Laura Hou - Academia.edu (original) (raw)
Papers by Laura Hou
International Journal of Gynecological Cancer, Mar 1, 2018
Objectives: Complete lymphadenectomy may be omitted in selected cases in which the risk of lymph ... more Objectives: Complete lymphadenectomy may be omitted in selected cases in which the risk of lymph node spread is low (low-risk cancer). In this study, we aimed to study the various clinicopathologic variables affecting lymph node metastasis, to evaluate the incidence and distribution of pelvic lymph nodes (PLN) and paraaortic lymph node (PALN) metastases in endometrial cancer, and to study intraoperative and postoperative complications of pelvic and para-aortic lymphadenectomy. Methods: Our study included 78 patients with endometrial cancer between June 2005 and May 2011. The surgical procedure involved peritoneal cytology, total or radical hysterectomy, and bilateral salpingooophorectomy with pelvic and para-aortic lymphadenectomy. Statistical analysis was performed using Fisher's exact probability test, and P b 0.05 was considered statistically significant. Results: Positive LN metastasis was diagnosed in 41% of patients: 23% with PLN and PALN metastasis, 10.3% with PLN metastasis only, and 7.7% with PALN metastasis only. The most commonly involved PLN groups were internal iliac and obturator LNs (67.9% and 61.5%). In the aortic area, the most commonly involved group (66.6%) was the preaortic LNs (supra-and inframesentric). PLN and PALN metastasis in stages III and IV was significantly higher than in stages I and II. Myometrial invasion, cervical invasion, adnexal metastasis, and lymphovascular invasion were significantly correlated with PLN metastasis, while myometrial invasion, adnexal metastasis, and lymphovascular invasion were significantly correlated with PALN metastasis. Postoperative complications were observed in 50 patients (64.1%). The most common complication was pelvic lymphocysts in 46.1%. Ileus and deep venous thrombosis were seen in 7.6%. None of the complications resulted in death. Conclusions: Our findings suggest that systemic lymphadenectomy can be omitted in endometrial carcinoma patients who have favorable clinicopathological determinants (stage I, endometroid type, myometrial invasion b50%, and absence of lymphovascular invasion) because of low risk for LN metastasis and to avoid perioperative complications. However, these results should be confirmed in prospective large-scale, randomized clinical trials.
Pharmaceutical medicine, Jan 19, 2019
The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic pro... more The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic programs for evaluation of medical product safety. Research on outpatient antibiotic exposures, and Clostridium difficile infection (CDI) with non-user reference groups led us to expect a higher rate of CDI among outpatient clindamycin users vs penicillin users. We evaluated the ability of the Cohort Identification and Descriptive Analysis and Propensity Score Matching tools to identify a higher rate of CDI among clindamycin users. Methods: We matched new users of outpatient dispensings of oral clindamycin or penicillin from 13 Data Partners 1:1 on propensity score and followed them for up to 60 days for development of CDI. We used Cox proportional hazards regression stratified by Data Partner and matched pair to compare CDI incidence. Results: Propensity score models at 3 Data Partners had convergence warnings and a limited range of predicted values. We excluded these Data Partners despite adequate covariate balance after matching. From the 10 Data Partners where these models converged without warnings, we identified 807 919 new clindamycin users and 8 815 441 new penicillin users eligible for the analysis. The stratified analysis of 807 769 matched pairs included 840 events among clindamycin users and 290 among penicillin users (hazard ratio 2.90, 95% confidence interval 2.53, 3.31). Conclusions: This evaluation produced an expected result and identified several potential enhancements to the Propensity Score Matching tool. This study has important limitations. CDI risk may have been related to factors other than the inherent properties of the drugs, such as duration of use or subsequent exposures.
BMJ Medicine
ObjectiveTo measure the 90 day risk of arterial thromboembolism and venous thromboembolism among ... more ObjectiveTo measure the 90 day risk of arterial thromboembolism and venous thromboembolism among patients diagnosed with covid-19 in the ambulatory (ie, outpatient, emergency department, or institutional) setting during periods before and during covid-19 vaccine availability and compare results to patients with ambulatory diagnosed influenza.DesignRetrospective cohort study.SettingFour integrated health systems and two national health insurers in the US Food and Drug Administration's Sentinel System.ParticipantsPatients with ambulatory diagnosed covid-19 when vaccines were unavailable in the US (period 1, 1 April-30 November 2020; n=272 065) and when vaccines were available in the US (period 2, 1 December 2020-31 May 2021; n=342 103), and patients with ambulatory diagnosed influenza (1 October 2018-30 April 2019; n=118 618).Main outcome measuresArterial thromboembolism (hospital diagnosis of acute myocardial infarction or ischemic stroke) and venous thromboembolism (hospital dia...
Inflammatory Bowel Diseases
Background Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patient... more Background Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patients with ulcerative colitis (UC). With time, patients tend to lose response or become intolerant, necessitating switching to small cell biologics such as tofacitinib or vedolizumab. In this real-world study of a large, geographically diverse US population of TNF-experienced patients with UC, we evaluated the effectiveness and safety of newly initiating treatment with tofacitinib vs vedolizumab. Methods We conducted a cohort study using secondary data from a large US insurer (Anthem, Inc.). Our cohort included patients with UC newly initiating treatment with tofacitinib or vedolizumab. Patients were required to have evidence of treatment with anti-TNF inhibitors in the 6 months prior to cohort entry. The primary outcome was treatment persistence >52 weeks. Additionally, we evaluated the following secondary outcomes as additional measures of effectiveness and safety: (1) all-cause hospita...
Copyright It is not permitted to download or to forward/distribute the text or part of it without... more Copyright It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content licence (like
American Journal of Gastroenterology
American Journal of Gastroenterology
Pharmacoepidemiology and Drug Safety
Comprehensive R Archive Network (CRAN), Nov 16, 2017
BMJ Open
ObjectivesTo examine valsartan, losartan and irbesartan usage and switching patterns in the USA, ... more ObjectivesTo examine valsartan, losartan and irbesartan usage and switching patterns in the USA, UK, Canada and Denmark before and after July 2018, when the first Angiotensin-Receptor-Blocker (ARB) (valsartan) was recalled.DesignRetrospective cohort study.SettingUSA, Canadian administrative healthcare data, Danish National Prescription Registry and UK primary care electronic health records.ParticipantsPatients aged 18 years and older between January 2014 and December 2020.InterventionValsartan, losartan and irbesartan.Main outcomeMonthly percentages of individual ARB episodes, new users and switches to another ARB, ACE inhibitors (ACEI) or calcium channel blockers containing products.ResultsWe identified 10.8, 3.2, 1.8 and 1.2 million ARB users in the USA, UK, Canada and Denmark, respectively. Overall proportions of valsartan, losartan and irbesartan use were 18.4%, 67.9% and 5.2% in the USA; 3.1%, 48.3% and 10.2% in the UK, 16.3%, 11.4% and 18.3% in Canada, 1%, 93.5% and 0.6% in De...
JAMA
ImportanceThe incidence of arterial thromboembolism and venous thromboembolism in persons with CO... more ImportanceThe incidence of arterial thromboembolism and venous thromboembolism in persons with COVID-19 remains unclear.ObjectiveTo measure the 90-day risk of arterial thromboembolism and venous thromboembolism in patients hospitalized with COVID-19 before or during COVID-19 vaccine availability vs patients hospitalized with influenza.Design, Setting, and ParticipantsRetrospective cohort study of 41 443 patients hospitalized with COVID-19 before vaccine availability (April-November 2020), 44 194 patients hospitalized with COVID-19 during vaccine availability (December 2020-May 2021), and 8269 patients hospitalized with influenza (October 2018-April 2019) in the US Food and Drug Administration Sentinel System (data from 2 national health insurers and 4 regional integrated health systems).ExposuresCOVID-19 or influenza (identified by hospital diagnosis or nucleic acid test).Main Outcomes and MeasuresHospital diagnosis of arterial thromboembolism (acute myocardial infarction or ischemi...
Drug Safety, 2021
There have been reports of clinically relevant uterine bleeding events among women of reproductiv... more There have been reports of clinically relevant uterine bleeding events among women of reproductive age exposed to rivaroxaban. The aim of this study was to compare the risk of severe abnormal uterine bleeding (SAUB) resulting in transfusion or surgical intervention among women on rivaroxaban versus apixaban, dabigatran and warfarin. We conducted a retrospective cohort study in the FDA’s Sentinel System (10/2010–09/2015) among females aged 18+ years with venous thromboembolism (VTE), or atrial flutter/fibrillation (AF) who newly initiated a direct oral anticoagulant (DOAC; rivaroxaban, apixaban, dabigatran) or warfarin. We followed women from dispensing date until the earliest of transfusion or surgery following vaginal bleeding, disenrollment, exposure or study end date, or recorded death. We estimated hazard ratios (HRs) using Cox proportional hazards regression via propensity score stratification. Four pairwise comparisons were conducted for each intervention. Overall, there was an increased risk of surgical intervention with rivaroxaban when compared with dabigatran (HR 1.19; 95% CI 1.03–1.38), apixaban (1.23; 1.04–1.47), and warfarin (1.34; 1.22–1.47). No difference in risk for surgical intervention was observed for dabigatran–apixaban comparisons. Increased risk of transfusion was observed for rivaroxaban compared with dabigatran (1.49; 1.03–2.17) only. For patients with no gynecological history, rivaroxaban was associated with risk of surgical intervention compared with dabigatran (1.22; 1.05–1.42), apixaban (1.25; 1.04–1.49), and warfarin (1.36; 1.23–1.50). Our study found increased SAUB risk with rivaroxaban use compared with other DOACs or warfarin. Increased risk with rivaroxaban was present among women without underlying gynecological conditions. Women on anticoagulant therapy should be aware of a risk of SAUB.
Pharmacoepidemiology and Drug Safety, 2021
Health plan claims may provide complete longitudinal data for timely, real‐world population‐level... more Health plan claims may provide complete longitudinal data for timely, real‐world population‐level COVID‐19 assessment. However, these data often lack laboratory results, the standard for COVID‐19 diagnosis.
Pharmacoepidemiology and Drug Safety, 2021
Purpose: Lymphoma is a health outcome of interest for drug safety studies. Studies using administ... more Purpose: Lymphoma is a health outcome of interest for drug safety studies. Studies using administrative claims data require the accurate identification of lymphoma cases. We developed and validated an International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM)-based algorithm to identify lymphoma in healthcare claims data. Methods: We developed a three-component algorithm to identify patients aged ≥15 years who were newly diagnosed with Hodgkin (HL) or non-Hodgkin (NHL) lymphoma from January 2016 through July 2018 among members of four Data Partners within the FDA's Sentinel System. The algorithm identified potential cases as patients with ≥2 ICD-10-CM lymphoma diagnosis codes on
Pharmacoepidemiology and Drug Safety, 2020
Funding information The Sentinel System is sponsored by the U.S. Food and Drug Administration (FD... more Funding information The Sentinel System is sponsored by the U.S. Food and Drug Administration (FDA) to proactively monitor the safety of FDA-regulated medical products and complements other existing FDA safety surveillance capabilities. The Sentinel System is one piece of FDA's Sentinel Initiative, a long-term, multifaceted effort to develop a national electronic system. Sentinel Collaborators include Data and Academic Partners that provide access to healthcare data and ongoing scientific, technical, methodological, and organizational expertise. The Sentinel Coordinating Center is funded by the FDA through the Department of Health and Human Services (HHS) Contract number HHSF223201400030I. This project was funded by the FDA through HHS Mini-Sentinel contract number HHSF223200910006I.
Pharmacoepidemiology and Drug Safety, 2019
Background: Epidemiological study reporting is improving but is not transparent enough for easy e... more Background: Epidemiological study reporting is improving but is not transparent enough for easy evaluation or replication. One barrier is insufficient details about design elements in published studies. Methods: Using a previously conducted drug safety evaluation in claims as a test case, we investigated the impact of small changes in five key design elements on risk estimation. These elements are index day of incident exposure's determination of look-back or follow-up periods, exposure duration algorithms, heparin exposure exclusion, propensity score model variables, and Cox proportional hazard model stratification. We covaried these elements using a fractional factorial design, resulting in 24 risk estimates for one outcome. We repeated eight of these combinations for two additional outcomes. We measured design effects on cohort sizes, follow-up time, and risk estimates. Results: Small changes in specifications of index day and exposure algorithm affected the risk estimation process the most. They affected cohort size on average by 8 to 10%, follow-up time by up to 31%, and magnitude of log hazard ratios by up to 0.22. Other elements affected cohort before matching or risk estimate's precision but not its magnitude. Any change in design substantially altered the matched control-group subjects in 1:1 matching. Conclusions: Exposure-related design elements require attention from investigators initiating, evaluating, or wishing to replicate a study or from analysts standardizing definitions. The methods we developed, using factorial design and mapping design effect on causal estimation process, are applicable to planning of sensitivity analyses in similar studies.
Environmental health perspectives, Jan 29, 2018
Pharmacoepidemiology and drug safety, Jan 13, 2018
The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic... more The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic programs for evaluation of medical product safety. Research on outpatient antibiotic exposures, and Clostridium difficile infection (CDI) with non-user reference groups led us to expect a higher rate of CDI among outpatient clindamycin users vs penicillin users. We evaluated the ability of the Cohort Identification and Descriptive Analysis and Propensity Score Matching tools to identify a higher rate of CDI among clindamycin users. We matched new users of outpatient dispensings of oral clindamycin or penicillin from 13 Data Partners 1:1 on propensity score and followed them for up to 60 days for development of CDI. We used Cox proportional hazards regression stratified by Data Partner and matched pair to compare CDI incidence. Propensity score models at 3 Data Partners had convergence warnings and a limited range of predicted values. We excluded these Data Partners despite adequate cova...
International Journal of Gynecological Cancer, Mar 1, 2018
Objectives: Complete lymphadenectomy may be omitted in selected cases in which the risk of lymph ... more Objectives: Complete lymphadenectomy may be omitted in selected cases in which the risk of lymph node spread is low (low-risk cancer). In this study, we aimed to study the various clinicopathologic variables affecting lymph node metastasis, to evaluate the incidence and distribution of pelvic lymph nodes (PLN) and paraaortic lymph node (PALN) metastases in endometrial cancer, and to study intraoperative and postoperative complications of pelvic and para-aortic lymphadenectomy. Methods: Our study included 78 patients with endometrial cancer between June 2005 and May 2011. The surgical procedure involved peritoneal cytology, total or radical hysterectomy, and bilateral salpingooophorectomy with pelvic and para-aortic lymphadenectomy. Statistical analysis was performed using Fisher's exact probability test, and P b 0.05 was considered statistically significant. Results: Positive LN metastasis was diagnosed in 41% of patients: 23% with PLN and PALN metastasis, 10.3% with PLN metastasis only, and 7.7% with PALN metastasis only. The most commonly involved PLN groups were internal iliac and obturator LNs (67.9% and 61.5%). In the aortic area, the most commonly involved group (66.6%) was the preaortic LNs (supra-and inframesentric). PLN and PALN metastasis in stages III and IV was significantly higher than in stages I and II. Myometrial invasion, cervical invasion, adnexal metastasis, and lymphovascular invasion were significantly correlated with PLN metastasis, while myometrial invasion, adnexal metastasis, and lymphovascular invasion were significantly correlated with PALN metastasis. Postoperative complications were observed in 50 patients (64.1%). The most common complication was pelvic lymphocysts in 46.1%. Ileus and deep venous thrombosis were seen in 7.6%. None of the complications resulted in death. Conclusions: Our findings suggest that systemic lymphadenectomy can be omitted in endometrial carcinoma patients who have favorable clinicopathological determinants (stage I, endometroid type, myometrial invasion b50%, and absence of lymphovascular invasion) because of low risk for LN metastasis and to avoid perioperative complications. However, these results should be confirmed in prospective large-scale, randomized clinical trials.
Pharmaceutical medicine, Jan 19, 2019
The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic pro... more The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic programs for evaluation of medical product safety. Research on outpatient antibiotic exposures, and Clostridium difficile infection (CDI) with non-user reference groups led us to expect a higher rate of CDI among outpatient clindamycin users vs penicillin users. We evaluated the ability of the Cohort Identification and Descriptive Analysis and Propensity Score Matching tools to identify a higher rate of CDI among clindamycin users. Methods: We matched new users of outpatient dispensings of oral clindamycin or penicillin from 13 Data Partners 1:1 on propensity score and followed them for up to 60 days for development of CDI. We used Cox proportional hazards regression stratified by Data Partner and matched pair to compare CDI incidence. Results: Propensity score models at 3 Data Partners had convergence warnings and a limited range of predicted values. We excluded these Data Partners despite adequate covariate balance after matching. From the 10 Data Partners where these models converged without warnings, we identified 807 919 new clindamycin users and 8 815 441 new penicillin users eligible for the analysis. The stratified analysis of 807 769 matched pairs included 840 events among clindamycin users and 290 among penicillin users (hazard ratio 2.90, 95% confidence interval 2.53, 3.31). Conclusions: This evaluation produced an expected result and identified several potential enhancements to the Propensity Score Matching tool. This study has important limitations. CDI risk may have been related to factors other than the inherent properties of the drugs, such as duration of use or subsequent exposures.
BMJ Medicine
ObjectiveTo measure the 90 day risk of arterial thromboembolism and venous thromboembolism among ... more ObjectiveTo measure the 90 day risk of arterial thromboembolism and venous thromboembolism among patients diagnosed with covid-19 in the ambulatory (ie, outpatient, emergency department, or institutional) setting during periods before and during covid-19 vaccine availability and compare results to patients with ambulatory diagnosed influenza.DesignRetrospective cohort study.SettingFour integrated health systems and two national health insurers in the US Food and Drug Administration's Sentinel System.ParticipantsPatients with ambulatory diagnosed covid-19 when vaccines were unavailable in the US (period 1, 1 April-30 November 2020; n=272 065) and when vaccines were available in the US (period 2, 1 December 2020-31 May 2021; n=342 103), and patients with ambulatory diagnosed influenza (1 October 2018-30 April 2019; n=118 618).Main outcome measuresArterial thromboembolism (hospital diagnosis of acute myocardial infarction or ischemic stroke) and venous thromboembolism (hospital dia...
Inflammatory Bowel Diseases
Background Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patient... more Background Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patients with ulcerative colitis (UC). With time, patients tend to lose response or become intolerant, necessitating switching to small cell biologics such as tofacitinib or vedolizumab. In this real-world study of a large, geographically diverse US population of TNF-experienced patients with UC, we evaluated the effectiveness and safety of newly initiating treatment with tofacitinib vs vedolizumab. Methods We conducted a cohort study using secondary data from a large US insurer (Anthem, Inc.). Our cohort included patients with UC newly initiating treatment with tofacitinib or vedolizumab. Patients were required to have evidence of treatment with anti-TNF inhibitors in the 6 months prior to cohort entry. The primary outcome was treatment persistence >52 weeks. Additionally, we evaluated the following secondary outcomes as additional measures of effectiveness and safety: (1) all-cause hospita...
Copyright It is not permitted to download or to forward/distribute the text or part of it without... more Copyright It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content licence (like
American Journal of Gastroenterology
American Journal of Gastroenterology
Pharmacoepidemiology and Drug Safety
Comprehensive R Archive Network (CRAN), Nov 16, 2017
BMJ Open
ObjectivesTo examine valsartan, losartan and irbesartan usage and switching patterns in the USA, ... more ObjectivesTo examine valsartan, losartan and irbesartan usage and switching patterns in the USA, UK, Canada and Denmark before and after July 2018, when the first Angiotensin-Receptor-Blocker (ARB) (valsartan) was recalled.DesignRetrospective cohort study.SettingUSA, Canadian administrative healthcare data, Danish National Prescription Registry and UK primary care electronic health records.ParticipantsPatients aged 18 years and older between January 2014 and December 2020.InterventionValsartan, losartan and irbesartan.Main outcomeMonthly percentages of individual ARB episodes, new users and switches to another ARB, ACE inhibitors (ACEI) or calcium channel blockers containing products.ResultsWe identified 10.8, 3.2, 1.8 and 1.2 million ARB users in the USA, UK, Canada and Denmark, respectively. Overall proportions of valsartan, losartan and irbesartan use were 18.4%, 67.9% and 5.2% in the USA; 3.1%, 48.3% and 10.2% in the UK, 16.3%, 11.4% and 18.3% in Canada, 1%, 93.5% and 0.6% in De...
JAMA
ImportanceThe incidence of arterial thromboembolism and venous thromboembolism in persons with CO... more ImportanceThe incidence of arterial thromboembolism and venous thromboembolism in persons with COVID-19 remains unclear.ObjectiveTo measure the 90-day risk of arterial thromboembolism and venous thromboembolism in patients hospitalized with COVID-19 before or during COVID-19 vaccine availability vs patients hospitalized with influenza.Design, Setting, and ParticipantsRetrospective cohort study of 41 443 patients hospitalized with COVID-19 before vaccine availability (April-November 2020), 44 194 patients hospitalized with COVID-19 during vaccine availability (December 2020-May 2021), and 8269 patients hospitalized with influenza (October 2018-April 2019) in the US Food and Drug Administration Sentinel System (data from 2 national health insurers and 4 regional integrated health systems).ExposuresCOVID-19 or influenza (identified by hospital diagnosis or nucleic acid test).Main Outcomes and MeasuresHospital diagnosis of arterial thromboembolism (acute myocardial infarction or ischemi...
Drug Safety, 2021
There have been reports of clinically relevant uterine bleeding events among women of reproductiv... more There have been reports of clinically relevant uterine bleeding events among women of reproductive age exposed to rivaroxaban. The aim of this study was to compare the risk of severe abnormal uterine bleeding (SAUB) resulting in transfusion or surgical intervention among women on rivaroxaban versus apixaban, dabigatran and warfarin. We conducted a retrospective cohort study in the FDA’s Sentinel System (10/2010–09/2015) among females aged 18+ years with venous thromboembolism (VTE), or atrial flutter/fibrillation (AF) who newly initiated a direct oral anticoagulant (DOAC; rivaroxaban, apixaban, dabigatran) or warfarin. We followed women from dispensing date until the earliest of transfusion or surgery following vaginal bleeding, disenrollment, exposure or study end date, or recorded death. We estimated hazard ratios (HRs) using Cox proportional hazards regression via propensity score stratification. Four pairwise comparisons were conducted for each intervention. Overall, there was an increased risk of surgical intervention with rivaroxaban when compared with dabigatran (HR 1.19; 95% CI 1.03–1.38), apixaban (1.23; 1.04–1.47), and warfarin (1.34; 1.22–1.47). No difference in risk for surgical intervention was observed for dabigatran–apixaban comparisons. Increased risk of transfusion was observed for rivaroxaban compared with dabigatran (1.49; 1.03–2.17) only. For patients with no gynecological history, rivaroxaban was associated with risk of surgical intervention compared with dabigatran (1.22; 1.05–1.42), apixaban (1.25; 1.04–1.49), and warfarin (1.36; 1.23–1.50). Our study found increased SAUB risk with rivaroxaban use compared with other DOACs or warfarin. Increased risk with rivaroxaban was present among women without underlying gynecological conditions. Women on anticoagulant therapy should be aware of a risk of SAUB.
Pharmacoepidemiology and Drug Safety, 2021
Health plan claims may provide complete longitudinal data for timely, real‐world population‐level... more Health plan claims may provide complete longitudinal data for timely, real‐world population‐level COVID‐19 assessment. However, these data often lack laboratory results, the standard for COVID‐19 diagnosis.
Pharmacoepidemiology and Drug Safety, 2021
Purpose: Lymphoma is a health outcome of interest for drug safety studies. Studies using administ... more Purpose: Lymphoma is a health outcome of interest for drug safety studies. Studies using administrative claims data require the accurate identification of lymphoma cases. We developed and validated an International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM)-based algorithm to identify lymphoma in healthcare claims data. Methods: We developed a three-component algorithm to identify patients aged ≥15 years who were newly diagnosed with Hodgkin (HL) or non-Hodgkin (NHL) lymphoma from January 2016 through July 2018 among members of four Data Partners within the FDA's Sentinel System. The algorithm identified potential cases as patients with ≥2 ICD-10-CM lymphoma diagnosis codes on
Pharmacoepidemiology and Drug Safety, 2020
Funding information The Sentinel System is sponsored by the U.S. Food and Drug Administration (FD... more Funding information The Sentinel System is sponsored by the U.S. Food and Drug Administration (FDA) to proactively monitor the safety of FDA-regulated medical products and complements other existing FDA safety surveillance capabilities. The Sentinel System is one piece of FDA's Sentinel Initiative, a long-term, multifaceted effort to develop a national electronic system. Sentinel Collaborators include Data and Academic Partners that provide access to healthcare data and ongoing scientific, technical, methodological, and organizational expertise. The Sentinel Coordinating Center is funded by the FDA through the Department of Health and Human Services (HHS) Contract number HHSF223201400030I. This project was funded by the FDA through HHS Mini-Sentinel contract number HHSF223200910006I.
Pharmacoepidemiology and Drug Safety, 2019
Background: Epidemiological study reporting is improving but is not transparent enough for easy e... more Background: Epidemiological study reporting is improving but is not transparent enough for easy evaluation or replication. One barrier is insufficient details about design elements in published studies. Methods: Using a previously conducted drug safety evaluation in claims as a test case, we investigated the impact of small changes in five key design elements on risk estimation. These elements are index day of incident exposure's determination of look-back or follow-up periods, exposure duration algorithms, heparin exposure exclusion, propensity score model variables, and Cox proportional hazard model stratification. We covaried these elements using a fractional factorial design, resulting in 24 risk estimates for one outcome. We repeated eight of these combinations for two additional outcomes. We measured design effects on cohort sizes, follow-up time, and risk estimates. Results: Small changes in specifications of index day and exposure algorithm affected the risk estimation process the most. They affected cohort size on average by 8 to 10%, follow-up time by up to 31%, and magnitude of log hazard ratios by up to 0.22. Other elements affected cohort before matching or risk estimate's precision but not its magnitude. Any change in design substantially altered the matched control-group subjects in 1:1 matching. Conclusions: Exposure-related design elements require attention from investigators initiating, evaluating, or wishing to replicate a study or from analysts standardizing definitions. The methods we developed, using factorial design and mapping design effect on causal estimation process, are applicable to planning of sensitivity analyses in similar studies.
Environmental health perspectives, Jan 29, 2018
Pharmacoepidemiology and drug safety, Jan 13, 2018
The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic... more The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic programs for evaluation of medical product safety. Research on outpatient antibiotic exposures, and Clostridium difficile infection (CDI) with non-user reference groups led us to expect a higher rate of CDI among outpatient clindamycin users vs penicillin users. We evaluated the ability of the Cohort Identification and Descriptive Analysis and Propensity Score Matching tools to identify a higher rate of CDI among clindamycin users. We matched new users of outpatient dispensings of oral clindamycin or penicillin from 13 Data Partners 1:1 on propensity score and followed them for up to 60 days for development of CDI. We used Cox proportional hazards regression stratified by Data Partner and matched pair to compare CDI incidence. Propensity score models at 3 Data Partners had convergence warnings and a limited range of predicted values. We excluded these Data Partners despite adequate cova...