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The Imprint of Labor Markets on Entrepreneurial Performance
No full textUsing the 1979–2010 waves of the National Longitudinal Survey of Youth, our study tracks the earnings of individual entrepreneurs from the beginning of their entrepreneurial careers, examining the effects of labor markets on their earnings trajectory. Results show that apart from self-selection, labor markets impose a penalty on the initial earnings of entrepreneurs who start a business in adverse economic conditions, a disadvantage that persist for up to a decade. We also identify two factors expected to alleviate the imprinting effect of labor markets: migration outside the imprinting environment and serial entrepreneurship
Goal-Striving Stress and Incident Cardiovascular Disease in Blacks: The Jackson Heart Study.
No full textBackground Goal-striving stress (GSS), the stress from striving for goals, is associated with poor health. Less is known about its association with cardiovascular disease (CVD). Methods and Results We used data from the JHS (Jackson Heart Study), a study of CVD among blacks (21-95 years old) from 2000 to 2015. Participants free of CVD at baseline (2000-2004) were included in this analysis (n=4648). GSS was examined in categories (low, moderate, high) and in SD units. Incident CVD was defined as fatal or nonfatal stroke, coronary heart disease (CHD), and/or heart failure. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident CVD by levels of GSS, adjusting for demographics, socioeconomic status, health behaviors, risk factors, and perceived stress. The distribution of GSS categories was as follows: 40.77% low, 33.97% moderate, and 25.26% high. Over an average of 12 years, there were 140 incident stroke events, 164 CHD events, and 194 heart failure events. After full adjustment, high (versus low) GSS was associated with a lower risk of stroke (HR, 0.38; 95% CI, 0.17-0.83) and a higher risk of CHD (HR, 1.91; 95% CI, 1.10-3.33) among women. A 1-standard deviation unit increase in GSS was associated with a 31% increased risk of CHD (HR, 1.31; 95% CI, 1.10-1.56) among women. Conclusions Higher GSS may be a risk factor for developing CHD among women; however, it appears to be protective of stroke among women. These analyses should be replicated in other samples of black individuals
Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA.
No full textPurposeTo describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical-thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA).MethodsMulticenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10° angle between UIV and UIV + 2 and >10° change in the angle from baseline to post-op.ResultsPJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p ConclusionsThe prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA
Predictors of Hospital Readmission and Surgical Site Infection in the United States, Denmark, and Japan: Is Risk Stratification a Universal Language?
No full textStudy designRetrospective review of three spine surgery databases.ObjectivesThe purpose of the present study is to determine whether predictors of hospital readmission and surgical site infection (SSI) after lumbar fusion will be the same in United States, Denmark, and Japan.Summary of background dataBecause clinical decision making becomes more data driven, risk stratification will be crucial to minimize complications. Spine surgeons worldwide face this issue, leading to parallel efforts to address risk stratification. This raises the question as to whether pooled data would be valuable and whether models generated in one country would be applicable to other populations.MethodsPredictors of SSI and 30-day readmission from three prospective databases (National Neurosurgery Quality and Outcomes Database [N2QOD] N = 2653, DaneSpine N = 1993, Japan Multicenter Spine Database [JAMSD] N = 3798) were determined and compared to identify common or divergent predictive risks.ResultsPredictive variables differed in the three databases, for both readmission and SSI. Factors predictive for hospital readmission were American Society of Anesthesiologists (ASA) grade in N2QOD (P = 0.013, odds ratio [OR] 2.08), fusion levels in DaneSpine (P = 0.005, OR 1.67), and sex in JAMSD (P = 0.001, OR = 2.81). Associated differences in demographics and procedural factors included mean ASA grade (N2QOD = 2.45, JAMSD = 1.72) and fusion levels (N2QOD = 1.39, DaneSpine = 1.52, JAMSD = 1.34). For SSI, sex (P = 0.000, OR = 3.30), diabetes (P = 0.000, OR = 2.90), and length of stay (P = 0.000, OR = 1.02) were predictive in JAMSD. No predictors were identified in N2QOD or DaneSpine.ConclusionPredictors of SSI and hospital readmission differ in the United States, Denmark, and Japan, suggesting that risk stratification models may need to be population specific or adjusted. Some differences in measured parameters exist in the three databases analyzed; however, patient and procedure selection also appear to differ and may limit the ability to directly pool data from different regions. Therefore, risk stratification models developed in one country may not be directly applicable to other countries.Level of evidence2
Machine Learning Prediction Models for Mortality in Intensive Care Unit Patients with Lactic Acidosis.
No full textLactic acidosis is the most common cause of anion gap metabolic acidosis in the intensive care unit (ICU), associated with poor outcomes including mortality. We sought to compare machine learning (ML) approaches versus logistic regression analysis for prediction of mortality in lactic acidosis patients admitted to the ICU. We used the Medical Information Mart for Intensive Care (MIMIC-III) database to identify ICU adult patients with lactic acidosis (serum lactate ≥4 mmol/L). The outcome of interest was hospital mortality. We developed prediction models using four ML approaches consisting of random forest (RF), decision tree (DT), extreme gradient boosting (XGBoost), artificial neural network (ANN), and statistical modeling with forward stepwise logistic regression using the testing dataset. We then assessed model performance using area under the receiver operating characteristic curve (AUROC), accuracy, precision, error rate, Matthews correlation coefficient (MCC), F1 score, and assessed model calibration using the Brier score, in the independent testing dataset. Of 1919 lactic acidosis ICU patients, 1535 and 384 were included in the training and testing dataset, respectively. Hospital mortality was 30%. RF had the highest AUROC at 0.83, followed by logistic regression 0.81, XGBoost 0.81, ANN 0.79, and DT 0.71. In addition, RF also had the highest accuracy (0.79), MCC (0.45), F1 score (0.56), and lowest error rate (21.4%). The RF model was the most well-calibrated. The Brier score for RF, DT, XGBoost, ANN, and multivariable logistic regression was 0.15, 0.19, 0.18, 0.19, and 0.16, respectively. The RF model outperformed multivariable logistic regression model, SOFA score (AUROC 0.74), SAP II score (AUROC 0.77), and Charlson score (AUROC 0.69). The ML prediction model using RF algorithm provided the highest predictive performance for hospital mortality among ICU patient with lactic acidosis
Assessment of impact of standing long-cassette radiographs on surgical planning for lumbar pathology: An international survey of spine surgeons
No full textOBJECT: The associations among global spinal alignment, patient-reported disability, and surgical outcomes have increasingly gained attention. The assessment of global spinal alignment requires standing long-cassette anteroposterior and lateral radiographs; however, spine surgeons routinely rely only on short-segment imaging when evaluating seemingly isolated lumbar pathology. This may prohibit adequate surgical planning and may predispose surgeons to not recognize associated pathology in the thoracic spine and sagittal spinopelvic malalignment. The authors used a case-based survey questionnaire to evaluate if including long-cassette radiographs led to changes to respondents' operative plans as compared with their chosen plan when cases contained standard imaging of the involved lumbar spine only. METHODS: A case-based survey was distributed to AOSpine International members that consisted of 15 cases of lumbar spine pathology and lumbar imaging only. The same 15 cases were then shuffled and presented a second time with additional long-cassette radiographs. Each case required participants to select a single operative plan with 5 choices ranging from least to most extensive. The cases included 5 "control" cases with normal global spinal alignment and 10 "test" cases with significant sagittal and/or coronal malalignment. Mean scores were determined for each question with higher scores representing more invasive and/or extensive operative plans. RESULTS: Of 712 spine surgeons who started the survey, 316 (44%) completed the entire series, including 68% of surgeons with spine fellowship training and representation from more than 40 countries. For test cases, but not for control cases, there were significantly higher average surgical invasiveness scores for cases presented with long-cassette radiographs (4.2) as compared with those cases with lumbar imaging only (3.4; p = 0.002). The addition of long-cassette radiographs resulted in 82.1% of respondents recommending instrumentation up to the thoracic spine, a 23.2% increase as compared with the same cases presented with lumbar imaging only (p = 0.008). CONCLUSIONS: This study demonstrates the importance of maintaining a low threshold for performing standing long-cassette imaging when assessing seemingly isolated lumbar pathology. Such imaging is necessary for the assessment of spinopelvic and global spinal alignment, which can be important in operative planning. Deformity, particularly positive sagittal malalignment, may go undetected unless one maintains a high index of suspicion and obtains long-cassette radiographs. It is recommended that spine surgeons recognize the prevalence and importance of such deformity when contemplating operative intervention
Adult revision surgery of prior hook-and-rod wire instrumentation for idiopathic scoliosis.
No full textAdolescent idiopathic scoliosis patients treated with spinal fusion may develop adjacent segment disease and curve progression into adulthood. Revision operations can be challenging, especially for adult patients treated with outdated instrumentation such as sublaminar hooks and/or wires. The authors demonstrate revision lumbar spine surgery in a 38-year-old female with scoliosis progression from junctional degeneration below a prior T5-L3 posterior instrumented arthrodesis with a hook-and-rod wire system. They also demonstrate safe application of an ultrasonic bone scalpel for completion of a Smith-Petersen osteotomy. The patient provided written, informed consent for all material presented in this case demonstration. The video can be found here: https://youtu.be/3PmaFtNcqKc
Maternal Health FemTech: A qualitative exploration of how companies serve minoritized populations in the U.S. and what prevents them from doing more
No full textBackground: The U.S. maternal mortality ratio (MMR) is 23.8 deaths per 100,000 live births. This ratio is the highest among high-income countries. Women of color (Black, Alaska Native, and American Indian women) disproportionally contribute to this statistic; they are 2 to 3 times more likely to die from pregnancy-related complications compared to white women and are more likely to be on Medicaid. This study focuses on FemTech’s (broadly defined as diagnostics, software, products, and services for women) role in maternal healthcare. The purpose of this research is to better understand how companies serve women of color and Medicaid recipients and the barriers that prevent them from doing more. Methods: Fifteen semi-structured interviews were conducted. Stakeholder categories included Medicaid representatives, FemTech startups, healthcare providers, healthcare consultants, and venture capitalists. All interviews consisted of approximately 6-8 open-ended questions and were analyzed through an emergent coding process focused on identifying interviewee themes. Results: This study found that startups mainly provided family planning offerings to women of color and/or Medicaid recipients during the prenatal and postpartum period. Key gaps that FemTech companies did not address include inaccessible pricing and lack of chronic condition management through primary care. These gaps are in line with broader FemTech trends. Conclusions: Until FemTech products and services address these gaps, they are unlikely to reduce maternal health disparities significantly. </p
A Hyb-Seq phylogeny of Boechera and related genera using a combination of Angiosperms353 and Brassicaceae-specific bait sets.
No full textPremiseAlthough Boechera (Boechereae, Brassicaceae) has become a plant model system for both ecological genomics and evolutionary biology, all previous phylogenetic studies have had limited success in resolving species relationships within the genus. The recent effective application of sequence data from target enrichment approaches to resolve the evolutionary relationships of several other challenging plant groups prompted us to investigate their usefulness in Boechera and Boechereae.MethodsTo resolve the phylogeny of Boechera and closely related genera, we utilized the Hybpiper pipeline to analyze two combined bait sets: Angiosperms353, with broad applicability across flowering plants; and a Brassicaceae-specific bait set designed for use in the mustard family. Relationships for 101 samples representing 81 currently recognized species were inferred from a total of 1114 low-copy nuclear genes using both supermatrix and species coalescence methods.ResultsOur analyses resulted in a well-resolved and highly supported phylogeny of the tribe Boechereae. Boechereae is divided into two major clades, one comprising all western North American species of Boechera, the other encompassing the eight other genera of the tribe. Our understanding of relationships within Boechera is enhanced by the recognition of three core clades that are further subdivided into robust regional species complexes.ConclusionsThis study presents the first broadly sampled, well-resolved phylogeny for most known sexual diploid Boechera. This effort provides the foundation for a new phylogenetically informed taxonomy of Boechera that is crucial for its continued use as a model system