S. Social Security Administration's Death Master File (DMF), 2) the proportion of patients marked as deceased according to the DMF records who had subsequent visits to our institution, and 3) the proportion of patients still living according to Columbia's CDW who were over 100 and 120 years of age. Of 33,295 deaths recorded in our institution's patient registration system, 13,167 (39.5%) did not exist in the DMF. Of 315,037 patients in our CDW who marked as deceased according to the DMF, 2.1% had a subsequent clinical encounter at our institution. The proportion of patients still living according to Columbia's CDW who were over 100 and 120 years of age was 43.6% and 43.1%, respectively. These measures may be useful to other clinical research investigators seeking to assess the quality of mortality data (1-4).

Increased mortality persists in an adult drug-resistant epilepsy prevalence cohort

OBJECTIVE

To investigate the cumulative probability of death and the standardised mortality ratio (SMR) in an adult drug-resistant epilepsy (DRE) population.

METHODS

In two separate centres during 2003-2006, we identified a total of 433 patients with DRE defined as at least one seizure per month and failure of at least two antiepileptic drugs. These patients were subsequently followed for a total follow-up of 6 years. We examined the cumulative probability of death, using Kaplan-Meier methodology, and the SMR based on mortality data from the Social Security Death Index. Clinical predictors of death were evaluated using Cox regression analysis.

RESULTS

The cumulative probability of death was 8.7% (95% CI 6.2% to 12.1%) at 6 years. The overall SMR was 2.4 (95% CI 1.7 to 3.3). It was 3.1; 95% CI 2.0 to 4.6 in subjects with remote or progressive aetiology and 1.7; 95% CI 0.8 to 2.8 in subjects with unknown aetiology. The SMR was significantly increased in those with a known remote aetiology (2.5; 95% CI (1.4 to 3.8)). Older age at enrolment and symptomatic generalised epilepsy syndrome were significant predictors of death.

DISCUSSION

Mortality is increased in this drug-resistant population; largely driven by those with a known epilepsy aetiology. The increased mortality remains even after exclusion of those with a progressive aetiology. Previous studies of incident epilepsy cohorts revealed increased mortality that declines to near-normal levels after the first several years, but in our DRE cohort, mortality remains elevated despite a median duration of epilepsy of 25 years at study entry.

Urinary L-FABP predicts poor outcomes in critically ill patients with early acute kidney injury

Biomarker studies for early detection of acute kidney injury (AKI) have been limited by non-selective testing and uncertainties in using small changes in serum creatinine as a reference standard. Here we examine the ability of urine L-type fatty acid binding protein (L-FABP), neutrophil gelatinase-associated lipocalin (NGAL), Interleukin-18 (IL-18), and Kidney Injury Moledule-1 (KIM-1) to predict injury progression, dialysis, or death within 7 days in critically ill adults with early AKI. Of 152 patients with known baseline creatinine examined, 36 experienced the composite outcome. Urine L-FABP demonstrated an area under the receiver-operating characteristic curve (AUC-ROC) of 0.79 (95% confidence interval 0.70-0.86), which improved to 0.82 (95% confidence interval 0.75-0.90) when added to the clinical model (AUC-ROC of 0.74). Urine NGAL, IL-18, and KIM-1 had AUC-ROCs of 0.65, 0.64, and 0.62, respectively, but did not significantly improve discrimination of the clinical model. The category free net reclassification index improved with urine L-FABP [total net reclassification index for non-events 31.0%] and urine NGAL [total net reclassification index for events 33.3%]. However, only urine L-FABP significantly improved the integrated discriminative index. Thus, modest early changes in serum creatinine can help target biomarker measurement for determining prognosis with urine L-FABP providing independent and additive prognostic information when combined with clinical predictors.

Death or revascularization among nonadmitted ED patients with low-positive vs negative troponin T results

STUDY OBJECTIVE

Compare outcomes among emergency department (ED) patients with low-positive (0.01-0.02 ng/mL) vs negative troponin T.

METHODS

Retrospective cohort study of nonadmitted ED patients with troponin testing at a tertiary-care hospital. Trained research assistants used a structured tool to review charts from all nonadmitted ED patients with troponin testing, 12/1/2009 to 11/30/2010. Outcomes of death and coronary revascularization were assessed at 30 days and 6 months via medical record review, Social Security Death Index searches, and patient contact.

RESULTS

There were 57596 ED visits; with 33388 (58%) discharged immediately, 6410 (11%) assigned to the observation unit, and 17798 (31%) admitted or other. Troponin was measured in 2684 (6.7%) of the nonadmitted cases. Troponin was negative in 2523 (94.0%), low positive in 78 (2.9%), and positive (≥0.03 ng/mL) in 83 (3.1%). Of troponin-negative cases, 0.8% (95% CI, 0.4-1.1%) died or were revascularized by 30 days, vs 2.8% (95% CI, 0.0-6.7%) of low-positive cases (risk difference [RD], 2.0%; 95% CI, -1.8 to 5.9%). At 6 months, the rates were 1.7% (95% CI, 1.1-2.2%) and 12.9% (95% CI, 5.0-20.7%) (RD, 11%; 95% CI, 3.3-19.1%). Death alone at 30 days occurred in 0.4% (95% CI, 0.1-0.6%) vs 1.3% (95% CI, 0.0-3.8%) (RD, 0.9%; 95% CI, -1.6 to 3.4%). Death at 6 months occurred in 1.2% (95% CI, 0.8-1.6%) vs 11.7% (95% CI, 4.5-18.9%) (RD, 10%; 95% CI, 3.3-17.7%).

CONCLUSION

Among patients not initially admitted, rates of death and coronary revascularization differed insignificantly at 30 days but significantly at 6 months. Detailed inspection of our results reveals that the bulk of the added risk at 6 months was due to non-cardiac mortality.

The association of red cell distribution width at hospital discharge and out-of-hospital mortality following critical illness*

OBJECTIVES

Red cell distribution width is associated with mortality and bloodstream infection risk in the critically ill. In hospitalized patients with critical illness, it is not known if red cell distribution width can predict subsequent risk of all-cause mortality following hospital discharge. We hypothesized that an increase in red cell distribution width at hospital discharge in patients who survived to discharge following critical care would be associated with increased postdischarge mortality.

DESIGN

Two-center observational cohort study

SETTING

: All medical and surgical ICUs at the Brigham and Women's Hospital and Massachusetts General Hospital.

PATIENTS

We studied 43,212 patients, who were 18 years old or older and received critical care between 1997 and 2007 and survived hospitalization.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The exposure of interest was red cell distribution width within 24 hours of hospital discharge and categorized a priori in quintiles as less than or equal to 13.3%, 13.3-14.0%, 14.0-14.7%, 14.7-15.8%, and more than 15.8%. The primary outcome was all-cause mortality in the 30 days following hospital discharge. Secondary outcomes included 90-day and 365-day mortality following hospital discharge. Mortality was determined using the U.S. Social Security Administration Death Master File, and 365-day follow-up was present in all cohort patients. Adjusted odds ratios were estimated by multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both red cell distribution width and mortality. Adjustment included age, race, gender, Deyo-Charlson Index, patient type (medical vs surgical), sepsis, and number of organs with acute failure. In patients who received critical care and survived hospitalization, the discharge red cell distribution width was a robust predictor of all-cause mortality and remained so following multivariable adjustment. Patients with a discharge red cell distribution width of 14.0-14.7%, 14.7-15.8%, and more than 15.8% have an odds ratio for mortality in the 30 days following hospital discharge of 2.86 (95% CI, 2.25-3.62), 4.57 (95% CI, 3.66-5.72), and 8.80 (95% CI, 7.15-10.83), respectively, all relative to patients with a discharge red cell distribution width less than or equal to 13.3%. Following multivariable adjustment, patients with a discharge red cell distribution width of 14.0-14.7%, 14.7-15.8%, and more than 15.8% have an odds ratio for mortality in the 30 days following hospital discharge of 1.63 (95% CI, 1.27-2.07), 2.36 (95% CI, 1.87-2.97), and 4.18 (95% CI, 3.36-5.20), respectively, all relative to patients with a discharge red cell distribution width less than or equal to 13.3%. Similar significant robust associations post multivariable adjustments are seen with death by days 90 and 365 postdischarge. Estimating the receiver-operating characteristic area under the curve shows that discharge red cell distribution width has moderate discriminative power for mortality 30 days following hospital discharge (area under the curve = 0.70; SE 0.006; 95% CI, 0.69-0.71; p < 0.0001).

CONCLUSION

In patients treated with critical care who survive hospitalization, an elevated red cell distribution width at the time of discharge is a robust predictor of subsequent all-cause patient mortality. Increased discharge red cell distribution width likely reflects the presence of proinflammatory state, oxidative stress, arterial underfilling, or a combination, thereof which may explain the observed impact on patient survival following discharge. Elevated red cell distribution width at hospital discharge may identify ICU survivors who are at risk for adverse outcomes following hospital discharge.

Evidence for a U-shaped relationship between prehospital vitamin D status and mortality: a cohort study

OBJECTIVE

The objective of the study was to examine the association between prehospital serum 25-hydroxyvitamin D [25(OH)D]and the risk of mortality after hospital admission.

DESIGN

We performed a retrospective cohort study of adults hospitalized for acute care between 1993 and 2011.

SETTING

The study was conducted at two Boston teaching hospitals.

PATIENTS

A total of 24,094 adult inpatients participated in the study.

INTERVENTION

There was no intervention.

MEASUREMENTS

All patients had serum 25(OH)D measured before hospitalization. The exposure of interest was 25(OH)D categorized as less than 10 ng/mL, 10-19.9 ng/mL, 20-29.9 ng/mL, 30-49.9 ng/mL, 50-59.9 ng/mL, 60-69.9 ng/mL, and 70 ng/mL or greater. The main outcome measure was 90-day mortality. Adjusted odds ratios (ORs) were estimated by multivariable logistic regression with inclusion of potential confounders.

RESULTS

After adjustment for age, gender, race (white vs nonwhite), patient type (surgical vs medical), season of 25(OH)D draw, and the Deyo-Charlson index, patients with 25(OH)D levels less than 30 ng/mL or 60 ng/mL or greater had higher odds of 90-day mortality compared with patients with levels of 30-49.9 ng/mL [adjusted OR (95% confidence interval) for 25(OH)D <10 ng/mL, 10-19.9 ng/mL, 20-29.9 ng/mL, 50-59.9 ng/mL, 60-69.9 ng/mL, and ≥70 ng/mL was 2.01 (1.68-2.40), 1.89 (1.64-2.18), 1.34 (1.16-1.56), 0.94 (0.69-1.26), 1.52 (1.03-2.25), and 1.69 (1.09-2.61), respectively, compared with patients with 25(OH)D levels 30-49.9 ng/mL].

LIMITATIONS

A causal relationship between either low or high 25(OH)D levels and increased mortality can not necessarily be inferred from this observational study.

CONCLUSIONS

Analysis of 24 094 adult patients showed that 25(OH)D levels less than 20 ng/mL and 60 ng/mL or greater before hospitalization were associated with an increased odds of 90-day mortality. Although previous reports have suggested an association between low vitamin D status and mortality, these data raise the issue of potential harm from high serum 25(OH)D levels, provide a rationale for an upper limit to supplementation, and emphasize the need for caution in the use of extremely high doses of vitamin D among patients.

Welfare programs that target workforce participation may negatively affect mortality

During the 1990s reforms to the US welfare system introduced new time limits on people's eligibility to receive public assistance. These limits were developed to encourage welfare recipients to seek employment. Little is known about how such social policy programs may have affected participants' health. We explored whether the Florida Family Transition Program randomized trial, a welfare reform experiment, led to long-term changes in mortality among participants. The Florida program included a 24-36-month time limit for welfare participation, intensive job training, and placement assistance. We linked 3,224 participants from the experiment to 17-18 years of prospective mortality follow-up data and found that participants in the program experienced a 16 percent higher mortality rate than recipients of traditional welfare. If our results are generalizable to national welfare reform efforts, they raise questions about whether the cost savings associated with welfare reform justify the additional loss of life.

Association of low serum 25-hydroxyvitamin D levels and sepsis in the critically ill

OBJECTIVE

We hypothesized that deficiency in 25-hydroxyvitamin D prior to hospital admission would be associated with sepsis in the critically ill.

DESIGN

Two-center observational study of patients treated in medical and surgical ICUs.

SETTING

Two hundred nine medical and surgical intensive care beds in two teaching hospitals in Boston, MA.

PATIENTS

Three thousand three hundred eighty-six patients, 18 years old or older, in whom 25-hydroxyvitamin D was measured prior to hospitalization between 1998 and 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

: Preadmission 25-hydroxyvitamin D was categorized as deficiency in 25-hydroxyvitamin D (≤ 15 ng/mL), insufficiency (15-30 ng/mL), and sufficiency (≥ 30 ng/mL). The primary outcome was sepsis as defined by International Classification of Diseases, 9th Edition, Clinical Modification and validated by the 2001 Society of Critical Care Medicine/European Society of Intensive Care Medicine, American College of Chest Physicians, American Thoracic Society, and Surgical Infection Society international sepsis definitions conference guidelines. Logistic regression examined the presence of sepsis 3 days prior to critical care initiation to 7 days after critical care initiation. Adjusted odds ratios were estimated by multivariable logistic regression models. Preadmission 25-hydroxyvitamin D deficiency is predictive for the risk of sepsis. In the full cohort, 25-hydroxyvitamin D deficiency is a significant predictor for the risk of International Classification of Diseases, 9th Edition, Clinical Modification-defined sepsis following multivariable adjustment, including age, gender, race, type (surgical vs medical), and Deyo-Charlson index (adjusted odds ratio, 1.51 [95% CI, 1.17-1.94]; p = 0.001) relative to patients with 25-hydroxyvitamin D sufficiency. In a subset of cohort patients enriched for those with International Classification of Diseases, 9th Edition, Clinical Modification-diagnosed sepsis (n = 444), preadmission 25-hydroxyvitamin D deficiency is a significant predictor for the risk of conference guideline-defined sepsis following multivariable adjustment, including age, gender, race, type (surgical vs medical), and Acute Physiology and Chronic Health Evaluation II (adjusted odds ratio, 2.05 [95% CI, 1.19-3.52]; p = 0.009) relative to patients with 25-hydroxyvitamin D sufficiency. Furthermore, in cohort patients with International Classification of Diseases, 9th Edition, Clinical Modification-defined sepsis (n = 568), the multivariable adjusted risk of 90-day mortality was 1.6-fold higher in those with preadmission 25-hydroxyvitamin D values in the insufficient and deficient range, compared with those with preadmission vitamin D sufficiency (adjusted odds ratio, 1.63 [95% CI, 1.11-2.39]; p = 0.01).

CONCLUSION

25-hydroxyvitamin D deficiency prior to hospital admission is a significant predictor of sepsis in the critically ill. Additionally, patients with sepsis who are not vitamin D sufficient have an increased risk of mortality following critical care initiation.

Association between prehospital vitamin D status and hospital-acquired Clostridium difficile infections

OBJECTIVE

To investigate whether preadmission 25-hydroxyvitamin D (25(OH)D) levels are associated with the risk of hospital-acquired Clostridium difficile infection (HACDI).

MATERIALS AND METHODS

Our retrospective cohort study focused on 568 adult patients from 2 Boston teaching hospitals between August 1993 and November 2006. All patients had 25(OH)D levels measured before hospitalization and were at risk for HACDI (defined as the presence of C difficile toxin A or B in stool samples obtained >48 hours after hospitalization). We performed multivariable regression analyses to test the association of prehospital 25(OH)D levels with HACDI while adjusting for clinically relevant covariates.

RESULTS

In these 568 patients, mean (SD) 25(OH)D level was 19 (12) ng/mL, and 11% of patients met criteria for incident HACDI. Following adjustment for age, sex, race (nonwhite vs white), patient type (medical vs surgical), and Deyo-Charlson index, patients with 25(OH)D levels <10 ng/mL had higher odds of HACDI (odds ratio [OR], 2.90; 95% confidence interval [CI], 1.01-8.34) compared with patients with 25(OH)D levels ≥30 ng/mL. When patients with HACDI were analyzed relative to a larger patient cohort without HACDI (n = 5047), those with 25(OH)D levels <10 ng/mL (OR, 4.96; 95% CI, 1.84-13.38) and 10-19.9 ng/mL (OR, 3.36; 95% CI, 1.28-8.85) had higher adjusted odds of HACDI compared with patients with 25(OH)D levels ≥30 ng/mL.

CONCLUSIONS

In our cohort of adult patients, vitamin D status before hospital admission was inversely associated with the risk of developing HACDI. These data support the need for randomized, controlled trials to test the role of vitamin D supplementation to prevent HACDI.

The Social Security Death Index (SSDI) most accurately reflects true survival for older oncology patients

INTRODUCTION

The ability to ascertain survival information is important for retrospective and prospective studies. Two databases that can be used are the Social Security Death Index (SSDI) and the National Death Index (NDI). Although the NDI is more complete, there are advantages to the SSDI such as ease of use and cost. The intent of this study was to determine accuracy of the SSDI.

METHODS

Publically available data on all known deceased individuals in the state of Ohio in 2003 were obtained from the State of Ohio Department of Health. A random sample of 63,557 of these were compared to the SSDI to identify risk factor for inclusion/exclusion.

RESULTS

Overall, 94.7% of all death records were confirmed by the SSDI. Age at death, gender, race, ethnicity, and cause of death were all found to significantly affect the likelihood of inclusion. Specifically, people aged 18-24 were included only 79.8% of the time compared to 96.2% for those over the age of 65. Also, malignancy as cause of death resulted in a 95.3% inclusion while trauma as a cause of death led to 86.5% inclusion. While Caucasians had an inclusion of 95.6%, African Americans were included only 87.8% of the time. Hispanics and women also had lower inclusion rates.

DISCUSSION

The SSDI is a strong tool for following up on participants lost to follow up in certain populations but is weaker in others. The SSDI would be particularly useful in a population that is largely older, Caucasian, or has malignant disease.

Diabetes mellitus and community-acquired bloodstream infections in the critically ill

INTRODUCTION

Community-acquired bloodstream infections have not been studied related to diabetes mellitus in the critically ill.

HYPOTHESIS

We hypothesized that the diagnosis of diabetes mellitus and poor chronic glycemic control would increase the risk of community-acquired bloodstream infections (CA-BSIs) in the critically ill.

METHODS

We performed an observational cohort study between 1998 and 2007 in 2 teaching hospitals in Boston, Massachusetts. We studied 2551 patients 18 years or older, who received critical care within 48 hours of admission and had blood cultures obtained within 48 hours of admission. The exposure of interest was diabetes mellitus defined by International Classification of Diseases, Ninth Revision, Clinical Modification, code 250.xx in outpatient or inpatient records. The primary end point was CA-BSI (<48 hours of hospital admission). Patients with a single coagulase-negative Staphylococcus positive blood culture were not considered to have bloodstream infection. Associations between diabetes groups and bloodstream infection were estimated by bivariable and multivariable logistic regression models. Subanalyses included evaluation of the association between hemoglobin A1c (HbA1c) and bloodstream infection, diabetes and risk of sepsis, and the proportion of the association between diabetes and CA-BSI that was mediated by acute glycemic control.

RESULTS

Diabetes is a predictor of CA-BSI. After adjustment for age, sex, race, patient type (medical vs surgical), and acute organ failure, the risk of bloodstream infection was significantly higher in patients with diabetes (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.10-1.82; P = .006) relative to patients without diabetes. The adjusted risk of bloodstream infection was increased in patients with HbA1c of 6.5% or higher (OR, 1.31; 95% CI, 1.04-1.65; P = .02) relative to patients with HbA1c less than 6.5%. Furthermore, the adjusted risk of sepsis was significantly higher in patients with diabetes (OR, 1.26; 95% CI, 1.04-1.54; P = .02) relative to patients without diabetes. Maximum glucose did not significantly mediate the relationship between diabetes mellitus diagnosis and CA-BSI.

CONCLUSIONS

A diagnosis of diabetes mellitus and HbA1c of 6.5% or higher is associated with the risk of CA-BSI in the critically ill.

A hypothetical protocol for the provisional use of perfusion imaging with exercise stress testing

BACKGROUND

Previous literature suggests that the results of myocardial perfusion imaging (MPI) add little to the prognosis of patients who exercise >10 metabolic equivalents (METS) during stress testing. With this in mind, we attempted to determine if a provisional injection protocol could be developed in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. This protocol would save a substantial amount of time, radiation exposure, and cost.

METHODS

All patients who underwent a stress SPECT MPI over a 6.5-year period from 2004 to 2010 were included. Patients who would have been considered for a standby injection protocol were: exercise stress, age < 65, no known coronary artery disease (CAD), and an interpretable ECG. Patients were retrospectively divided into two groups based on whether they would have received radioisotope or not. Criteria for not injecting included a maximal predicted heart rate ≥ 85%, ≥10 METS of exercise, no symptoms of chest pain or shortness of breath, and no ECG changes (ST depression or arrhythmia). The two groups were then compared based on MPI results and all-cause mortality derived from the Social Security Death Index.

RESULTS

A total of 24,689 patients underwent SPECT MPI during this period, and 5,352 would have been eligible for a provisional injection protocol. There were 3,791 (70.8%), who would have been injected and 1,561 (29.2%), who would not have been. Perfusion results were abnormal in 5.9% of non-injected group compared to 14.4% in those who would have been injected. After a mean follow-up of 60.6 ± 21.4 months, 1.1% had died in the non-injected cohort compared to 2.2% in the injected group.

CONCLUSION

A provisional injection protocol defined as age < 65, normal rest ECG, no history of CAD, and high level exercise with a negative ECG response and no symptoms has a very low 5-year all-cause mortality and low yield of MPI. If adopted it would decrease radiation exposure and save time and health care costs without jeopardizing prognosis.

The association between primary language spoken and all-cause mortality in critically ill patients

PURPOSE

The study objective was to investigate the association between primary language spoken and all-cause mortality in critically ill patients.

MATERIALS AND METHODS

We performed a cohort study on 48 581 patients 18 years or older who received critical care between 1997 and 2007 in 2 Boston hospitals. The exposure of interest was primary language spoken determined by the patient or family members who interacted with administrative staff during hospital registration. The primary outcome was 30-day mortality. Associations between language and mortality were estimated by bivariable and multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both language and mortality. Adjustment included age, race, sex, Deyo-Charlson index, patient type (medical vs surgical), sepsis, creatinine, hematocrit, white blood count, and number of organs with acute failure.

RESULTS

Validation showed that primary language spoken was highly accurate for a statement in the medical record noting the language spoken that matched the assigned language. Patients whose primary language spoken was not English had improved outcomes (odds ratio 30-day mortality, 0.69 [95% confidence interval, 0.60-0.81; P < .001), relative to patients with English as the primary language spoken, fully adjusted. Similar significant associations are seen with death by days 90 and 365 as well as in-hospital mortality. The improved survival in patients with a non-English primary language spoken is not confounded by indicators of severity of disease and is independent of the specific language spoken and neighborhood poverty rate, a proxy for socioeconomic status. There are significant limitations inherent to large database studies that we have acknowledged and addressed with controlling for measured confounding and evaluation of effect modification.

CONCLUSIONS

In a regional cohort, not speaking English as a primary language is associated with improved outcomes after critical care. Our observations may have clinical relevance and illustrate the intersection of several factors in critical illness outcome including severity of illness, comorbidity, and social and economic factors.

Pre-hospital vitamin D concentration, mortality, and bloodstream infection in a hospitalized patient population

OBJECTIVE

The study objective was to examine the association between pre-hospital serum vitamin D concentration and mortality after hospitalization.

METHODS

We performed a retrospective cohort study in 2 tertiary hospitals in Boston, Mass, on 23,603 patients aged ≥18 years in whom 25(OH)D was measured before hospitalization between 1993 and 2010. The main outcome measures were all-cause mortality by day 30 post-hospital admission, in-hospital mortality, and community-acquired bloodstream infection.

RESULTS

Compared with patients with pre-hospital 25(OH)D ≥30 ng/mL, patients with pre-hospital 25(OH)D ≤15 ng/mL or 15 to 30 ng/mL have higher odds of mortality 30 days after hospital admission. After adjustment for age, gender, race, Deyo-Charlson index, season, type (surgical vs medical), creatinine, blood urea nitrogen, hematocrit, and time between 25(OH)D draw and hospital admission, the adjusted odds ratio (OR) of 30-day mortality in patients with 25(OH)D ≤15 ng/mL is 1.45 (95% confidence interval [CI], 1.21-1.74; P<.0001) and the adjusted OR of 30-day mortality in patients with 25(OH)D 15 to 30 ng/mL is 1.30 (95% CI, 1.10-1.54; P = .003) both compared with patients with pre-hospital 25(OH)D ≥30 ng/mL. In a subgroup analysis of patients who had blood cultures drawn (n = 5628), pre-hospital serum 25(OH)D ≤15 ng/mL was associated with increased odds of community-acquired bloodstream infection (adjusted OR, 1.29; 95% CI, 1.06-1.57; P = .01) relative to patients with 25(OH)D ≥30 ng/mL.

CONCLUSIONS

Analysis of 23,603 hospitalized patients identified both 25(OH)D ≤15 ng/mL and 25(OH)D 15 to 30 ng/mL before hospital admission as associated with the odds of all-cause patient mortality at 30 days after hospitalization. In addition, pre-hospital serum 25(OH)D ≤15 ng/mL is significantly associated with the odds of community-acquired bloodstream infection.

Distinct injury markers for the early detection and prognosis of incident acute kidney injury in critically ill adults with preserved kidney function

The use of novel biomarkers to detect incident acute kidney injury (AKI) in the critically ill is hindered by heterogeneity of injury and the potentially confounding effects of prevalent AKI. Here we examined the ability of urine NGAL (NGAL), L-type Fatty Acid Binding Protein (L-FABP), and Cystatin C to predict AKI development, death, and dialysis in a nested case-control study of 380 critically ill adults with an eGFR over 60 ml/min/1.73 m². One-hundred thirty AKI cases were identified following biomarker measurement and were compared to 250 controls without AKI. Areas under the receiver-operator characteristic curves (AUC-ROCs) for discriminating incident AKI from non-AKI were 0.58(95%CI: 0.52-0.64), 0.59(0.52-0.65), and 0.50(0.48-0.57) for urine NGAL, L-FABP, and Cystatin C, respectively. The combined AUC-ROC for NGAL and L-FABP was 0.59(56-0.69). Both urine NGAL and L-FABP independently predicted AKI during multivariate regression; however, risk reclassification indices were mixed. Neither urine biomarker was independently associated with death or acute dialysis [NGAL hazard ratio 1.35(95%CI: 0.93-1.96), L-FABP 1.15(0.82-1.61)] though both independently predicted the need for acute dialysis [NGAL 3.44(1.73-6.83), L-FABP 2.36(1.30-4.25)]. Thus, urine NGAL and L-FABP independently associated with the development of incident AKI and receipt of dialysis but exhibited poor discrimination for incident AKI using conventional definitions.

Obstructive sleep apnea screening and postoperative mortality in a large surgical cohort

OBJECTIVE

A recent investigation at Barnes-Jewish Hospital located in St. Louis, Missouri, found that an estimated 22% of adults presenting for inpatient surgery screened as high risk for obstructive sleep apnea (OSA). Surgical patients with OSA have multiple comorbidities and are at increased risk for perioperative complications. Our objective was to determine if a prior diagnosis of OSA or a positive screen for OSA was associated with increased risk for 30-day and one-year mortality.

METHODS

B-J APNEAS (Barnes-Jewish Apnea Prevalence in Every Admission Study) was a prospective cohort study. Unselected adult surgical patients at Barnes Jewish Hospital were prospectively enrolled between February 2006 and April 2010. All patients completed preoperative OSA screening and those who were at risk for OSA according to a combination of the Berlin and Flemons screening tools received targeted postoperative interventions. STOP (loud Snoring, daytime Tiredness, Observed apneas, and high blood Pressure) and STOP-BANG (STOP, plus body mass index [BMI], age, neck circumference, and gender) scores also were obtained.

RESULTS

Overall, the sample included 14,962 patients, of whom 1939 (12.9%) reported a history of OSA. All four screening tools identified a high prevalence of undiagnosed patients at risk for OSA (9.5%-41.6%), but agreement among screens was not strong with κ statistic ranging from 0.225 to 0.611. There was no significant difference in 30-day postoperative mortality between patients with possible OSA (based on their history or on a positive OSA screen with any of the four instruments) and the rest of the surgical population. Significant differences in one-year mortality were noted between the low-risk and high-risk groups as identified by the Flemons' (4.96% vs 6.91%; p<0.0001), STOP (5.28% vs 7.57%; p<0.0001) and STOP-BANG (4.13% vs 7.45%; p<0.0001) screens. After adjusting for risk factors, none of the OSA screening tools independently predicted mortality rate up to one year postoperatively.

CONCLUSION

Neither a prior diagnosis of OSA nor a positive screen for OSA risk was associated with increased 30-day or one-year postoperative mortality. Differences in 1 year postoperative mortality were noted with three of the screening tools. The results of our study highlight uncertainties and research priorities for the medical community.

Regional variability in liver waiting list removals causes false ascertainment of waiting list deaths

Inconsistent identification of reasons for removal from the liver transplant waiting list by Organ Procurement and Transplantation Network (OPTN) regions may contribute to regional variability in wait-list death rates. We analyzed OPTN and Social Security Administration (SSA) reported deaths of 103 364 liver transplant candidates listed May 8, 2003-April 17, 2011, and determined regional variability in risk of death attributable to differences in use of OPTN removal codes. Only 26% of candidates removed as "too sick" died within 90 days of delisting; 6335 deaths after delisting were not reported to OPTN. The ratio of number of candidates removed as "too sick" to number who died on the waiting list varied by region from 0.23 to 0.94, indicating substantial variability in use of removal codes. Including SSA-reported deaths within 90 days of delisting reduced regional variability in risk of death by 48% compared with deaths on the list alone, and by 35% compared with deaths plus the "too sick" designation. Codes for delisting liver transplant candidates are inconsistently applied among OPTN regions, spuriously elevating estimated regional variability in risk of wait-list death. This variability is ameliorated by including SSA- reported deaths within 90 days of delisting.

Cognitive impairment in older adults with heart failure: prevalence, documentation, and impact on outcomes

BACKGROUND

Despite the fact that 80% of patients with heart failure are aged more than 65 years, recognition of cognitive impairment by physicians in this population has received relatively little attention. The current study evaluated physician documentation (as a measure of recognition) of cognitive impairment at the time of discharge in a cohort of older adults hospitalized for heart failure.

METHODS

We performed a prospective cohort study of older adults hospitalized with a primary diagnosis of heart failure. Cognitive status was evaluated with the Folstein Mini-Mental State Examination at the time of hospitalization. A score of 21 to 24 was used to indicate mild cognitive impairment, and a score of ≤20 was used to indicate moderate to severe impairment. To evaluate physician documentation of cognitive impairment, we used a standardized form with a targeted keyword strategy to review hospital discharge summaries. We calculated the proportion of patients with cognitive impairment documented as such by physicians and compared characteristics between groups with and without documented cognitive impairment. We then analyzed the association of cognitive impairment and documentation of cognitive impairment with 6-month mortality or readmission using Cox proportional hazards regression.

RESULTS

A total of 282 patients completed the cognitive assessment. Their mean age was 80 years of age, 18.8% were nonwhite, and 53.2% were female. Cognitive impairment was present in 132 of 282 patients (46.8% overall; 25.2% mild, 21.6% moderate-severe). Among those with cognitive impairment, 30 of 132 (22.7%) were documented as such by physicians. Compared with patients whose cognitive impairment was documented by physicians, those whose impairment was not documented were younger (81.3 vs 85.2 years, P<.05) and had less severe impairment (median Mini-Mental State Examination score 22.0 vs 18.0, P<.01). After multivariable adjustment, patients whose cognitive impairment was not documented were significantly more likely to experience 6-month mortality or hospital readmission than patients without cognitive impairment.

CONCLUSIONS

Cognitive impairment is common in older adults hospitalized for heart failure, yet it is frequently not documented by physicians. Implementation of strategies to improve recognition and documentation of cognitive impairment may improve the care of these patients, particularly at the time of hospital discharge.

Association of low serum 25-hydroxyvitamin D levels and acute kidney injury in the critically ill

OBJECTIVE

Given the importance of inflammation in acute kidney injury and the relationship between vitamin D and inflammation, we sought to elucidate the effect of vitamin D on acute kidney injury. We hypothesized that deficiency in 25-hydroxyvitamin D prior to hospital admission would be associated with acute kidney injury in the critically ill.

DESIGN

Two-center observational study of patients treated in medical and surgical intensive care units.

SETTING

Two hundred nine medical and surgical intensive care beds in two teaching hospitals in Boston, Massachusetts.

PATIENTS

Two thousand seventy-five patients, aged ≥ 18 yrs, in whom serum 25-hydroxyvitamin D was measured prior to hospitalization between 1998 and 2009.

INTERVENTIONS

: None.

MEASUREMENTS AND MAIN RESULTS

The exposure of interest was preadmission serum 25-hydroxyvitamin D and categorized a priori as deficiency (25-hydroxyvitamin D <15 ng/mL), insufficiency (25-hydroxyvitamin D 15-30 ng/mL), or sufficiency (25-hydroxyvitamin D ≥ 30 ng/mL). The primary outcome was acute kidney injury defined as meeting Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) Injury or Failure criteria. Logistic regression examined the RIFLE criteria outcome. Adjusted odds ratios were estimated by multivariate logistic regression models. Preadmission 25-hydroxyvitamin D deficiency is predictive of acute kidney injury. Patients with 25-hydroxyvitamin D deficiency have an odds ratio for acute kidney injury of 1.73 (95% confidence interval 1.30-2.30; p < .0001) relative to patients with 25-hydroxyvitamin D sufficiency. 25-Hydroxyvitamin D deficiency remains a significant predictor of acute kidney injury following multivariable adjustment (adjusted odds ratio 1.50; 95% confidence interval 1.42-2.24; p < .0001). Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for acute kidney injury of 1.49 (95% confidence interval 1.15-1.94; p = .003) and an adjusted odds ratio of 1.23 (95% confidence interval 1.12-1.72; p = .003) relative to patients with 25-hydroxyvitamin D sufficiency. In addition, preadmission 25-hydroxyvitamin D deficiency is predictive of mortality. Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for 30-day mortality of 1.60 (95% confidence interval 1.18-2.17; p = .003) and an adjusted odds ratio of 1.61 (95% confidence interval 1.06-1.57; p = .004) relative to patients with 25-hydroxyvitamin D sufficiency.

CONCLUSION

Deficiency of 25-hydroxyvitamin D prior to hospital admission is a significant predictor of acute kidney injury and mortality in a critically ill patient population.

The prognosis of a normal Tl-201 stress-only SPECT MPI study

BACKGROUND

Stress-only Tc-99m SPECT myocardial perfusion imaging (MPI) decreases test time and patient radiation exposure with a proven benign prognosis of a normal study. The imaging sequence of Tl-201 MPI always starts with the stress portion; therefore, no pre-test decisions are needed regarding the imaging sequence. The recent intermittent Tc-99m shortage afforded the unique opportunity to study an unselected group of patients undergoing Tl-201 imaging.

METHODS

We retrospectively reviewed all the patients who had SPECT MPI with Tc-99m or Tl-201 over a 1-year period. When Tc-99m was not available, patients received Tl-201. All stress Tl-201 images were routinely processed, and if normal, rest imaging was not done. When Tc-99m was used, patients with lower pre-test probability were selected for a stress-first protocol. We compared the all-cause mortality of patients with normal Tl-201 studies to those with normal stress-only and rest-stress Tc-99m studies using the Social Security Death Index. Unadjusted and risk-adjusted survival analysis was performed. Specific causes of death (cardiac or non-cardiac) were determined by medical record review and contact with treating physicians.

RESULTS

A total of 3,658 patients underwent stress MPI during this time period. Of the 1,215 patients who had Tl-201 MPI, 716 (67%) had a normal stress-only study. Out of 2,443 patients who underwent Tc-99m MPI, 70% had normal perfusion with 1,098 normal stress-only studies and 493 normal rest-stress studies. The average follow-up was 23.3 ± 5.3 months. Unadjusted all-cause mortality at the end of follow-up was 7.1% in the Tl-201 stress-only group, 6.3% for Tc-99m stress-only patients, and 4.3% in the Tc-99m rest-stress cohort. After controlling for confounding variables, survival was similar in the three groups (HR 1.07, 95% CI 0.62-1.82, P = .82 for normal Tl-201 stress-only compared to normal Tc-99m rest-stress). The risk-adjusted 1-year survival was between 98.5 and 98.8% in the three groups.

CONCLUSIONS

Normal stress-only Tl-201 SPECT MPI study has a similarly benign prognosis when compared to Tc-99m rest-stress and Tc-99m stress-only normal SPECT MPI studies. The stress-first design allowed for early triage of over 60% of patients and marked improvement in laboratory efficiency due to shortened test time.

30-Day risk-standardized mortality and readmission rates after ischemic stroke in critical access hospitals

BACKGROUND AND PURPOSE

The critical access hospital (CAH) designation was established to provide rural residents with local access to emergency and inpatient care. CAHs, however, have poorer short-term outcomes for pneumonia, heart failure, and myocardial infarction compared with other hospitals. We assessed whether 30-day risk-standardized mortality rates (RSMRs) and risk-standardized readmission rates (RSRRs) after ischemic stroke differ between CAHs and non-CAHs.

METHODS

The study included all fee-for-service Medicare beneficiaries 65 years of age or older with a primary discharge diagnosis of ischemic stroke (International Classification of Diseases, 9th revision codes 433, 434, 436) in 2006. Hierarchical generalized linear models calculated hospital-level RSMRs and RSRRs, adjusting for patient demographics, medical history, and comorbid conditions. Non-CAHs were categorized by hospital volume quartiles and the RSMR and RSRR posterior probabilities in comparison with CAHs were determined using linear regression with Markov chain Monte Carlo simulation.

RESULTS

There were 10 267 ischemic stroke discharges from 1165 CAHs and 300 114 discharges from 3381 non-CAHs. The RSMRs of CAHs were higher than non-CAHs (11.9%± 1.4% vs 10.9%± 1.7%; P<0.001), but the RSRRs were comparable (13.7%± 0.6% vs 13.7%± 1.4%; P=0.3). The RSMRs for the 2 higher volume quartiles of non-CAHs were lower than CAHs (posterior probability of RSMRs higher than CAHs=0.007 for quartile 3; P<0.001 for quartile 4), but there were no differences for lower volume hospitals; RSRRs did not vary by annual hospital volume.

CONCLUSIONS

CAHs had higher RSMRs compared with non-CAHs, but readmission rates were similar. The observed differences may be partly explained by patient characteristics and annual hospital volume.

QTc prolongation is associated with impaired right ventricular function and predicts mortality in pulmonary hypertension

BACKGROUND

In rodent models of pulmonary hypertension (PH) and right ventricular hypertrophy (RVH), the QTc interval is prolonged, reflecting downregulation of repolarizing Kv channels in RV myocytes. The significance of QTc prolongation in human PH is unknown. We hypothesized that QTc prolongation occurs in human PH, is associated with RVH and decreased RV function, and predicts adverse prognosis.

METHODS

Patients receiving a PAH-specific therapy (a prostanoid, endothelin-receptor antagonist and/or a phosphodiesterase-5 inhibitor), who had a 12-lead electrocardiogram (ECG) (n=202) were compared to age- and sex-matched controls (n=100). The duration of QTc on ECG was correlated with invasive hemodynamics (n=156) and with the status of the RV, as measured by Brain Natriuretic Peptide (NT-proBNP, n=145) and magnetic resonance imaging (n=24). Survival of the entire PH cohort and a subgroup with WHO Groups 1 and 4 PAH was prospectively determined from the Social Security Death Index.

RESULTS

QTc intervals were longer in PH vs. controls (454.8 ± 29 ms vs. 429.8 ± 18 ms, p<0.001) and did not differ based on PAH-specific therapy. NT-proBNP increased proportionately with QTc and was higher for those in the upper quintile (QTc ≥ 480 ms) vs. those with QTc<480 ms (4004 ± 6682 pg/mL vs. 1501 ± 1822 pg/mL, p<0.001). The QTc interval also correlated directly with increasing RV end-diastolic volume (r=.67, p<0.001) and mass (r=.0.51, p<0.05), and inversely with RV ejection fraction (r=-.49, p<0.05). In the entire PH cohort and WHO Groups 1 and 4 subgroup, QTc ≥ 480 ms and cardiac index were independent predictors of mortality.

CONCLUSIONS

QTc prolongation in PH patients reflects the status of the RV and is an independent predictor of mortality.

Downstream procedures and outcomes after stress testing for chest pain without known coronary artery disease in the United States

BACKGROUND

Millions of Americans with suspected coronary artery disease undergo noninvasive cardiac stress testing annually. Downstream procedures and subsequent outcomes among symptomatic patients without known coronary disease referred for stress testing are not well characterized in contemporary community practice.

METHODS

We examined administrative insurance billing data from a national insurance provider from November 2004 through June 2007. After excluding patients with prior cardiac disease or chest pain evaluation, we identified 80,676 people age 40 to 64 years with outpatient cardiac stress testing within 30 days after an office visit for chest pain. We evaluated rates of invasive coronary angiography, coronary revascularization, and cardiovascular events after stress testing.

RESULTS

Within 60 days, only 8.8% of stress test patients underwent cardiac catheterization and only 2.7% underwent revascularization; within 1 year, only 0.5% died and had myocardial infarction or stroke. There were marked geographic variations in 1-year rates of catheterization (3.8%-14.8%) and revascularization (1.2%-3.0%) across 20 hospital referral regions.

CONCLUSIONS

In this large national cohort of middle-aged patients without previously coded cardiac diagnosis who were referred for stress testing after outpatient chest pain evaluation, few proceeded to invasive angiography or revascularization, and subsequent cardiovascular events were infrequent.