Browsing by Author "Zhao, Bo"

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    Association of Hospitalization and Mortality Among Patients Initiating Dialysis With Hemodialysis Facility Ownership and Acquisitions
    (JAMA, 2019) Erickson, Kevin F.; Zhao, Bo; Niu, Jingbo; Winkelmayer, Wolfgang C.; Bhattacharya, Jay; Chertow, Glenn M.; Ho, Vivian; James A. Baker III Institute for Public Policy
    Importance: Mergers and acquisitions among health care institutions are increasingly common, and dialysis markets have undergone several decades of mergers and acquisitions. Objective: To examine the outcomes of hemodialysis facility acquisitions independent of associated changes in market competition resulting from acquisitions. Design, Setting, and Participants: Cohort study using difference-in-differences (DID) analyses to compare changes in health outcomes over time among in-center US dialysis facilities that were acquired by a hemodialysis chain with facilities located nearby but not acquired. Multivariable Cox proportional hazards regression models and negative binomial models with predicted marginal effects were developed to examine health outcomes, controlling for patient, facility, and geographic characteristics. All facility ownership types were examined together and stratified analyses were conducted of facilities that were independently owned and chain owned prior to acquisitions. The study was conducted from January 2001 to September 2015; 174 905 patients starting in-center dialysis in the 3 years before and following dialysis facility acquisitions were included. Data were analyzed from March 2017 to December 2018. Exposures: Acquisition by a hemodialysis chain. Main Outcomes and Measures: Twelve-month hazard of death and hospital days per patient-year were the primary outcomes. Results: Of the 174 905 patients included in the study, 79 705 were women (45.6%), 24 409 (14.0%) were of Hispanic ethnicity, 61 815 (35.3%) were black, 105 272 (60.2%) were white, and 1247 (0.7%) were Native American. Mean (SD) age was 65 (15) years. Before acquisitions, adjusted mortality and hospitalization rates were 10% (95% CI, −16% to −5%) and 2.9 days per patient-year (95% CI, −3.8 to −2.0) lower, respectively, at independently owned facilities that were acquired compared with those that were not acquired, while hospitalization rates were 0.7 days (95% CI, −1.2 to −2.0) lower at chain-owned facilities that were acquired compared with those that were not acquired. In stratified analyses of independently owned facilities, mortality decreases were smaller at acquired (−8.4%; 95% CI, −14% to −25%) vs nonacquired (−20.3%; 95% CI, −25.8% to −14.3%) facilities (DID P < .001). Similarly, hospitalization rates did not change at acquired facilities and decreased by 2.6 days per patient-year (95% CI, −3.6 to −1.7 days) at nonacquired facilities (DID P < .001). Acquisitions were not associated with changes in health outcomes at chain-owned facilities. Slower reductions in mortality and hospitalization rates at independently owned facilities contributed to significant differences in hospitalizations (−2.0 days; 95% CI, −2.5 to −1.6, at nonacquired vs 0.9 days; 95% CI, −1.3 to −0.5, at acquired facilities; DID, P < .001) across all ownership types but not mortality (DID, P = .28) with regard to acquisitions. Conclusions and Relevance: Acquisition of independently owned dialysis facilities by larger dialysis organizations was associated with slower decreases in mortality and hospitalization rates, as nonacquired facilities appeared to experience more rapid improvements in outcomes over time.
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    Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV
    (IOP Publishing, 2022) Imai, Muneaki; Oya, Yoko; Svoboda, Brian; Liu, Hauyu Baobab; Lefloch, Bertrand; Viti, Serena; Zhang, Yichen; Ceccarelli, Cecilia; Codella, Claudio; Chandler, Claire J.; Sakai, Nami; Aikawa, Yuri; Alves, Felipe O.; Balucani, Nadia; Bianchi, Eleonora; Bouvier, Mathilde; Busquet, Gemma; Caselli, Paola; Caux, Emmanuel; Charnley, Steven; Choudhury, Spandan; Cuello, Nicolas; Simone, Marta De; Dulieu, Francois; Durán, Aurora; Evans, Lucy; Favre, Cécile; Fedele, Davide; Feng, Siyi; Fontani, Francesco; Francis, Logan; Hama, Tetsuya; Hanawa, Tomoyuki; Herbst, Eric; Hirano, Shingo; Hirota, Tomoya; Isella, Andrea; Jímenez-Serra, Izaskun; Johnstone, Doug; Kahane, Claudine; Gal, Romane Le; Loinard, Laurent; López-Sepulcre, Ana; Maud, Luke T.; Maureira, María José; Menard, Francois; Mercimek, Seyma; Miotello, Anna; Moellenbrock, George; Mori, Shoji; Murillo, Nadia M.; Nakatani, Riouhei; Nomura, Hideko; Oba, Yasuhiro; O'Donoghue, Ross; Ohashi, Satoshi; Okoda, Yuki; Ospina-Zamudio, Juan; Pineda, Jaime; Podio, Linda; Rimola, Albert; Sakai, Takeshi; Segura-Cox, Dominique; Shirley, Yancy; Taquet, Vianney; Testi, Leonardo; Vastel, Charlotte; Watanabe, Naoki; Watanabe, Yoshimasa; Witzel, Arezu; Xue, Ci; Zhao, Bo; Yamamoto, Satoshi
    The chemical diversity of low-mass protostellar sources has so far been recognized, and environmental effects are invoked as its origin. In this context, observations of isolated protostellar sources without the influence of nearby objects are of particular importance. Here, we report the chemical and physical structures of the low-mass Class 0 protostellar source IRAS 16544−1604 in the Bok globule CB 68, based on 1.3 mm Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of ∼70 au that were conducted as part of the large program FAUST. Three interstellar saturated complex organic molecules (iCOMs), CH3OH, HCOOCH3, and CH3OCH3, are detected toward the protostar. The rotation temperature and the emitting region size for CH3OH are derived to be 131 ± 11 K and ∼10 au, respectively. The detection of iCOMs in close proximity to the protostar indicates that CB 68 harbors a hot corino. The kinematic structure of the C18O, CH3OH, and OCS lines is explained by an infalling–rotating envelope model, and the protostellar mass and the radius of the centrifugal barrier are estimated to be 0.08–0.30 M ⊙ and <30 au, respectively. The small radius of the centrifugal barrier seems to be related to the small emitting region of iCOMs. In addition, we detect emission lines of c-C3H2 and CCH associated with the protostar, revealing a warm carbon-chain chemistry on a 1000 au scale. We therefore find that the chemical structure of CB 68 is described by a hybrid chemistry. The molecular abundances are discussed in comparison with those in other hot corino sources and reported chemical models.
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    Employment among Patients Starting Dialysis in the United States
    (American Society of Nephrology, 2018) Erickson, Kevin F.; Zhao, Bo; Ho, Vivian; Winkelmayer, Wolfgang C.; Baker Institute for Public Policy
    BACKGROUND AND OBJECTIVES: Patients with ESRD face significant challenges to remaining employed. It is unknown when in the course of kidney disease patients stop working. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We examined employment trends over time among patients ages 18-54 years old who initiated dialysis in the United States between 1996 and 2013 from a national ESRD registry. We compared unadjusted trends in employment at the start of dialysis and 6 months before ESRD and used linear probability models to estimate changes in employment over time after adjusting for patient characteristics and local unemployment rates in the general population. We also examined employment among selected vulnerable patient populations and changes in employment in the 6 months preceding dialysis initiation. RESULTS: Employment was low among patients starting dialysis throughout the study period at 23%-24%, and 38% of patients who were employed 6 months before ESRD stopped working by dialysis initiation. However, after adjusting for observed characteristics, the probability of employment increased over time; patients starting dialysis between 2008 and 2013 had a 4.7% (95% confidence interval, 4.3% to 5.1%) increase in the absolute probability of employment at the start of dialysis compared with patients starting dialysis between 1996 and 2001. Black and Hispanic patients were less likely to be employed than other patients starting dialysis, but this gap narrowed during the study period. CONCLUSIONS: Although working-aged patients in the United States starting dialysis have experienced increases in the adjusted probability of employment over time, employment at the start of dialysis has remained low.
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    Misaligned Rotations of the Envelope, Outflow, and Disks in the Multiple Protostellar System of VLA 1623–2417: FAUST. III
    (IOP Publishing, 2022) Ohashi, Satoshi; Codella, Claudio; Sakai, Nami; Chandler, Claire J.; Ceccarelli, Cecilia; Alves, Felipe; Fedele, Davide; Hanawa, Tomoyuki; Durán, Aurora; Favre, Cécile; López-Sepulcre, Ana; Loinard, Laurent; Mercimek, Seyma; Murillo, Nadia M.; Podio, Linda; Zhang, Yichen; Aikawa, Yuri; Balucani, Nadia; Bianchi, Eleonora; Bouvier, Mathilde; Busquet, Gemma; Caselli, Paola; Caux, Emmanuel; Charnley, Steven; Choudhury, Spandan; Cuello, Nicolas; Simone, Marta De; Dulieu, Francois; Evans, Lucy; Feng, Siyi; Fontani, Francesco; Francis, Logan; Hama, Tetsuya; Herbst, Eric; Hirano, Shingo; Hirota, Tomoya; Imai, Muneaki; Isella, Andrea; Jímenez-Serra, Izaskun; Johnstone, Doug; Kahane, Claudine; Gal, Romane Le; Lefloch, Bertrand; Maud, Luke T.; Maureira, María José; Menard, Francois; Miotello, Anna; Moellenbrock, George; Mori, Shoji; Nakatani, Riouhei; Nomura, Hideko; Oba, Yasuhiro; O'Donoghue, Ross; Okoda, Yuki; Ospina-Zamudio, Juan; Oya, Yoko; Pineda, Jaime; Rimola, Albert; Sakai, Takeshi; Segura-Cox, Dominique; Shirley, Yancy; Svoboda, Brian; Taquet, Vianney; Testi, Leonardo; Vastel, Charlotte; Viti, Serena; Watanabe, Naoki; Watanabe, Yoshimasa; Witzel, Arezu; Xue, Ci; Zhao, Bo; Yamamoto, Satoshi
    We report a study of the low-mass Class 0 multiple system VLA 1623AB in the Ophiuchus star-forming region, using H13CO+ (J = 3–2), CS (J = 5–4), and CCH (N = 3–2) lines as part of the ALMA Large Program FAUST. The analysis of the velocity fields revealed the rotation motion in the envelope and the velocity gradients in the outflows (about 2000 au down to 50 au). We further investigated the rotation of the circumbinary VLA 1623A disk, as well as the VLA 1623B disk. We found that the minor axis of the circumbinary disk of VLA 1623A is misaligned by about 12° with respect to the large-scale outflow and the rotation axis of the envelope. In contrast, the minor axis of the circumbinary disk is parallel to the large-scale magnetic field according to previous dust polarization observations, suggesting that the misalignment may be caused by the different directions of the envelope rotation and the magnetic field. If the velocity gradient of the outflow is caused by rotation, the outflow has a constant angular momentum and the launching radius is estimated to be 5–16 au, although it cannot be ruled out that the velocity gradient is driven by entrainments of the two high-velocity outflows. Furthermore, we detected for the first time a velocity gradient associated with rotation toward the VLA 16293B disk. The velocity gradient is opposite to the one from the large-scale envelope, outflow, and circumbinary disk. The origin of its opposite gradient is also discussed.
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    Pre-ESKD Nephrology Care and Employment at the Start of Dialysis
    (2020) Awan, Ahmed A.; Zhao, Bo; Anumudu, Samaya J.; Winkelmayer, Wolfgang C.; Ho, Vivian; Erickson, Kevin F.
    Introduction: Employment is associated with an improved sense of well-being and quality of life in patients with kidney disease. Earlier nephrology referral and longer duration of pre–end-stage kidney disease (ESKD) nephrology care are associated with improved health outcomes in patients with advanced kidney disease who initiate dialysis. It is unknown if pre-ESKD nephrology care helps patients stay employed leading up to dialysis initiation. Methods: We used the US ESKD registry to identify adults aged 18–54 years who initiated dialysis between 2007 and 2014. Analyses were restricted to patients who reported being employed 6 months prior to ESKD. We used multivariable regression models with estimated average marginal effects to examine the independent association between ≥6 months of pre-ESKD nephrology care and employment at dialysis initiation. To reduce bias, we conducted an instrumental variable (IV) analysis based on geographic variation in pre-ESKD care. Results: Of 75,700 patients included in study cohort, 49% reported receiving pre-ESKD nephrology care for ≥6 months, and 62% were employed at dialysis initiation. Although geographic variation in pre-ESKD nephrology care was strongly associated with the likelihood that working-aged patients in our analytic cohort received pre-ESKD care, the receipt of pre-ESKD nephrology care was not significantly associated with employment at dialysis initiation; estimated probability: 5%; 95% confidence interval (CI) –6% to 14%. Conclusions: Pre-ESKD nephrology care 6 months prior to initiation of dialysis is not associated with the likelihood of remaining employed at the initiation of dialysis. Although nephrology care has potential to help patients remain employed, this benefit is not manifested in current practice.