Use of Statewide Administrative Data to Assess Clinical Outcomes: A Retrospective Cohort Study of Therapeutic Anticoagulation for Isolated Calf Vein Thrombosis.

BACKGROUND: Single-center comparative effectiveness studies evaluating outcomes that can occur posthospitalization may become biased if outcomes diagnosed at other facilities are not ascertained. Administrative datasets that link patients' records across facilities may improve outcome ascertainment. OBJECTIVE: To determine whether use of linked administrative data significantly augments thromboembolic outcome ascertainment. RESEARCH DESIGN: Retrospective cohort study. SUBJECTS: Patients with an acute isolated calf deep vein thrombosis (DVT) diagnosed at 1 Californian center during 2010-2013. MEASURES: Proximal DVT or pulmonary embolism (PE) within 180 days. We ascertained outcomes from linked California hospitalization, emergency department, and ambulatory surgery data and compared this information to outcomes previously identified from review of the center's medical records. RESULTS: Among 384 patients with an isolated calf DVT, 333 could be linked to longitudinal administrative data records. Ten patients had a possible proximal DVT or PE (4 more clearly so) from administrative data; all were unknown from medical record review. Eleven patients with known outcomes from medical record review had no outcome from administrative data. The adjusted odds ratio of proximal DVT or PE with therapeutic anticoagulation attenuated from 0.33 [95% confidence interval (CI), 0.12-0.87] using only medical record review to 0.64 (95% CI, 0.29-1.40) using both medical record review and possible outcomes from administrative data. Restricting the outcome to diagnoses clearly involving proximal DVT or PE, the adjusted odds ratio was 0.46 (95% CI, 0.19-1.10). CONCLUSIONS: Use of linked hospital administrative data augmented detection of outcomes but imperfect linkage, nonspecific diagnoses, and documentation/coding errors introduced uncertainty regarding the accuracy of outcome ascertainment.

Probabilistic Linkage of Prehospital and Outcomes Data in Out-of-hospital Cardiac Arrest.

OBJECTIVE: Lack of longitudinal patient outcome data is an important barrier in emergency medical services (EMS) research. We aimed to demonstrate the feasibility of linking prehospital data from the California EMS Information Systems (CEMSIS) database to outcomes data from the California Office of Statewide Health Planning and Development (OSHPD) database for patients with out-of-hospital cardiac arrest (OHCA). METHODS: We included patients age 18 years or older who sustained nontraumatic OHCA and were included in the 2010-2011 CEMSIS databases. The CEMSIS database is a unified EMS data collection system for California. The OSHPD database is a comprehensive data collection system for patient-level inpatient and emergency department encounters in California. OHCA patients were identified in the CEMSIS database using cardiac rhythm, procedures, medications, and provider impression. Probabilistic linkage blocks were created using in-hospital death or one of the following primary or secondary diagnoses (ICD-9-CM) in the OSHPD databases: cardiac arrest (427.5), sudden death (798), ventricular tachycardia (427.1), ventricular fibrillation (427.4), and acute myocardial infarction (410.xx). Blocking variables included incident date, gender, date of birth, age, and/or destination facility. Due to the volume of cases, match thresholds were established based on clerical record review for each block individually. Match variables included incident date, destination facility, date of birth, sex, race, and ethnicity. RESULTS: Of the 14,603 cases of OHCA we identified in CEMSIS, 91 (0.6%) duplicate records were excluded. Overall, 46% of the data used in the linkage algorithm were missing in CEMSIS. We linked 4,961/14,512 (34.2%) records. Linkage rates varied significantly by local EMS agency, ranging from 1.4 to 61.1% (OR for linkage 0.009-0.76; p < 0.0001). After excluding the local EMS agency with the outlying low linkage rate, we linked 4,934/12,596 (39.2%) records. CONCLUSION: Probabilistic linkage of CEMSIS prehospital data with OSHPD outcomes data was severely limited by the completeness of the EMS data. States and EMS agencies should aim to overcome data limitations so that more effective linkages are possible.

Hospital variation in medical and surgical treatment of patent ductus arteriosus.

OBJECTIVE: This study aims to characterize population risks for diagnosis, medical treatment, and surgical ligation of patent ductus arteriosus (PDA) in very low-birth-weight infants. STUDY DESIGN: Maternal and neonatal data were collected in 40 hospitals in California during 2011 for infants with birth weight ≤ 1,500 g without any congenital malformation, with a diagnosis of PDA. Multivariable logistic regression was used to determine independent risks for PDA diagnosis and for surgical ligation. RESULTS: There were 770/1,902 (40.4%) infants diagnosed with PDA. Low birth weight, gestational age, respiratory distress syndrome, and surfactant administration were associated with PDA diagnosis. Ligation occurred in 43% of patients with birth weight ≤ 750 g, in 24% of patients weighing between 715 and 1,000 g, and in 12% of patients weighing from 1,001 to 1,500 g. Older gestational age (1 week, odds ratio 0.55, 95% confidence interval 0.48-0.63) and absence of respiratory distress syndrome (odds ratio 0.14, 95% confidence interval 0.03-0.59) were associated with lower ligation risk. The median hospital ligation rate was 14% (interquartile range 0-38%). CONCLUSION: Most patients with PDA receive treatment for closure. Practice variation may set the stage for further exploration of experimental trials.

Incidence and Time Course of Symptomatic Thromboembolic Outcomes After Lower Extremity Arthroscopic Surgery, Ankle Fracture Surgery, and Achilles Tendon Repair.

BACKGROUND: The incidence and time course of acute venous thromboembolism (VTE) after ambulatory surgery for lower extremity orthopaedic conditions is not well-defined. HYPOTHESIS: The purpose of this study was to analyze the incidence, the time course, and risk factors associated with clinically diagnosed acute deep vein thrombosis or pulmonary embolism within 3 months of surgery in patients undergoing specific operations for lower extremity injuries. METHODS: Patients undergoing arthroscopic procedures of the knee, ankle fracture surgery, Achilles tendon repair, and ankle arthroscopy from January 1, 2005, to December 31, 2010, were identified in the California Ambulatory Surgery database with linkage to hospital discharge data, emergency department data, and a death registry. Outcomes were acute VTE and death within 90 days. Time courses were compared using Kaplan-Meier analysis, and risk factors were analyzed using proportional hazard modeling. RESULTS: Analysis of data from 468,699 surgeries showed that the cumulative incidence of acute VTE was significantly higher after Achilles tendon repair (0.72%, P < 0.001) than ankle fracture surgery (0.33%), knee arthroscopy procedures (range, 0.29% to 0.41%), or ankle arthroscopy (0.24%). The time course of diagnosis of VTE was similar for all arthroscopic procedures (median postoperative day for diagnosis = 9 to 10; 80% by 22 to 36 days), whereas for Achilles tendon surgery, the time course was protracted (median postoperative day for diagnosis = 29 days; 80% by 51 days). Ninety-day mortality was low (<0.06%) after all procedures except ankle fracture (0.12%). Predictors of pulmonary embolism included age older than 60 years (HR, 3.1; 95% CI; 2.0 to 4.8, versus younger than 30 years), Achilles tendon repair (HR, 3.8; 95% CI; 2.8 to 5.3), and ankle fracture surgery (Hazard Ratio [HR], 2.1; 95% Confidence Interval [CI]; 1.5 to 2.8); Asian/Pacific Islander (HR, 0.3; 95% CI; 0.1 to 0.6) and Hispanic patients (HR, 0.5; 95% CI; 0.4 to 0.7) had significantly lower risk. DISCUSSION: The incidence and time course of onset of acute VTE after lower extremity orthopaedic surgeries varies significantly depending on the surgical procedure. These findings have implications regarding the use and duration of pharmacologic thromboprophylaxis.

Linked birth cohort files for perinatal health research: California as a model for methodology and implementation.

PURPOSE: Rigorous perinatal epidemiologic research depends on population-based parental and neonatal sociodemographic and clinical data. Here we describe the creation of linked birth cohort files, an enriched data source that combines information from vital records with maternal delivery and infant hospital encounter records. METHODS: Probabilistic linkage techniques were used to link vital records (i.e., birth and fetal death certificates) from the California Department of Public Health with hospital inpatient, ambulatory surgery and emergency department encounter data for mothers and infants from the California Department of Health Care Access and Information. RESULTS: From 2012 to 2018, 95% of live birth records were successfully linked to maternal and newborn hospital records while 85% of fetal death records were linked to a maternal delivery record. Overall, 93% of postnatal hospital encounters of infants (i.e., <1 year old) were matched to a linked record. CONCLUSIONS: The linked birth cohort files is a rich resource opening many possibilities for understanding perinatal health outcomes and opportunities for linkage to longitudinal, social determinant, and environmental data. To optimally use this file for research, analysts should evaluate possible shortcomings or biases of the data sources being linked.

Regional Variation in the Use and Outcomes of Transcatheter Aortic Valve Replacement in California.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has been widely adopted for management of aortic stenosis. The purpose of this study was to examine regional access to and outcomes following TAVR in California. METHODS: Patients undergoing TAVR or isolated surgical aortic valve replacement (SAVR) from 2008 to 2019 in California were identified in the Office of Statewide Health Planning and Development database. California was divided into seven regions: Northern California, San Francisco Bay Area, Central California, Los Angeles, Inland Empire, Orange, and San Diego. Regional TAVR volumes were normalized to Medicare beneficiaries or isolated SAVR volume. Outcomes included risk-adjusted 30-day mortality and major adverse cardiovascular and cerebral events (MACCE). Trends were studied using non-parametric tests, and regional outcomes using logistic regression. RESULTS: TAVR volume increased annually since 2011, with 7148 cases performed in California in 2019. After normalization, variation in utilization of TAVR was evident, with the least performed in Central California. TAVR to SAVR ratios in 2019 were greatest in Northern California, Los Angeles, and San Diego, and least in the Inland Empire. After risk adjustment, there were no significant regional differences in 30-day mortality, but lower 30-day MACCE in the San Francisco Bay Area. CONCLUSIONS: Regional differences in TAVR utilization exist, with limited access in Central California and the Inland Empire, but risk-adjusted outcomes are similar. Efforts to reach underserved areas through existing program expansion or regional referrals may distribute transcatheter technology more equitably across California.

Left atrial appendage closure during cardiac surgery: Safe but underutilized in California.

Objective: Left atrial appendage (LAA) closure is associated with reduced rates of stroke in patients with atrial fibrillation (AF). We evaluated trends in LAA closure, the association of LAA closure with stroke/systemic embolism, and its safety profile in patients with AF who underwent cardiac surgery in California. We further tested for hospital-level variation in concomitant LAA closure. Methods: Adults who underwent coronary artery bypass grafting and/or valve surgery with preoperative AF were identified in the 2016 to 2019 Office of Statewide Health Planning and Development databases. Propensity score matching was performed to study risk-adjusted associations of LAA closure with ischemic stroke/systemic embolism. Hospital-level variation was studied using intraclass correlation coefficients. Results: Among 18,434 patients with AF who underwent coronary artery bypass grafting/valve surgery, 47.7% received LAA closure. Rates of LAA closure increased from 44.4% to 51.4% from 2016 to 2019 (P < .001). In 4652 propensity score-matched patients, LAA closure was associated with reduced incidence of stroke/systemic embolism at discharge (1.6% vs 3.1%; P < .001) and readmission with stroke/systemic embolism at 1 year (2.9% vs 4.5%; P = .004). LAA closure was not associated with acute kidney injury, pulmonary complications, blood transfusion, reoperation, or in-hospital mortality. Approximately 18% of the risk-adjusted variation in LAA use was attributed to the hospital, with median center-level rate of 44.9% (interquartile range, 29.6%-57.4%). Conclusions: LAA closure was associated with minimal surgical morbidity, and reduced short- and midterm incidence of stroke/systemic embolism. Although the use of LAA closure has increased, substantial variation exists among programs in California, suggesting the need for further standardization of care.

Nighttime delivery and risk of neonatal encephalopathy.

OBJECTIVE: The objective of the study was to determine the relationship between nighttime delivery and neonatal encephalopathy (NE). STUDY DESIGN: The design of the study was a retrospective population-based cohort of 1,864,766 newborns at a gestation of 36 weeks or longer in California, 1999-2002. We determined the risk of NE associated with nighttime delivery (7:00 (PM) to 6:59 (AM)). RESULTS: Two thousand one hundred thirty-one patients had NE (incidence 1.1 per 1000 births). Nighttime delivery was associated with increased NE (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.03-1.20), birth asphyxia (OR, 1.18; 95% CI, 1.08-1.29), and neonatal seizures (OR, 1.17; 95% CI, 1.07-1.28). In adjusted analyses, nighttime delivery was an independent risk factor for NE (OR, 1.10; 95% CI, 1.01-1.21), as were severe intrauterine growth retardation (OR, 3.8; 95% CI, 3.1-4.8); no prenatal care (OR, 2.0; 95% CI, 1.4-2.9); primiparity (OR, 1.5; 95% CI, 1.4-1.7); advanced maternal age (OR, 1.3; 95% CI, 1.16-1.45); and infant male sex (OR, 1.3; 95% CI, 1.2-1.4). CONCLUSION: Future studies of time of delivery may generate new strategies to reduce the burden of NE.

Level and volume of neonatal intensive care and mortality in very-low-birth-weight infants.

BACKGROUND: There has been a large increase in both the number of neonatal intensive care units (NICUs) in community hospitals and the complexity of the cases treated in these units. We examined differences in neonatal mortality among infants with very low birth weight (below 1500 g) among NICUs with various levels of care and different volumes of very-low-birth-weight infants. METHODS: We linked birth certificates, hospital discharge abstracts (including interhospital transfers), and fetal and infant death certificates to assess neonatal mortality rates among 48,237 very-low-birth-weight infants who were born in California hospitals between 1991 and 2000. RESULTS: Mortality rates among very-low-birth-weight infants varied according to both the volume of patients and the level of care at the delivery hospital. The effect of volume also varied according to the level of care. As compared with a high level of care and a high volume of very-low-birth-weight infants (more than 100 per year), lower levels of care and lower volumes (except for those of two small groups of hospitals) were associated with significantly higher odds ratios for death, ranging from 1.19 (95% confidence interval [CI], 1.04 to 1.37) to 2.72 (95% CI, 2.37 to 3.12). Less than one quarter of very-low-birth-weight deliveries occurred in facilities with NICUs that offered a high level of care and had a high volume, but 92% of very-low-birth-weight deliveries occurred in urban areas with more than 100 such deliveries. CONCLUSIONS: Mortality among very-low-birth-weight infants was lowest for deliveries that occurred in hospitals with NICUs that had both a high level of care and a high volume of such patients. Our results suggest that increased use of such facilities might reduce mortality among very-low-birth-weight infants.

Adverse obstetric events are associated with significant risk of cerebral palsy.

OBJECTIVE: To examine adverse birth events on the development of cerebral palsy in California. STUDY DESIGN: A retrospective population-based study of children with cerebral palsy (as of Nov. 30, 2006), matched to their maternal/infant delivery records (Jan. 1, 1991 to Dec. 31, 2001) was performed. Demographic data and intrapartum events were examined. Six adverse birth-related events were chosen. Children without cerebral palsy were controls. RESULTS: There were 7242 children who had cerebral palsy (59% term) and 31.3% had 1 or more of the 6 adverse intrapartum events (12.9% in controls P < .0001). This held for both term (28.3% vs 12.7% controls) and preterm (36.8% vs 15.9%, controls) neonates (both P < .0001). Maternal (15.1% vs 6.6%) and neonatal (0.9% vs 0.1%) infection were increased in cerebral palsy cases (P < .0001). CONCLUSION: Almost one-third of children with cerebral palsy had at least 1 adverse birth-related event. Higher rates in the preterm group may partially explain the higher rates of cerebral palsy in this group.

Antenatal and intrapartum risk factors for seizures in term newborns: a population-based study, California 1998-2002.

OBJECTIVE: To assess antenatal and intrapartum risk factors for seizures occurring during the birth admission. STUDY DESIGN: Using multivariable logistic regression analysis, we evaluated the association between maternal characteristics and birth admission seizures in a cohort of 2.3 million California children born at >or=36 weeks' gestation between 1998 and 2002 using the California Office of Statewide Planning and Development database containing birth certificates linked to infant and maternal hospital discharge abstracts. RESULTS: The incidence of seizures during the birth admission was 0.95/1000 live births. In an adjusted analysis, infants of women age 40 years and older who were nulliparous; had diabetes mellitus, intrapartum fever, or infection or delivered at >or=42 weeks had an increased risk of seizures. Infants of Hispanic and Asian mothers had a lower risk compared with infants of Caucasian mothers. CONCLUSIONS: Several maternal antenatal and intrapartum factors increased the risk of seizures during the birth admission. Identifying and avoiding risks for neonatal seizures may lead to lower infant neurologic morbidity and mortality.

Female Sex and Longer Fusion Constructs Significantly Increase the Risk of Total Hip Arthroplasty Following Spinal Fusion.

BACKGROUND: Previous studies have noted the progression of arthritis due to increased forces in articular structures adjacent to a fused joint. It is unknown whether spinal fusion generates increased forces at the hip joint causing progression to arthritis leading to total hip arthroplasty (THA). We sought to determine (1) is there a relationship between spinal fusion and THA, (2) what are risk factors for subsequent THA, and (3) is there a time interval from spinal fusion to THA? METHODS: A large patient discharge dataset was utilized to evaluate all patients who underwent spinal fusion and subsequent THA in California from 2004 through 2013. Patients were categorized by age, sex, hospital type, hospital volume, and number of spinal levels fused. Multivariate analysis was performed to investigate the relationship between spinal fusion and THA. Hazard ratios were calculated for risk factors for THA after spinal fusion. Patients were excluded for previous spinal fusion or hip arthroplasty, inflammatory arthropathy, cancer, and an age of ≤40 years, a surrogate for adolescent and neuromuscular scoliosis. RESULTS: A total of 101,206 patients underwent spinal fusion; 2,803 (2.77%) subsequently underwent THA. In a bivariate analysis comparing 1 to 2 levels versus >2 levels fused, males had a 17% increased relative risk of undergoing subsequent THA (relative risk [RR] = 1.17; 95% confidence interval [CI] = 1.16 to 1.17) and female patients had a 35% increased relative risk (RR = 1.35; 95% CI = 1.34 to 1.35) when the fusion involved >2 levels. For females, the relative risk increased by 119% when >7 levels were fused compared with 1 to 7 levels (RR = 2.19; 95% CI = 2.16 to 2.21). Using multivariate random-effects analysis, significant risk factors for THA after spinal fusion included female sex (hazard ratio [HR] = 1.21; 95% CI = 1.13 to 1.31; p < 0.0001) and spinal fusion of >7 levels (HR = 1.52; 95% CI = 1.03 to 2.24; p = 0.035). CONCLUSIONS: Patients with longer spinal fusion constructs, especially female patients, had a significantly increased risk of undergoing subsequent THA. Patients should be educated regarding the potential for the progression to hip arthritis after spinal fusion and the possibility of future THA. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Evidence of poorer survival in pregnancy-associated breast cancer.

OBJECTIVE: To compare stage distribution, tumor characteristics, and survival outcome in pregnancy-associated and non-pregnancy-associated breast cancer, and to evaluate pregnancy as a risk factor for mortality in breast cancer. METHODS: The California Cancer Registry (1991-1999) was linked with the California Patient Discharge Data Set to identify women with breast cancer occurring within 9 months before or 1 year after an obstetric delivery. Age-matched, non-pregnancy-associated breast cancer controls were also identified. Demographics, cancer stage, tumor size, histology, hormone receptor status, type of treatment, and survival were reviewed and compared. Predictive factors for death from breast cancer were identified using proportional hazards modeling. RESULTS: Seven hundred ninety-seven pregnancy-associated breast cancer cases were compared with 4,177 non-pregnancy-associated breast cancer controls. Pregnancy-associated breast cancer cases were significantly more likely to have more advanced stage, larger primary tumor, hormone receptor negative tumor, and mastectomy as a component of their treatment. In survival analysis, pregnancy-associated breast cancer had a higher death rate than non-pregnancy-associated breast cancer (39.2% compared with 33.4%, P=.002). In a multivariable analysis, advancing stage (2.22-10.76 times the risk of death for stages II-IV), race (African Americans had 68% increased risk of death over non-Hispanic whites), hormone receptor-negative tumors (20% increased risk of death over receptor-positive tumors), and pregnancy (14% increased risk of death over nonpregnant women) all were significant predictors of death. CONCLUSION: Pregnancy-associated breast cancer presented with more advanced disease, larger tumors, and increased percentage of hormone receptor-negative tumors. When controlled for stage, race, and hormone receptor status, pregnancy-associated breast cancer cases had a slightly higher risk of death, even when only localized-stage disease was considered. LEVEL OF EVIDENCE: II.

Implementation of transcatheter aortic valve replacement in California: Influence on aortic valve surgery.

OBJECTIVE: Transcatheter aortic valve replacement (TAVR) procedures were introduced in 2011. Initially, procedures were limited to patients who were not surgical candidates, but subsequently high-risk surgical candidates were considered for TAVR. The influence on aortic valve surgery in California is unknown. METHODS: The California Office of Statewide Health Planning and Development hospitalized patient discharge database was queried for the years 2009 through 2014. isolated surgical aortic valve and aortic valve/coronary artery bypass graft (SAVR) and TAVR procedures were identified by International Classification of Diseases-9th revision clinical modification procedure codes. Seven TAVR programs were introduced in 2011, 12 in 2012, 3 in 2013, and 6 in 2014. SAVR procedure volumes were compared from the 2 years before institution with SAVR volumes during the year(s) after institution of the TAVR program in these 28 hospitals. RESULTS: Overall, surgical volumes increased during the first, second, and third years after implementation of TAVR procedures. Among 7 hospitals with 4-year programs, surgical volumes increased to a maximum of 15.5% during the third year, then began to decrease. The hospital performing the largest number of TAVR procedures showed a marked decrease in SAVR volume by the fourth year, suggesting a shift of SAVR candidates to TAVR. Among all hospitals with 4-year programs, TAVR exceeded SAVR procedures by the fourth year. In California overall, SAVR increased during 2011 through 2013, due primarily to increasing volume of isolated SAVR procedures. Statewide, isolated SAVR increased from a yearly average of 3111 procedures during 2009-2010 to 3592 (+15.5%) in 2013, then decreased slightly in 2014. SAVR plus coronary artery bypass graft procedures decreased during the same time period. CONCLUSIONS: After implementation of TAVR, hospital SAVR volumes increased moderately, then began to decrease by the fourth year, when TAVR volume exceeded SAVR. Surgical candidates may be identified during evaluation for TAVR, resulting in increased SAVR volume. Increasing SAVR volume may also be related to improved patient and provider awareness of aortic valve disease.

Selection of Higher Risk Pregnancies into Veterans Health Administration Programs: Discoveries from Linked Department of Veterans Affairs and California Birth Data.

OBJECTIVE: To describe variation in payer and outcomes in Veterans' births. DATA/SETTING: Secondary data analyses of deliveries in California, 2000-2012. STUDY DESIGN: We performed a retrospective, population-based study of all live births to Veterans (confirmed via U.S. Department of Veterans Affairs (VA) enrollment records), to identify payer and variations in outcomes among: (1) Veterans using VA coverage and (2) Veteran vs. all other births. We calculated odds ratios (aOR) adjusted for age, race, ethnicity, education, and obstetric demographics. METHODS: We anonymously linked VA administrative data for all female VA enrollees with California birth records. PRINCIPAL FINDINGS: From 2000 to 2012, we identified 17,495 births to Veterans. VA covered 8.6 percent (1,508), Medicaid 17.3 percent, and Private insurance 47.6 percent. Veterans who relied on VA health coverage had more preeclampsia (aOR 1.4, CI 1.0-1.8) and more cesarean births (aOR 1.2, CI 1.0-1.3), and, despite similar prematurity, trended toward more neonatal intensive care (NICU) admissions (aOR 1.2, CI 1.0-1.4) compared to Veterans using other (non-Medicaid) coverage. Overall, Veterans' birth outcomes (all-payer) mirrored California's birth outcomes, with the exception of excess NICU care (aOR 1.15, CI 1.1-1.2). CONCLUSIONS: VA covers a higher risk fraction of Veterans' births, justifying maternal care coordination and attention to the maternal-fetal impacts of Veterans' comorbidities.

CAABL-AF (California Study of Ablation for Atrial Fibrillation): Mortality and Stroke, 2005 to 2013.

BACKGROUND: Ablation for atrial fibrillation (AF) is superior to medical therapy for rhythm control. We compared stroke and mortality among patients undergoing ablation for AF to matched controls in a large multiethnic population. METHODS: Using discharge and surgical records from California nonfederal hospitals, we identified patients who had ablation and principal diagnosis of AF with at least 1 prior hospitalization for AF. We excluded cases with valve disease, open maze, other arrhythmias, or implantable devices. Matched controls were selected based on years of AF diagnosis, age, sex, and being alive the same number of days from the initial AF encounter to the ablation date. Clinical outcomes, including mortality, ischemic stroke, or hemorrhagic stroke, were assessed using a weighted proportional hazard model, adjusting for demographics, prior admissions with AF before the ablation, calendar year, and presence of chronic comorbidities. RESULTS: There were 4169 ablation cases and 4169 weighted-matched controls; 39% percent of the ablation group was >65 years, 72% men, 84% white; mean follow-up was up to 3.6±0.9 years. In adjusted models, ablation was associated with significantly lower mortality (per patient-years) 0.9% versus 1.9%, hazard ratio=0.59 (P<0.0001; confidence interval: 0.45-0.77); ischemic stroke (>30 days post-ablation ≤5 years), 0.37% versus 0.59%, hazard ratio=0.68 (P=0.04; confidence interval: 0.47-0.97); hemorrhagic stroke 0.11% versus 0.35%, hazard ratio=0.36 (P=0.001; confidence interval: 0.20-0.64) compared with controls. CONCLUSIONS: In this large population-based study of hospitalized patients with nonvalvular AF, ablation was associated with lower mortality, ischemic stroke, and hemorrhagic stroke compared with controls.

Pregnancy outcomes in women with chronic hypertension: a population-based study.

OBJECTIVE: To determine the pregnancy outcomes associated with maternal chronic hypertension. STUDY DESIGN: Retrospective, population-based cohort study of maternal and infant discharge records linked to birth records in California from 1991 to 2001 were examined for demographics and pregnancy outcomes, and comparisons were made between those with and without chronic hypertension. One randomly selected pregnancy per subject was included. RESULTS: The number of women who delivered with chronic hypertension (0.69% incidence) was 29,842. As compared to non-chronic hypertensive patients, fetal and neonatal mortality and in-hospital maternal mortality were increased (ORs and 95% CIs 2.3, (2.1, 2.6); 2.3, (2.0, 2.7); and 4.8, (3.1, 7.6) respectively). Major maternal morbidity was increased: stroke, OR 5.3, (3.7, 7.5); renal failure, OR 6.0, (4.4, 8.1); pulmonary edema, OR 5.2, (3.9, 6.7); severe preeclampsia, OR 2.7, (2.5, 2.9); and placental abruption OR 2.1, (2.0, 2.3). Neonatal morbidity was increased as well: fetal growth restriction, OR 4.9, (4.7, 5.2); prematurity, OR 3.2, (3.1, 3.3); low birth weight, OR 5.4, (5.2, 5.5); very low birth weight, OR 6.5, (6.2, 6.8); and respiratory distress syndrome, OR 4.0, (3.8, 4.2). CONCLUSION: Pregnant women with chronic hypertension have significantly increased risks of maternal and perinatal morbidity and mortality. Women with this condition should be treated as high risk with appropriate maternal and fetal surveillance.

Vaginal vs. cesarean delivery for preterm breech presentation of singleton infants in California: a population-based study.

OBJECTIVE: To examine the morbidity and mortality associated with vaginal breech delivery (VBD) of premature, low-birth-weight (LBW) (< 2.5 kg) newborns as compared to delivery by cesarean section. STUDY DESIGN: A retrospective cohort study of singleton, preterm (< 37 weeks), LBW, nonanomalous newborns in California (January 1, 1991-December 31, 1999) was performed. Neonatal morbidity and mortality by route of delivery were compared. RESULTS: Overall, 14,417 LBW, preterm, breech newborns were delivered (14% vaginally and 86% by cesarean). There were 150,570 LBW, preterm, cephalic newborns, of whom 82% were delivered vaginally. VBD of LBW newborns in nulliparous women was associated with increased neonatal mortality in newborns weighing 500-1,000 g (OR 11.7; 95% CI 7.9, 17.2), 1,001-1,500 g (OR 17.0; 95% CI 6.8, 42.7), 1,501-2,000 g (OR 7.2; 95% CI 2.4, 21.4), and 2,001-2,500 g (OR 6.6; 95% CI 2.1, 21.2) as compared with breech delivery by cesarean in nulliparous women. Birth trauma was increased in VBD of newborns weighing 1,500-2,000 g (OR 3.8; 95% CI 1.4, 10.1) and 2,001-2,500 g (OR 4.5; 95% CI 2.6, 7.9) as compared to breech delivery by cesarean in nulliparous women. Birth asphyxia was increased in breech newborns weighing 2,001-2,500 g (OR 3.5; 95% CI 2.2, 5.6) delivered vaginally in nulliparous women as compared to cephalic vaginal deliveries. CONCLUSION: VBD of the preterm, LBW newborn is associated with significantly increased neonatal mortality as compared to cesarean section at similar birth weights. Birth trauma (> 1,500 g) was greater with VBD as compared to breech delivery by cesarean, and asphyxia (> 2,000 g) was greater with VBD as compared to cephalic vaginal delivery, suggesting that cesarean delivery may be a safer route of delivery for preterm breech fetuses.

Postoperative Stiffness Requiring Manipulation Under Anesthesia Is Significantly Reduced After Simultaneous Versus Staged Bilateral Total Knee Arthroplasty.

BACKGROUND: For patients with symptomatic bilateral knee arthritis, it is unknown whether the risk of developing stiffness requiring manipulation under anesthesia postoperatively is higher or lower for those undergoing simultaneous bilateral total knee arthroplasty (TKA) compared with those having staged bilateral TKA. Therefore, we undertook this study to evaluate the risk of requiring manipulation under anesthesia in staged versus simultaneous bilateral TKA as well as patients undergoing unilateral TKA. METHODS: We utilized the California Patient Discharge Database, which is linked with the California Emergency Department, Ambulatory Surgery, and master death file databases. Using a literature-based estimate of the number of patients who failed to undergo the second stage of a staged bilateral TKA, replacement cases were randomly selected from patients who had unilateral TKA and were matched on 8 clinical characteristics of the patients who had staged bilateral TKA. Hierarchical multivariate logistic regression was performed to determine the risk-adjusted odds of manipulation in patients undergoing unilateral TKA, staged bilateral TKA, and simultaneous bilateral TKA using yearly hospital TKA volume as a random effect. Adjustment was made to allow fair comparison of the outcome at 90 and 180 days of follow-up after staged compared with simultaneous bilateral TKA. RESULTS: During the time period from 2005 through 2013, the cumulative incidence of manipulation within 90 days was 2.14% for unilateral TKA (4,398 events per 205,744 patients), 2.11% for staged bilateral TKA (724 events per 34,352 patients), and 1.62% for simultaneous bilateral TKA (195 events per 12,013 patients). At 180 days of complete follow-up, the cumulative incidence of manipulation was 3.07% after unilateral TKA (6,313 events per 205,649 patients), 2.89% after staged bilateral TKAs (957 events per 33,169 patients), and 2.29% after simultaneous bilateral TKA (267 events per 11,653 patients). With multivariate analyses used to adjust for relevant risk factors, the 90-day odds ratio (OR) of undergoing manipulation after simultaneous bilateral TKA was significantly lower than that for unilateral TKA (OR = 0.70; 95% confidence interval [CI], 0.57 to 0.86) and staged bilateral TKA (OR = 0.71; 95% CI, 0.57 to 0.90). Similarly, at 180 days, the odds of undergoing manipulation were significantly lower after simultaneous bilateral TKA than after both unilateral TKA (OR = 0.71; 95% CI, 0.59 to 0.84) and staged bilateral TKA (OR = 0.76; 95% CI, 0.63 to 0.93). The frequency of manipulation was significantly associated with younger age, fewer comorbidities, black race, and the absence of obesity. CONCLUSIONS: Although the ORs were small (close to 1), simultaneous bilateral TKA had a significantly decreased rate of stiffness requiring manipulation under anesthesia at 90 days and 180 days after knee replacement compared with that after staged bilateral TKA and unilateral TKA. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

California study of Ablation (CAABL):early utilization after index hospitalization for non-valvular atrial fibrillation.

BACKGROUND: Catheter ablation (ABL) for non-valvular AF (NVAF) is recommended for symptomatic patients refractory to medical therapy and its success is related to the duration of the arrhythmia prior to intervention.Our aim was to assess the early utilization and the factors that prompted ABL in patients hospitalized for new onset NVAF. METHODS: Using de-identified administrative discharge records for hospitalizations and emergency department (ED) visits, we determined the patients who had a first-time (since 1991) health record diagnosis of AF between2005 - 2011. We linked ambulatory surgery encounters for ABL based on ICD 9 code occurring within two years of initial hospitalization. After excluding other cardiac arrhythmias, atrio-ventricular nodal ablation or pacemaker/defibrillator placement and cardiac valve disease, bivariate comparisons were made with those who did not undergo ABL. RESULTS: During the study period,3,440 of 424,592 patients (0.81%) hospitalized for new onset NVAF underwent ABL. Parameters significantly (p<0.001) associated with ABL compared tonon-ABL patientsincluded: principal diagnosis of AF (55% vs 25%), age 35-64 yrs (46.1% vs. 22.4%), male (58.9% vs. 48.2%), private insurance (46.6% vs. 21.1%), Caucasian (81.0% vs.71.6%), lower frequency of ED visit < 6 months before index AF hospitalization (10.7% vs. 15.9%), lower severityofillness at time of AF diagnosis (16.5% vs. 35.6%) anda lower prevalence ofmajor comorbidities (p< 0.001). CONCLUSIONS: Ablation has low utilization for treatment of new onset NVAF within two years of diagnosis. Earlier utilization of ABL may reduce health care burden related to NVAF and requires further evaluation.