Pharmacoepidemiology and Drug Safety Journal Impact Factor & Information

Publisher: International Society for Pharmacoepidemiology; International Society of Pharmacovigilance, Wiley

Journal description

The aim of Pharmacoepidemiology and Drug Safety is to provide an international forum for the communication and evaluation of data methods and opinion in the emerging discipline of pharmacoepidemiology. The Journal publishes peer-reviewed reports of original research invited reviews and a variety of guest editorials and commentaries embracing scientific medical statistical and legal aspects of pharmacoepidemiology and post-marketing surveillance of drug safety. Appropriate material in these categories may also be considered for publication as a Brief Communication. Particular areas of interest include: design results analysis and interpretation of post-marketing surveillance and other studies looking at specific drugs populations and outcomes methods for detection and evaluation of drug-associated adverse events assessments of risk versus benefit ratios in drug therapy patterns of drug utilization relationships between pharmacoepidemiology and the formulation and interpretation of regulatory guidelines The Publishers recognize the need of journal users to access articles through a variety of channels and are committed to providing a wide range of options in the future. The Publishers are also aware that new communication media increase the threat to authors' own rights through unauthorized distribution alteration or attribution. To enable the Publishers to make the published version of articles available as widely as possible while protecting authors' rights to be associated with their work it is essential that a Copyright Transfer Agreement form is signed for every article which is to be considered for publication in the journal. The form can be photocopied from the journal or copies can be obtained on request from the Publisher or printed from this Web site. Inclusion of a signed form with the manuscript at the original submission stage will speed up processing and eventual publication of the article.

Current impact factor: 3.17

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 3.172
2012 Impact Factor 2.897
2011 Impact Factor 2.528
2010 Impact Factor 2.339
2009 Impact Factor 2.527
2008 Impact Factor 2.516
2007 Impact Factor 2.475
2006 Impact Factor 2.155
2005 Impact Factor 1.773
2004 Impact Factor 2.098
2003 Impact Factor 1.257
2002 Impact Factor 1.092
2001 Impact Factor 1.33
2000 Impact Factor 0.867
1999 Impact Factor 0.848

Impact factor over time

Impact factor

Additional details

5-year impact 2.91
Cited half-life 4.70
Immediacy index 1.30
Eigenfactor 0.01
Article influence 1.06
Website Pharmacoepidemiology and Drug Safety website
Other titles Pharmacoepidemiology and drug safety (Online), Pharmacoepidemiology and drug safety
ISSN 1099-1557
OCLC 44084438
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details


  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • 12 months embargo
  • Conditions
    • Some journals have separate policies, please check with each journal directly
    • On author's personal website, institutional repositories, arXiv, AgEcon, PhilPapers, PubMed Central, RePEc or Social Science Research Network
    • Author's pre-print may not be updated with Publisher's Version/PDF
    • Author's pre-print must acknowledge acceptance for publication
    • Non-Commercial
    • Publisher's version/PDF cannot be used
    • Publisher source must be acknowledged with citation
    • Must link to publisher version with set statement (see policy)
    • If OnlineOpen is available, BBSRC, EPSRC, MRC, NERC and STFC authors, may self-archive after 12 months
    • If OnlineOpen is available, AHRC and ESRC authors, may self-archive after 24 months
    • Publisher last contacted on 07/08/2014
    • This policy is an exception to the default policies of 'Wiley'
  • Classification
    ​ yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: PurposeThe aim of this research was to examine the association between statin use and the risk of acute pancreatitis.Methods This register-based case–control study with incidence density sampling was based on 4376 patients hospitalized in 2008–2010 for acute pancreatitis and 19 859 randomly selected age and sex-matched controls from the adult population of Finland. The relationship between statin use from 1 January 2004 to the index date and the relative incidence rate of acute pancreatitis was modelled by conditional logistic regression. The rate ratios were adjusted for comorbidities.ResultsA total of 826 (19%) cases and 2589 (13%) controls had been exposed to statins. Statin use was associated with an increased incidence rate of acute pancreatitis (odds ratio (OR) 1.25, 95% confidence interval (CI) 1.13–1.39). This increase was seen especially during the first year of use both among current (OR 1.37, 95% CI 0.94–2.00 for at most 3 months of use and OR 1.32, 95% CI 1.07–1.63 for 4–12 months of use) and former users (OR 1.64, 95% CI 1.33–2.03). The overall association remained when restricting analyses to participants with current use only, or with no history of gallstone or alcohol-related diseases, or with no comorbidities or medicines other than statins.Conclusions Statin use seems to be associated with an increased risk of acute pancreatitis. The association is more apparent during the first year of statin use and among former users. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3858
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    ABSTRACT: To determine which 10 prescription-only drugs used in outpatient treatment in Germany are most frequently reported to induce severe drug hypersensitivity reactions taking into account their prescription numbers. In addition, the reader should be made aware of respective databases available to the public and their limitations. Reports of anaphylactic and severe cutaneous adverse reactions were identified in the adverse drug reaction database of the German competent authority for the time period January 1998 to December 2012. For frequently reported drugs, the total number of reports was matched with their total number of prescriptions resulting in the reporting rate. Among the 10 drugs with the highest reporting rate for anaphylactic reactions, there were six antibiotics (moxifloxacin, levofloxacin, clindamycin, ciprofloxacin, cefuroxime and amoxicillin), three of which were fluoroquinolones. The other four drugs were glatiramer, metamizole and two angiotensin-converting-enzyme inhibitors. Concerning severe cutaneous adverse reactions, four out of ten drugs were antibiotics (clindamycin, sulfamethoxazol + trimethoprim, ciprofloxacin and amoxicillin), and three were anticonvulsives. Because dental prescription numbers were not available to the public, the real reporting rates for clindamycin and to a lesser extent for amoxicillin are presumably lower. The predominance of antibiotics among the reports of severe immediate and delayed-type drug hypersensitivity reactions is largely in accordance with literature although fluoroquinolones seem to be slightly overrepresented concerning anaphylactic reactions. The reader should be aware of the limitations of adverse drug reaction and prescription databases available to the public, and that over-the-counter drugs, such as non-steroidal anti-inflammatory drugs, and drugs typically administered in hospitals could not be considered. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3857
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    ABSTRACT: PurposeThe purpose of this review is to assist researchers in developing, using, and interpreting case-identifying algorithms in electronic healthcare databases.Methods We review clinical characteristics of health outcomes, data settings and informatics, and epidemiologic and statistical methods aspects as they pertain to the development and use of case-identifying algorithms.ResultsWe offer a framework for thinking critically about the use of electronic health insurance data and electronic health records to identify the occurrence of health outcomes. Accuracy of case ascertainment in database research depends on many factors, including clinical and behavioral aspects of the health outcome, and details of database construction as it pertains to completeness and reliability of database content. Existing methods for diagnostic and screening tests, misclassification, validation studies, and predictive modelling can be usefully applied to improve case ascertainment in database research.Conclusions Good case-identifying algorithms are based on a sound understanding of care-seeking behavior and patterns of clinical diagnosis and treatment in the study population and details about the construction and characteristics of the database. Researchers should use quantitative bias analyses to take into account the performance characteristics of case-identifying algorithms and their impact on study results. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3856
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    ABSTRACT: PurposeSeveral survey studies have documented misuse of methylphenidate defined as the use of non-prescribed methylphenidate or use different from what was prescribed. We aimed to identify and characterize adults with deviant patterns of methylphenidate use in Denmark during 2007–2012. Further, we aimed to identify risk factors associated with deviant patterns of use.Methods Based on individual-level prescription data, new users of methylphenidate were followed for one year after filling their first prescription on methylphenidate. Adult patients were identified with deviant patterns of use if they had ≥4 different prescribers and filled ≥1095 defined daily doses of methylphenidate during the year of follow-up. Risk factors were estimated by using logistic regression.ResultsAmong 20 829 new users of methylphenidate, we identified 82 (0.39%) patients displaying deviant patterns of use. Characteristics associated with deviant patterns of use included an initial prescription for extended-release methylphenidate (OR2 4.35), age 25–49 years at first prescription (OR2 2.49), general practitioners or hospital doctors as initial prescribers (OR2 3.06 and OR2 4.07) and prior use of drugs used in addictive disorders (OR2 2.08) or opioids (OR2 1.75). Sensitivity analyses revealed that the number of different prescribers alone does not seem to effectively identify deviant users of methylphenidate.Conclusion We have identified characteristics associated with deviant patterns of methylphenidate use. Our results do not allow us to conclude if deviant users truly represent medical misusers. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3852
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    ABSTRACT: Anemia-correction trials indicated higher mortality rates in chronic kidney disease patients assigned to higher hemoglobin targets. The safety of the high erythropoiesis-stimulating agent (ESA) doses that these patients received has therefore been questioned. However, no trial that directly compares treatment with different ESA doses has been published. We thus aimed to estimate the effect of high ESA dose on mortality in an observational cohort of dialysis patients. The Netherlands Cooperative Study on the Adequacy of Dialysis is a Dutch cohort study of incident dialysis patients in which ESA dose, comorbidities, and laboratory parameters were collected every 6 months. Mortality in patients with a high ESA dose (above median 6000 units/week) was compared with that in patients with no or low ESA dose with Cox regression analyses. To handle time-dependent confounding, a sequential Cox approach was used conditional on baseline covariates, with inverse probability of censoring weights (IPCW) for dependent censoring. Analyses were repeated with a marginal structural model (MSM) with inverse probability of treatment weights and IPCW. Hazard ratio (HR) for high ESA dose was 1.20 (95%CI 0.83-1.73) with a sequential Cox and 1.54 (95%CI 1.08-2.18) with an MSM. Truncation of weights in the MSM did not affect estimates. To compare, conventional Cox analyses indicated a baseline adjusted HR of 1.66 (95%CI 1.20-2.31). Patients treated with high ESA dose have a 1.2-1.5 increased risk of mortality. Our analyses support guidelines advising a conservative ESA dosing regimen, which carefully weighs the patients' benefits and risks. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3855
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    ABSTRACT: Outpatient pediatric polypharmacy is poorly characterized. Identification of at-risk populations has clinical implications for pharmacy case management programs. We described the degree of exposure to polypharmacy using parameters of depth (concurrent medication count) and duration, reported commonly dispensed medications and exposure to three example potential drug-drug interactions by different depths of polypharmacy, and determined patient characteristics associated with exposure to increased degrees (a function of depth and duration) of polypharmacy. Retrospective cohort study of Colorado fee-for-service Medicaid patients aged <18 years with 12 months of continuous enrollment. We calculated depth of polypharmacy using daily concurrent medication counts and duration of polypharmacy using days exposed to a certain depth. Multinomial logistic regression was used to assess patient characteristics associated with different degrees of polypharmacy. Of 242 230 patients, 35% percent were exposed to any depth of polypharmacy, most commonly to anti-infective medications. Patients with higher depth polypharmacy were exposed to less common medications (psychotropic drugs, anticonvulsants, cardiovascular agents, and opioids) and to higher rates of exposure to potential drug-drug interactions. Of 47 972 patients exposed to ≥3 concurrent medications, 50% were exposed for <15 days, 25% for 15-38 days, 15% for 39-111 days, and 10% for 112-327 days. High-degree polypharmacy was associated with increasing age, male gender, and presence of a complex chronic condition. Outpatient pediatric polypharmacy occurs to a substantial degree for a small but vulnerable population of children, who may be candidates for pharmacy case management. We must determine whether increased exposure to high-degree polypharmacy causes harm. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3843
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    ABSTRACT: Prolonged ventricular repolarization (measured as heart-rate corrected QT (QTc) prolongation or JT-interval prolongation) is a risk factor for ventricular arrhythmias and can be drug-induced. Drugs can be classified as having known or possible QTc-prolonging properties. Regulatory agencies recommend avoiding concomitant use of multiple QTc-prolonging drugs, but evidence is lacking to what degree ventricular repolarization is influenced by concomitant use of these drugs. Within a population-based cohort of persons aged 45 years and older, with up to five electrocardiograms recorded per participant between 1991 and 2010, we used generalised estimating equations to study the association between concomitant use of multiple QTc-prolonging drugs and repolarization duration. The study population consisted of 13 009 participants with 26 908 electrocardiograms. With the addition of a second or third QTc-prolonging drug there was no substantial increase in QTc and JT interval and no increased risk of a prolonged QTc interval, compared to use of one QTc-prolonging drug. There was a large difference between the effect of one known or one possible QTc-prolonging drugs on QTc interval: 15 ms for known, and 3 ms for possible QTc-prolonging drugs. In this study, the added prolongation in users of two or three QTc-prolonging drugs on QTc was small. There was a large difference in QTc prolongation between known and possible QTc-prolonging drugs. Further research in larger or high-risk populations is needed to establish whether it is safe to use multiple QTc-prolonging drugs concomitantly to prevent that the current advice might unnecessarily withhold beneficial drugs from patients. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3853
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    ABSTRACT: Our aim is to determine if propoxyphene withdrawal from the US market was associated with opioid continuation, continued chronic opioid use, and secondary propoxyphene-related adverse events (emergency department visits, opioid-related events, and acetaminophen toxicity). Medical service use and pharmacy data from 19/11/08 to 19/11/11 were collected from the national Veterans Healthcare Administration healthcare databases. A quasi-experimental pre-post retrospective cohort design utilizing a historical comparison group provided the study framework. Logistic regression controlling for baseline covariates was used to estimate the effect of propoxyphene withdrawal. There were 24 328 subjects (policy affected n = 10 747; comparison n = 13 581) meeting inclusion criteria. In the policy-affected cohort, 10.6% of users ceased using opioids, and 26.6% stopped chronic opioid use compared with 3.8% and 13.5% in the historical comparison cohort, respectively. Those in the policy-affected cohort were 2.7 (95%CI: 2.5-2.8) and 3.2 (95%CI: 2.9-3.6) times more likely than those in the historical comparison cohort to discontinue chronic opioid and any opioid use, respectively. Changes in adverse events and Emergency Department (ED) visits were not different between policy-affected and historical comparison cohorts (p > 0.05). The withdrawal of propoxyphene-containing products resulted in rapid and virtually complete elimination in propoxyphene prescribing in the veterans population; however, nearly 90% of regular users of propoxyphene switched to an alternate opioid, and three quarters continued to use opioids chronically. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3851
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    ABSTRACT: PurposeTo evaluate changes in thiazolidinedione use and quality of prescription following safety warnings for thiazolidinediones and cardiac risk in 2007, Risk Management Plan (RMP) policy for rosiglitazone in 2010, and warning for pioglitazone and bladder cancer risk in 2010 in Taiwan.Methods We obtained 2003–2011 claims data from Taiwan's National Health Insurance Research Database. Using an interrupted time series design and segmented regression, we estimated changes in monthly prescribing rates for thiazolidinediones among all and prevalent diabetes patients with and without cardiovascular disease history (CV history). We also compared time to prescription of thiazolidinediones among new diabetes patients with CV history before and after each regulatory action using survival analysis.ResultsAmong prevalent patients with and without CV history, the prescribing rates of rosiglitazone decreased 36.88% and 28.92% after safety warnings in 2007 respectively. Pioglitazone prescriptions increased 13% among patients with CV history, but no changes were detected among patients without CV history. After rosiglitazone's RMP policy in 2010, large reductions in prescriptions were observed in patients with CV history (−101.67%) and those without CV history (−88.04%). Among new diabetes patients with CV history, cardiac safety warnings in 2007 significantly delayed the prescription of rosiglitazone, but no significant change was found for pioglitazone.Conclusions The Taiwan FDA regulatory actions for thiazolidinediones communicated possible risks of cardiac events and bladder cancer. Different safety regulatory actions had differential impacts on the use of rosiglitazone and pioglitazone and the quality use of these drugs among the high-risk patients. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3834
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    ABSTRACT: PurposeThe aims of this study were two-fold: (i) to investigate the effect of exposure to antibiotic agents on the risk of acute liver injury using a self-controlled case series and case-crossover study and (ii) to compare the results between the case-only studies.Methods For the self-controlled case series study relative incidence ratios (IRR) were calculated by dividing the rate of acute liver injury experienced during patients' periods of exposure to antibiotics to patients' rate of events during non-exposed time using conditional Poisson regression. For the case-crossover analysis we calculated Odds Ratios (OR) using conditional logistic regression by comparing exposure during 14- and 30-day risk windows with exposure during control moments.ResultsUsing the self-controlled case series approach, the IRR was highest during the first 7 days after receipt of a prescription (10.01, 95% CI 6.59–15.18). Omitting post-exposure washout periods lowered the IRR to 7.2. The highest estimate in the case-crossover analysis was found when two 30-day control periods 1 year prior to the 30-day ALI risk period were retained in the analysis: OR = 6.5 (95% CI, 3.95–10.71). The lowest estimate was found when exposure in the 14-day risk period was compared to exposure in four consecutive 14-day control periods immediately prior to the risk period (OR = 3.05, 95% CI, 2.06–4.53).Conclusion An increased relative risk of acute liver injury was consistently observed using both self-controlled case series and case-crossover designs. Case-only designs can be used as a viable alternative study design to study the risk of acute liver injury, albeit with some limitations. © 2015 The Authors Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3846
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    ABSTRACT: To examine the robustness of findings of case-control studies on the association between acute liver injury (ALI) and antibiotic use in the following different situations: (i) Replication of a protocol in different databases, with different data types, as well as replication in the same database, but performed by a different research team. (ii) Varying algorithms to identify cases, with and without manual case validation. (iii) Different exposure windows for time at risk. Five case-control studies in four different databases were performed with a common study protocol as starting point to harmonize study outcome definitions, exposure definitions and statistical analyses. All five studies showed an increased risk of ALI associated with antibiotic use ranging from OR 2.6 (95% CI 1.3-5.4) to 7.7 (95% CI 2.0-29.3). Comparable trends could be observed in the five studies: (i) without manual validation the use of the narrowest definition for ALI showed higher risk estimates, (ii) narrow and broad algorithm definitions followed by manual validation of cases resulted in similar risk estimates, and (iii) the use of a larger window (30 days vs 14 days) to define time at risk led to a decrease in risk estimates. Reproduction of a study using a predefined protocol in different database settings is feasible, although assumptions had to be made and amendments in the protocol were inevitable. Despite differences, the strength of association was comparable between the studies. In addition, the impact of varying outcome definitions and time windows showed similar trends within the data sources. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3841
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    ABSTRACT: Large data-based studies have reported excess cardiovascular mortality in high-risk patients treated with azithromycin, but whether or not azithromycin causes QT prolongation remains controversial. The purpose of this study was to examine the association of azithromycin treatment on QT prolongation in a cohort of patients hospitalized with community-acquired pneumonia (CAP) METHODS: One-hundred twenty-two hospitalized patients with CAP were enrolled in the study. We compared the baseline QTc, with daily post antibiotic QTc. Other risk factors for QT prolongation such as medication or electrolyte abnormalities were recorded. Ninety (73.8%) patients were treated with azithromycin (usually in combination with ceftriaxone), and 32 (26.2%) patients with other antibiotics (ampicillin-clavulanate, chloramphenicol, doxcycline, or ceftriaxone); 72.1% (88) of the cohort experienced QT lengthening; 72.7% with QT lengthening had a normal baseline QTc. Azithromycin was not associated with the post-antibiotic QTc. Wide (pathological) post-antibiotic QTc was associated with the pneumonia score. Every 10-point increase in the pneumonia score raised the risk for a pathological post antibiotic QTc by 1.249 (95%CI: 1.050-1.486). Analysis of patients with non-pathological baseline QTc revealed that pathological post-antibiotic QTc was only associated with previous stroke and not with the type of antibiotic. Azithromycin treatment was not associated with QT prolongation in patients with severe CAP. Nonetheless, in a large majority of hospitalized CAP patients, QT prolongation and pathological QTc develop regardless of the antibiotic used, especially in patients with previous stroke or a higher pneumonia score. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; 37(8). DOI:10.1002/pds.3842
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    ABSTRACT: Cinacalcet is indicated for treatment of secondary hyperparathyroidism in patients receiving hemodialysis. Cinacalcet reduces serum calcium concentrations by decreasing parathyroid hormone secretion, but the frequency and degree of calcium reduction following cinacalcet initiation, subsequent physician response, and ultimate calcium recovery in clinical practice are not well described. Patients receiving hemodialysis at a large dialysis organization who enrolled in the organization's prescription benefits service and initiated cinacalcet at serum calcium ≥8.4 mg/dL were studied (N = 13 723). Patients were categorized by whether they experienced a reduction in calcium to <8.4 mg/dL and to what level (<7.5, 7.5-7.9, and 8.0-8.3 mg/dL). Baseline characteristics, frequency of subsequent intervention, and calcium recovery were compared. Of those who experienced a reduction in calcium to <8.4 mg/dL (n = 6437 [46.9%]), 6.6% had calcium <7.5 mg/dL and 24.5% had calcium 7.5-7.9 mg/dL, while the majority (68.9%) had a level of 8-8.3 mg/dL. Higher baseline parathyroid hormone and alkaline phosphatase were associated with lower resultant calcium. Among patients with calcium reductions, 45.6-63.5% received one or more directed clinical therapeutic responses, including 15.6-28.4% for whom cinacalcet was discontinued; the majority of patients recovered to calcium ≥8.4 mg/dL within 90 days of first detection. Only modest differences in recovery were noted between patients who did and did not receive any therapeutic response and patients who did and did not discontinue cinacalcet. Serum calcium reductions following cinacalcet initiation were common; declines <7.5 mg/dL were infrequent. Calcium recovery occurred in the majority of patients, with or without therapeutic intervention. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 08/2015; DOI:10.1002/pds.3845
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    ABSTRACT: Pharmacoepidemiology researchers often utilize data from two UK electronic medical record databases, the Clinical Practice Research Datalink (CPRD) and The Health Improvement Network (THIN), and may choose to combine the two in an effort to increase sample size. To minimize duplication of data, previous studies examined the practice-level overlap between these databases. However, the proportion of overlapping patients remains unknown. We developed a method using demographic and pharmacy variables to identify patients included in both CPRD and THIN, and applied this method to measure the proportion of overlapping patients who initiated the oral anti-diabetic drug saxagliptin. We conducted a cross-sectional study among patients initiating saxagliptin in CPRD and THIN between October 2009 and September 2012. Within both databases, we identified patients: (i) ≥18 years, (ii) newly prescribed saxagliptin, and (iii) with ≥180 days enrollment prior to saxagliptin initiation. Demographic data (birth year, sex, patient registration date, family number, and marital status) and prescriptions (including dates) for the first two oral anti-diabetic drugs prescribed within the study period were used to identify matching patients. Among 4202 CPRD and 3641 THIN patients initiating saxagliptin, 2574 overlapping patients (61% of CPRD saxagliptin initiators; 71% of THIN saxagliptin initiators) were identified. Among these patients, 2474 patients (96%) perfectly matched on all demographic and prescription data. Within each database, over 60% of patients initiating saxagliptin were included within both CPRD and THIN. Combined demographic and prescription data can be used to identify patients included in both CPRD and THIN. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 07/2015; DOI:10.1002/pds.3844
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    ABSTRACT: Dipeptidyl peptidase-4 inhibitors (DPP4-Is) are a new class of anti-hyperglycemic drugs which might have a potential beneficial effect on bone metabolism. Data on the effect of DPP4-I use and fracture risk is limited and conflicting. The aim of the present study was to investigate the association between use of DPP4-Is and fracture risk. A case-control study was conducted using data from the Danish National Health Service. Cases were those who sustained a fracture, and controls were those without a fracture during the study period (2007-2011), all aged 18 years and older. Conditional logistic regression estimated the odds ratios of fracture with current use of DPP4-I use. Analyses were adjusted for comorbidities and recent drug use. Among the cases there were 6993 current non-insulin anti-diabetic drug (NIAD) users (excluding incretin users) and 643 DPP4-I users. There were 7209 NIAD users (excluding incretin users) among the controls and 707 DPP4-I users. Current DPP4-I use was not associated with risk of any fracture (adjusted [adj.] OR: 0.97, 95% CI: 0.79-1.18) or major osteoporotic fracture (adj. OR: 0.96, 95% CI: 0.72-1.28). Stratification of current DPP4-I use to cumulative and average daily dose did not show an association. In a population-based case-control study we identified that short-term use of DPP4-I was not associated with fracture risk as compared to users of other anti-hyperglycemic drugs. Additionally, results suggest that increasing daily dose and cumulative DPP4-I exposure were not associated with fracture risk. However, more research is needed to assess the effect of long-term DPP4-I use on the risk of fracture. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 07/2015; DOI:10.1002/pds.3837
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    ABSTRACT: Our aim is to estimate the effect of nonadherence to evidence-based cardioprotective medications on all-cause mortality in survivors of acute myocardial infarction (AMI). A patient-based retrospective cohort study of 1-year survivors of AMI, members of a health organization in Israel, between 2005 and 2010 was used. Adherence was measured using the proportion-of-days-covered metric and defined as a proportion of days covered ≥80%. In order to determine the independent impact of medication nonadherence on all-cause mortality, Cox proportional hazards models were constructed, adjusting for patient demographic and clinical characteristics. Of 4655 patients prescribed at least one medication, 864 died during an 8-year follow-up (median 4.5 years). Except for beta-blockers, medication nonadherence was significantly associated with increased adjusted all-cause mortality risk for aspirin [hazard ratio (HR), 1.28; 95% confidence interval (CI), 1.11-1.47], statins (HR, 1.36; 95%CI, 1.18-1.57), and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers only among ischemic heart disease patients with documented heart failure (HR, 1.57; 95%CI, 1.16-2.14). Multidrug-combined therapy exerted incremental survival benefit in a dose-response gradient, exceeding that of single-component treatment. The highest risk of mortality was observed in patients adherent to none of the medications compared with adherents to all medications, with a 38% increase in risk of mortality (HR, 1.38; 95%CI, 1.06-1.80). Outpatient nonadherence to evidence-based cardioprotective medications in patients with AMI is common, and in the case of aspirin, statin or combined therapy is associated with a marked risk increase in all-cause mortality. Further research is needed to elucidate the role of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker in patient subgroups. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 07/2015; DOI:10.1002/pds.3840
  • Pharmacoepidemiology and Drug Safety 07/2015; DOI:10.1002/pds.3833
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    ABSTRACT: In pharmacoepidemiology, one of the main concerns is analysis of drug exposure time. However, in real-life settings, patient's behavior is complex and characterized by drug exposure dynamics. Multi-state models allow assessing the probabilities of various patterns, instead of just continuous use and/or discontinuation. The aim of this study was to illustrate with methadone, the use of multi-state model (MSM) in a large claims database. This study is based on the French health insurance reimbursement database. Methadone exposure is defined using four states for each period of follow-up: syrup only, capsule only, syrup-capsule and no dispensing. The model considered 12 possible transitions (including reverse transitions) from one state to another. To describe these transitions a time-homogeneous Markov model was used. A total of 1265 methadone users were included. When patients belonged to the syrup-capsule state, they had a 61.8% chance of moving to capsules the following month and 20.9% of moving to syrup. The probability of moving from the syrup to the non-user state was 13.6% (11.7% from capsule state to non-user state). The average length of stay was 5.9 months (CI95%: [5.5-6.4]) in capsule state, 4.9 (CI95%: [4.6-5.2]) in syrup state and 5.9 (CI95%: [5.5-6.3]) in non user state. MSM provided a good description of methadone patterns of use. It outlined behaviors which have led to a rapid spread of capsule formulation among methadone users. Therefore, it illustrates the utility of MSM for modeling multiple sequences of drug use in a large claims database. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    Pharmacoepidemiology and Drug Safety 07/2015; DOI:10.1002/pds.3835