Publications

2021

Gandle, Cassandra, Frank I Scott, Akbar Waljee, Ravy K Vajravelu, Shubhada Sansgiry, and Jason K Hou. (2021) 2021. “Development and Validation of an Administrative Codes Algorithm to Identify Abdominal Surgery and Bowel Obstruction in Patients With Inflammatory Bowel Disease.”. Crohn’s & Colitis 360 3 (1): otab010. https://doi.org/10.1093/crocol/otab010.

BACKGROUND: Validated administrative codes (CPT and ICD) can permit the use of large databases to study diseases and outcomes. The aim of this study was to validate administrative codes for surgery and obstructive complications in patients with inflammatory bowel disease (IBD).

METHODS: We performed a retrospective study of IBD patients within the Veterans Affairs Health Administration (VA) from 2000 to 2015 with administrative codes for bowel surgery and complications validated by chart review. Positive predictive values (PPVs) and negative predictive value (NPV) were calculated.

RESULTS: The PPV for bowel surgery was 96.4%; PPV of obstruction codes for bowel obstruction was 80.5% (95% confidence interval: 69.1%, 89.2%).

CONCLUSIONS: CPT and ICD codes for abdominal surgery and obstructive complications can be accurately utilized in IBD patients in VA.

Scott, Frank I, Ravy K Vajravelu, Ronac Mamtani, Nicholas Bianchina, Najjia Mahmoud, Jason K Hou, Qufei Wu, Xingmei Wang, Kevin Haynes, and James D Lewis. (2021) 2021. “Association Between Statin Use at the Time of Intra-Abdominal Surgery and Postoperative Adhesion-Related Complications and Small-Bowel Obstruction.”. JAMA Network Open 4 (2): e2036315. https://doi.org/10.1001/jamanetworkopen.2020.36315.

IMPORTANCE: Adhesion-related complications (ARCs), including small-bowel obstruction, are common complications of intra-abdominal surgery. Statins, which have antifibrotic pleiotropic effects, inhibit adhesion formation in murine models but have not been assessed in humans.

OBJECTIVE: To assess whether statin use at the time of intra-abdominal surgery is associated with a reduction in ARCs.

DESIGN, SETTING, AND PARTICIPANTS: These 2 separate retrospective cohort studies (The Health Improvement Network [THIN] and Optum's Clinformatics Data Mart [Optum]) compared adults receiving statins with those not receiving statins at the time of intra-abdominal surgery. Individuals undergoing intra-abdominal surgery from January 1, 1996, to December 31, 2013, in the United Kingdom and from January 1, 2000, to December 31, 2016, in the US were included in the study. Those with obstructive events before surgery or a history of inflammatory bowel disease were excluded. Data analysis was performed from September 1, 2012, to November 24, 2020.

EXPOSURE: The primary exposure was statin use at the time of surgery.

MAIN OUTCOMES AND MEASURES: The primary outcome was ARCs, defined as small-bowel obstruction or need for adhesiolysis, occurring after surgery. Sensitivity analyses included statin use preceding but not concurrent with surgery, fibrate use, and angiotensin-converting enzyme inhibitor use. All analyses were adjusted for age, sex, and conditions associated with microvascular disease, such as hypertension, hyperlipidemia, obesity, and tobacco use; surgical approach and site; and diagnosis of a malignant tumor.

RESULTS: A total of 148 601 individuals met the inclusion criteria for THIN (mean [SD] age, 49.6 [17.7] years; 70.1% female) and 1 188 217 for Optum (mean [SD] age, 48.2 [16.4] years; 72.6% female). A total of 2060 participants (1.4%) experienced an ARC in THIN and 54 136 (4.6%) in Optum. Statin use at the time of surgery was associated with decreased risk of ARCs (THIN: adjusted hazard ratio [HR], 0.81; 95% CI, 0.71-0.92; Optum: adjusted HR, 0.92; 95% CI, 0.90-0.95). Similar associations were appreciated between statins and small-bowel obstruction (THIN: adjusted HR, 0.80; 95% CI, 0.70-0.92; Optum: adjusted HR, 0.88; 95% CI, 0.85-0.91).

CONCLUSIONS AND RELEVANCE: This study's findings suggest that, among individuals in 2 separate cohorts undergoing intra-abdominal surgery, statin use may be associated with a reduced risk of postoperative ARCs. Statins may represent an inexpensive, well-tolerated pharmacologic option for preventing ARCs.

Vajravelu, Ravy K, Lawrence Copelovitch, and Michelle R Denburg. (2021) 2021. “Reply.”. Clinical Gastroenterology and Hepatology : The Official Clinical Practice Journal of the American Gastroenterological Association 19 (9): 1994. https://doi.org/10.1016/j.cgh.2020.11.031.
Han, Samuel, Jennifer M Kolb, Patrick Hosokawa, Chloe Friedman, Charlie Fox, Frank I Scott, Christopher H Lieu, et al. (2021) 2021. “The Volume-Outcome Effect Calls for Centralization of Care in Esophageal Adenocarcinoma: Results From a Large National Cancer Registry.”. The American Journal of Gastroenterology 116 (4): 811-15. https://doi.org/10.14309/ajg.0000000000001046.

INTRODUCTION: Using the National Cancer Database, we assessed the relationship between facility overall esophageal adenocarcinoma (EAC) case volume and survival.

METHODS: We categorized facilities into volume quintiles based on annual EAC patient volume and performed a multivariable Cox proportional hazards regression between facility patient volume and survival.

RESULTS: In a cohort of 116,675 patients, facilities with higher vs lower (≥25 vs 1-4 cases) annual EAC patient volume demonstrated improved survival (adjusted hazard ratio: 0.80. 95% confidence interval: 0.70-0.91).

DISCUSSION: This robust volume-outcome effect calls for centralization of care for EAC patients at high annual case volume facilities.

Vajravelu, Ravy K, Lawrence Copelovitch, and Michelle R Denburg. (2021) 2021. “Reply.”. Clinical Gastroenterology and Hepatology : The Official Clinical Practice Journal of the American Gastroenterological Association 19 (9): 1994. https://doi.org/10.1016/j.cgh.2020.11.031.
Han, Samuel, Jennifer M Kolb, Patrick Hosokawa, Chloe Friedman, Charlie Fox, Frank I Scott, Christopher H Lieu, et al. (2021) 2021. “The Volume-Outcome Effect Calls for Centralization of Care in Esophageal Adenocarcinoma: Results From a Large National Cancer Registry.”. The American Journal of Gastroenterology 116 (4): 811-15. https://doi.org/10.14309/ajg.0000000000001046.

INTRODUCTION: Using the National Cancer Database, we assessed the relationship between facility overall esophageal adenocarcinoma (EAC) case volume and survival.

METHODS: We categorized facilities into volume quintiles based on annual EAC patient volume and performed a multivariable Cox proportional hazards regression between facility patient volume and survival.

RESULTS: In a cohort of 116,675 patients, facilities with higher vs lower (≥25 vs 1-4 cases) annual EAC patient volume demonstrated improved survival (adjusted hazard ratio: 0.80. 95% confidence interval: 0.70-0.91).

DISCUSSION: This robust volume-outcome effect calls for centralization of care for EAC patients at high annual case volume facilities.

Vajravelu, Ravy K, Lawrence Copelovitch, and Michelle R Denburg. (2021) 2021. “Reply.”. Clinical Gastroenterology and Hepatology : The Official Clinical Practice Journal of the American Gastroenterological Association 19 (9): 1994. https://doi.org/10.1016/j.cgh.2020.11.031.
Han, Samuel, Jennifer M Kolb, Patrick Hosokawa, Chloe Friedman, Charlie Fox, Frank I Scott, Christopher H Lieu, et al. (2021) 2021. “The Volume-Outcome Effect Calls for Centralization of Care in Esophageal Adenocarcinoma: Results From a Large National Cancer Registry.”. The American Journal of Gastroenterology 116 (4): 811-15. https://doi.org/10.14309/ajg.0000000000001046.

INTRODUCTION: Using the National Cancer Database, we assessed the relationship between facility overall esophageal adenocarcinoma (EAC) case volume and survival.

METHODS: We categorized facilities into volume quintiles based on annual EAC patient volume and performed a multivariable Cox proportional hazards regression between facility patient volume and survival.

RESULTS: In a cohort of 116,675 patients, facilities with higher vs lower (≥25 vs 1-4 cases) annual EAC patient volume demonstrated improved survival (adjusted hazard ratio: 0.80. 95% confidence interval: 0.70-0.91).

DISCUSSION: This robust volume-outcome effect calls for centralization of care for EAC patients at high annual case volume facilities.

Vajravelu, Ravy K, Lawrence Copelovitch, and Michelle R Denburg. (2021) 2021. “Reply.”. Clinical Gastroenterology and Hepatology : The Official Clinical Practice Journal of the American Gastroenterological Association 19 (9): 1994. https://doi.org/10.1016/j.cgh.2020.11.031.
Han, Samuel, Jennifer M Kolb, Patrick Hosokawa, Chloe Friedman, Charlie Fox, Frank I Scott, Christopher H Lieu, et al. (2021) 2021. “The Volume-Outcome Effect Calls for Centralization of Care in Esophageal Adenocarcinoma: Results From a Large National Cancer Registry.”. The American Journal of Gastroenterology 116 (4): 811-15. https://doi.org/10.14309/ajg.0000000000001046.

INTRODUCTION: Using the National Cancer Database, we assessed the relationship between facility overall esophageal adenocarcinoma (EAC) case volume and survival.

METHODS: We categorized facilities into volume quintiles based on annual EAC patient volume and performed a multivariable Cox proportional hazards regression between facility patient volume and survival.

RESULTS: In a cohort of 116,675 patients, facilities with higher vs lower (≥25 vs 1-4 cases) annual EAC patient volume demonstrated improved survival (adjusted hazard ratio: 0.80. 95% confidence interval: 0.70-0.91).

DISCUSSION: This robust volume-outcome effect calls for centralization of care for EAC patients at high annual case volume facilities.