Distinct antibody responses to SARS-CoV-2 in children and adults across the COVID-19 clinical spectrum.

Clinical manifestations of COVID-19 caused by the new coronavirus SARS-CoV-2 are associated with age1,2. Adults develop respiratory symptoms, which can progress to acute respiratory distress syndrome (ARDS) in the most severe form, while children are largely spared from respiratory illness but can develop a life-threatening multisystem inflammatory syndrome (MIS-C)3-5. Here, we show distinct antibody responses in children and adults after SARS-CoV-2 infection. Adult COVID-19 cohorts had anti-spike (S) IgG, IgM and IgA antibodies, as well as anti-nucleocapsid (N) IgG antibody, while children with and without MIS-C had reduced breadth of anti-SARS-CoV-2-specific antibodies, predominantly generating IgG antibodies specific for the S protein but not the N protein. Moreover, children with and without MIS-C had reduced neutralizing activity as compared to both adult COVID-19 cohorts, indicating a reduced protective serological response. These results suggest a distinct infection course and immune response in children independent of whether they develop MIS-C, with implications for developing age-targeted strategies for testing and protecting the population.

Longitudinal profiling of respiratory and systemic immune responses reveals myeloid cell-driven lung inflammation in severe COVID-19.

Immune response dynamics in coronavirus disease 2019 (COVID-19) and their severe manifestations have largely been studied in circulation. Here, we examined the relationship between immune processes in the respiratory tract and circulation through longitudinal phenotypic, transcriptomic, and cytokine profiling of paired airway and blood samples from patients with severe COVID-19 relative to heathy controls. In COVID-19 airways, T cells exhibited activated, tissue-resident, and protective profiles; higher T cell frequencies correlated with survival and younger age. Myeloid cells in COVID-19 airways featured hyperinflammatory signatures, and higher frequencies of these cells correlated with mortality and older age. In COVID-19 blood, aberrant CD163+ monocytes predominated over conventional monocytes, and were found in corresponding airway samples and in damaged alveoli. High levels of myeloid chemoattractants in airways suggest recruitment of these cells through a CCL2-CCR2 chemokine axis. Our findings provide insights into immune processes driving COVID-19 lung pathology with therapeutic implications for targeting inflammation in the respiratory tract.

Improved pulmonary function and exercise tolerance despite persistent pulmonary fibrosis over 1 year after severe COVID-19 infection.

We conducted a prospective single-centre cohort study of 104 multi-ethnic severe COVID-19 survivors from the first wave of the pandemic 15 months after hospitalisation. Of those who were assessed at 4 and 15 months, improvement of ground glass opacities correlated with worsened fibrotic reticulations. Despite a high prevalence of fibrotic patterns (64%), pulmonary function, grip strength, 6 min walk distance and frailty normalised. Overall, dyspnoea, cough and exhaustion did not improve and were not correlated with pulmonary function or radiographic fibrosis at 15 months, suggesting non-respiratory aetiologies. Monitoring persistent, and often subclinical, fibrotic interstitial abnormalities will be needed to determine their potential for future progression.

Mortality in Patients with Obesity and Acute Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation: The Multicenter ECMObesity Study.

Rationale: Patients with obesity are at increased risk for developing acute respiratory distress syndrome (ARDS). Some centers consider obesity a relative contraindication to receiving extracorporeal membrane oxygenation (ECMO) support, despite growing implementation of ECMO for ARDS in the general population. Objectives: To investigate the association between obesity and mortality in patients with ARDS receiving ECMO. Methods: In this large, international, multicenter, retrospective cohort study, we evaluated the association of obesity, defined as body mass index ⩾ 30 kg/m2, with ICU mortality in patients receiving ECMO for ARDS by performing adjusted multivariable logistic regression and propensity score matching. Measurements and Main Results: Of 790 patients with ARDS receiving ECMO in our study, 320 had obesity. Of those, 24.1% died in the ICU, compared with 35.3% of patients without obesity (P < 0.001). In adjusted models, obesity was associated with lower ICU mortality (odds ratio, 0.63 [95% confidence interval, 0.43-0.93]; P = 0.018). Examined as a continuous variable, higher body mass index was associated with decreased ICU mortality in multivariable regression (odds ratio, 0.97 [95% confidence interval, 0.95-1.00]; P = 0.023). In propensity score matching of 199 patients with obesity to 199 patients without, patients with obesity had a lower probability of ICU death than those without (22.6% vs. 35.2%; P = 0.007). Conclusions: Among patients receiving ECMO for ARDS, those with obesity had lower ICU mortality than patients without obesity in multivariable and propensity score matching analyses. Our findings support the notion that obesity should not be considered a general contraindication to ECMO.

Fibrotic-Like Pulmonary Radiographic Patterns Are Not Associated With Adverse Outcomes in COVID-19 Chronic Critical Illness.

OBJECTIVES: Pulmonary fibrosis is a feared complication of COVID-19. To characterize the risks and outcomes associated with fibrotic-like radiographic abnormalities in patients with COVID-19-related acute respiratory distress syndrome (ARDS) and chronic critical illness. DESIGN: Single-center prospective cohort study. SETTING: We examined chest CT scans performed between ICU discharge and 30 days after hospital discharge using established methods to quantify nonfibrotic and fibrotic-like patterns. PATIENTS: Adults hospitalized with COVID-19-related ARDS and chronic critical illness (> 21 d of mechanical ventilation, tracheostomy, and survival to ICU discharge) between March 2020 and May 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We tested associations of fibrotic-like patterns with clinical characteristics and biomarkers, and with time to mechanical ventilator liberation and 6-month survival, controlling for demographics, comorbidities, and COVID-19 therapies. A total of 141 of 616 adults (23%) with COVID-19-related ARDS developed chronic critical illness, and 64 of 141 (46%) had a chest CT a median (interquartile range) 66 days (42-82 d) after intubation. Fifty-five percent had fibrotic-like patterns characterized by reticulations and/or traction bronchiectasis. In adjusted analyses, interleukin-6 level on the day of intubation was associated with fibrotic-like patterns (odds ratio, 4.40 per quartile change; 95% CI, 1.90-10.1 per quartile change). Other inflammatory biomarkers, Sequential Organ Failure Assessment score, age, tidal volume, driving pressure, and ventilator days were not. Fibrotic-like patterns were not associated with longer time to mechanical ventilator liberation or worse 6-month survival. CONCLUSIONS: Approximately half of adults with COVID-19-associated chronic critical illness have fibrotic-like patterns that are associated with higher interleukin-6 levels at intubation. Fibrotic-like patterns are not associated with longer time to liberation from mechanical ventilation or worse 6-month survival.

Do Interventions Improve Symptoms Among ICU Surrogates Facing End-of-Life Decisions? A Prognostically-Enriched Systematic Review and Meta-Analysis.

OBJECTIVES: Evaluate the efficacy of interventions to improve symptoms for ICU surrogates at highest risk of developing psychologic distress: those facing end-of-life care decisions. DATA SOURCES: MEDLINE, CINAHL, PsycInfo, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched through April 16, 2022. STUDY SELECTION: Following an a priori protocol, randomized trials of interventions delivered to surrogates of adult ICU patients who died or had high likelihood of mortality evaluating surrogate symptoms were identified. DATA EXTRACTION: Two reviewers performed screening and data extraction and assessed risk of bias (Cochrane Risk of Bias [RoB] 2 tool). Trials were eligible for meta-analysis if group mean symptom scores were provided at 3 or 6 months. Pooled effects were estimated using a random effects model. Heterogeneity was assessed (Cochrane Q, I2 ). Certainty of evidence was assessed (Grading of Recommendations Assessment, Development and Evaluation). DATA SYNTHESIS: Of 1,660 records, 10 trials met inclusion criteria representing 3,824 surrogates; eight were included in the meta-analysis. Overall RoB was rated Some Concerns. Most ( n = 8) interventions focused on improving communication and enhancing psychologic support in the ICU. All trials measured anxiety, depression, and posttraumatic stress. Significant improvement was seen at 3 months (depression, mean difference [MD], -0.68; 95% CI, -1.14 to -0.22, moderate certainty; posttraumatic stress, standardized MD, -0.25; 95% CI, -0.49 to -0.01, very low certainty) and 6 months (anxiety, MD, -0.70; 95% CI, -1.18 to -0.22, moderate certainty). Sensitivity analyses suggest significant findings may be unstable. Subgroup analyses demonstrated differences in effect by trial location, interventionist, and intervention dose. CONCLUSIONS: Communication and psychological support interventions in the ICU yielded small but significant improvement in psychological symptoms with moderate to very low certainty evidence in a prognostically-enriched sample of ICU surrogates facing end-of-life care decisions. A new approach to interventions that extend beyond the ICU may be needed.

Latent Class Analysis Reveals COVID-19-related Acute Respiratory Distress Syndrome Subgroups with Differential Responses to Corticosteroids.

Rationale: Two distinct subphenotypes have been identified in acute respiratory distress syndrome (ARDS), but the presence of subgroups in ARDS associated with coronavirus disease (COVID-19) is unknown. Objectives: To identify clinically relevant, novel subgroups in COVID-19-related ARDS and compare them with previously described ARDS subphenotypes. Methods: Eligible participants were adults with COVID-19 and ARDS at Columbia University Irving Medical Center. Latent class analysis was used to identify subgroups with baseline clinical, respiratory, and laboratory data serving as partitioning variables. A previously developed machine learning model was used to classify patients as the hypoinflammatory and hyperinflammatory subphenotypes. Baseline characteristics and clinical outcomes were compared between subgroups. Heterogeneity of treatment effect for corticosteroid use in subgroups was tested. Measurements and Main Results: From March 2, 2020, to April 30, 2020, 483 patients with COVID-19-related ARDS met study criteria. A two-class latent class analysis model best fit the population (P = 0.0075). Class 2 (23%) had higher proinflammatory markers, troponin, creatinine, and lactate, lower bicarbonate, and lower blood pressure than class 1 (77%). Ninety-day mortality was higher in class 2 versus class 1 (75% vs. 48%; P < 0.0001). Considerable overlap was observed between these subgroups and ARDS subphenotypes. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR cycle threshold was associated with mortality in the hypoinflammatory but not the hyperinflammatory phenotype. Heterogeneity of treatment effect to corticosteroids was observed (P = 0.0295), with improved mortality in the hyperinflammatory phenotype and worse mortality in the hypoinflammatory phenotype, with the caveat that corticosteroid treatment was not randomized. Conclusions: We identified two COVID-19-related ARDS subgroups with differential outcomes, similar to previously described ARDS subphenotypes. SARS-CoV-2 PCR cycle threshold had differential value for predicting mortality in the subphenotypes. The subphenotypes had differential treatment responses to corticosteroids.

Epidemiology, clinical course, and outcomes of critically ill adults with COVID-19 in New York City: a prospective cohort study.

BACKGROUND: Over 40 000 patients with COVID-19 have been hospitalised in New York City (NY, USA) as of April 28, 2020. Data on the epidemiology, clinical course, and outcomes of critically ill patients with COVID-19 in this setting are needed. METHODS: This prospective observational cohort study took place at two NewYork-Presbyterian hospitals affiliated with Columbia University Irving Medical Center in northern Manhattan. We prospectively identified adult patients (aged ≥18 years) admitted to both hospitals from March 2 to April 1, 2020, who were diagnosed with laboratory-confirmed COVID-19 and were critically ill with acute hypoxaemic respiratory failure, and collected clinical, biomarker, and treatment data. The primary outcome was the rate of in-hospital death. Secondary outcomes included frequency and duration of invasive mechanical ventilation, frequency of vasopressor use and renal replacement therapy, and time to in-hospital clinical deterioration following admission. The relation between clinical risk factors, biomarkers, and in-hospital mortality was modelled using Cox proportional hazards regression. Follow-up time was right-censored on April 28, 2020 so that each patient had at least 28 days of observation. FINDINGS: Between March 2 and April 1, 2020, 1150 adults were admitted to both hospitals with laboratory-confirmed COVID-19, of which 257 (22%) were critically ill. The median age of patients was 62 years (IQR 51-72), 171 (67%) were men. 212 (82%) patients had at least one chronic illness, the most common of which were hypertension (162 [63%]) and diabetes (92 [36%]). 119 (46%) patients had obesity. As of April 28, 2020, 101 (39%) patients had died and 94 (37%) remained hospitalised. 203 (79%) patients received invasive mechanical ventilation for a median of 18 days (IQR 9-28), 170 (66%) of 257 patients received vasopressors and 79 (31%) received renal replacement therapy. The median time to in-hospital deterioration was 3 days (IQR 1-6). In the multivariable Cox model, older age (adjusted hazard ratio [aHR] 1·31 [1·09-1·57] per 10-year increase), chronic cardiac disease (aHR 1·76 [1·08-2·86]), chronic pulmonary disease (aHR 2·94 [1·48-5·84]), higher concentrations of interleukin-6 (aHR 1·11 [95%CI 1·02-1·20] per decile increase), and higher concentrations of D-dimer (aHR 1·10 [1·01-1·19] per decile increase) were independently associated with in-hospital mortality. INTERPRETATION: Critical illness among patients hospitalised with COVID-19 in New York City is common and associated with a high frequency of invasive mechanical ventilation, extrapulmonary organ dysfunction, and substantial in-hospital mortality. FUNDING: National Institute of Allergy and Infectious Diseases and the National Center for Advancing Translational Sciences, National Institutes of Health, and the Columbia University Irving Institute for Clinical and Translational Research.

Pulmonary fibrosis 4 months after COVID-19 is associated with severity of illness and blood leucocyte telomere length.

The risk factors for development of fibrotic-like radiographic abnormalities after severe COVID-19 are incompletely described and the extent to which CT findings correlate with symptoms and physical function after hospitalisation remains unclear. At 4 months after hospitalisation, fibrotic-like patterns were more common in those who underwent mechanical ventilation (72%) than in those who did not (20%). We demonstrate that severity of initial illness, duration of mechanical ventilation, lactate dehydrogenase on admission and leucocyte telomere length are independent risk factors for fibrotic-like radiographic abnormalities. These fibrotic-like changes correlate with lung function, cough and measures of frailty, but not with dyspnoea.

Frailty subtypes and recovery in older survivors of acute respiratory failure: a pilot study.

BACKGROUND: Identifying subtypes of acute respiratory failure survivors may facilitate patient selection for post-intensive care unit (ICU) follow-up clinics and trials. METHODS: We conducted a single-centre prospective cohort study of 185 acute respiratory failure survivors, aged ≥ 65 years. We applied latent class modelling to identify frailty subtypes using frailty phenotype and cognitive impairment measurements made during the week before hospital discharge. We used Fine-Gray competing risks survival regression to test associations between frailty subtypes and recovery, defined as returning to a basic Activities of Daily Living disability count less than or equal to the pre-hospitalisation count within 6 months. We characterised subtypes by pre-ICU frailty (Clinical Frailty Scale score ≥ 5), the post-ICU frailty phenotype, and serum inflammatory cytokines, hormones and exosome proteomics during the week before hospital discharge. RESULTS: We identified five frailty subtypes. The recovery rate decreased 49% across each subtype independent of age, sex, pre-existing disability, comorbidity and Acute Physiology and Chronic Health Evaluation II score (recovery rate ratio: 0.51, 95% CI 0.41 to 0.63). Post-ICU frailty phenotype prevalence increased across subtypes, but pre-ICU frailty prevalence did not. In the subtype with the slowest recovery, all had cognitive impairment. The three subtypes with the slowest recovery had higher interleukin-6 levels (p=0.03) and a higher prevalence of ≥ 2 deficiencies in insulin growth factor-1, dehydroepiandrostersone-sulfate, or free-testosterone (p=0.02). Exosome proteomics revealed impaired innate immunity in subtypes with slower recovery. CONCLUSIONS: Frailty subtypes varied by prehospitalisation frailty and cognitive impairment at hospital discharge. Subtypes with the slowest recovery were similarly characterised by greater systemic inflammation and more anabolic hormone deficiencies at hospital discharge.

Body Mass Index and Risk for Intubation or Death in SARS-CoV-2 Infection : A Retrospective Cohort Study.

BACKGROUND: Obesity is a risk factor for pneumonia and acute respiratory distress syndrome. OBJECTIVE: To determine whether obesity is associated with intubation or death, inflammation, cardiac injury, or fibrinolysis in coronavirus disease 2019 (COVID-19). DESIGN: Retrospective cohort study. SETTING: A quaternary academic medical center and community hospital in New York City. PARTICIPANTS: 2466 adults hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection over a 45-day period with at least 47 days of in-hospital observation. MEASUREMENTS: Body mass index (BMI), admission biomarkers of inflammation (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]), cardiac injury (troponin level), and fibrinolysis (D-dimer level). The primary end point was a composite of intubation or death in time-to-event analysis. RESULTS: Over a median hospital length of stay of 7 days (interquartile range, 3 to 14 days), 533 patients (22%) were intubated, 627 (25%) died, and 59 (2%) remained hospitalized. Compared with overweight patients, patients with obesity had higher risk for intubation or death, with the highest risk among those with class 3 obesity (hazard ratio, 1.6 [95% CI, 1.1 to 2.1]). This association was primarily observed among patients younger than 65 years and not in older patients (P for interaction by age = 0.042). Body mass index was not associated with admission levels of biomarkers of inflammation, cardiac injury, or fibrinolysis. LIMITATIONS: Body mass index was missing for 28% of patients. The primary analyses were conducted with multiple imputation for missing BMI. Upper bounding factor analysis suggested that the results are robust to possible selection bias. CONCLUSION: Obesity is associated with increased risk for intubation or death from COVID-19 in adults younger than 65 years, but not in adults aged 65 years or older. PRIMARY FUNDING SOURCE: National Institutes of Health.

Skeletal muscle adiposity and outcomes in candidates for lung transplantation: a lung transplant body composition cohort study.

CT measurement of body composition may improve lung transplant candidate selection. We assessed whether skeletal muscle adipose deposition on abdominal and thigh CT scans was associated with 6 min walk distance (6MWD) and wait-list survival in lung transplant candidates. Each ½-SD decrease in abdominal muscle attenuation (indicating greater lipid content) was associated with 14 m decrease in 6MWD (95% CI -20 to -8) and 20% increased risk of death or delisting (95% CI 10% to 40%). Each ½-standard deviation decrease in thigh muscle attenuation was associated with 15 m decrease in 6MWD (95% CI -21 to -10). CT imaging may improve candidate risk stratification.

Critical Illness and the Frailty Syndrome: Mechanisms and Potential Therapeutic Targets.

Frailty is a syndrome characterized by decreased reserves across multiple physiologic systems resulting in functional limitations and vulnerability to new stressors. Physical frailty develops over years in community-dwelling older adults but presents or worsens within days in the intensive care unit (ICU) because common mechanisms governing age-related physical frailty are often exacerbated by critical illness. The hallmark of physical frailty is a combined loss of muscle mass, force, and endurance. About one-third of ICU patients have frailty before hospitalization, which increases their risk for both short- and long-term disability and mortality. While there are several valid ways to measure clinical frailty in patients before or after an ICU admission, the mechanistic underpinnings of frailty in critically ill patients and ICU survivors have not been thoroughly investigated. Furthermore, therapeutic interventions to treat frailty during and after time in the ICU are lacking. In this narrative review, we examine studies that identify potential biological mechanisms underlying the development and propagation of physical frailty in both aging and critical illness (eg, inflammation, mitochondrial myopathy, and neuroendocrinopathy). We discuss specific aspects of these frailty mechanisms in older adults, critically ill patients, and ICU survivors that may represent therapeutic targets. Consistent with complexity underlying frailty, this syndrome is unlikely to result from an excess of a single harmful mediator or deficit of a single protective mediator. Rather, frailty occurs in the presence of an incompletely understood state of multisystem dysregulation. We further describe knowledge gaps that warrant clinical and translational research in frailty and critical care with an overall goal of developing effective frailty treatments in critically ill patients and ICU survivors.

Moral distress and burnout in caring for older adults during medical school training.

BACKGROUND: Moral distress is a reason for burnout in healthcare professionals, but the clinical settings in which moral distress is most often experienced by medical students, and whether moral distress is associated with burnout and career choices in medical students is unknown. We assessed moral distress in medical students while caring for older patients, and examined associations with burnout and interest in geriatrics. METHODS: A cross-sectional survey study of second-, third-, and fourth-year medical students at an American medical school. The survey described 12 potentially morally distressing clinical scenarios involving older adult patients. Students reported if they encountered each scenario, and whether they experienced moral distress, graded on a 1-10 scale. We conducted a principal axis factor analysis to assess the dimensionality of the survey scenarios. A composite moral distress score was calculated as the sum of moral distress scores across all 12 scenarios. Burnout was assessed using the Maslach Abbreviated Burnout Inventory, and interest in geriatrics was rated on a 7-point Likert scale. RESULTS: Two-hundred and nine students responded (47%), of whom 90% (188/209) reported moral distress in response to ≥1 scenario with a median (IQR) score of 6 (4-7). Factor analysis suggested a unidimensional factor structure of the 12 survey questions that reliably measured individual distress (Cronbach alpha = 0.78). Those in the highest tertile of composite moral distress scores were more likely to be burnt out (51%) than those in the middle tertile of scores (34%), or lowest tertile of scores (31%) (p = 0.02). There was a trend towards greater interest in geriatrics among those in the higher tertiles of composite moral distress scores (16% lowest tertile, 20% middle tertile, 25% highest tertile, p-for-tend = 0.21). Respondents suggested that moral distress might be mitigated with didactic sessions in inpatient geriatric care, and debriefing sessions with peers and faculty on the inpatient clerkships on medicine, neurology, and surgery, where students most often reported experiencing moral distress. CONCLUSIONS: Moral distress is highly prevalent among medical students while caring for older patients, and associated with burnout. Incorporating geriatrics education and debriefing sessions into inpatient clerkships could alleviate medical student moral distress and burnout.

Growth differentiation factor-15 as a biomarker of strength and recovery in survivors of acute respiratory failure.

Muscle mitochondrial dysfunction is implicated in intensive care unit-acquired weakness, but there is no serum biomarker of muscle mitochondrial function for critical illness survivors. Higher serum growth differentiation factor-15 (GDF-15) is a biomarker of inherited mitochondrial myopathy disease and is associated with mortality in several age-related diseases. Among 142 older (age ≥ 65 years) survivors of acute respiratory failure, we found that higher serum GDF-15 measured during the week prior to hospital discharge was cross-sectionally associated with weaker diaphragm, limb and hand-grip strength, and longitudinally associated with lower rates of functional recovery over 6 months, independent of age, sex, pre-existing disability, comorbidity, frailty, Acute Physiology and Chronic Health Evaluation II scores and concurrent interleukin-6 levels.

Race, Ethnicity, Health Insurance, and Mortality in Older Survivors of Critical Illness.

OBJECTIVES: To determine whether minority race or ethnicity is associated with mortality and mediated by health insurance coverage among older (≥ 65 yr old) survivors of critical illness. DESIGN: A retrospective cohort study. SETTING: Two New York City academic medical centers. PATIENTS: A total of 1,947 consecutive white (1,107), black (361), and Hispanic (479) older adults who had their first medical-ICU admission from 2006 through 2009 and survived to hospital discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We obtained demographic, insurance, and clinical data from electronic health records, determined each patient's neighborhood-level socioeconomic data from 2010 U.S. Census tract data, and determined death dates using the Social Security Death Index. Subjects had a mean (SD) age of 79 years (8.6 yr) and median (interquartile range) follow-up time of 1.6 years (0.4-3.0 yr). Blacks and Hispanics had similar mortality rates compared with whites (adjusted hazard ratio, 0.92; 95% CI, 0.76-1.11 and adjusted hazard ratio, 0.92; 95% CI, 0.76-1.12, respectively). Compared to those with commercial insurance and Medicare, higher mortality rates were observed for those with Medicare only (adjusted hazard ratio, 1.43; 95% CI, 1.03-1.98) and Medicaid (adjusted hazard ratio, 1.30; 95% CI, 1.10-1.52). Medicaid recipients who were the oldest ICU survivors (> 82 yr), survivors of mechanical ventilation, and discharged to skilled-care facilities had the highest mortality rates (p-for-interaction: 0.08, 0.03, and 0.17, respectively). CONCLUSIONS: Mortality after critical illness among older adults varies by insurance coverage but not by race or ethnicity. Those with federal or state insurance coverage only had higher mortality rates than those with additional commercial insurance.