Association of Household Income Level and In-Hospital Mortality in Patients With Sepsis: A Nationwide Retrospective Cohort Analysis.

OBJECTIVE: Associations between low socioeconomic status (SES) and poor health outcomes have been demonstrated in a variety of conditions. However, the relationship in patients with sepsis is not well described. We investigated the association of lower household income with in-hospital mortality in patients with sepsis across the United States. METHODS: Retrospective nationwide cohort analysis utilizing the Nationwide Inpatient Sample (NIS) from 2011. Patients aged 18 years or older with sepsis were included. Socioeconomic status was approximated by the median household income of the zip code in which the patient resided. Multivariate logistic modeling incorporating a validated illness severity score for sepsis in administrative data was performed. RESULTS: A total of 8 023 590 admissions from the 2011 NIS were examined. A total of 671 858 patients with sepsis were included in the analysis. The lowest income residents compared to the highest were younger (66.9 years, standard deviation [SD] = 16.5 vs 71.4 years, SD = 16.1, P < .01), more likely to be female (53.5% vs 51.9%, P < .01), less likely to be white (54.6% vs 76.6%, P < .01), as well as less likely to have health insurance coverage (92.8% vs 95.9%, P < .01). After controlling for severity of sepsis, residing in the lowest income quartile compared to the highest quartile was associated with a higher risk of mortality (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.03-1.08, P < .01). There was no association seen between the second (OR: 1.02, 95% CI: 0.99-1.05, P = .14) and third (OR: 0.99, 95% CI: 0.97-1.01, P = .40) quartiles compared to the highest. CONCLUSION: After adjustment for severity of illness, patients with sepsis who live in the lowest median income quartile had a higher risk of mortality compared to residents of the highest income quartile. The association between SES and mortality in sepsis warrants further investigation with more comprehensive measures of SES.

A prospective multicenter cohort study of frailty in younger critically ill patients.

BACKGROUND: Frailty is a multidimensional syndrome characterized by loss of physiologic and cognitive reserve that heightens vulnerability. Frailty has been well described among elderly patients (i.e., 65 years of age or older), but few studies have evaluated frailty in nonelderly patients with critical illness. We aimed to describe the prevalence, correlates, and outcomes associated with frailty among younger critically ill patients. METHODS: We conducted a prospective cohort study of 197 consecutive critically ill patients aged 50-64.9 years admitted to intensive care units (ICUs) at six hospitals across Alberta, Canada. Frailty was defined as a score ≥5 on the Clinical Frailty Scale before hospitalization. Multivariable analyses were used to evaluate factors independently associated with frailty before ICU admission and the independent association between frailty and outcome. RESULTS: In the 197 patients in the study, mean (SD) age was 58.5 (4.1) years, 37 % were female, 73 % had three or more comorbid illnesses, and 28 % (n = 55; 95 % CI 22-35) were frail. Factors independently associated with frailty included not being completely independent (adjusted OR [aOR] 4.4, 95 % CI 1.8-11.1), connective tissue disease (aOR 6.0, 95 % CI 2.1-17.0), and hospitalization within the preceding year (aOR 3.3, 95 % CI 1.3-8.1). There were no significant differences between frail and nonfrail patients in reason for admission, Acute Physiology and Chronic Health Evaluation II score, preference for life support, or treatment intensity. Younger frail patients did not have significantly longer (median [interquartile range]) hospital stay (26 [9-68] days vs. 19 [10-43] days; p = 0.4), but they had greater 1-year rehospitalization rates (61 % vs. 40 %; p = 0.02) and higher 1-year mortality (33 % vs. 20 %; adjusted HR 1.8, 95 % CI 1.0-3.3; p = 0.039). CONCLUSIONS: Prehospital frailty is common among younger critically ill patients, and in this study it was associated with higher rates of mortality at 1 year and with rehospitalization. Our data suggest that frailty should be considered in younger adults admitted to the ICU, not just in the elderly. Additional research is needed to further characterize frailty in younger critically ill patients, along with the ideal instruments for identification.

Long-term association between frailty and health-related quality of life among survivors of critical illness: a prospective multicenter cohort study.

OBJECTIVE: Frailty is a multidimensional syndrome characterized by loss of physiologic reserve that gives rise to vulnerability to poor outcomes. We aimed to examine the association between frailty and long-term health-related quality of life among survivors of critical illness. DESIGN: Prospective multicenter observational cohort study. SETTING: ICUs in six hospitals from across Alberta, Canada. PATIENTS: Four hundred twenty-one critically ill patients who were 50 years or older. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Frailty was operationalized by a score of more than 4 on the Clinical Frailty Scale. Health-related quality of life was measured by the EuroQol Health Questionnaire and Short-Form 12 Physical and Mental Component Scores at 6 and 12 months. Multiple logistic and linear regression with generalized estimating equations was used to explore the association between frailty and health-related quality of life. In total, frailty was diagnosed in 33% (95% CI, 28-38). Frail patients were older, had more comorbidities, and higher illness severity. EuroQol-visual analogue scale scores were lower for frail compared with not frail patients at 6 months (52.2 ± 22.5 vs 64.6 ± 19.4; p < 0.001) and 12 months (54.4 ± 23.1 vs 68.0 ± 17.8; p < 0.001). Frail patients reported greater problems with mobility (71% vs 45%; odds ratio, 3.1 [1.6-6.1]; p = 0.001), self-care (49% vs 15%; odds ratio, 5.8 [2.9-11.7]; p < 0.001), usual activities (80% vs 52%; odds ratio, 3.9 [1.8-8.2]; p < 0.001), pain/discomfort (68% vs 47%; odds ratio, 2.0 [1.1-3.8]; p = 0.03), and anxiety/depression (51% vs 27%; odds ratio, 2.8 [1.5-5.3]; p = 0.001) compared with not frail patients. Frail patients described lower health-related quality of life on both physical component score (34.7 ± 7.8 vs 37.8 ± 6.7; p = 0.012) and mental component score (33.8 ± 7.0 vs 38.6 ± 7.7; p < 0.001) at 12 months. CONCLUSIONS: Frail survivors of critical illness experienced greater impairment in health-related quality of life, functional dependence, and disability compared with those not frail. The systematic assessment of frailty may assist in better informing patients and families on the complexities of survivorship and recovery.

Seeking worldwide professional consensus on the principles of end-of-life care for the critically ill. The Consensus for Worldwide End-of-Life Practice for Patients in Intensive Care Units (WELPICUS) study.

Great differences in end-of-life practices in treating the critically ill around the world warrant agreement regarding the major ethical principles. This analysis determines the extent of worldwide consensus for end-of-life practices, delineates where there is and is not consensus, and analyzes reasons for lack of consensus. Critical care societies worldwide were invited to participate. Country coordinators were identified and draft statements were developed for major end-of-life issues and translated into six languages. Multidisciplinary responses using a web-based survey assessed agreement or disagreement with definitions and statements linked to anonymous demographic information. Consensus was prospectively defined as >80% agreement. Definitions and statements not obtaining consensus were revised based on comments of respondents, and then translated and redistributed. Of the initial 1,283 responses from 32 countries, consensus was found for 66 (81%) of the 81 definitions and statements; 26 (32%) had >90% agreement. With 83 additional responses to the original questionnaire (1,366 total) and 604 responses to the revised statements, consensus could be obtained for another 11 of the 15 statements. Consensus was obtained for informed consent, withholding and withdrawing life-sustaining treatment, legal requirements, intensive care unit therapies, cardiopulmonary resuscitation, shared decision making, medical and nursing consensus, brain death, and palliative care. Consensus was obtained for 77 of 81 (95%) statements. Worldwide consensus could be developed for the majority of definitions and statements about end-of-life practices. Statements achieving consensus provide standards of practice for end-of-life care; statements without consensus identify important areas for future research.

Association between frailty and short- and long-term outcomes among critically ill patients: a multicentre prospective cohort study.

BACKGROUND: Frailty is a multidimensional syndrome characterized by loss of physiologic and cognitive reserves that confers vulnerability to adverse outcomes. We determined the prevalence, correlates and outcomes associated with frailty among adults admitted to intensive care. METHODS: We prospectively enrolled 421 critically ill adults aged 50 or more at 6 hospitals across the province of Alberta. The primary exposure was frailty, defined by a score greater than 4 on the Clinical Frailty Scale. The primary outcome measure was in-hospital mortality. Secondary outcome measures included adverse events, 1-year mortality and quality of life. RESULTS: The prevalence of frailty was 32.8% (95% confidence interval [CI] 28.3%-37.5%). Frail patients were older, were more likely to be female, and had more comorbidities and greater functional dependence than those who were not frail. In-hospital mortality was higher among frail patients than among non-frail patients (32% v. 16%; adjusted odds ratio [OR] 1.81, 95% CI 1.09-3.01) and remained higher at 1 year (48% v. 25%; adjusted hazard ratio 1.82, 95% CI 1.28-2.60). Major adverse events were more common among frail patients (39% v. 29%; OR 1.54, 95% CI 1.01-2.37). Compared with nonfrail survivors, frail survivors were more likely to become functionally dependent (71% v. 52%; OR 2.25, 95% CI 1.03-4.89), had significantly lower quality of life and were more often readmitted to hospital (56% v. 39%; OR 1.98, 95% CI 1.22-3.23) in the 12 months following enrolment. INTERPRETATION: Frailty was common among critically ill adults aged 50 and older and identified a population at increased risk of adverse events, morbidity and mortality. Diagnosis of frailty could improve prognostication and identify a vulnerable population that might benefit from follow-up and intervention.

Frailty Predicts Dementia and Death in Older Adults Living in Long-Term Care.

OBJECTIVES: To investigate how the accumulation of deficits traditionally related and not traditionally related to dementia predicts dementia and mortality. DESIGN: A retrospective cohort study with up to 9 years of follow-up. SETTING AND PARTICIPANTS: Long-term care residents aged ≥65 with or without dementia. METHODS: Frailty indices based on health deficit accumulation were constructed. The FI-t consisted of 27 deficits traditionally related to dementia; the FI-n consisted of 27 deficits not traditionally related to dementia; the FI-a consisted of all 54 deficits taken from the FI-t and the FI-n. RESULTS: In this long-term care sample (n = 29,758; mean age = 84.6 ± 8.0; 63.8% female), 91% of the residents had at least 1 impairment in activities of daily living, 61% had a diagnosis of dementia, and the vast majority were frail (53% had FI-a > 0.2). Residents with dementia had a higher FI-t compared with those without dementia (0.278 ± 0.110 vs. 0.272 ± 0.108), whereas residents without dementia had a higher FI-n (0.143 ± 0.082 vs. 0.136 ± 0.079). Within 9 years, 97% of the sample had died; a 0.01 increase of the FI-a was associated with a 4% increase of the mortality risk, adjusting for age, sex, admission year, stay length, and dementia type. Residents who developed dementia after admission to long-term care had higher baseline FI-t and FI-a (P's < .003) than those who remained without dementia. CONCLUSIONS AND IMPLICATIONS: Frailty is highly prevalent in older adults living in long-term care, irrespective of the presence or absence of dementia. Accumulation of deficits, either traditionally related or unrelated to dementia, is associated with risks of death and dementia, and more deficits increases the probability. Our findings have implications for improving the quality of care of older adults in long-term care, by monitoring the degree of frailty at admission, managing distinct needs in relation to dementia, and enhancing frailty level-informed care and services.

The role of frailty in outcomes from critical illness.

PURPOSE OF REVIEW: Frailty is a multidimensional syndrome characterized by loss of physiologic reserves that gives rise to vulnerability to adverse events. RECENT FINDINGS: Frailty has been described in older patients undergoing geriatric assessment and in noncardiac and cardiac surgical settings, in which it closely correlates with heightened risk for major morbidity including functional decline, postoperative complications, institutionalization, and short-term and long-term mortality. Critically ill patients may represent a population with similar vulnerabilities to older frail patients. Prior data have described the association with less favorable outcomes and poor premorbid functional status (i.e., activities of daily living, cognitive impairment, body mass index), used perhaps as a surrogate for frailty. Preliminary epidemiologic data suggest the prevalence of frailty (and intermediate frail states) among critically ill patients is high and likely to increase with the greater demand placed on ICU resources associated with population demographic transition. SUMMARY: The concept of frailty, as a marker of biologic age and physiologic reserve, may have direct relevance to critical care, and clearly identifies a population at greater risk of adverse events, morbidity, and mortality. Its recognition in critical care settings may enable improved prognostication and shared decision-making and identify vulnerable subgroups with specific needs who might benefit from targeted follow-up.

Octogenarians in the ICU: are you ever too old?

Long-term morbidity and mortality rates for older patients admitted to the ICU remain substantial. In this issue of Critical Care, Roch and colleagues describe a retrospective study evaluating factors associated with survival and quality-of-life of octogenarians (aged ≥80 years) admitted to a medical ICU. This study proposes to address a highly relevant and increasingly encountered scenario in ICUs - what factors can best estimate prognosis for elderly patients at the time of evaluation for ICU admission? While perhaps not unique to octogenarians, such data have the potential to better inform on decision-making regarding advanced life support along with facilitating discussion on the perceived benefit and on patient treatment preferences concerning intensive care.

Frailty in the critically ill: a novel concept.

The concept of frailty has been defined as a multidimensional syndrome characterized by the loss of physical and cognitive reserve that predisposes to the accumulation of deficits and increased vulnerability to adverse events. Frailty is strongly correlated with age, and overlaps with and extends aspects of a patient's disability status (that is, functional limitation) and/or burden of comorbid disease. The frail phenotype has more specifically been characterized by adverse changes to a patient's mobility, muscle mass, nutritional status, strength and endurance. We contend that, in selected circumstances, the critically ill patient may be analogous to the frail geriatric patient. The prevalence of frailty amongst critically ill patients is currently unknown; however, it is probably increasing, based on data showing that the utilization of intensive care unit (ICU) resources by older people is rising. Owing to the theoretical similarities in frailty between geriatric and critically ill patients, this concept may have clinical relevance and may be predictive of outcomes, along with showing important interaction with several factors including illness severity, comorbid disease, and the social and structural environment. We believe studies of frailty in critically ill patients are needed to evaluate how it correlates with outcomes such as survival and quality of life, and how it relates to resource utilization, such as length of mechanical ventilation, ICU stay and duration of hospitalization. We hypothesize that the objective measurement of frailty may provide additional support and reinforcement to clinicians confronted with end-of-life decisions on the appropriateness of ICU support and/or withholding of life-sustaining therapies.

The Influence of Geography, Religion, Religiosity and Institutional Factors on Worldwide End-of-Life Care for the Critically Ill: The WELPICUS Study.

PURPOSE: To evaluate the association between provider religion and religiosity and consensus about end-of-life care and explore if geographical and institutional factors contribute to variability in practice. MATERIALS AND METHODS: Using a modified Delphi method 22 end-of-life issues consisting of 35 definitions and 46 statements were evaluated in 32 countries in North America, South America, Eastern Europe, Western Europe, Asia, Australia and South Africa. A multidisciplinary, expert group from specialties treating patients at the end-of-life within each participating institution assessed the association between 7 key statements and geography, religion, religiosity and institutional factors likely influencing the development of consensus. RESULTS: Of 3049 participants, 1366 (45%) responded. Mean age of respondents was 45 ± 9 years and 55% were females. Following 2 Delphi rounds, consensus was obtained for 77 (95%) of 81 definitions and statements. There was a significant difference in responses across geographical regions. South African and North American respondents were more likely to encourage patients to write advance directives. Fewer Eastern European and Asian respondents agreed with withdrawing life-sustaining treatments without consent of patients or surrogates. While respondent's religion, years in practice or institution did not affect their agreement, religiosity, physician specialty and responsibility for end-of-life decisions did. CONCLUSIONS: Variability in agreement with key consensus statements about end-of-life care is related primarily to differences among providers, with provider-level variations related to differences in religiosity and specialty. Geography also plays a role in influencing some end-of-life practices. This information may help understanding ethical dilemmas and developing culturally sensitive end-of-life care strategies.

A case-control study of single-pass albumin dialysis for acetaminophen-induced acute liver failure.

BACKGROUND: Extracorporeal support with single-pass albumin dialysis (SPAD) may remove protein-bound toxins in acute liver failure. We evaluated the clinical, physiological and laboratory parameters of SPAD in acetaminophen-induced acute liver failure (AALF). METHODS: Retrospective case-control studies of AALF patients were used. RESULTS: We identified 13 AALF patients (6 SPAD-treated, 7 controls). The average age was 38 years, 92% were female, none had cirrhosis and the Model for End-Stage Liver Disease (MELD) scores were 43. Eleven patients (85%) fulfilled the King's College criteria for a liver transplant. SPAD-treated patients received 21 sessions (total: 147 h, mean 3.5 runs or 24.5 h/patient). There were no complications. No significant changes in clinical, physiological or biochemical parameters occurred during SPAD. Compared with the controls, there were no significant differences in ICU or 1-year survival, liver recovery or referral for a liver transplant. CONCLUSION: SPAD was well-tolerated in AALF; however, it was not associated with differences in clinical outcomes. While SPAD may be an adjuvant supportive therapy in AALF, prospective trials are needed.

Patterns of Palliative Care Referral in Patients Admitted With Heart Failure Requiring Mechanical Ventilation.

BACKGROUND: Palliative care is recommended for advanced heart failure (HF) by several major societies, though prior studies indicate that it is underutilized. AIM: To investigate patterns of palliative care referral for patients admitted with HF exacerbations, as well as to examine patient and hospital factors associated with different rates of palliative care referral. DESIGN: Retrospective nationwide cohort analysis utilizing the National Inpatient Sample from 2006 to 2012. Patients referred to palliative care were compared to those who were not. SETTING/PARTICIPANTS: Patients ≥18 years of age with a primary diagnosis of HF requiring mechanical ventilation (MV) were included. A cohort of non-HF patients with metastatic cancer was created for temporal comparison. RESULTS: Between 2006 and 2012, 74 824 patients underwent MV for HF. A referral to palliative care was made in 2903 (3.9%) patients. The rate of referral for palliative care in HF increased from 0.8% in 2006 to 6.4% in 2012 ( P < .01). In comparison, rate of palliative care referral in patients with cancer increased from 2.9% in 2006 to 11.9% in 2012 ( P < .01). In a multivariate logistic regression model, higher socioeconomic status (SES) was associated with increased access to palliative care ( P < .01). Racial differences were also observed in rates of referral to palliative care. CONCLUSION: The use of palliative care for patients with advanced HF increased during the study period; however, palliative care remains underutilized in this setting. Patient factors such as race and SES affect access to palliative care.

Use of Palliative Care in Patients With End-Stage COPD and Receiving Home Oxygen: National Trends and Barriers to Care in the United States.

BACKGROUND: To investigate the use of palliative care (PC) in patients with end-stage COPD receiving home oxygen hospitalized for an exacerbation. METHODS: A retrospective nationwide cohort analysis was performed, using the Nationwide Inpatient Sample. All patients ≥ 18 years of age with a diagnosis of COPD, receiving home oxygen, and admitted for an exacerbation were included. RESULTS: A total of 55,208,382 hospitalizations from the 2006-2012 Nationwide Inpatient Sample were examined. There were 181,689 patients with COPD, receiving home oxygen, and admitted for an exacerbation; 3,145 patients (1.7%) also had a PC contact. There was a 4.5-fold relative increase in PC referral from 2006 (0.45%) to 2012 (2.56%) (P < .01). Patients receiving PC consultations compared with those who did not were older (75.0 years [SD 10.9] vs 70.6 years [SD 9.7]; P < .01), had longer hospitalizations (4.9 days [interquartile range, 2.6-8.2] vs 3.5 days [interquartile range, 2.1-5.6]), and more likely to die in hospital (32.1% vs 1.5%; P < .01). Race was significantly associated with referral to palliative care, with white patients referred more often than minorities (P < .01). Factors associated with PC referral included age (OR, 1.03; 95% CI, 1.02-1.04; P < .01), metastatic cancer (OR, 2.40; 95% CI, 2.02-2.87; P < .01), nonmetastatic cancer (OR, 2.75; 95% CI, 2.43-3.11; P < .01), invasive mechanical ventilation (OR, 4.89; 95% CI, 4.31-5.55; P < .01), noninvasive mechanical ventilation (OR, 2.84; 95% CI, 2.58-3.12; P < .01), and Do Not Resuscitate status (OR, 7.95; 95% CI, 7.29-8.67; P < .01). CONCLUSIONS: The use of PC increased dramatically during the study period; however, PC contact occurs only in a minority of patients with end-stage COPD admitted with an exacerbation.

Impact of hospital case-volume on subarachnoid hemorrhage outcomes: A nationwide analysis adjusting for hemorrhage severity.

OBJECTIVE: There have been suggestions that patients with subarachnoid hemorrhage (SAH) have a better outcome when treated in high-volume centers. Much of the published literature on the subject is limited by an inability to control for severity of SAH. METHODS: This is a nationwide retrospective cohort analysis using the Nationwide Inpatient Sample (NIS). The NIS Subarachnoid Severity Scale was used to adjust for severity of SAH in multivariate logistic regression modeling. RESULTS: The records of 47 911 414 hospital admissions from the 2006-2011 NIS samples were examined. There were 11 607 patients who met inclusion criteria for the study. Of these, 7787 (67.0%) were treated at a high-volume center compared with 3820 (32.9%) treated at a low-volume center. Patients treated at high-volume centers compared with low-volume centers were more likely to receive endovascular aneurysm control (58.5% vs 51.2%, P=.04), be transferred from another hospital (35.4% vs 19.7%, P<.01), be treated in a teaching facility (97.3% vs 72.9%, P<.01), and have a longer length of stay (14.9 days [interquartile range 10.3-21.7] vs 13.9 days [interquartile range, 8.9-20.1], P<.01). After adjustment for all baseline covariates, including severity of SAH, treatment in a high-volume center was associated with an odds ratio for death of 0.82 (95% confidence interval, 0.72-0.95; P<.01) and a higher odds of a good functional outcome (odds ratio, 1.16; 95% confidence interval, 1.04-1.28; P<.01). CONCLUSION: After adjustment for severity of SAH, treatment in a high-volume center was associated with a lower risk of in-hospital mortality and a higher odds of a good functional outcome.

Association between chronic exposure to air pollution and mortality in the acute respiratory distress syndrome.

The impact of chronic exposure to air pollution and outcomes in the acute respiratory distress syndrome (ARDS) is unknown. The Nationwide Inpatient Sample (NIS) from 2011 was utilized for this analysis. The NIS is a national database that captures 20% of all US in-patient hospitalizations from 47 states. Patients with ARDS who underwent mechanical ventilation from the highest 15 ozone pollution cities were compared with the rest of the country. Secondary analyses assessed outcomes of ARDS patients for ozone pollution and particulate matter pollution on a continuous scale by county of residence. A total of 8,023,590 hospital admissions from the 2011 NIS sample were analyzed. There were 93,950 patients who underwent mechanical ventilation for ARDS included in the study. Patients treated in high ozone regions had significantly higher unadjusted hospital mortality (34.9% versus 30.8%, p < 0.01) than patients in cities with control levels of ozone. After controlling for all variables in the model, treatment in a hospital located in a high ozone pollution area was associated with an increased odds of in-hospital mortality (OR 1.11, 95% CI 1.08-1.15, p < 0.01). After adjustment for all variables in the model, for each increase in ozone exposure by 0.01 ppm the OR for death was 1.07 (95% CI 1.06-1.08, p < 0.01). Similarly, for each increase in particulate matter exposure by 10 µg/m3, the OR for death was 1.08 (95% CI 1.02-1.16, p < 0.01). Chronic exposure to both ozone and particulate matter pollution is associated with higher rates of mortality in ARDS. These preliminary findings need to be confirmed by further detailed studies.

Acute Respiratory Distress Syndrome in Pregnant Women.

OBJECTIVE: To estimate the rate of acute respiratory distress syndrome (ARDS) in pregnant patients as well as to investigate clinical conditions associated with mortality. METHODS: We used the Nationwide Inpatient Sample from 2006 to 2012 to identify a cohort of pregnant patients who underwent mechanical ventilation for ARDS. A multivariate model predicting in-hospital mortality was created. RESULTS: A total of 55,208,382 hospitalizations from the 2006-2012 Nationwide Inpatient Samples were analyzed. There were 2,808 pregnant patients with ARDS who underwent mechanical ventilation included in the cohort. The overall mortality rate for the cohort was 9%. The rate of ARDS requiring mechanical ventilation increased from 36.5 cases (95% confidence interval [CI] 33.1-39.8) per 100,000 live births in 2006 to 59.6 cases (95% CI 57.7-61.4) per 100,000 live births in 2012. Factors associated with a higher risk of death were prolonged mechanical ventilation (adjusted odds ratio [OR] 1.69, 95% CI 1.25-2.28), renal failure requiring hemodialysis (adjusted OR 3.40, 95% CI 2.11-5.47), liver failure (adjusted OR 1.71, 95% CI 1.09-2.68), amniotic fluid embolism (adjusted OR 2.31, 95% CI 1.16-4.59), influenza infection (OR 2.26, 95% CI 1.28-4.00), septic obstetric emboli (adjusted OR 2.15, 95% CI 1.17-3.96), and puerperal infection (adjusted OR 1.86, 95% CI 1.28-2.70). Factors associated with a lower risk of death were: insurance coverage (adjusted OR 0.56, 95% CI 0.37-0.85), tobacco use (adjusted OR 0.53, 95% CI 0.31-0.90), and pneumonia (adjusted OR 0.70, 95% CI 0.50-0.98). CONCLUSION: In this nationwide study, the overall mortality rate for pregnant patients mechanically ventilated for ARDS was 9%. The rate of ARDS requiring mechanical ventilation increased from 36.5 cases (95% CI 33.5-41.8) per 100,000 live births in 2006 to 59.6 cases (95% CI 54.3-65.3) per 100,000 live births in 2012.