Eum K.-D.,Harvard University |
Wang F.T.,Optum Epidemiology |
Schwartz J.,Harvard University |
Hersh C.P.,Harvard University |
And 8 more authors.
NeuroToxicology | Year: 2013
Background: Glutathione-S-transferase gene (. GST) polymorphisms can result in variable ability of these enzymes to remove electrophilic substrates. We investigated whether the GSTP1 Val105 and GSTM1 deletion polymorphisms modify the lead-cognitive function association. Methods: We used repeated measures analysis to compare the association between cumulative lead biomarkers-bone lead measured using K-shell X-Ray Fluorescence-and Mini-Mental State Exam (MMSE) score by GST variants, adjusted for covariates, among Normative Aging Study participants, a Boston-based prospective cohort of men. We had complete data for 698 men (providing 1292 observations) for GSTM1 analyses and 595 men (providing 1142 observations) for GSTP1 analyses. Results: A 15. μg/g higher tibia lead concentration (interquartile range of tibia lead) was associated with a 0.24 point decrement in MMSE score among GSTP1 Val105 variant carriers, which was significantly stronger than the association among men with only wild-type alleles (. p=. 0.01). The association among GSTP1 Val105 carriers was comparable to that of 3 years of age in baseline MMSE scores. The association between tibia lead and MMSE score appeared progressively steeper in participants with increasingly more GSTP1 Val105 alleles. A modest association between tibia lead and lower MMSE score was seen among participants with the GSTM1 deletion polymorphism. Neither of the glutathione S-transferase variants was independently associated with cognitive function, nor with lead biomarker measures. The results pertaining to patella lead were similar to those observed for tibia lead. Conclusion: Our results suggest that the GSTP1 Val105 polymorphism confers excess susceptibility to the cognitive effects of cumulative lead exposure. © 2013.
Dore D.D.,Center for Gerontology and Health Care Research |
Hussein M.,IMS Consulting |
Hoffman C.,Optum Epidemiology |
Pelletier E.M.,IMS Consulting |
And 3 more authors.
Current Medical Research and Opinion | Year: 2013
Objective: To estimate the association between exenatide BID use and acute pancreatitis across two claims-based studies. Research design and methods: We pooled two cohort studies within separate commercial health insurance databases. We included initiators of exenatide BID and all other antihyperglycemic drugs without prior pancreatitis from 2005-2008. Poisson regression models provided rate ratios (RRs) and 95% confidence intervals (CIs) of the association of exenatide BID with acute pancreatitis adjusted for quintiles of propensity scores. Main outcome measures: Primary inpatient diagnoses of acute pancreatitis with correction for misclassification via a validation sub-study. Results: There were 49,956 initiators of exenatide BID and 692,333 initiators of other antihyperglycemic drugs. Patients in the two studies were similar on many demographic and clinical characteristics. Exenatide BID initiators had a higher prevalence of diagnoses consistent with diabetes complications (e.g. peripheral neuropathy) and cardiovascular risk factors (e.g. hypertension). In both studies, current exenatide BID use was not associated with uncorrected outcomes of acute pancreatitis (pooled RR 1.0; CI 0.8-1.3). PPV correction resulted in a slightly higher point estimate for current use (pooled RR 1.3; CI 1.0-1.7) and past use (pooled RR 1.6; 95% CI 1.2-2.1). Conclusions: These data are consistent with little or no higher risk of acute pancreatitis associated with current exenatide BID use relative to nonuse. Although previous work identified non-causal mechanisms, an increased incidence of acute pancreatitis following cessation of treatment remains a possibility. Bias due to residual confounding or outcome misclassification may remain, and should be considered a potential explanation for these findings. © 2013 All rights reserved.
McCarthy N.L.,Centers for Disease Control and Prevention |
Gee J.,Centers for Disease Control and Prevention |
Lin N.D.,Optum Epidemiology |
Thyagarajan V.,Optum Epidemiology |
And 5 more authors.
Vaccine | Year: 2013
Introduction: As part of the Centers for Disease Control and Prevention's monitoring and evaluation activities for influenza vaccines, we examined relationships between influenza vaccination and selected outcomes in the 2009-2010 and 2010-2011 influenza seasons in a claims-based data environment. Methods: We included patients with claims for trivalent influenza vaccine (TIV) and/or 2009 pandemic influenza A H1N1 vaccine (H1N1) during the 2009-2010 and 2010-2011 influenza seasons. Patients were followed for several pre-specified outcomes identified in claims. Seizures and Guillain-Barré Syndrome were selected a priori for medical record confirmation. We estimated incidence rate ratios (IRR) using a self-controlled risk interval (SCRI) or a historical comparison design. Outcomes with elevated IRRs, not selected a priori for medical record review, were further investigated with review of claims histories surrounding the outcome date to determine whether the potential event could be ruled-out or attributed to other causes based on the pattern of medical care. Results: In the 2009-2010 season, no significant increased risks for outcomes following H1N1 vaccination were observed. Following TIV administration, the IRR for peripheral nervous system disorders and neuropathy was slightly elevated (1.07, 95% CI: 1.01-1.13). The IRR for anaphylaxis following TIV was 28.55 (95% CI: 3.57-228.44). After further investigation of claims histories, the majority of potential anaphylaxis cases had additional claims around the time of the event indicating alternate explanatory factors or diagnoses. In the 2010-2011 season following TIV administration, a non-significant elevated IRR for anaphylaxis was observed with no other significant outcome findings. Conclusion: After claims history review, we ultimately found no increased outcome risk following administration of 998,881 TIV and 538,257 H1N1 vaccine doses in the 2009-2010 season, and 1,158,932 TIV doses in the 2010-2011 season. © 2013.
PubMed | Optum Epidemiology, Brown University and Merck And Co.
Type: | Journal: Diabetes research and clinical practice | Year: 2016
Accurate measures of hypoglycemia within electronic health records (EHR) can facilitate clinical population management and research. We quantify the occurrence of serious and mild-to-moderate hypoglycemia in a large EHR database in the US, comparing estimates based only on structured data to those from structured data and natural language processing (NLP) of clinical notes.This cohort study included patients with type 2 diabetes identified from January 2009 through March 2014. We compared estimates of occurrence of hypoglycemia derived from diagnostic codes to those recorded within clinical notes and classified via NLP. Measures of hypoglycemia from only structured data (ICD-9 Algorithm), only note mentions (NLP Algorithm), and either structured data or notes (Combined Algorithm) were compared with estimates of the period prevalence, incidence rate, and event rate of hypoglycemia, overall and by seriousness.Of the 844,683 eligible patients, 119,695 had at least one recorded hypoglycemic event identified with ICD-9 or NLP. The period prevalence of hypoglycemia was 12.4%, 25.1%, and 32.2% for the ICD-9 Algorithm, NLP Algorithm, and Combined Algorithm, respectively. There were 6128 apparent non-serious events utilizing the ICD-9 Algorithm, which increased to 152,987 non-serious events within the Combined Algorithm.Ascertainment of events from clinical notes more than doubled the completeness of hypoglycemia capture overall relative to measures from structured data, and increased capture of non-serious events more than 20-fold. The structured data and clinical notes are complementary within the EHR, and both need to be considered in order to fully assess the occurrence of hypoglycemia.
PubMed | Optum Epidemiology, HealthCore Inc. and GSK Vaccines
Type: Journal Article | Journal: Pharmacoepidemiology and drug safety | Year: 2016
We validated procedure codes used in health insurance claims for reimbursement of rotavirus vaccination by comparing claims for monovalent live-attenuated human rotavirus vaccine (RV1) and live, oral pentavalent rotavirus vaccine (RV5) to medical records.Using administrative data from two commercially insured United States populations, we randomly sampled vaccination claims for RV1 and RV5 from a cohort of infants aged less than 1year from an ongoing post-licensure safety study of rotavirus vaccines. The codes for RV1 and RV5 found in claims were confirmed through medical record review. The positive predictive value (PPV) of the Current Procedural Terminology codes for RV1 and RV5 was calculated as the number of medical record-confirmed vaccinations divided by the number of medical records obtained.Medical record review confirmed 92 of 104 RV1 vaccination claims (PPV: 88.5%; 95% CI: 80.7-93.9%) and 98 of 113 RV5 vaccination claims (PPV: 86.7%; 95% CI: 79.1-92.4%). Among the 217 medical records abstracted, only three (1.4%) of vaccinations were misclassified in claims-all were RV5 misclassified as RV1. The medical records corresponding to 9 RV1 and 15 RV5 claims contained insufficient information to classify the type of rotavirus vaccine.Misclassification of rotavirus vaccines is infrequent within claims. The PPVs reported here are conservative estimates as those with insufficient information in the medical records were assumed to be incorrectly coded in the claims. Copyright 2016 John Wiley & Sons, Ltd.
PubMed | Souro Sanou Teaching Hospital, University of Witwatersrand, Healthcare Global, Taiwan Centers for Disease Control and 12 more.
Type: Journal Article | Journal: Vaccine | Year: 2016
Preterm birth is commonly defined as any birth before 37 weeks completed weeks of gestation. An estimated 15 million infants are born preterm globally, disproportionately affecting low and middle income countries (LMIC). It contributes directly to estimated one million neonatal deaths annually and is a significant contributor to childhood morbidity. However, in many clinical settings, the information available to calculate completed weeks of gestation varies widely. Accurate dating of the last menstrual period (LMP), as well as access to clinical and ultrasonographic evaluation are important components of gestational age assessment antenatally. This case definition assign levels of confidence to categorisation of births as preterm, utilising assessment modalities which may be available across different settings. These are designed to enable systematic safety evaluation of vaccine clinical trials and post-implementation programmes of immunisations in pregnancy.
PubMed | Optum Epidemiology, Otsuka America Pharmaceutical Inc., University of North Carolina at Charlotte and Truven Health Analytics
Type: | Journal: Drugs in context | Year: 2015
Risk evaluation and mitigation strategies (REMS), as mandated by the US Food and Drug Administration (FDA) for medications with the potential for harm, are increasingly incorporating rigid protocols for patient evaluation, but little is known about compliance with these programs. Despite the inherent limitations, data on administrative claims may provide an opportunity to investigate adherence to these programs.We assessed adherence to liver function test (LFT) requirements included in the REMS program for bosentan through use of administrative claims. Patients observed in the Optum Research Database who were initiators of bosentan from November 20, 2001 to March 31, 2013 were included. Adherence to LFTs was calculated using pharmacy claims for bosentan dispensation and medical claims for laboratory services, and was assessed at the time of drug initiation and within specified time intervals throughout follow-up.Of 742 patients, 523 (70.5%) had 1 qualifying LFT. Among patients with 12 dispensations, claims for LFTs at individual dispensations were 53.2-64.0%. Median proportion of dispensations with 1 LFT was 0.8 among patients with 6 (interquartile range, 0.7-1.0) or 12 (0.7-0.9) dispensations. Adherence was 90-100% for 33.3% of all initiators, whereas 29.3% of initiators were non-adherent (defined as <50% of on-therapy LFTs).Analyses of administrative claims suggest that the REMS program for bosentan may not have adequately guaranteed adherence to the programs monthly monitoring of LFTs. Such investigations of existing REMS programs may provide insight on how to accomplish more successful evaluation of REMS.
Danilack V.A.,Brown University |
Nunes A.P.,Optum Epidemiology |
Phipps M.G.,Brown University
American Journal of Obstetrics and Gynecology | Year: 2015
Objective Determining appropriate sites of care for any type of medical issue assumes successful matching of patient risks to facility capabilities and resources. In obstetrics, predicting patients who will have a need for additional resources beyond routine obstetric and neonatal care is difficult. Women without prenatal risk factors and their newborns may experience unexpected complications during delivery or postpartum. In this study, we report the risk of unexpected maternal and newborn complications among pregnancies without identified prenatal risk factors. Study Design We conducted a cross-sectional investigation utilizing US natality data to analyze 10 million birth certificate records from 2011 through 2013. We categorized pregnancies as low risk (no prenatal risk factors) or high risk (at least 1 prenatal risk factor) according to 19 demographic, medical, and pregnancy characteristics. We evaluated 21 individual unexpected or adverse intrapartum and postpartum outcomes in addition to a composite indicator of any adverse outcome. Results Among 10,458,616 pregnancies, 38% were identified as low risk and 62% were identified as high risk for unexpected complications. At least 1 unexpected complication was indicated on the birth certificate for 46% of all pregnancies, 29% of low-risk pregnancies, and 57% of high-risk pregnancies. While the risk for unexpected or adverse outcomes was greatly reduced for the low-risk group compared to the high-risk group overall and for several of the individual outcomes, low-risk pregnancies had higher risks of vacuum delivery, forceps delivery, meconium staining, and chorioamnionitis compared to high-risk pregnancies. Conclusion Of births, 29% identified to be low risk had an unexpected complication that would require nonroutine obstetric or neonatal care. Additionally, for select outcomes, risks were higher in the low-risk group compared to the group with identified risk factors. This information is important for planning location of birth and evaluating birthing centers and hospitals for necessary resources to ensure quality care and patient safety. © 2015 Elsevier Inc. All rights reserved.
PubMed | Optum Epidemiology, Brown University and Harvard University
Type: Journal Article | Journal: Annals of epidemiology | Year: 2016
The amount of immortal time bias in studies with nonfatal outcomes is unclear. To quantify the magnitude of bias from mishandling of immortal person-time in studies of nonfatal outcomes.We derived formulas for quantifying bias from misclassified or excluded immortal person-time in settings with nonfatal outcomes, assuming a constant rate of outcome. In the situation of misclassified or excluded immortal person-time, the quantification includes the immortal time and corresponding events mistakenly attributed to the exposed group (misclassified) or excluded from study (excluded) that must be attributed to the comparison group.With misclassified immortal person-time, the magnitude of bias varies according to the incidence rate ratio of immortal time and comparison group as well as the rate ratio of immortal time and exposed group: toward null for both ratios less than 1, no bias for both ratios equal to 1, away from null for both ratios greater than 1. For one ratio less than 1 and the other greater than 1, the direction and magnitude of bias can be obtained from the formula provided. With excluded immortal person-time, the magnitude of bias is associated with the incidence rate ratio of immortal time and comparison group: toward null for the ratio less than 1, no bias for the ratio equal to 1, and away from null for the ratio greater than 1.Bias due to immortal person-time in studies with nonfatal outcomes can vary widely and can be quantified under assumptions that apply to many studies.
Christopher Mast T.,Merck And Co. |
Wang F.T.,Optum Epidemiology |
Su S.,Optum Epidemiology |
Seeger J.D.,Optum Epidemiology |
Seeger J.D.,Harvard University
Pediatric Infectious Disease Journal | Year: 2015
Background: Rotavirus (RV) is the leading cause of severe acute gastroenteritis among young children. Since the US licensure of the pentavalent RV vaccine (RV5) and the monovalent RV vaccine (RV1), a decline of RV activity has been observed. Objective: To describe patterns of RV-related health care utilization among infants receiving RV vaccines (RVVs). Methods: A large national health insurance claims database was used to identify infants born from January 2002 through July 2011. From this cohort, infants were divided into three groups: (1) those who received a RVV, (2) those receiving a diphtheria, tetanus, and acellular pertussis (DTaP) vaccine before the introduction of RVV (February 2006), and (3) those receiving DTaP without a concurrent RVV during the period of RVV availability. Study outcomes were rotavirus gastroenteritis (RGE) and acute gastroenteritis. Longitudinal, seasonal RGE incidence patterns among the RVV cohort (n = 140,952) were compared with the referent DTaP-vaccine cohort (n = 131,529). Results: More than 91% of administered RVV were RV5. Mean peak incidence of RV medical encounters in RV-vaccinated infants was 95-96% lower than among DTaP-vaccinated infants who did not receive RVV. RGE incidence among the non-RV-vaccinated DTaP recipients in the RVV-available period (110 per 100,000 infants) was lower than among DTaP recipients in the pre-RVV period (151 per 100,000 infants). The highest RGE incidence in the 2007-2011 period was among older non-RV-vaccinated infants. Conclusions: Analysis of a national medical claims database indicates a sustained and substantial decrease in the seasonal RV medical claims pattern after the introduction of RVV. This analysis also reveals evidence of herd immunity, although unvaccinated infants continue to be at risk and contribute to smaller seasonal peaks in RV disease activity. © 2015 Wolters Kluwer Health, Inc. All rights reserved.