Comparative Safety of Sleeve Gastrectomy and Roux-en-Y: A Propensity Score Analysis.

BACKGROUND: Use of bariatric surgery has increased dramatically in the USA. However, there are growing concerns regarding the safety outcomes of different bariatric procedures. We aim to compare the safety of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), which includes hospital readmissions, emergency room (ER) visits, gastrointestinal bleeding, and revisional surgery. METHODS: A retrospective cohort analysis was conducted for adults (≥ 18 years) who received SG and RYGB in the USA. We used Truven MarketScan Commercial and Medicare supplemental claims databases from January 1, 2005, to October 1, 2015. To adjust for baseline demographic and clinical characteristics, we used stabilized inverse probability of treatment weighting using propensity score. Cox proportional hazard models was used to compare safety outcomes between SG and RYGB after bariatric surgery. RESULTS: A total of 194,248 patients met inclusion criteria; 79,813 patients (41%) received SG and 114,435 patients (59%) received RYGB. The use of SG was associated with a significantly lower 30-day hospital readmission rate [adjusted hazard ratios (aHRs) 0.77; 95% confidence interval (CI), 0.74-0.81] and ER visits [aHR, 0.82; 95% CI, 0.80-0.83], and decreased risk of gastrointestinal bleeding [aHR, 0.87; 95% CI, 0.78-0.98] compared to RYGB. However, SG was associated with an increased risk of revisional surgery, compared to RYGB [aHR,1.21; 95% CI, 1.08-1.35]. CONCLUSIONS: Among patients receiving bariatric surgery in a real-world setting, SG was associated with lower complication rate but a higher risk of revisional surgery compared to RYGB. Further longitudinal studies are needed to assess long-term findings.

Challenges facing drug utilization research in the Latin American region.

PURPOSE: The International Society of Pharmacoepidemiology (ISPE) in collaboration with the Latin America Drug Utilization Research Group (LatAm DURG), the Medicines Utilization Research in Africa (MURIA) group, and the Uppsala Monitoring Center, is leading an initiative to understand challenges to drug utilization research (DUR) in the Latin American (LatAm) and African regions with the goal of communicating results and proposing solutions to these challenges in four scientific publications. The purpose of this first manuscript is to identify the main challenges associated with DUR in the LatAm region. METHODS: Drug utilization (DU) researchers in the LatAm region voluntarily participated in multiple discussions, contributed with local data and reviewed successive drafts and the final manuscript. Additionally, we carried out a literature review to identify the most relevant publications related to DU studies from the LatAm region. RESULTS: Multiple challenges were identified in the LatAm region for DUR including socioeconomic inequality, access to medical care, complexity of the healthcare system, limited investment in research and development, limited institutional and organization resources, language barriers, limited health education and literacy. Further, there is limited use of local DUR data by decision makers particularly in the identification of emerging health needs coming from social and demographic transitions. CONCLUSIONS: The LatAm region faces challenges to DUR which are inherent in the healthcare and political systems, and potential solutions should target changes to the system.

Increased Risk of Acute Pancreatitis with Codeine Use in Patients with a History of Cholecystectomy.

BACKGROUND: Codeine has a spasmodic effect on sphincter of Oddi and is suspected to cause acute pancreatitis in patients with a history of cholecystectomy. AIMS: To assess the association between codeine use and acute pancreatitis in patients with a previous cholecystectomy. METHODS: We conducted a retrospective nested case-control study using the 2005-2015 MarketScan® Commercial Claims and Encounters Database. The cohort included patients aged 18-64; cohort entry began 365 days after cholecystectomy. Odds ratios (ORs) and 95% CIs for acute pancreatitis hospitalization were estimated comparing use of codeine with non-use of codeine. In a secondary analysis, use of codeine was compared with an active comparator: use of non-steroidal anti-inflammatory drugs (NSAIDs). RESULTS: Of the 664,083 patients included in the cohort, 1707 patients were hospitalized for acute pancreatitis (incidence 1.1 per 1000 person-years) and were matched to 17,063 controls. Compared with non-use of codeine, use of codeine was associated with an increased risk of acute pancreatitis (OR 2.67; 95% CI 1.63, 4.36), particularly elevated in the first 15 days of codeine use (OR 5.37; 95% CI 2.70, 10.68). Compared with use of NSAIDs, use of codeine was also associated with an increased risk of acute pancreatitis (OR 2.64; 95% CI 1.54, 4.52). CONCLUSION: Codeine is associated with an increased risk of acute pancreatitis in patients who have previously undergone cholecystectomy; greater clinician awareness of this association is needed.

High Generic Drug Prices and Market Competition: A Retrospective Cohort Study.

BACKGROUND: Prices for some generic drugs have increased in recent years, adversely affecting patients who rely on them. OBJECTIVE: To determine the association between market competition levels and the change in generic drug prices in the United States. DESIGN: Retrospective cohort study. SETTING: Prescription claims from commercial health plans between 2008 and 2013. MEASUREMENTS: The 5.5 years of data were divided into 11 study periods of 6 months each. The Herfindahl-Hirschman Index (HHI)-calculated by summing the squares of individual manufacturers' market shares, with higher values indicating a less competitive market-and average drug prices were estimated for the generic drugs in each period. The HHI value estimated in the baseline period (first half of 2008) was modeled as a fixed covariate. Models estimated price changes over time by level of competition, adjusting for drug shortages, market size, and dosage forms. RESULTS: From 1.08 billion prescription claims, a cohort of 1120 generic drugs was identified. After adjustment, drugs with quadropoly (HHI value of 2500, indicating relatively high levels of competition), duopoly (HHI value of 5000), near-monopoly (HHI value of 8000), and monopoly (HHI value of 10 000) levels of baseline competition were associated with price changes of -31.7% (95% CI, -34.4% to -28.9%), -11.8% (CI, -18.6% to -4.4%), 20.1% (CI, 5.5% to 36.6%), and 47.4% (CI, 25.4% to 73.2%), respectively, over the study period. LIMITATION: Study findings may not be generalizable to drugs that became generic after 2008. CONCLUSION: Market competition levels were associated with a change in generic drug prices. Such measurements may be helpful in identifying older prescription drugs at higher risk for price change in the future. PRIMARY FUNDING SOURCE: None.

Combining adverse pregnancy and perinatal outcomes for women exposed to antiepileptic drugs during pregnancy, using a latent trait model.

BACKGROUND: Application of latent variable models in medical research are becoming increasingly popular. A latent trait model is developed to combine rare birth defect outcomes in an index of infant morbidity. METHODS: This study employed four statewide, retrospective 10-year data sources (1999 to 2009). The study cohort consisted of all female Florida Medicaid enrollees who delivered a live singleton infant during study period. Drug exposure was defined as any exposure to Antiepileptic drugs (AEDs) during pregnancy. Mothers with no AED exposure served as the AED unexposed group for comparison. Four adverse outcomes, birth defect (BD), abnormal condition of new born (ACNB), low birth weight (LBW), and pregnancy and obstetrical complication (PCOC), were examined and combined using a latent trait model to generate an overall severity index. Unidimentionality, local independence, internal homogeneity, and construct validity were evaluated for the combined outcome. RESULTS: The study cohort consisted of 3183 mother-infant pairs in total AED group, 226 in the valproate only subgroup, and 43,956 in the AED unexposed group. Compared to AED unexposed group, the rate of BD was higher in both the total AED group (12.8% vs. 10.5%, P < .0001), and the valproate only subgroup (19.6% vs. 10.5%, P < .0001). The combined outcome was significantly correlated with the length of hospital stay during delivery in both the total AED group (Rho = 0.24, P < .0001) and the valproate only subgroup (Rho = 0.16, P = .01). The mean score for the combined outcome in the total AED group was significantly higher (2.04 ± 0.02 vs. 1.88 ± 0.01, P < .0001) than AED unexposed group, whereas the valproate only subgroup was not. CONCLUSIONS: Latent trait modeling can be an effective tool for combining adverse pregnancy and perinatal outcomes to assess prenatal exposure to AED, but evaluation of the selected components is essential to ensure the validity of the combined outcome.

Stimulant use following the publicity of cardiovascular safety and the introduction of patient medication guides.

PURPOSE: To explore changes in stimulant utilization and pre-treatment electrocardiography (ECG) screening in response to cardiovascular (CV) safety concerns. METHODS: Two source populations were established from Florida Medicaid Fee-for-service beneficiaries between 2001 and 2008: approximately 44 571 newly diagnosed attention deficit/hyperactivity disorder patients and 33 000 new stimulant users. Time-series design and Joinpoint analysis were used to describe monthly trend changes in stimulant initiation, persistence, dosing, and pre-treatment ECG screening. RESULTS: Initial and maintenance daily dose declined 6 mg (95% confidence interval [CI] -14 to -1.9) methylphenidate (MPH) equivalent dose from a steady 27 mg after Canada withdrew Adderall XR in February 2005; the trend rebounded to a daily dose of 23 mg, after the remarketing of Adderall XR and a debate in the US over issuing a boxed warning on stimulant CV safety in early 2006. Monthly initiation increased 3.9% (CI -1.0 to 9.1) after the boxed warning debate to 54 per 100 patients per month (CI 44 to 68), but declined 2.4% (CI -3.6 to -1.2) after requirement of medication guides in February 2007. Monthly ECG screening increased 3.2% (CI 2.3 to 4.2) after Adderall XR withdrawal and further increased 13% (CI 4 to 23) after the American Heart Association recommended pre-treatment ECG screening to 40 per 100 patients per month (CI 17 to 48). CONCLUSIONS: The first signal of stimulant CV safety concerns was followed by varying responses depending on the outcome measure used, suggesting that patients and physicians responded at different times after the publicity of safety concerns. Clinical consequences of the changes are uncertain. Copyright © 2015 John Wiley & Sons, Ltd.

Application of multicategory exposure marginal structural models to investigate the association between long-acting beta-agonists and prescribing of oral corticosteroids for asthma exacerbations in the Clinical Practice Research Datalink.

OBJECTIVE: To examine the comparative effectiveness of inhaled long-acting beta-agonist (LABA), inhaled corticosteroid (ICS), and ICS/LABA combinations. METHODS: We used a retrospective cohort design of patients older than 12 years with asthma diagnosis in the Clinical Practice Research Datalink to evaluate asthma-related morbidity measured by oral corticosteroid (OCS) initiation within 12 months of initiating LABAs, ICSs, or ICSs/LABAs. Asthma severity 12 months before drug initiation (use of OCSs, asthma-related hospital or emergency department visits, and number of short-acting beta-agonist prescriptions) and during follow-up (short-acting beta-agonist prescriptions and total number of asthma drug classes) was adjusted as a time-varying variable via marginal structural models. RESULTS: A total of 51,103 patients with asthma were followed for 12 months after receiving first prescription for study drugs from 1993 to 2010. About 92% initiated ICSs, 1% initiated LABAs, and 7% initiated ICSs/LABAs. Compared with ICSs, LABAs were associated with a 10% increased risk of asthma exacerbations requiring short courses of OCSs (hazard ratio [HR] 1.10; 95% confidence interval [CI] 1.07-1.18). ICS/LABA initiators were 62% less likely than ICS initiators (HR 0.38; 95% CI 0.12-0.66) and 50% less likely than LABA initiators to receive OCS prescriptions for asthma exacerbations (HR 0.50; 95% CI 0.14-0.78). CONCLUSIONS: In concordance with current asthma management guidelines, inhaled LABAs should not be prescribed as monotherapy to patients with asthma. The findings suggest the presence of time-dependent confounding by asthma severity, which was accounted for by the marginal structural model.

Pediatric exclusivity: evolving legislation and novel complexities within pediatric therapeutic development.

OBJECTIVE: To review the successes and omissions of the Food and Drug Administration (FDA) pediatric exclusivity incentive. DATA SOURCES: Pediatric drug development receives less attention and funding than drug development targeting adults resulting in fewer appropriately labeled pediatric drugs. Newly introduced legislation aims to correct this deficit using market exclusivity incentives. Under the Food and Drug Administration Modernization Act (FDAMA, 1997), the FDA established the exclusivity principle. This legislation was renewed and amended in 2007 under Food and Drug Administration Amendments Act (FDAAA) allowing drug companies to receive a 6-month patent extension for initiating clinical investigation in pediatric populations. Fostering improved knowledge in pediatric indications and dosing is the motivating force behind this program. STUDY SELECTION AND DATA EXTRACTION: We examined drugs granted exclusivity through FDA published database as well as relevant drug labeling and postmarket safety studies. Our examination shows that studies conducted in support of patent protection are often not designed to meet current pediatric needs. CONCLUSION: Amendments to FDAAA are needed to ensure that studies approved for exclusivity strive to meet the following requirements: relevant pediatric clinical indication ; disease addressed should represent a significant disease burden to the appropriate population; important age ranges should be covered; studies should not be allowed when a safety signal is identified prior to initiation of the study; and trials where endpoints are successfully achieved providing considerable contribution to pediatric dosing knowledge or result in labeling changes may gain an additional incentive.

Evaluating the impact of database heterogeneity on observational study results.

Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications. In this paper, we systematically study heterogeneity among databases, holding other study methods constant, by exploring relative risk estimates for 53 drug-outcome pairs and 2 widely used study designs (cohort studies and self-controlled case series) across 10 observational databases. When holding the study design constant, our analysis shows that estimated relative risks range from a statistically significant decreased risk to a statistically significant increased risk in 11 of 53 (21%) of drug-outcome pairs that use a cohort design and 19 of 53 (36%) of drug-outcome pairs that use a self-controlled case series design. This exceeds the proportion of pairs that were consistent across databases in both direction and statistical significance, which was 9 of 53 (17%) for cohort studies and 5 of 53 (9%) for self-controlled case series. Our findings show that clinical studies that use observational databases can be sensitive to the choice of database. More attention is needed to consider how the choice of data source may be affecting results.

Male breast cancer and 5α-reductase inhibitors finasteride and dutasteride.

PURPOSE: We examined the association between 5α-reductase inhibitors and male breast cancer. MATERIALS AND METHODS: Study participants were men 40 to 85 years old, with prescription and medical coverage, enrolled in the United States IMS LifeLink™ Health Plan claims database between 2001 and 2009. Cases required a primary breast cancer diagnosis (ICD-9-CM 175.x) on 2 different dates and a procedural code for mastectomy or lumpectomy/partial mastectomy with evidence of continuous care (radiation/chemotherapy or diagnoses in 2 or more months). Eligible controls were within 5 years in age and had duration of prior health care enrollment within 6 weeks. Risk set sampling selected 20 controls per case. We assessed the rate ratio for male breast cancer with 5α-reductase inhibitor exposure using conditional logistic regression. Analyses were stratified by duration of health care enrollment before diagnosis (1 year or more, 2 years or more and 3 years or more), each incremental 180 and 365 days of cumulative 5α-reductase inhibitor exposure, and period specific time frames before diagnosis (years 1, 2 and 3). RESULTS: We identified 339 breast cancer cases matched to 6,780 controls. No statistically significant associations were observed between 5α-reductase inhibitors and breast cancer regardless of exposure assessment before the index date (1 year or more-RR 0.70, 95% CI 0.34-1.45; 2 years or more-RR 0.59, 95% CI 0.24-1.48; or 3 years or more-RR 0.75, 95% CI 0.27-2.10). Each subsequent 180 days (RR 1.02, 95% CI 0.67-1.53) and 365 days (RR 1.03, 95% CI 0.45-2.37) of cumulative 5α-reductase inhibitor therapy and period specific rate ratios also showed null associations. CONCLUSIONS: The lack of an association in our study suggests that the development of breast cancer should not influence the prescribing of 5α-reductase inhibitor therapy.

Risk of venous thromboembolism in women with polycystic ovary syndrome: a population-based matched cohort analysis.

BACKGROUND: There is an increased risk of venous thromboembolism among women taking oral contraceptives. However, whether there is an additional risk among women with polycystic ovary syndrome (PCOS) is unknown. METHODS: We developed a population-based cohort from the IMS LifeLink Health Plan Claims Database, which includes managed care organizations in the United States. Women aged 18-46 years taking combined oral contraceptives and who had a claim for PCOS (n = 43 506) were matched, based on a propensity score, to control women (n = 43 506) taking oral contraceptives. Venous thromboembolism was defined using administrative coding and use of anticoagulation. We used Cox proportional hazards models to assess the relative risk (RR) of venous thromboembolism among users of combined oral contraceptives with and without PCOS. RESULTS: The incidence of venous thromboembolism among women with PCOS was 23.7/10 000 person-years, while that for matched controls was 10.9/10 000 person-years. Women with PCOS taking combined oral contraceptives had an RR for venous thromboembolism of 2.14 (95% confidence interval [CI] 1.41-3.24) compared with other contraceptive users. The incidence of venous thromboembolism was 6.3/10 000 person-years among women with PCOS not taking oral contraceptives; the incidence was 4.1/10 000 person-years among matched controls. The RR of venous thromboembolism among women with PCOS not taking oral contraceptives was 1.55 (95% CI 1.10-2.19). INTERPRETATION: We found a 2-fold increased risk of venous thromboembolism among women with PCOS who were taking combined oral contraceptives and a 1.5-fold increased risk among women with PCOS not taking oral contraceptives. Physicians should consider the increased risk of venous thromboembolism when prescribing contraceptive therapy to women with PCOS.

Risk of acute kidney injury associated with the use of fluoroquinolones.

BACKGROUND: Case reports indicate that the use of fluoroquinolones may lead to acute kidney injury. We studied the association between the use of oral fluoroquinolones and acute kidney injury, and we examined interaction with renin-angiotensin-system blockers. METHODS: We formed a nested cohort of men aged 40-85 enrolled in the United States IMS LifeLink Health Plan Claims Database between 2001 and 2011. We defined cases as men admitted to hospital for acute kidney injury, and controls were admitted to hospital with a different presenting diagnosis. Using risk-set sampling, we matched 10 controls to each case based on hospital admission, calendar time (within 6 wk), cohort entrance (within 6 wk) and age (within 5 yr). We used conditional logistic regression to assess the rate ratio (RR) for acute kidney injury with current, recent and past use of fluoroquinolones, adjusted by potential confounding variables. We repeated this analysis with amoxicillin and azithromycin as controls. We used a case-time-control design for our secondary analysis. RESULTS: We identified 1292 cases and 12 651 matched controls. Current fluoroquinolone use had a 2.18-fold (95% confidence interval [CI] 1.74-2.73) higher adjusted RR of acute kidney injury compared with no use. There was no association between acute kidney injury and recent (adjusted RR 0.87, 95% CI 0.66-1.16) or past (RR 0.86, 95% CI 0.66-1.12) use. The absolute increase in acute kidney injury was 6.5 events per 10 000 person-years. We observed 1 additional case per 1529 patients given fluoroquinolones or per 3287 prescriptions dispensed. The dual use of fluoroquinolones and renin-angiotensin-system blockers had an RR of 4.46 (95% CI 2.84-6.99) for acute kidney injury. Our case-time-control analysis confirmed an increased risk of acute kidney injury with fluoroquinolone use (RR 2.16, 95% CI 1.52-3.18). The use of amoxicillin or azithromycin was not associated with acute kidney injury. INTERPRETATION: We found a small, but significant, increased risk of acute kidney injury among men with the use of oral fluoroquinolones, as well as a significant interaction between the concomitant use of fluoroquinolones and renin-angiotensin-system blockers.

Polycystic ovary syndrome and combined oral contraceptive use: a comparison of clinical practice in the United States to treatment guidelines.

The October 2010 ESHRE/ASRM polycystic ovary syndrome (PCOS) workshop concluded: (1) all combined oral contraceptives (COC) appear to have equal efficacy for PCOS, (2) addition of antiandrogens (spironolactone) to COCs has little treatment benefit and (3) metformin does not improve the live-birth rate and should only be used with impaired glucose tolerance. We compared these guidelines to current practice in the United States IMS claims-database. Time-series analyses were conducted by calendar-year in women with PCOS to evaluate prescribing preferences for COCs, concomitant use of spironolactone, and utilization of metformin. Trends were analyzed with linear regression. Our cohort included 1.6 million women taking COCs, 46 780 with a PCOS claim. Drospirenone utilization increased by 1.52% (SE:0.48%, p = 0.007) per-year more in women with PCOS (4.16%, SE:0.45%, p < 0.001) than in women without PCOS (2.64%, SE:0.17%, p < 0.001)). Concomitant use of drospirenone and spironolactone was common (14.26%) and increased by 0.75% (SE:0.15%, p = 0.002) per-year. Although plasma glucose tests were unavailable, women with PCOS were more likely to take metformin than have a diabetes claim (45.8% versus 15.2%, p < 0.001), indicating some women likely receive metformin solely for PCOS. Our data suggests further attention is needed to medication management of PCOS to bridge the gap between guidelines and practice.

Comparative Safety Analysis of Opioid Agonist Treatment in Pregnant Women with Opioid Use Disorder: A Population-Based Study.

INTRODUCTION AND OBJECTIVE: Receipt of opioid agonist treatment during early and late pregnancy for opioid use disorder may relate to varying perinatal risks. We aimed to assess the effect of time-varying prenatal exposure to opioid agonist treatment using buprenorphine or methadone on adverse neonatal and pregnancy outcomes. METHODS: We conducted a retrospective cohort study of pregnant women with opioid use disorder using Rhode Island Medicaid claims data and vital statistics during 2008-16. Time-varying exposure was evaluated in early (0-20 weeks) and late (≥ 21 weeks) pregnancy. Marginal structural models with inverse probability of treatment weighting were applied. RESULTS: Of 400 eligible pregnancies, 85 and 137 individuals received buprenorphine and methadone, respectively, during early pregnancy. Compared with 152 untreated pregnancies with opioid use disorders, methadone exposure in both periods was associated with an increased risk of preterm birth (adjusted odds ratio [aOR]: 2.52; 95% confidence interval [CI] 1.07-5.95), low birth weight (aOR: 2.99; 95% CI 1.34-6.66), neonatal intensive care unit admission (aOR, 5.04; 95% CI 2.49-10.21), neonatal abstinence syndrome (aOR: 11.36; 95% CI 5.65-22.82), respiratory symptoms (aOR, 2.71; 95% CI 1.17-6.24), and maternal hospital stay > 7 days (aOR, 14.51; 95% CI 7.23-29.12). Similar patterns emerged for buprenorphine regarding neonatal abstinence syndrome (aOR: 10.27; 95% CI 4.91-21.47) and extended maternal hospital stay (aOR: 3.84; 95% CI 1.83-8.07). However, differences were found favoring the use of buprenorphine for preterm birth versus untreated pregnancies (aOR: 0.17; 95% CI 0.04-0.77), and for several outcomes versus methadone. CONCLUSIONS: Methadone and buprenorphine prescribed for the treatment of opioid use disorder during pregnancy are associated with varying perinatal risks. However, buprenorphine may be preferred in the setting of pregnancy opioid agonist treatment. Further research is necessary to confirm our findings and minimize residual confounding.

Empirical assessment of methods for risk identification in healthcare data: results from the experiments of the Observational Medical Outcomes Partnership.

BACKGROUND: Expanded availability of observational healthcare data (both administrative claims and electronic health records) has prompted the development of statistical methods for identifying adverse events associated with medical products, but the operating characteristics of these methods when applied to the real-world data are unknown. METHODS: We studied the performance of eight analytic methods for estimating of the strength of association-relative risk (RR) and associated standard error of 53 drug-adverse event outcome pairs, both positive and negative controls. The methods were applied to a network of ten observational healthcare databases, comprising over 130 million lives. Performance measures included sensitivity, specificity, and positive predictive value of methods at RR thresholds achieving statistical significance of p < 0.05 or p < 0.001 and with absolute threshold RR > 1.5, as well as threshold-free measures such as area under receiver operating characteristic curve (AUC). RESULTS: Although no specific method demonstrated superior performance, the aggregate results provide a benchmark and baseline expectation for risk identification method performance. At traditional levels of statistical significance (RR > 1, p < 0.05), all methods have a false positive rate >18%, with positive predictive value <38%. The best predictive model, high-dimensional propensity score, achieved an AUC = 0.77. At 50% sensitivity, false positive rate ranged from 16% to 30%. At 10% false positive rate, sensitivity of the methods ranged from 9% to 33%. CONCLUSIONS: Systematic processes for risk identification can provide useful information to supplement an overall safety assessment, but assessment of methods performance suggests a substantial chance of identifying false positive associations.

Drug absorption in bariatric surgery patients: A narrative review.

Background: Despite the increase in the number of bariatric surgeries performed, little is known about the impact of the surgery on drug absorption. Unpredictability is assumed with drugs, given the anatomical changes after surgery. Objective: To evaluate the impact of bariatric surgery on drug absorption based on the type of procedure performed. Methods: We conducted a comprehensive literature review searching PubMed/Medline for published studies (from inception to December 2017) that evaluate the use of drugs and the assessment of drug absorption after bariatric surgery. Pharmacokinetic/pharmacodynamic studies, case reports, and observational studies were included in our review. Results: We found 60 studies addressing drug use after bariatric surgery. Twenty-eight studies reported a decrease in drug absorption after bariatric surgery while only four studies showed an increase in drug absorption. Unchanged absorption of drugs was seen in 23 studies after the surgery. Conclusion: The available information shows variations in drug absorption after bariatric surgery. The unpredictability may result from factors related to the patient, drug, and/or type of surgery. Therefore, pharmacists' involvement and close monitoring of patients after bariatric surgery could be effective to avoid sub-/supratherapeutic responses.

Utilizing Medicare claims data for real­time drug safety evaluations:is it feasible?

PURPOSE: The Centers for Medicare & Medicaid Services claims comprise an administrative database of beneficiary-specific clinical information. This study evaluates the impacts of (i) claim information updates (claims adjudication) and (ii) delay in claim processing (claims delay) on real-time evaluation of health service and drug safety signals using the Medicare database. METHODS: Using Medicare claims data accumulated through May 2009 on health services rendered in 2006 and drugs dispensed in 2007, this study measures the frequency with which clinical information changes in the database as a result of (i) claims adjudication and (ii) claims delay. RESULTS: Over 85% of health services claims were processed within 8 weeks after the date of service, and 72% of drug claims were processed within 3 months after the dispense date. Clinical information changed for no more than 3% of unique claim groups in inpatient hospital, outpatient institutional, physician's office, and prescription drug Medicare claim settings. CONCLUSIONS: Claims delay is consistent across time and is minimal. Claims adjudication does not substantially impact the content of clinical information in the Medicare claims database. Therefore, the Medicare claims database provides consistent information regarding health services and prescription drugs in a manner that is prompt enough to facilitate medical product safety evaluations in real time.

Advancing the science for active surveillance: rationale and design for the Observational Medical Outcomes Partnership.

The U.S. Food and Drug Administration (FDA) Amendments Act of 2007 mandated that the FDA develop a system for using automated health care data to identify risks of marketed drugs and other medical products. The Observational Medical Outcomes Partnership is a public-private partnership among the FDA, academia, data owners, and the pharmaceutical industry that is responding to the need to advance the science of active medical product safety surveillance by using existing observational databases. The Observational Medical Outcomes Partnership's transparent, open innovation approach is designed to systematically and empirically study critical governance, data resource, and methodological issues and their interrelationships in establishing a viable national program of active drug safety surveillance by using observational data. This article describes the governance structure, data-access model, methods-testing approach, and technology development of this effort, as well as the work that has been initiated.