Indoor particulate matter concentrations and air cleaner intervention association with biomarkers in former smokers with COPD.

BACKGROUND: Indoor pollutants have been associated with worse clinical outcomes in chronic obstructive pulmonary disease (COPD). Elevated biomarkers are associated with ambient pollution exposure, however the association with indoor pollution remains unclear. METHODS: Former smokers with spirometry-confirmed COPD were randomized to portable air cleaner or placebo. Indoor particulate matter (PM2.5, PM10, and ultrafine particles [UFP; PM<0.1]) and biomarkers were measured longitudinally at pre-specified intervals and course PM fraction (PM10-2.5) was calculated. Biomarkers were categorized based on associations with biologic mechanisms: inflammation (white blood cell count, interleukin [IL]-6, IL-8, IL-1ß, tumor necrosis factor-α, interferon-γ, serum amyloid A), platelet activation (P-selectin, CD40 ligand [CD40L], 11-dehdydro-thromboxane-B2 [11dTxB2]), endothelial dysfunction (Vascular Cell Adhesion Molecule [VCAM]-1, Intercellular Adhesion Molecule [ICAM]-1), and oxidative stress (thiobarbituric acid reactive substances [TBARS], 8-hydroxydeoxyguanosine, 8-isoprostane). Associations between PM concentrations and each biomarker were analyzed using multivariable linear mixed models. An intention-to-treat analysis was performed to evaluate the air cleaner intervention on the biomarker levels longitudinally. RESULTS: Fifty-eight participants were randomized to each group. Finer PM was more strongly associated with higher IL-8 (mean difference per doubling: UFP 13.9% [p = 0.02], PM2.5 6.8% [p = 0.002], PM10-2.5 5.0% [p = 0.02]) while interferon-γ was associated with UFP and IL-1ß with PM10-2.5. UFP and PM2.5 were associated with elevated levels of the oxidative stress biomarkers TBARS and 8-isoprostane respectively. For platelet activation markers, UFP was associated with higher 11dTxB2 while PM2.5 was associated with higher P-selectin and CD40L. Pollutants were not associated with biomarkers of endothelial dysfunction. In intention-to-treat analysis there was no association of the air cleaner intervention with any of the biomarkers. DISCUSSION: Among former smokers with COPD, elevated levels of indoor air pollutants, particularly ultrafine particles (PM<0.1), were associated with elevated biomarkers of inflammation, platelet activation, and oxidative stress. However, an air cleaner intervention that reduced PM did not significantly reduce biomarker levels.

Indoor Air Pollution and Impaired Cardiac Autonomic Function in Chronic Obstructive Pulmonary Disease.

Rationale: Indoor air pollution represents a modifiable risk factor for respiratory morbidity in chronic obstructive pulmonary disease (COPD). The effects of indoor air pollution, as well as the impact of interventions to improve indoor air quality, on cardiovascular morbidity in COPD remain unknown. Objectives: To determine the association between indoor particulate matter (PM) and heart rate variability (HRV), a measure of cardiac autonomic function tied to cardiovascular morbidity and mortality, as well as the impact of household air purifiers on HRV. Methods: Former smokers with moderate-severe COPD were recruited from a 6-month randomized controlled trial of a portable air cleaner intervention to undergo paired assessment of both in-home PM and HRV using 24-hour Holter monitoring at up to five time points. Primary outcomes were HRV measures tied to cardiovascular morbidity (standard deviation of normal-to-normal intervals [SDNN] and root mean square of successive differences between normal-to-normal intervals [RMSSD]). Measurements and Results: Eighty-five participants contributed 317 HRV measurements. A twofold increase in household PM ⩽2.5 µm in aerodynamic diameter was associated with decreases in SDNN (ß, -2.98% [95% confidence interval (CI), -5.12 to -0.78]) and RMSSD (ß, -4.57% [95% CI, -10.1 to -1.60]). The greatest effects were observed with ultrafine particles (<100 nm) (RMSSD; ß, -16.4% [95% CI, -22.3 to -10.1]) and among obese participants. Participants randomized to the active air cleaner saw improvements in RMSSD (ß, 25.2% [95% CI, 2.99 to 52.1]), but not SDNN (ß, 2.65% [95% CI, -10.8 to 18.1]), compared with the placebo group. Conclusions: This is the first U.S. study to describe the association between household PM and cardiac autonomic function among individuals with COPD, as well as the potential cardiovascular health benefits of household air cleaners.

Indoor Pollution and Lung Function Decline in Current and Former Smokers: SPIROMICS AIR.

Rationale: Indoor pollutants have been associated with chronic obstructive pulmonary disease morbidity, but it is unclear whether they contribute to disease progression. Objectives: We aimed to determine whether indoor particulate matter (PM) and nitrogen dioxide (NO2) are associated with lung function decline among current and former smokers. Methods: Of the 2,382 subjects with a history of smoking in SPIROMICS AIR, 1,208 participants had complete information to estimate indoor PM and NO2, using individual-based prediction models, in relation to measured spirometry at two or more clinic visits. We used a three-way interaction model between time, pollutant, and smoking status and assessed the indoor pollutant-associated difference in FEV1 decline separately using a generalized linear mixed model. Measurements and Main Results: Participants had an average rate of FEV1 decline of 60.3 ml/yr for those currently smoking compared with 35.2 ml/yr for those who quit. The association of indoor PM with FEV1 decline differed by smoking status. Among former smokers, every 10 µg/m3 increase in estimated indoor PM was associated with an additional 10 ml/yr decline in FEV1 (P = 0.044). Among current smokers, FEV1 decline did not differ by indoor PM. The results of indoor NO2 suggest trends similar to those for PM ⩽2.5 µm in aerodynamic diameter. Conclusions: Former smokers with chronic obstructive pulmonary disease who live in homes with high estimated PM have accelerated lung function loss, and those in homes with low PM have lung function loss similar to normal aging. In-home PM exposure may contribute to variability in lung function decline in people who quit smoking and may be a modifiable exposure.

Home Dust Allergen Exposure Is Associated with Outcomes among Sensitized Individuals with Chronic Obstructive Pulmonary Disease.

Rationale: Environmental exposures have been associated with adverse outcomes in chronic obstructive pulmonary disease (COPD). Approximately one-third of individuals with COPD have allergic sensitization, but it is unknown whether exposure to allergens in the home is associated with outcomes. Objectives: To determine the prevalence and associations of allergen sensitization with exposure to common indoor allergens with symptoms and exacerbation risk in COPD. Methods: Allergen sensitization to five common indoor allergens was assessed in former smokers with COPD. Home settled dust was assessed for presence of corresponding allergens. Sensitization and exposure status was determined and associations evaluated in adjusted models with longitudinal outcomes including symptoms, lung function, and exacerbations. Interactions were assessed between sensitization/exposure status and lung function. Measurements and Main Results: One hundred eighty-three individuals studied were on average 67.3 years of age (SD, 8.22) with average FEV1 of 53.2% (SD, 17.6%). Seventy-seven percent of participants were exposed to at least one tested allergen, and 17% had sensitization with corresponding allergen exposure. After adjustment, sensitization with exposure was associated with lower lung function (ß, -8.29; 95% confidence interval [CI], -14.80 to -1.77), higher St. George's Respiratory Questionnaire Total Score (ß, 6.71; 95% CI, 0.17 to 13.25), and higher exacerbation risk (odds ratio, 2.31; 95% CI, 1.11 to 4.79). Associations appeared to be more pronounced among individuals with lower lung function. Conclusions: Allergen exposures are common in COPD and associated with adverse outcomes among those with concomitant allergen sensitization. This study establishes allergens as an important home exposure that potentially could be addressed with comprehensive home environmental modification strategies to improve COPD outcomes.

Randomized Clinical Trial of Air Cleaners to Improve Indoor Air Quality and Chronic Obstructive Pulmonary Disease Health: Results of the CLEAN AIR Study.

Rationale: Indoor particulate matter is associated with worse chronic obstructive pulmonary disease (COPD) outcomes. It remains unknown whether reductions of indoor pollutants improve respiratory morbidity. Objectives: To determine whether placement of active portable high-efficiency particulate air cleaners can improve respiratory morbidity in former smokers. Methods: Eligible former smokers with moderate-to-severe COPD received active or sham portable high-efficiency particulate absolute air cleaners and were followed for 6 months in this blinded randomized controlled trial. The primary outcome was 6-month change in St. George's Respiratory Questionnaire (SGRQ). Secondary outcomes were exacerbation risk, respiratory symptoms, rescue medication use, and 6-minute-walk distance (6MWD). Intention-to-treat analysis included all subjects, and per-protocol analysis included adherent participants (greater than 80% use of air cleaner). Measurements and Main Results: A total of 116 participants were randomized, of which 84.5% completed the study. There was no statistically significant difference in total SGRQ score, but the active filter group had greater reduction in SGRQ symptom subscale (ß, -7.7 [95% confidence interval (CI), -15.0 to -0.37]) and respiratory symptoms (Breathlessness, Cough, and Sputum Scale, ß, -0.8 [95% CI, -1.5 to -0.1]); and lower rate of moderate exacerbations (incidence rate ratio, 0.32 [95% CI, 0.12-0.91]) and rescue medication use (incidence rate ratio, 0.54 [95% CI, 0.33-0.86]) compared with sham group (all P < 0.05). In per-protocol analysis, there was a statistically significant difference in primary outcome between the active filter versus sham group (SGRQ, ß -4.76 [95% CI, -9.2 to -0.34]) and in moderate exacerbation risk, Breathlessness, Cough, and Sputum Scale, and 6MWD. Participants spending more time indoors were more likely to have treatment benefit. Conclusions: This is the first environmental intervention study conducted among former smokers with COPD showing potential health benefits of portable high-efficiency particulate absolute air cleaners, particularly among those with greater adherence and spending a greater time indoors.

Black carbon content in airway macrophages is associated with increased severe exacerbations and worse COPD morbidity in SPIROMICS.

BACKGROUND: Airway macrophages (AM), crucial for the immune response in chronic obstructive pulmonary disease (COPD), are exposed to environmental particulate matter (PM), which they retain in their cytoplasm as black carbon (BC). However, whether AM BC accurately reflects environmental PM2.5 exposure, and can serve as a biomarker of COPD outcomes, is unknown. METHODS: We analyzed induced sputum from participants at 7 of 12 sites SPIROMICS sites for AM BC content, which we related to exposures and to lung function and respiratory outcomes. Models were adjusted for batch (first vs. second), age, race (white vs. non-white), income (<$35,000, $35,000~$74,999, ≥$75,000, decline to answer), BMI, and use of long-acting beta-agonist/long-acting muscarinic antagonists, with sensitivity analysis performed with inclusion of urinary cotinine and lung function as covariates. RESULTS: Of 324 participants, 143 were current smokers and 201 had spirometric-confirmed COPD. Modeled indoor fine (< 2.5 µm in aerodynamic diameter) particulate matter (PM2.5) and urinary cotinine were associated with higher AM BC. Other assessed indoor and ambient pollutant exposures were not associated with higher AM BC. Higher AM BC was associated with worse lung function and odds of severe exacerbation, as well as worse functional status, respiratory symptoms and quality of life. CONCLUSION: Indoor PM2.5 and cigarette smoke exposure may lead to increased AM BC deposition. Black carbon content in AMs is associated with worse COPD morbidity in current and former smokers, which remained after sensitivity analysis adjusting for cigarette smoke burden. Airway macrophage BC, which may alter macrophage function, could serve as a predictor of experiencing worse respiratory symptoms and impaired lung function.

Metformin: Experimental and Clinical Evidence for a Potential Role in Emphysema Treatment.

Rationale: Cigarette smoke (CS) inhalation triggers oxidative stress and inflammation, leading to accelerated lung aging, apoptosis, and emphysema, as well as systemic pathologies. Metformin is beneficial for protecting against aging-related diseases. Objectives: We sought to investigate whether metformin may ameliorate CS-induced pathologies of emphysematous chronic obstructive pulmonary disease (COPD). Methods: Mice were exposed chronically to CS and fed metformin-enriched chow for the second half of exposure. Lung, kidney, and muscle pathologies, lung proteostasis, endoplasmic reticulum (ER) stress, mitochondrial function, and mediators of metformin effects in vivo and/or in vitro were studied. We evaluated the association of metformin use with indices of emphysema progression over 5 years of follow-up among the COPDGene (Genetic Epidemiology of COPD) study participants. The association of metformin use with the percentage of emphysema and adjusted lung density was estimated by using a linear mixed model. Measurements and Main Results: Metformin protected against CS-induced pulmonary inflammation and airspace enlargement; small airway remodeling, glomerular shrinkage, oxidative stress, apoptosis, telomere damage, aging, dysmetabolism in vivo and in vitro; and ER stress. The AMPK (AMP-activated protein kinase) pathway was central to metformin's protective action. Within COPDGene, participants receiving metformin compared with those not receiving it had a slower progression of emphysema (-0.92%; 95% confidence interval [CI], -1.7% to -0.14%; P = 0.02) and a slower adjusted lung density decrease (2.2 g/L; 95% CI, 0.43 to 4.0 g/L; P = 0.01). Conclusions: Metformin protected against CS-induced lung, renal, and muscle injury; mitochondrial dysfunction; and unfolded protein responses and ER stress in mice. In humans, metformin use was associated with lesser emphysema progression over time. Our results provide a rationale for clinical trials testing the efficacy of metformin in limiting emphysema progression and its systemic consequences.

Risk factors associated with chronic kidney disease progression: Long-term retrospective analysis from Qatar.

INTRODUCTION: The risk factors influencing the natural course of chronic kidney disease (CKD) are complex and heterogeneous. Recognizing the factors associated with CKD progression can enable the identification of high-risk patients for more intensive treatment. PATIENTS AND METHODS: A retrospective evaluation of CKD patients was performed under follow-up between January 1, 2001 and December 31, 2016 at a tertiary health care center. RESULTS: Among 5370 screened patients, 1020 patients with complete data were included in the analysis. The median follow-up period for the studied patients was 9.3 years. Based on the analysis, 120 (11.8%) patients had reached end-stage kidney disease "ESKD" or death. The study revealed that the risk factors associated with reaching ESKD and/or death using Kaplan-Meier survival curve and log rank test included higher hemoglobin A1c among diabetic patients, higher grade of proteinuria, and non use of renin-angiotensin system blockers. The patients with CKD progression constituted 77.2% of all CKD patients. The study findings indicated that older age, Arab ethnicity, smoking habit, diabetes mellitus and hypertension (presumed as original kidney diseases) are among the significant risk factors associated with a further decline of the estimated glomerular filtration rate (eGFR) and further CKD progression. CONCLUSION: This study summarized the demographic and clinical risk factors associated with CKD progression and patients' outcomes among a unique and heterogeneous population in the state of Qatar. Intensive treatment of modifiable risk factors could be of value in halting the progression of CKD. However, prospective studies are warranted to confirm our findings.

Metformin use and respiratory outcomes in asthma-COPD overlap.

BACKGROUND: Metformin is associated with improved respiratory outcomes in asthma; however, metformin in COPD and asthma-COPD overlap (ACO) remains unexplored. OBJECTIVE: To determine the association between metformin use and respiratory outcomes in COPD and ACO. STUDY DESIGN AND METHODS: Participants with COPD (FEV1/FVC < 0.70) in the Genetic Epidemiology of COPD study (COPDGene®) were categorized as ACO (n = 510), defined as concurrent physician-diagnosed asthma before age 40 years, or COPD alone (n = 3459). We estimated the association of baseline metformin use with (1) rate of total and severe respiratory exacerbations during follow-up, (2) cross-sectional St. George's Respiratory Questionnaire (SGRQ) score, six-minute walk distance (6MWD), and post-bronchodilator FEV1 percent predicted (FEV1pp), and (3) 5-year change in SGRQ, 6MWD, and FEV1pp. We also examined change in SGRQ, 6MWD and FEV1pp among participants who initiated metformin during follow-up (n = 108) compared to persistent metformin non-users (n = 2080). Analyses were adjusted for sociodemographic factors, medications, and comorbidities. RESULTS: Among participants with ACO, metformin use was associated with lower rate of total (adjusted incidence rate ratio [aIRR] 0.3; 95% confidence interval [95%CI] 0.11, 0.77) and severe exacerbations (aIRR 0.29; 95%CI 0.10, 0.89). Among participants with COPD alone, there was no association between metformin use with total (aIRR 0.98; 95%CI 0.62, 1.5) or severe exacerbations (aIRR 1.3; 95% CI 0.68, 2.4) (p-interaction < 0.05). Metformin use was associated with lower baseline SGRQ score (adjusted mean difference [aMD] - 2.7; 95%CI - 5.3, - 0.2) overall. Metformin initiation was associated with improved SGRQ score (aMD -10.0; 95% CI - 18.7, - 1.2) among participants with ACO but not COPD alone (p-interaction < 0.05). There was no association between metformin use and 6MWD or FEV1pp in any comparison. CONCLUSIONS: Metformin use was associated with fewer respiratory exacerbations and improved quality of life among individuals with ACO but not COPD alone. Results suggest a potential role for metformin in ACO which requires further prospective study. TRIAL REGISTRY: NCT00608764.

Association of platelet count with all-cause mortality and risk of cardiovascular and respiratory morbidity in stable COPD.

BACKGROUND: Platelet count is a prognostic indicator in the general population and elderly. Thrombocytosis during acute exacerbation of COPD (AECOPD) has been associated with mortality; however, the relationship between platelet count and mortality in stable COPD is unknown. METHODS: We performed post hoc secondary analysis on a subsample of 1797 patients in the Study to Understand Mortality and Morbidity in COPD (SUMMIT) who had blood samples drawn at baseline. Participants were current or former smokers, 40-80 years old with moderate COPD and history or increased risk of cardiovascular (CV) disease. The primary outcome was on and post-treatment all-cause mortality. Secondary outcomes included first-on-treatment moderate/severe AECOPD and on-treatment CV composite event (CV death, myocardial infarction, stroke, unstable angina and transient ischemic attack). Multivariable Cox proportional hazards models were used to investigate study endpoint associations with platelet count quintile grouping, continuous platelet count utilizing two-term fractional polynomials, and categories of low, normal and high platelet count (< 150, ≥150 to < 300, ≥300 × 109/L). RESULTS: Patients were followed for 2.3 ± 0.9 years for vital status and 1.6 ± 1.1 years for morbidity endpoints during which 105 (5.8%) died, 651 (36.2%) experienced AECOPD (159 with severe AECOPD) and 86 (4.8%) experienced a CV event. A U-shaped association between platelet count and all-cause mortality was observed. Compared to the third quintile group (Q3) of platelet count, risk of death was increased in the lowest quintile group (Q1; hazard ratio [HR]: 1.73; 95% confidence interval [CI]: 0.93-3.23) and highest quintile group (Q5; HR: 1.66; 95%CI: 0.89-3.10), though point estimates were imprecise. Using clinical cutoffs, compared with normal platelet counts (≥150 to < 300 × 109/L), risk of all-cause mortality was nominally increased among patients with thrombocytopenia (HR: 1.46; 95%CI: 0.81-2.64) and high platelet count (HR: 1.66; 95%CI: 0.96-2.86). Compared with Q3, CV events were nominally increased for Q5 (HR: 1.71; 95%CI: 0.83-3.49) and Q1 (HR: 1.41; 95%CI: 0.70, 2.85). There was no association between platelet count and AECOPD. CONCLUSIONS: In stable COPD platelet count demonstrated a U-shaped association with increased risk of 3-year all-cause mortality, though a platelet count level above or below which risk of mortality was increased could not be definitively identified. TRIAL REGISTRATION: ClinicalTrials.gov NCT01313676 .

Association of thrombocytosis with COPD morbidity: the SPIROMICS and COPDGene cohorts.

BACKGROUND: Thrombocytosis has been associated with COPD prevalence and increased all-cause mortality in patients with acute exacerbation of COPD (AECOPD); but whether it is associated with morbidity in stable COPD is unknown. This study aims to determine the association of thrombocytosis with COPD morbidity including reported AECOPD, respiratory symptoms and exercise capacity. METHODS: Participants with COPD were included from two multi-center observational studies (SPIROMICS and COPDGene). Cross-sectional associations of thrombocytosis (platelet count ≥350 × 109/L) with AECOPD during prior year (none vs. any), exertional dyspnea (modified Medical Research Council (mMRC) score ≥ 2), COPD Assessment Test (CAT) score ≥ 10, six-minute-walk distance (6MWD), and St. George Respiratory questionnaire (SGRQ) were modeled using multivariable logistic or linear regression. A pooled effect estimate for thrombocytosis was produced using meta-analysis of data from both studies. RESULTS: Thrombocytosis was present in 124/1820 (6.8%) SPIROMICS participants and 111/2185 (5.1%) COPDGene participants. In meta-analysis thrombocytosis was associated with any AECOPD (adjusted odds ratio [aOR] 1.5; 95% confidence interval [95% CI]: 1.1-2.0), severe AECOPD (aOR 1.5; 95% CI: 1.1-2.2), dyspnea (mMRC ≥ 2 aOR 1.4; 95% CI: 1.0-1.9), respiratory symptoms (CAT ≥ 10 aOR 1.6; 95% CI: 1.1-2.4), and higher SGRQ score (ß 2.7; 95% CI: 0.5, 5). Thrombocytosis was also associated with classification into Global Initiative for Chronic Obstructive Lung Disease (GOLD) group D (aOR 1.7 95% CI: 1.2-2.4). CONCLUSIONS: Thrombocytosis was associated with higher likelihood of prior exacerbation and worse symptoms. Platelet count, a commonly measured clinical assay, may be a biomarker for moderate-severe COPD symptoms, guide disease classification and intensity of treatment. Future longitudinal studies investigating the role of platelets in COPD progression may be warranted. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01969344 (SPIROMICS) and NCT00608764 (COPDGene).

Safety and efficacy of taurolidine/urokinase versus taurolidine/heparin as a tunneled catheter lock solution in hemodialysis patients: a prospective, randomized, controlled study.

Background: Taurolidine citrate with heparin (Taurolock/Hep) is a promising central venous catheter lock solution. Despite its universal use among our hemodialysis patients, the prevalence of catheter malfunction was high. We aimed to compare Taurolock/Hep and taurolidine citrate with urokinase (Taurolock/U) as a catheter lock solution in order to identify whether either solution could reduce catheter-related dysfunction. Methods: In this prospective, randomized, controlled trial, patients were randomized to receive either Taurolock/Hep or Taurolock/U and were followed for 6 months. Episodes of acute catheter thrombosis, requirement of recombinant tissue plasminogen activator (rt-PA) and incidence of catheter-related blood stream infection (CRBSI) were recorded, along with dialysis adequacy (Kt/V), blood flow rates (BFRs) and adverse events. Results: There were 93 inclusions (85 patients) in the Taurolock/Hep group and 84 inclusions in the Taurolock/U group (79 patients). Three catheters were removed in the Taurolock/Hep group because of acute thrombosis, while no catheter was removed for the same reason in the Taurolock/U group. The total number of all-causes catheter exchange (acute thrombosis and CRBSI) was significantly lower in Taurolock/U group (P = 0.028). rt-PA was used significantly less often in the Taurolock/U group than in the Taurolock/Hep group (P = 0.006). Moreover, higher BFR and Kt/V were noted in the Taurolock/U group than in the Taurolock/Hep group, although the differences were not uniformly significant. Conclusion: Taurolock/U is a safe and effective tunneled dialysis catheter lock solution, with a low rate of catheter exchange.

Association Between Hospital Case Volume of Sepsis, Adherence to Evidence-Based Processes of Care and Patient Outcomes.

OBJECTIVES: We sought to explore potential mechanisms underlying hospital sepsis case volume-mortality associations by investigating implementation of evidence-based processes of care. DESIGN: Retrospective cohort study. We determined associations of sepsis case volume with three evidence-based processes of care (lactate measurement during first hospital day, norepinephrine as first vasopressor, and avoidance of starch-based colloids) and assessed their role in mediation of case volume-mortality associations. SETTING: Enhanced administrative data (Premier, Charlotte, NC) from 534 U.S. hospitals. SUBJECTS: A total of 287,914 adult patients with sepsis present at admission between July 2010 and December 2012 of whom 58,045 received a vasopressor for septic shock during the first 2 days of hospitalization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among patients with sepsis, 1.9% received starch, and among patients with septic shock, 68.3% had lactate measured and 64% received norepinephrine as initial vasopressor. Patients at hospitals with the highest case volume were more likely to have lactate measured (adjusted odds ratio quartile 4 vs quartile 1, 2.8; 95% CI, 2.1-3.7) and receive norepinephrine as initial vasopressor (adjusted odds ratio quartile 4 vs quartile 1, 2.1; 95% CI, 1.6-2.7). Case volume was not associated with avoidance of starch products (adjusted odds ratio quartile 4 vs quartile 1, 0.73; 95% CI, 0.45-1.2). Adherence to evidence-based care was associated with lower hospital mortality (adjusted odds ratio, 0.81; 95% CI, 0.70-0.94) but did not strongly mediate case volume-mortality associations (point estimate change ≤ 2%). CONCLUSIONS: In a large cohort of U.S. patients with sepsis, select evidence-based processes of care were more likely implemented at high-volume hospitals but did not strongly mediate case volume-mortality associations. Considering processes and case volume when regionalizing sepsis care may maximize patient outcomes.

Impact of Physical Activity on Reporting of Childhood Asthma Symptoms.

This study aims to determine the impact of physical activity on asthma symptom reporting among children living in an inner city. Among 147 children aged 5-12 years with physician-diagnosed asthma, we assessed asthma symptoms using twice-daily diaries and physical activity using the physical activity questionnaire for children during three 8-day periods (baseline, 3 and 6 months). Linear, logistic, and quasi-poisson regression models were used to determine the association between physical activity and asthma symptoms; adjusting for age, sex, race, BMI, caregiver's education, asthma severity, medication use, and season. A 1-unit increase in PAQ score was significantly associated with reporting more nocturnal symptoms [risk ratio (RR): 1.03; 95% CI 1.00-1.06], daytime symptoms (RR: 1.04; 95% CI 1.00-1.09), being bothered by asthma (RR: 1.05; 95% CI 1.00-1.09), and trouble breathing (RR: 1.05; 95% CI 1.00-1.10). Level of physical activity should be taken into account in clinical management of asthma and epidemiological studies of asthma symptom burden.

Practice Patterns and Outcomes Associated With Choice of Initial Vasopressor Therapy for Septic Shock.

OBJECTIVES: Clinical guidelines recommend norepinephrine as initial vasopressor of choice for septic shock, with dopamine suggested as an alternative vasopressor in selected patients with low risk of tachyarrhythmias and absolute or relative bradycardia. We sought to determine practice patterns and outcomes associated with vasopressor selection in a large, population-based cohort of patients with septic shock that allows for assessment of outcomes in clinically important subgroups. DESIGN: We performed a retrospective cohort study to determine factors associated with choice of dopamine as compared with norepinephrine as initial vasopressor for patients with septic shock. We used propensity score matching to compare risk of hospital mortality based on initial vasopressor. We performed multiple sensitivity analyses using alternative methods to address confounding and hospital-level clustering. We investigated interaction between vasopressor selection and mortality in clinical subgroups based on arrhythmia and cardiovascular risk. SETTING: Enhanced administrative data (Premier, Charlotte, NC) from 502 U.S. hospitals during the years 2010-2013. SUBJECTS: A total of 61,122 patients admitted with septic shock who received dopamine or norepinephrine as initial vasopressor during the first 2 days of hospitalization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Norepinephrine (77.6%) was the most frequently used initial vasopressor during septic shock. Dopamine was preferentially selected by cardiologists, in the Southern United States, at nonteaching hospitals, for older patients with more cardiovascular comorbidities and was used less frequently over time. Patients receiving dopamine experienced greater hospital mortality (propensity-matched cohort: n = 38,788; 25% vs 23.7%; odds ratio, 1.08; 95% CI, 1.02-1.14). Sensitivity analyses showed similar results. Subgroup analyses showed no evidence for effect modification based on arrhythmia risk or underlying cardiovascular disease. CONCLUSIONS: In a large population-based sample of patients with septic shock in the United States, use of dopamine as initial vasopressor was associated with increased mortality among multiple clinical subgroups. Areas where use of dopamine as initial vasopressor is more common represent potential targets for quality improvement intervention.

Risk factors for loss to follow-up prior to ART initiation among patients enrolling in HIV care with CD4+ cell count ≥200 cells/µL in the multi-country MTCT-Plus Initiative.

BACKGROUND: In resource-limited settings, many HIV-infected patients are lost to follow-up (LTF) before starting ART; risk factors among those not eligible for ART at enrollment into care are not well described. METHODS: We examined data from 4,278 adults (3,613 women, 665 men) enrolled in HIV care through March 2007 in the MTCT-Plus Initiative with a CD4 count ≥200 cells/mm(3) and WHO stage ≤ 2 at enrollment. Patients were considered LTF if > 12 months elapsed since their last clinic visit. Gender-specific Cox regression models were used to assess LTF risk factors. RESULTS: The proportion LTF was 8.2 % at 12 months following enrollment, and was higher among women (8.4 %) than men (7.1 %). Among women, a higher risk of LTF was associated with younger age (adjusted hazard ratio [AHR]15-19/30+: 2.8, 95 % CI:2.1-3.6; AHR20-24/30+:1.9, 95 % CI:1.7-2.2), higher baseline CD4 count (AHR350-499/200-349:1.5; 95 % CI:1.0-2.1; AHR500+/200-349:1.5; 95 % CI:1.0-2.0), and being pregnant at the last clinic visit (AHR:1.9, 95 % CI:1.4-2.5). Factors associated with a lower risk of LTF included, employment outside the home (AHR:0.73, 95 % CI:0.59-0.90), co-enrollment of a family/household member (AHR:0.40, 95 % CI:0.26-0.61), and living in a household with ≥4 people (AHR:0.74, 95 % CI:0.64-0.85). Among men, younger age (AHR15-19/30+: 2.1, 95 % CI:1.2-3.5 and AHR30-34/35+:1.5, 95 % CI:1.0-2.4) had a higher risk of LTF. Electricity in the home (AHR:0.61, 95 % CI:0.41-0.91) and living in a household with ≥4 people (AHR:0.58, 95 % CI:0.39-0.85) had a lower risk of LTF. CONCLUSIONS: Socio-economic status and social support may be important determinants of retention in patients not yet eligible for ART. Among women of child-bearing age, strategies around sustaining HIV care during and after pregnancy require attention.

Does nurse use of a standardized flowsheet to document communication with advanced providers provide a mechanism to detect pulse oximetry failures? A retrospective study of electronic health record data.

BACKGROUND: Pulse oximetry guides clinical decisions, yet does not uniformly identify hypoxemia. We hypothesized that nursing documentation of notifying providers, facilitated by a standardized flowsheet for documenting communication to providers (physicians, nurse practitioners, and physician assistants), may increase when hypoxemia is present, but undetected by the pulse oximeter, in events termed "occult hypoxemia." OBJECTIVE: To compare nurse documentation of provider notification in the 4 h preceding cases of occult hypoxemia, normal oxygenation, and evident hypoxemia confirmed by an arterial blood gas reading. METHODS: We conducted a retrospective study using electronic health record data from patients with COVID-19 at five hospitals in a healthcare system with paired SpO2 and SaO2 readings (measurements within 10 min of oxygen saturation levels in arterial blood, SaO2, and by pulse oximetry, SpO2). We applied multivariate logistic regression to assess if having any nursing documentation of provider notification in the 4 h prior to a paired reading confirming occult hypoxemia was more likely compared to a paired reading confirming normal oxygen status, adjusting for characteristics significantly associated with nursing documentation. We applied conditional logistic regression to assess if having any nursing documentation of provider notification was more likely in the 4-hour window preceding a paired reading compared to the 4-hour window 24 h earlier separately for occult hypoxemia, visible hypoxemia, and normal oxygenation. RESULTS: There were data from 1910 patients hospitalized with COVID-19 who had 44,972 paired readings and an average of 26.5 (34.5) nursing documentation of provider notification events. The mean age was 63.4 (16.2). Almost half (866/1910, 45.3 %) were White, 701 (36.7 %) were Black, and 239 (12.5 %) were Hispanic. Having any nursing documentation of provider notification was 46 % more common in the 4 h before an occult hypoxemia paired reading compared to a normal oxygen status paired reading (OR 1.46, 95 % CI: 1.28-1.67). Comparing the 4 h immediately before the reading to the 4 h one day preceding the paired reading, there was a higher likelihood of having any nursing documentation of provider notification for both evident (OR 1.45, 95 % CI 1.24-1.68) and occult paired readings (OR 1.26, 95 % CI 1.04-1.53). CONCLUSION: This study finds that nursing documentation of provider notification significantly increases prior to confirmed occult hypoxemia, which has potential in proactively identifying occult hypoxemia and other clinical issues. There is potential value to encouraging standardized documentation of nurse concern, including communication to providers, to facilitate its inclusion in clinical decision-making.

Diffusing Capacity as a Predictor of Hospitalizations in a Clinical Cohort of Chronic Obstructive Pulmonary Disease.

Rationale: Chronic obstructive pulmonary disease (COPD) hospitalizations are a major burden on patients. Diffusing capacity of the lung for carbon monoxide (DlCO) is a potential predictor that has not been studied in large cohorts. Objectives: This study used electronic health record data to evaluate whether clinically obtained DlCO predicts COPD hospitalizations. Methods: We performed time-to-event analyses of individuals with COPD and DlCO measurements from the Johns Hopkins COPD Precision Medicine Center of Excellence. Cox proportional hazard methods were used to model time from DlCO measurement to first COPD hospitalization and composite first hospitalization or death, adjusting for age, sex, race, body mass index, smoking status, forced expiratory volume in 1 second (FEV1), history of prior COPD hospitalization, and comorbidities. To identify the utility of including DlCO in risk models, area under the receiver operating curve (AUC) values were calculated for models with and without DlCO. Results were externally validated in a separate analogous cohort. Results: Of 2,793 participants, 368 (13%) had a COPD hospitalization within 3 years. In adjusted analyses, for every 10% decrease in DlCO% predicted, risk of COPD hospitalization increased by 10% (hazard ratio, 1.1; 95% confidence interval, 1.1-1.2; P < 0.001). Similar associations were observed for COPD hospitalizations or death. The model including demographics, comorbidities, FEV1, DlCO, and prior COPD hospitalizations performed well, with an AUC of 0.85 and an AUC of 0.84 in an external validation cohort. Conclusions: Diffusing capacity is a strong predictor of COPD hospitalizations in a clinical cohort of individuals with COPD, independent of airflow obstruction and prior hospitalizations. These findings support incorporation of DlCO in risk assessment of patients with COPD.