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Sarah E Little - One of the best experts on this subject based on the ideXlab platform.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American journal of perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p < 0.01) and inversely correlated with VBAC rate (r = - 0.42, p < 0.01). Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American Journal of Perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:Objective The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. Methods We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Results Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p Conclusion Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume.
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obstetrician Volume as a potentially modifiable risk factor for cesarean Delivery
Obstetrics & Gynecology, 2014Co-Authors: Mark A Clapp, Alexander Melamed, Julian N. Robinson, Neel Shah, Sarah E LittleAbstract:OBJECTIVE To examine the relationship between an obstetrician's Delivery Volume and a patient's risk for cesarean Delivery. METHODS This retrospective cohort study examined patient-level and obstetrician-level data between 2000 and 2012 at a large academic hospital. All laboring patients who delivered viable, liveborn, singleton newborns (N=58,328) were included. We measured the association of Delivery Volume and cesarean Delivery using a multivariate logistic regression. We also assessed the association of Volume by calculating adjusted cesarean Delivery rates using the least squares means method. These analyses were performed on the subset of nulliparous patients with term, singleton, vertex-presenting fetuses. In addition, the association of obstetrician experience was compared against Delivery Volume. RESULTS There was a twofold increase in the odds of cesarean Delivery for patients whose obstetricians performed fewer than the median (60) number of deliveries per year (quartile 1: odds ratio 2.00, 95% confidence interval 1.68-2.38; quartile 2: odds ratio 2.73, 95% CI 2.40-3.11) as compared with quartile 4. The adjusted cesarean Delivery rate decreased from 18.2% to 9.2% from the highest to lowest Volume quartile (P<.001). Compared with the Volume effects, an obstetrician's experience had a smaller effect on a patient's risk of cesarean Delivery. CONCLUSION Patients delivered by obstetricians with low Delivery Volume are at significantly increased risk for cesarean Delivery after controlling for patient and obstetrician characteristics. In contrast, obstetrician experience had a less significant effect. These findings may prompt discussions regarding the role of Volume in credentialing and practice models that direct patients to obstetricians with high Delivery Volume. LEVEL OF EVIDENCE : II.
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Obstetrician Volume as a potentially modifiable risk factor for cesarean Delivery.
Obstetrics and gynecology, 2014Co-Authors: Mark A Clapp, Alexander Melamed, Julian N. Robinson, Neel Shah, Sarah E LittleAbstract:OBJECTIVE To examine the relationship between an obstetrician's Delivery Volume and a patient's risk for cesarean Delivery. METHODS This retrospective cohort study examined patient-level and obstetrician-level data between 2000 and 2012 at a large academic hospital. All laboring patients who delivered viable, liveborn, singleton newborns (N=58,328) were included. We measured the association of Delivery Volume and cesarean Delivery using a multivariate logistic regression. We also assessed the association of Volume by calculating adjusted cesarean Delivery rates using the least squares means method. These analyses were performed on the subset of nulliparous patients with term, singleton, vertex-presenting fetuses. In addition, the association of obstetrician experience was compared against Delivery Volume. RESULTS There was a twofold increase in the odds of cesarean Delivery for patients whose obstetricians performed fewer than the median (60) number of deliveries per year (quartile 1: odds ratio 2.00, 95% confidence interval 1.68-2.38; quartile 2: odds ratio 2.73, 95% CI 2.40-3.11) as compared with quartile 4. The adjusted cesarean Delivery rate decreased from 18.2% to 9.2% from the highest to lowest Volume quartile (P
Julian N. Robinson - One of the best experts on this subject based on the ideXlab platform.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American journal of perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p < 0.01) and inversely correlated with VBAC rate (r = - 0.42, p < 0.01). Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American Journal of Perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:Objective The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. Methods We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Results Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p Conclusion Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume.
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obstetrician Volume as a potentially modifiable risk factor for cesarean Delivery
Obstetrics & Gynecology, 2014Co-Authors: Mark A Clapp, Alexander Melamed, Julian N. Robinson, Neel Shah, Sarah E LittleAbstract:OBJECTIVE To examine the relationship between an obstetrician's Delivery Volume and a patient's risk for cesarean Delivery. METHODS This retrospective cohort study examined patient-level and obstetrician-level data between 2000 and 2012 at a large academic hospital. All laboring patients who delivered viable, liveborn, singleton newborns (N=58,328) were included. We measured the association of Delivery Volume and cesarean Delivery using a multivariate logistic regression. We also assessed the association of Volume by calculating adjusted cesarean Delivery rates using the least squares means method. These analyses were performed on the subset of nulliparous patients with term, singleton, vertex-presenting fetuses. In addition, the association of obstetrician experience was compared against Delivery Volume. RESULTS There was a twofold increase in the odds of cesarean Delivery for patients whose obstetricians performed fewer than the median (60) number of deliveries per year (quartile 1: odds ratio 2.00, 95% confidence interval 1.68-2.38; quartile 2: odds ratio 2.73, 95% CI 2.40-3.11) as compared with quartile 4. The adjusted cesarean Delivery rate decreased from 18.2% to 9.2% from the highest to lowest Volume quartile (P<.001). Compared with the Volume effects, an obstetrician's experience had a smaller effect on a patient's risk of cesarean Delivery. CONCLUSION Patients delivered by obstetricians with low Delivery Volume are at significantly increased risk for cesarean Delivery after controlling for patient and obstetrician characteristics. In contrast, obstetrician experience had a less significant effect. These findings may prompt discussions regarding the role of Volume in credentialing and practice models that direct patients to obstetricians with high Delivery Volume. LEVEL OF EVIDENCE : II.
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Obstetrician Volume as a potentially modifiable risk factor for cesarean Delivery.
Obstetrics and gynecology, 2014Co-Authors: Mark A Clapp, Alexander Melamed, Julian N. Robinson, Neel Shah, Sarah E LittleAbstract:OBJECTIVE To examine the relationship between an obstetrician's Delivery Volume and a patient's risk for cesarean Delivery. METHODS This retrospective cohort study examined patient-level and obstetrician-level data between 2000 and 2012 at a large academic hospital. All laboring patients who delivered viable, liveborn, singleton newborns (N=58,328) were included. We measured the association of Delivery Volume and cesarean Delivery using a multivariate logistic regression. We also assessed the association of Volume by calculating adjusted cesarean Delivery rates using the least squares means method. These analyses were performed on the subset of nulliparous patients with term, singleton, vertex-presenting fetuses. In addition, the association of obstetrician experience was compared against Delivery Volume. RESULTS There was a twofold increase in the odds of cesarean Delivery for patients whose obstetricians performed fewer than the median (60) number of deliveries per year (quartile 1: odds ratio 2.00, 95% confidence interval 1.68-2.38; quartile 2: odds ratio 2.73, 95% CI 2.40-3.11) as compared with quartile 4. The adjusted cesarean Delivery rate decreased from 18.2% to 9.2% from the highest to lowest Volume quartile (P
Sarah Rae Easter - One of the best experts on this subject based on the ideXlab platform.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American Journal of Perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:Objective The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. Methods We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Results Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p Conclusion Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume.
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The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.
American journal of perinatology, 2017Co-Authors: Sarah Rae Easter, Julian N. Robinson, Daniela Carusi, Sarah E LittleAbstract:The objective of this study was to test whether hospitals experienced in twin Delivery have lower rates of cesarean Delivery for twins. We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean Delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean Delivery rate to its overall cesarean Delivery and vaginal birth after cesarean (VBAC) rates. Annual twin Delivery Volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean Delivery were independent of Delivery Volume with a rate of 75.5 versus 74.8% in the lowest and highest Volume hospitals (p = 0.09 across quartiles). A hospital's cesarean Delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p < 0.01) and inversely correlated with VBAC rate (r = - 0.42, p < 0.01). Most U.S. obstetrical units perform a low Volume of twin deliveries with no decrease in cesarean Delivery rates at higher Volume hospitals. Twin cesarean Delivery rates correlate with other obstetric parameters such as singleton cesarean Delivery and VBAC rates suggesting twin cesarean Delivery rate is more closely related to a hospital's general obstetric practice than its twin Delivery Volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Chi Xie - One of the best experts on this subject based on the ideXlab platform.
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Efficient Insertion Heuristic Algorithms for Multi-Trip Inventory Routing Problem with Time Windows, Shift Time Limits and Variable Delivery Time
Networks and Spatial Economics, 2017Co-Authors: Ampol Karoonsoontawong, Onwasa Kobkiattawin, Chi XieAbstract:Efficient insertion heuristic algorithms allowing multi trips per vehicle (EIH-MT) and allowing a single trip per vehicle with post-processing greedy heuristic (EIH-ST-GH) are proposed to solve the multi-trip inventory routing problem with time windows, shift time limit and variable Delivery time (MTIRPTW-STL-VDT) with short planning horizon. The proposed algorithms are developed based on an original algorithm with two enhancements. First, the Delivery Volumes, the associated beginning Delivery times and the exact profits are calculated and maintained. Second, the process to finalize a best-objective and feasible solution is developed. These algorithms are shown to have the complexity of O(n 4 ). These heuristics maximize the profit function, which is the weighted summation of total Delivery Volume and negative total travel time. EIH-MT and EIH-ST-GH are performed on 280 instances based on Solomon’s test problems with three weight sets. Best-objective solutions are examined to illustrate the feasibility of various constraints. The trade-offs between total Delivery Volume and total travel time are observed when varying weight values. There is not a single winner heuristic based on the number-of-vehicles, profit and CPU criteria across the three customer configuration types. On average performance, EIH-ST-GH is preferred over EIH-MT for cluster configuration type with the following average improvement percentages: 1.03% for profit, 2.93% for number-of-vehicles and 38.68% for CPU. For random and random-cluster configuration types, EIH-ST-GH should be preferred because of better profit (0.27% for random and 0.22% for random-cluster) and CPU (46.96% for random and 44.06% for random-cluster) improvements. In the comparison of the multi-trip algorithms against the single-trip algorithm, the benefits in reducing the number of vehicles on-average are shown across all customer configuration types.
Ampol Karoonsoontawong - One of the best experts on this subject based on the ideXlab platform.
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Efficient Insertion Heuristic Algorithms for Multi-Trip Inventory Routing Problem with Time Windows, Shift Time Limits and Variable Delivery Time
Networks and Spatial Economics, 2017Co-Authors: Ampol Karoonsoontawong, Onwasa Kobkiattawin, Chi XieAbstract:Efficient insertion heuristic algorithms allowing multi trips per vehicle (EIH-MT) and allowing a single trip per vehicle with post-processing greedy heuristic (EIH-ST-GH) are proposed to solve the multi-trip inventory routing problem with time windows, shift time limit and variable Delivery time (MTIRPTW-STL-VDT) with short planning horizon. The proposed algorithms are developed based on an original algorithm with two enhancements. First, the Delivery Volumes, the associated beginning Delivery times and the exact profits are calculated and maintained. Second, the process to finalize a best-objective and feasible solution is developed. These algorithms are shown to have the complexity of O(n 4 ). These heuristics maximize the profit function, which is the weighted summation of total Delivery Volume and negative total travel time. EIH-MT and EIH-ST-GH are performed on 280 instances based on Solomon’s test problems with three weight sets. Best-objective solutions are examined to illustrate the feasibility of various constraints. The trade-offs between total Delivery Volume and total travel time are observed when varying weight values. There is not a single winner heuristic based on the number-of-vehicles, profit and CPU criteria across the three customer configuration types. On average performance, EIH-ST-GH is preferred over EIH-MT for cluster configuration type with the following average improvement percentages: 1.03% for profit, 2.93% for number-of-vehicles and 38.68% for CPU. For random and random-cluster configuration types, EIH-ST-GH should be preferred because of better profit (0.27% for random and 0.22% for random-cluster) and CPU (46.96% for random and 44.06% for random-cluster) improvements. In the comparison of the multi-trip algorithms against the single-trip algorithm, the benefits in reducing the number of vehicles on-average are shown across all customer configuration types.
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Efficient Insertion Heuristics for Multi-Trip Inventory Routing Problem with Time Windows, Shift Time Limits and Variable Delivery Time
2016Co-Authors: Ampol KaroonsoontawongAbstract:Efficient insertion heuristic algorithms allowing multi trips per vehicle (EIH-MT) and allowing a single trip per vehicle with post-processing greedy heuristic (EIH-ST-GH) are proposed to solve the multi-trip inventory routing problem with time windows, shift time limit and variable Delivery time (MTIRPTW-STL-VDT) with short planning horizon. The proposed algorithms are developed based on an original algorithm with two enhancements. First, the Delivery Volumes, the associated beginning Delivery times and the exact profits are calculated and maintained. Second, the process to finalize a best-objective and feasible solution is developed. These algorithms are shown to have the complexity of O(n⁴). These heuristics maximize the profit function, which is the weighted summation of total Delivery Volume and negative total travel time. EIH-MT and EIH-ST-GH are performed on 280 instances based on Solomon’s test problems with three weight sets. Best-objective solutions are examined to illustrate the feasibility of various constraints. The trade-offs between total Delivery Volume and total travel time are observed when varying weight values. There is not a single winner heuristic based on the number-of-vehicles, profit and CPU criteria across the three customer configuration types. On average performance, EIH-ST-GH is preferred over EIH-MT for cluster configuration type with the following average improvement percentages: 1.03% for profit, 2.93% for number-of-vehicles and 38.68% for CPU. For random and random-cluster configuration types, EIH-ST-GH should be preferred because of better profit (0.27% for random and 0.22% for random-cluster) and CPU (46.96% for random and 44.06% for random-cluster) improvements.