BACKGROUND Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limite... more BACKGROUND Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limited clinical benefit for older patients given the competing risk of non-cancer death. The objective of this study is to model the clinical effect and cost of adjuvant therapy in stage IIIA melanoma across age groups. STUDY DESIGN A Markov decision analysis model simulated the overall survival of patients with resected stage IIIA melanoma treated with adjuvant therapy vs observation. In the adjuvant approach, patients are modeled to receive adjuvant pembrolizumab (BRAF wild type) or dabrafenib/trametinib (BRAF mutant). In the observation approach, treatment is deferred until recurrence. Transition variables were derived from landmark randomized trials in adjuvant and salvage therapy. The model was analyzed for age groups spanning 40 to 89 years. The primary outcome was the number needed to treat (NNT) to prevent one melanoma-related death at 10 years. Cost per mortality avoided was estimated using Medicare reimbursement rates. RESULTS Projections for NNT among BRAF wild type patients increased by age from 14.71 (age 40 to 44) to 142.86 (age 85 to 89), with patients in cohorts over the age of 75 having an NNT over 25. The cost per mortality avoided ranged from $2.75 million (M) (age 40 to 44) to $27.57M (age 85 to 89). Corresponding values for BRAF mutant patients were as follows: NNT 18.18 to 333.33; cost per mortality avoided ranged from $2.75M to $54.70M. CONCLUSION Universal adjuvant therapy for stage IIIA melanoma is costly and provides limited clinical benefit in patients older than 75 years.
Soil organic carbon (SOC) plays a critical role in major ecosystem processes, agriculture, and cl... more Soil organic carbon (SOC) plays a critical role in major ecosystem processes, agriculture, and climate mitigation. Accurate SOC predictions are challenging due to natural variation, as well as variation in data sources, sampling design, and modeling approaches. The goal of this study was to (i) understand SOC stock distribution due to land use (restored prairie grass—PG; lawn grass—LG; and forest—F), and local topography, and (ii) assess the scalability of SOC stock predictions from the study site in North Carolina (Lat: 36°7′ N; Longitude: 80°16′ W) to the geographic extension of the Fairview soil series based on the US Soil Survey Geographic (gSSURGO) database. Overall, LG had the highest SOC stock (82 Mg ha−1) followed by PG (79 Mg ha−1) and forest (73.1 Mg ha−1). SOC stock decreased with the depth for LG and PG, which had about 60% concentrated on the surface horizon (0–23 cm), while forest had only 40%. The differences between measured SOC stocks and those estimated by gSSURGO ...
INTRODUCTION The American Thyroid Association (ATA) updated consensus guidelines in 2015 for radi... more INTRODUCTION The American Thyroid Association (ATA) updated consensus guidelines in 2015 for radioactive iodine (RAI) and resection for low-risk papillary thyroid cancer. The objective of this study was to describe the evolution of institutional practice patterns and estimate the cost implications of these trends. MATERIALS AND METHODS Patients with cT1-T2N0 papillary thyroid cancer were identified via an institutional tumor registry. Incidences of total thyroidectomy or RAI were tracked longitudinally using cumulative sum. Real-world costs for RAI and each surgical encounter were adjusted for inflation and standardized to national average costs from National Inpatient Sample cost data. RESULTS Sixty-one patients met inclusion criteria between 2007 and 2018. Among these, 28 patients underwent total thyroidectomies and received RAI treatments based on criteria pre-dating the 2015 ATA guidelines. Cumulative sum revealed significant decreases in the rate of total thyroidectomy following May 2015 (15.8% versus 59.5%, P = 0.002) and RAI following March 2013 (3.0% versus 32.1%, P = 0.002). There were no locoregional recurrences in either period. The average cost savings attributable to these institutional practice changes was $1580 per patient. CONCLUSIONS De-escalation in surgical and RAI utilization for low-risk papillary thyroid cancer according to 2015 ATA guidelines is associated with a substantial decrease in real-world costs.
BACKGROUND Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limite... more BACKGROUND Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limited clinical benefit for older patients given the competing risk of non-cancer death. The objective of this study is to model the clinical effect and cost of adjuvant therapy in stage IIIA melanoma across age groups. STUDY DESIGN A Markov decision analysis model simulated the overall survival of patients with resected stage IIIA melanoma treated with adjuvant therapy vs observation. In the adjuvant approach, patients are modeled to receive adjuvant pembrolizumab (BRAF wild type) or dabrafenib/trametinib (BRAF mutant). In the observation approach, treatment is deferred until recurrence. Transition variables were derived from landmark randomized trials in adjuvant and salvage therapy. The model was analyzed for age groups spanning 40 to 89 years. The primary outcome was the number needed to treat (NNT) to prevent one melanoma-related death at 10 years. Cost per mortality avoided was estimated using Medicare reimbursement rates. RESULTS Projections for NNT among BRAF wild type patients increased by age from 14.71 (age 40 to 44) to 142.86 (age 85 to 89), with patients in cohorts over the age of 75 having an NNT over 25. The cost per mortality avoided ranged from $2.75 million (M) (age 40 to 44) to $27.57M (age 85 to 89). Corresponding values for BRAF mutant patients were as follows: NNT 18.18 to 333.33; cost per mortality avoided ranged from $2.75M to $54.70M. CONCLUSION Universal adjuvant therapy for stage IIIA melanoma is costly and provides limited clinical benefit in patients older than 75 years.
Soil organic carbon (SOC) plays a critical role in major ecosystem processes, agriculture, and cl... more Soil organic carbon (SOC) plays a critical role in major ecosystem processes, agriculture, and climate mitigation. Accurate SOC predictions are challenging due to natural variation, as well as variation in data sources, sampling design, and modeling approaches. The goal of this study was to (i) understand SOC stock distribution due to land use (restored prairie grass—PG; lawn grass—LG; and forest—F), and local topography, and (ii) assess the scalability of SOC stock predictions from the study site in North Carolina (Lat: 36°7′ N; Longitude: 80°16′ W) to the geographic extension of the Fairview soil series based on the US Soil Survey Geographic (gSSURGO) database. Overall, LG had the highest SOC stock (82 Mg ha−1) followed by PG (79 Mg ha−1) and forest (73.1 Mg ha−1). SOC stock decreased with the depth for LG and PG, which had about 60% concentrated on the surface horizon (0–23 cm), while forest had only 40%. The differences between measured SOC stocks and those estimated by gSSURGO ...
INTRODUCTION The American Thyroid Association (ATA) updated consensus guidelines in 2015 for radi... more INTRODUCTION The American Thyroid Association (ATA) updated consensus guidelines in 2015 for radioactive iodine (RAI) and resection for low-risk papillary thyroid cancer. The objective of this study was to describe the evolution of institutional practice patterns and estimate the cost implications of these trends. MATERIALS AND METHODS Patients with cT1-T2N0 papillary thyroid cancer were identified via an institutional tumor registry. Incidences of total thyroidectomy or RAI were tracked longitudinally using cumulative sum. Real-world costs for RAI and each surgical encounter were adjusted for inflation and standardized to national average costs from National Inpatient Sample cost data. RESULTS Sixty-one patients met inclusion criteria between 2007 and 2018. Among these, 28 patients underwent total thyroidectomies and received RAI treatments based on criteria pre-dating the 2015 ATA guidelines. Cumulative sum revealed significant decreases in the rate of total thyroidectomy following May 2015 (15.8% versus 59.5%, P = 0.002) and RAI following March 2013 (3.0% versus 32.1%, P = 0.002). There were no locoregional recurrences in either period. The average cost savings attributable to these institutional practice changes was $1580 per patient. CONCLUSIONS De-escalation in surgical and RAI utilization for low-risk papillary thyroid cancer according to 2015 ATA guidelines is associated with a substantial decrease in real-world costs.
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Papers by Kyle Blackburn