Regiochemistry-Driven Organic Electrochemical Transistor Performance Enhancement in Ethylene Glycol-Functionalized Polythiophenes.

Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired in bioelectronics. Glycol side chains have proven to be an efficient method to increase bulk electrochemical doping and optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol side chains in the 3,3' positions of the bithiophene repeat unit. In this paper, the analogous regioisomeric polymer, namely pgBTTT, was synthesized by relocating the glycol side chains position on the bithiophene unit of p(g2T-TT) from the 3,3' to the 4,4' positions and compared with the original p(g2T-TT). By changing the regio-positioning of the side chains, the planarizing effects of the S-O interactions were redistributed along the backbone, and the influence on the polymer's microstructure organization was investigated using grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. The newly designed pgBTTT exhibited lower backbone disorder, closer π-stacking, and higher scattering intensity in both the in-plane and out-of-plane GIWAXS measurements. The effect of the improved planarity of pgBTTT manifested as higher hole mobility (µ) of 3.44 ± 0.13 cm2 V-1 s-1. Scanning tunneling microscopy (STM) was in agreement with the GIWAXS measurements and demonstrated, for the first time, that glycol side chains can also facilitate intermolecular interdigitation analogous to that of pBTTT. Electrochemical quartz crystal microbalance with dissipation of energy (eQCM-D) measurements revealed that pgBTTT maintains a more rigid structure than p(g2T-TT) during doping, minimizing molecular packing disruption and maintaining higher hole mobility in operation mode.

Public Reporting of Hospital-Level Cancer Surgical Volumes in California: An Opportunity to Inform Decision Making and Improve Quality.

PURPOSE: Most patients, providers, and payers make decisions about cancer hospitals without any objective data regarding quality or outcomes. We developed two online resources allowing users to search and compare timely data regarding hospital cancer surgery volumes. METHODS: Hospital cancer surgery volumes for all California hospitals were calculated using ICD-9 coded hospital discharge summary data. Cancer surgeries included (bladder, brain, breast, colon, esophagus, liver, lung, pancreas, prostate, rectum, and stomach) were selected on the basis of a rigorous literature review to confirm sufficient evidence of a positive association between volume and mortality. The literature could not identify threshold numbers of surgeries associated with better or worse outcomes. A multidisciplinary working group oversaw the project and ensured sound methodology. RESULTS: In California in 2014, about 60% of surgeries were performed at top-quintile-volume hospitals, but the per-hospital median numbers of surgeries for esophageal, pancreatic, stomach, liver, or bladder cancer surgeries were four or fewer. At least 670 patients received cancer surgery at hospitals that performed only one or two surgeries for a particular cancer type; 72% of those patients lived within 50 miles of a top-quintile-volume hospital. CONCLUSION: There is clear potential for more readily available information about hospital volumes to help patient, providers, and payers choose cancer surgery hospitals. Our successful public reporting of hospital volumes in California represents an important first step toward making publicly available even more provider-specific data regarding cancer care quality, costs, and outcomes, so those data can inform decision-making and encourage quality improvement.

Hospital variation in readmission after coronary artery bypass surgery in California.

BACKGROUND: Readmissions are common after coronary artery bypass grafting (CABG) surgery and account for a significant percentage of hospital healthcare costs. Readmission rates also vary widely between hospitals, but the reasons for this variation have not been studied previously. METHODS AND RESULTS: We linked 2009 California CABG clinical registry data to hospital discharge data for 2009 and 2010 to identify 30-day readmissions for all patients undergoing isolated CABG surgery. Both standard and hierarchical logistic models were developed to predict readmission risk and explore sources of hospital readmission variation. Among 11 823 patients discharged alive after isolated CABG in 2009, 1565 (13.2%) patients were readmitted within 30 days of surgery. Heart failure and postoperative infections were the most frequent reasons for readmission (15.3% and 12.9%, respectively). Multiple patient risk factors, including age, sex, and lower zip code-level median household income, were significant predictors of readmission (all adjusted odds ratios >1.0; P<0.05). The readmission rates among the 119 hospitals performing CABG varied from 0% to 26.9%. Compared with hospitals in lower quartiles for readmission, hospitals in higher quartiles had a significantly higher readmission rates due to circulatory diseases, infections, complications for surgical and medical care and digestive diseases (all P<0.05). In a hierarchical model, including several hospital characteristics, hospital-level variables did not predict readmission risk (all P>0.05, with an intraclass correlation of 0.004 for hospitals). CONCLUSIONS: California hospitals performing CABG surgery vary widely in 30-day readmission rates. Patient demographic and clinical risk factors, rather than measured hospital characteristics, accounted for most of the observed hospital-level variation in CABG readmissions.

Off-pump bypass surgery and postoperative stroke: California coronary bypass outcomes reporting program.

BACKGROUND: Coronary artery bypass surgery (CABG) is associated with a significant risk of stroke. Some studies suggest that off-pump CABG (OPCAB) may reduce postoperative stroke rate. We performed this study to evaluate the relationship between postoperative stroke and OPCAB compared with conventional on-pump CABG (CCB) in a recent, large cohort of patients. METHODS: Data from the California CABG Outcomes Reporting Program were analyzed in patients who had OPCAB or CCB for isolated CABGs in 2006 to 2007. Two multivariable logistic regression models were developed for the analysis, and the "recycled predictions" method was used to compute risk-adjusted postoperative stroke rates in the two surgical groups. RESULTS: Of 30,426 isolated CABGs, 7,720 (23.7%) were OPCAB. The model developed in the CCB subset indicated that CCB had a lower predicted stroke risk than OPCAB, yet the observed rate of stroke was higher in the CCB subset. The model using both CCB and OPCAB patients revealed that OPCAB was associated with a reduction in postoperative stroke (adjusted odds ratio: 0.76, 95% confidence interval [CI] 0.59 to 0.98). For patients with cardiogenic shock, OPCAB was also associated with a lower risk-adjusted postoperative stroke rate compared with CCB (OPCAB: 3.06%, 95% CI 2.83% to 3.28%; CCB: 4.05%, 95% CI 3.76% to 4.33%, p < 0.001). However, the 793 (11%) OPCAB patients who were converted to CCB intraoperatively had an increased postoperative stroke rate (with conversion: 2.02%, 95% CI 1.04% to 3.00% versus without conversion: 0.96%, 95% CI 0.73% to 1.20%, p < 0.001). CONCLUSIONS: The OPCAB was associated with a significantly lower postoperative stroke rate compared with CCB even for older and higher risk patients. However, intraoperative OPCAB to CCB conversion was associated with the highest postoperative stroke rate.

Off-pump coronary artery bypass graft surgery in California, 2003 to 2005.

BACKGROUND: The impact of off-pump coronary artery bypass graft surgery (OPCAB) on operative mortality compared to conventional coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CCB) has not been clarified. METHOD: Patient clinical characteristics were compared between OPCAB and CCB for isolated CABG surgeries in 2003 to 2005 using data from the California CABG outcomes reporting program. A propensity score method and logistic regression models were used to compute propensity-adjusted operative mortality for patients undergoing OPCAB or CCB. RESULTS: Of 57,284 isolated CABGs, 13,515 (22.9%) were OPCAB. Compared to CCB, OPCAB patients were older, more females/nonwhite, and had a higher prevalence of certain noncardiac risk factors but were fewer with diabetes, acute myocardial infarction, New York Heart Association class IV heart failure or angina, cardiogenic shock, prior cardiac surgery, left main coronary disease, or > or =3-vessel coronary disease (all P < .01). Overall, the propensity-adjusted operative mortalities (PAOMRs) were significantly lower in OPCAB patients compared to CCB patients (OPCAB 2.59% [95% CI 2.52%-2.67%] vs CCB 3.22% [95% CI 3.17%-3.27%]). Off-pump CABG had a protective advantage for all quintile subgroups (all P < .05). However, within the OPCAB cohort, those who converted to CCB intraoperately had higher PAOMR (converters 3.47% [95% CI 3.16%-3.77%] vs nonconverters 2.53% [95% CI 2.46%-2.61%]). Age, female sex, nonwhite race, diabetes, congestive heart failure, prior cadiac surgery, left main disease, and with > or =3 diseased coronary arteries were associated with a higher risk of intraoperative conversion from OPCAB to CCB (all <0.05). CONCLUSION: OPCAB and CCB patients had significantly different preoperative risk profiles, and OPCAB was associated with lower operative mortality compared to CCB.

The "occasional open heart surgeon" revisited.

OBJECTIVES: Case volume in cardiac surgery has been a concern since the term "the occasional open heart surgeon" was used more than 40 years ago, indicating one who performs cardiac surgery infrequently. METHODS: Risk-adjusted operative mortality (in-hospital or 30-day mortality) for isolated coronary artery bypass grafting procedures reported to the California CABG Outcomes Reporting Program for 2003-2004 was determined by surgeon and by hospital. Standard Society of Thoracic Surgeons item definitions were used. A total of 49,421 coronary artery bypass grafting (40,377 isolated) procedures were performed by 302 surgeons at 121 hospitals. Low-volume surgeons (n = 117) were defined as performing a total of less than 1 coronary artery bypass grafting (isolated or nonisolated) procedure per week at all hospitals (mean +/- standard deviation, 22 +/- 15/y). High-volume surgeons (n = 185) performed a total of 1 or more cases per week (mean +/- standard deviation, 120 +/- 62/y). Logistic regression and hierarchic analysis were used to compare volume cohorts. RESULTS: The overall risk-adjusted mortality rate was 3.62% for low-volume and 3.02% for high-volume surgeons. Analysis by surgeon per hospital produced 610 surgeon-hospital pairs. The lowest risk-adjusted mortality rates were found among surgeons performing more than 1 procedure per week at a single hospital (2.70%). When high-volume surgeons performed less than 1 procedure per week at a hospital, their mortality rates were similar to those of low-volume surgeons (3.39%-4.11%). High-volume surgeons performing procedures at multiple sites had higher mortality than high-volume surgeons working at a single institution. CONCLUSION: A high-volume surgeon becomes an "occasional open heart surgeon" when working at multiple hospitals and performing a small volume of procedures at some of them. This study suggests that volume is not as important as processes of care in determining outcomes of coronary artery bypass grafting procedures and that system factors might be more important to outcomes than surgeon experience.

Administrative versus clinical data for coronary artery bypass graft surgery report cards: the view from California.

OBJECTIVE: The objective of this study was to compare the performance of a risk model for isolated coronary artery bypass graft (CABG) surgery based on administrative data with that of a clinical risk model in predicting mortality and identifying hospital performance outliers. METHODS: Clinical data records from the California CABG Mortality Reporting Program for 38,230 isolated CABG patients undergoing surgery in 2000-2001 were linked to records in the California patient discharge data (PDD) abstract. Risk factors based on administrative data that mirrored clinical risk factors were developed using the condition present at admission indicator in the PDD to separate preoperative acute conditions from complications of surgery. Using logistic regression, risk model performance across data sources was compared along with hospital risk-adjusted mortality ranks and quality ratings. RESULTS: The administrative data showed lower prevalence of risk factors when compared with the clinical data. The clinical risk model had somewhat better discrimination (C = 0.824) than the administrative model (C = 0.799). The clinical model yielded 17 outliers and the administrative model 16 with agreement on 12 hospitals' status. Performance of the administrative risk model was minimally affected by removal of information from prior admissions and removal of risk factors not confirmed in the clinical record. CONCLUSIONS: Unique properties of the California administrative data, including the ability to distinguish acute preoperative risk factors from complications of surgery, permitted construction of an administrative risk model that predicts mortality on par with most published clinical models. Despite this, the administrative model identified slightly different hospital outliers, which may indicate somewhat biased assessments of hospital patient risk.

Hospital discharge to other healthcare facilities: impact on in-hospital mortality.

BACKGROUND: In-hospital mortality is frequently used as an outcomes measure for surgical procedures. Recently, hospitals have developed subacute care facilities to allow earlier discharge. Outcomes of patients discharged (transferred) to these units or to other similar facilities may not be captured in reports of in-hospital mortality. STUDY DESIGN: The California Office of Statewide Health Planning and Development (OSHPD) patient discharge abstract database was examined to determine the rates of discharge to other facilities (transfer) and the number of in-hospital deaths occurring during the index hospitalization and after transfer in patients undergoing cardiac surgery procedures. Data were collected for 1997, 1998, and 1999 for coronary artery bypass grafting (CABG-only, n = 82,897), CABG plus additional procedures (CABG-plus, n = 11,869), and valve repair or replacement (Valve-only, n = 14,872). In-hospital mortality and transfer rates (same-day discharge and readmission to another facility) were determined for all hospitals through the index hospitalization and subsequent transfers. RESULTS: Aggregated 3-year in-hospital mortality rates for the index hospitalization were 2.98% for CABG-only, 9.25% for CABG-plus, and 4.85% in Valve-only groups. Transfer rates were 12.41%, 23.16%, and 13.43%, respectively. The percentages of all in-hospital deaths occurring after transfer from the index hospital were 13.5% (385 of 2,857) in CABG-only, 13.3% (168 of 1,266) in CABG-plus, and 11.0% (89 of 811) in Valve-only patients. When corrected for these additional deaths, the actual in-hospital mortality rate was 3.45% for CABG-only, 10.67% for CABG-plus, and 5.45% for Valve-only procedures. CONCLUSIONS: Transfer to another healthcare facility rather than discharge home is a common practice after cardiac surgery. A substantial percentage of in-hospital deaths occurs after discharge from the primary institution.

Can pharmacy data improve prediction of hospital outcomes? Comparisons with a diagnosis-based comorbidity measure.

OBJECTIVES: The performance of comorbidity measures derived from the hospital discharge abstract, the outpatient pharmacy record, and from both sources combined, were compared in predicting all-cause and unplanned hospital readmission and length of stay. MATERIALS AND METHODS: Automated hospital and pharmacy data came from Kaiser-Permanente and included 6721 acute hospitalizations in Southern California from April 1993 to February 1995. The Deyo adaptation of Charlson's 17 comorbidities was derived from hospital discharge data and the 29 Chronic Disease Score (CDS) comorbidity markers were derived from outpatient pharmacy claims data. Logistic and OLS regression models were used to compare the performance of each measure in baseline models and to evaluate whether the CDS contributed additional explanatory power in a combined model. RESULTS: The CDS was a significant predictor of unplanned readmission (C = 0.68) and LOS (Adjusted R(2) = 0.26) in multivariable models adjusted for baseline patient demographic and hospitalization characteristics. The Deyo measure was a significant predictor of all-cause readmission (C = 0.63), unplanned readmission (C = 0.68), and LOS (Adjusted R(2) = 0.26). When pharmacy-based disease markers were added to the Deyo baseline model, modest, statistically significant improvements in predictive power were noted in the unplanned readmission and LOS models. CONCLUSIONS: The finding that both measures of comorbid disease demonstrated similar predictive power is noteworthy, because secondary diagnosis data document relevant illness in hospital patients and pharmacy claims data were never intended for that purpose. The results suggest that small improvements in model performance may come from combining both sources of data in models to predict hospital readmission and LOS.