A Large Cross-Sectional Survey Study of the Prevalence of Alopecia Areata in the United States.

PURPOSE: Alopecia areata (AA) is an autoimmune disease characterized by the development of non-scarring alopecia. The prevalence is not well known, and estimates vary considerably with no recent estimates in the United States (US). The objective of this study was to define the current AA point prevalence estimate among the general population in the US overall and by severity. PATIENTS AND METHODS: We administered an online, cross-sectional survey to a representative sample of the US population. Participants self-screening as positive for AA using the Alopecia Assessment Tool (ALTO) also completed the Severity of Alopecia Tool (SALT) to measure the severity of disease as a percent of scalp hair loss. Self-reported AA participants were invited to upload photographs for adjudication of AA by 3 clinicians. RESULTS: The average age of participants was 43 years. Approximately half of the participants (49.2%) were male, and the majority were white (77.1%) and not of Hispanic origin (93.2%). Among the 511 self-reported AA participants, 104 (20.4%) uploaded photographs for clinician evaluation. Clinician-adjudicated point prevalence of AA was 0.21% (95% CI: 0.17%, 0.25%) overall, 0.12% (95% CI: 0.09%, 0.15%) for "mild" disease (≤50% SALT score), and 0.09% (95% CI: 0.06%, 0.11%) for "moderate to severe" disease (>50% SALT score) with 0.04% (95% CI: 0.02%, 0.06%) for the alopecia totalis/alopecia universalis (100% SALT score) "moderate to severe" subgroup. The average SALT score was 44.4% overall, 8.8% for "mild", and 93.4% for "moderate to severe". CONCLUSION: This study suggests that the current AA prevalence in the US is similar to the upper estimates from the 1970s at approximately 0.21% (700,000 persons) with the current prevalence of "moderate to severe" disease at approximately 0.09% (300,000 persons). Given this prevalence and the substantial impact of AA on quality of life, the burden of AA within the US is considerable.

Health care utilization and costs following amplified versus non-amplified molecular probe testing for symptomatic patients with suspected vulvovaginitis: a US commercial payer population.

BACKGROUND: Vulvovaginitis (VV) is a common reason women seek medical attention in the USA. Both the non-specific clinical presentation and risk of preterm labor or delivery necessitate accurate identification of the causative agents to guide appropriate therapy. The diagnostic accuracy of amplified molecular probe testing (AMP) has been shown to exceed that of non-amplified molecular probe (NAMP) by 20%-25%. OBJECTIVE: To evaluate the impact of diagnosis with AMP testing on health care utilization, direct costs, and health outcomes, compared with NAMP, for symptomatic patients with suspected VV from a commercial payer perspective. METHODS: Symptomatic women (aged 18-64 years) who underwent VV testing with AMP or NAMP from January 1, 2012-December 31, 2016 were identified using the Truven Health Analytics MarketScan Database; those with continuous medical and pharmacy benefit enrollment 6 months pre/post AMP or NAMP testing were included. Patients were propensity score (PS) matched and 6-month all-cause health care resource utilization, all-cause direct costs (2017 USD), risk of all-cause hospitalization, and risk of preterm labor or delivery were compared between cohorts. RESULTS: After PS match (N=46,810 per group, mean age 34.2 years), AMP had significantly (all P<0.0001) fewer mean hospital outpatient visits (AMP 0.9 vs NAMP 1.0), primary care physician office visits (AMP 1.1 vs NAMP 1.2), and prescription medications (AMP 7.3 vs NAMP 8.0), and a 21% reduction in risk of hospitalization (risk ratio [RR]=0.79, 95% CI= 0.75-0.83, P<0.0001). Total medical expenditures per patient were lower for AMP than NAMP (mean AMP $3,287 vs NAMP $3,555, P<0.0001). Among pregnant women (N=2,175 per group), AMP had a 12% reduction in risk of preterm labor or delivery (RR =0.88, 95% CI=0.77-0.99, P=0.041). CONCLUSION: This real-world study offers evidence on the clinical utility for symptomatic patients with suspected VV diagnosed with AMP compared to NAMP - demonstrating an opportunity to improve the patient journey while delivering value-based care.

Projected Medicare Savings Associated With Lowering the Risk of Total Hip Arthroplasty Revision: An Administrative Claims Data Analysis.

In the United States, demand for total hip arthroplasty (THA) and THA revision procedures are increasing due to an aging population, a longer life expectancy, and an increasing prevalence of osteoarthritis. This retrospective cohort study identified patients 65 years and older in the Medicare 5% Standard Analytic Files who underwent THA for osteoarthritis between January 1, 2009, and September 30, 2010. The authors estimated the 5-year cumulative revision risk (CRR) using the Kaplan-Meier method, revision-related complications, and Medicare expenditures. Using a 6.22% compound annual growth rate from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, the authors estimated the number of THAs that will be performed from 2018 to 2027 and calculated the 10-year projected savings to Medicare for a 1% reduction in CRR. Among 7820 patients, the mean age was 74.4 years, and 62.4% were female. Cumulative revision risk was 4.2% at 5 years (through September 30, 2015), with 30.8% of revisions occurring within 90 days of the THA. At least 24.4% of revision patients had a complication. Median revision inpatient stay and episode of care (through 90 days) expenditures were $23,847 and $36,157, respectively. With a 1% absolute reduction in CRR, Medicare could save $697 million over a 10-year period, or $985 million when including Medicare Advantage, which represented 29.2% of 2016 Medicare payments. Strategies to reduce the risk of THA revision, such as the use of implant constructs with lower CRR and value-based payment models, are needed to achieve Medicare payment reductions while maintaining or improving quality of care for Medicare beneficiaries. [Orthopedics. 2019; 42(1):e86-e92.].

Risk of acute liver injury associated with the use of moxifloxacin and other oral antimicrobials: a retrospective, population-based cohort study.

STUDY OBJECTIVE: To estimate the incidence and relative risk of a hospitalization or emergency visit for noninfectious liver injury in users of eight oral antimicrobials-amoxicillin, amoxicillin-clavulanic acid, clarithromycin, cefuroxime, doxycycline, levofloxacin, moxifloxacin, telithromycin-compared with nonusers of these antimicrobials. DESIGN: Retrospective, observational cohort study with a nested case-control analysis. DATA SOURCE: HealthCore Integrated Research Database. PATIENTS: Adults with continuous health plan enrollment for at least 6 months before study entry who had a new dispensing of a study antimicrobial between July 1, 2001, and March 31, 2009. Cases had diagnoses indicating noninfectious liver injury during follow-up. To control for potentially confounding risk factors, 10 controls at risk for liver injury during follow-up were matched to each case by age, sex, and event date (liver injury date of the case), and analyses were adjusted for medical history, concomitant drugs, and health care service use. MEASUREMENTS AND MAIN RESULTS: Two physician reviewers (blind to exposure) validated the cases. Among 1.3 million antimicrobial users, we identified 607 cases of liver injury, including 82 cases of severe hepatocellular injury and 11 cases of liver failure. Liver injury incidence in nonusers of study antimicrobials was 35/100,000 person-years (95% confidence interval [CI] 29-42/100,000 person-years). For valid cases, the adjusted relative risk among current users of multiple antimicrobials was 3.2 (95% CI 1.6-6.7). Levofloxacin had the highest relative risk for current single use (3.2, 95% CI 1.8-5.8). Relative risks were also elevated for amoxicillin-clavulanic acid (2.5, 95% CI 1.3-5.0), doxycycline (2.5, 95% CI 1.2-5.2), moxifloxacin (2.3, 95% CI 1.1-4.7), and amoxicillin (2.3, 95% CI 1.1-4.7). CONCLUSION: The results support a comparatively high adjusted relative risk of liver injury among patients exposed concurrently to multiple antimicrobials and modest elevations in the risk for several antimicrobials used alone; however, we found little evidence of any strong effect of commonly used antimicrobials on the risk of liver injury.

Validation of acute liver injury cases in a population-based cohort study of oral antimicrobial users.

We conducted a cohort study of acute, noninfectious liver injury among oral antimicrobial users. Potential cases were identified in the HealthCore Integrated Research Database (HIRD(SM)) population between July 1, 2001, and March 31, 2009, using ICD-9-CM codes primarily for acute and subacute necrosis of the liver, hepatic coma, and unspecified hepatitis. Liver test results were used to confirm case status according to published criteria. Two physician reviewers experienced in studying acute liver injury (blinded to study drug exposures) evaluated data abstracted from hospital and emergency department records to validate potential cases. Of 715 potential cases having claims associated with any of the primary screening codes, 312 (44%) were valid cases, 108 (15%) were not cases, and 295 (41%) were of uncertain status (records inadequate for validation). Among potential cases with adequate medical records, the PPV for presence of any of the primary codes was 74% (95% CI, 70%-78%). The highest PPV for a single code was for acute and subacute necrosis of the liver (84%; 95% CI, 77%-90%). Evaluation of cases of noninfectious liver injury using hospital and emergency department medical records continues to represent the preferred approach in studies using insurance claims data.

Risk of ischemic cerebrovascular and coronary events in adult users of anticonvulsant medications in routine care settings.

BACKGROUND: Older-generation anticonvulsants that highly induce cytochrome P450 enzyme system activity produce metabolic abnormalities that may increase cardiovascular risk. The objective of this study was to evaluate the risk of ischemic cerebrovascular and coronary events in adult new users of anticonvulsants that highly induce cytochrome P450 activity compared with other anticonvulsant agents, as observed in a routine care setting. METHODS AND RESULTS: This was a cohort study of patients 40 to 64 years old from the HealthCore Integrated Research Database who had initiated an anticonvulsant medication between 2001 and 2006 and had no recorded major coronary or cerebrovascular condition in the 6 months before treatment initiation. Propensity score (PS) matching was used to evaluate ischemic cerebrovascular and coronary risk among anticonvulsant new users. High-dimensional propensity score (hdPS)-matched analyses were used to confirm adjusted findings. The study identified 913 events in 166 031 unmatched new treatment episodes with anticonvulsant drugs. In a PS-matched population of 22 864 treatment episodes, the rate ratio (RR) for ischemic coronary or cerebrovascular events associated with highly inducing agents versus other agents was 1.22 (95% CI, 0.90-1.65). The RR moved to 0.99 (95% CI, 0.73-1.33) with adjustment for hdPS matching (RR, 1.47; 95% CI, 0.95-2.28 for cerebrovascular events; RR, 0.70; 95% CI, 0.47-1.05 for coronary events). CONCLUSIONS: In this exploratory analysis, there was no evidence of a consistent and statistically significant effect of initiating anticonvulsants that highly induce cytochrome P450 activity on ischemic coronary or cerebrovascular outcomes compared with other agents, given routine care utilization patterns.

Algorithms for identification of Guillain-Barré Syndrome among adolescents in claims databases.

BACKGROUND: Health insurance claims databases can provide data for studies of vaccine-related Guillain-Barre' Syndrome (GBS), but not all patients with a diagnostic ICD-9-CM code for GBS have the disease. The objective of this study was to evaluate the positive predictive values (PPVs) of claims-based algorithms for identifying GBS cases in 4 claims database environments. METHODS: Potential cases were adolescents ages 11-21 with at least one claim for GBS (ICD-9-CM code 357.0). Medical record reviews by a panel of 3 neurologists were conducted for case confirmation. Claims data considered for inclusion in the case-ascertainment algorithm included coding position, physician specialty, visit type, diagnostic tests. PPVs were used to assess the contribution of study factors in predicting case status. RESULTS: Among 361 individuals with a GBS diagnosis code, 106 were confirmed overall (PPV=0.29), varying from 0.24 to 0.56 across the 4 sites. Requiring the GBS code to be associated with a neurologist visit (PPV=0.53) or to be in a primary position on an inpatient claim (0.56) improved the performance. A composite algorithm including a primary inpatient GBS code and a neurologist visit associated with any GBS code gave the highest PPV (0.70). Incorporating claims for diagnostic testing had little impact on the PPV. Findings were generally similar across study sites. CONCLUSIONS: Algorithms were able to identify GBS cases better than the single occurrence of the diagnostic code for GBS, and these algorithms may perform similarly in different claims environments.

Risk of Guillain-Barré syndrome after meningococcal conjugate vaccination.

PURPOSE: A new meningococcal conjugate vaccine (MCV4) was introduced in 2005. Shortly after, case reports of Guillain-Barré syndrome (GBS), a serious demyelinating disease, began to be reported to the Vaccine Adverse Event Reporting System. In 2006, the Centers for Disease Control and Prevention and the Food and Drug Administration requested the evaluation of GBS risk after MCV4 vaccination. We conducted a study to assess the risk of GBS after MCV4 vaccination using health plan administrative and claims data together with the review of primary medical records of potential cases. METHODS: Retrospective cohort study among 12.6 million 11- to 21-year-old members of five US health plans with a total membership of 50 million. Automated enrollment and medical claims data from March 2005 through August 2008 were used to identify the population, the vaccinations administered, and the medical services associated with possible GBS. Medical records were reviewed and adjudicated by a neurologist panel to confirm cases of GBS. The study used distributed data analysis methods that minimized sharing of protected health information. RESULTS: We confirmed 99 GBS cases during 18,322,800 person-years (5.4/1,000,000 person-years). More than 1.4 million MCV4 vaccinations were observed. No confirmed cases of GBS occurred within 6 weeks after vaccination. The upper 95% CI for the attributable risk of GBS associated with MCV4 is estimated as 1.5 cases per 1,000,000 doses. CONCLUSIONS: Among members of five US health plans, MCV4 vaccination was not associated with increased GBS risk.

Health care utilization of patients diagnosed with idiopathic thrombotic thrombocytopenic purpura in a commercially insured population in the United States.

BACKGROUND: Incident idiopathic thrombotic thrombocytopenic purpura (TTP) is an uncommon, potentially fatal blood disorder for which there are little or no data on health care costs. STUDY DESIGN AND METHODS: Patients satisfying a validated claims-based algorithm including an inpatient diagnosis of TTP and plasma exchange (PE) procedure during the period January 1, 2001 to May 31, 2008 were identified in the HealthCore Integrated Research Database. To characterize patterns of treatment and payments, a quantitative evaluation of comorbidities and treatments, health care utilization, and payments among this population of patients was conducted. All patients were followed until death, end of health plan enrollment, or 365 days after the TTP hospitalization, whichever occurred first. RESULTS: One hundred fifty-one patients met the claims coding algorithm. Mean total health care payments for the TTP hospitalization were $56,347 (standard deviation [SD] $80,230). Ten patients (6.6%) died during the hospitalization for TTP. Mean payments for PE services in the month following discharge were $9127 (SD $20,840). Several patients required prolonged PE during the acute TTP phase (up to 116 separate exchanges over a period of 365 days), prolonging required treatment and skewing payments and resource utilization during the 365-day period following discharge from the index TTP hospitalization. CONCLUSION: These data document the health care resource utilization by patients with idiopathic TTP, demonstrating that management of these patients is not only expensive but also skewed, with some patients requiring prolonged treatment. These data can contribute to cost-effectiveness models when new treatments for TTP become available.

Surveillance for adverse events following receipt of pandemic 2009 H1N1 vaccine in the Post-Licensure Rapid Immunization Safety Monitoring (PRISM) System, 2009-2010.

The Post-Licensure Rapid Immunization Safety Monitoring (PRISM) system is a cohort-based active surveillance network initiated by the US Department of Health and Human Services to supplement preexisting and other vaccine safety monitoring systems in tracking the safety of monovalent pandemic 2009 H1N1 influenza vaccine in the United States during 2009-2010. PRISM investigators conducted retrospective analysis to determine whether 2009 H1N1 vaccination was associated with increased risk of any of 14 prespecified outcomes. Five health insurance and associated companies with 38 million members and 9 state/city immunization registries contributed records on more than 2.6 million doses of 2009 H1N1 vaccine. Data on outcomes came from insurance claims. Complementary designs (self-controlled risk interval, case-centered, and current-vs.-historical comparison) were used to optimize control for confounding and statistical power. The self-controlled risk interval analysis of chart-confirmed Guillain-Barré syndrome found an elevated but not statistically significant incidence rate ratio following receipt of inactivated 2009 H1N1 vaccine (incidence rate ratio = 2.50, 95% confidence interval: 0.42, 15.0) and no cases following live attenuated 2009 H1N1 vaccine. The study did not control for infection prior to Guillain-Barré syndrome, which may have been a confounder. The risks of other health outcomes of interest were generally not significantly elevated after 2009 H1N1 vaccination.

Validation of a claims-based diagnostic code for Stevens-Johnson syndrome in a commercially insured population.

PURPOSE: To validate the administrative claims identification of a diagnosis of Stevens-Johnson syndrome (SJS) using medical records as the "gold standard" in a large, commercially insured US population. METHODS: Patients with >1 medical claim with the International Classification of Diseases, Ninth Revision, Clinical Modification code 695.1x between 1 July 2000 and 31 May 2007 were queried in the HealthCore Integrated Research Database(SM) , which contains administrative claims data for 14 commercial health insurance plans. Trained nurses and pharmacists abstracted pertinent information from the identified patients' medical records, which were then reviewed by two independent dermatologists to identify criteria to determine SJS diagnosis. Positive predictive values (PPVs) based on the claims and chart data were computed for all the cases. RESULTS: Medical charts for 200 claims-identified cases, with the International Classification of Diseases, Ninth Revision, Clinical Modification code 695.1x, were abstracted and reviewed by the dermatologists. A total of five cases (PPV = 2.50%, 95%CI = 0.8%-5.7%) were determined to be SJS with clinical certainty. PPVs varied with data stratification: PPV for inpatient claims only (PPV = 2.00%, 95%CI = 0.24%-7.04%), inpatient claims with 695.1x in first diagnosis field (PPV = 4.11%, 95%CI = 0.86%-11.54%), and final decisions of either clinical certainty or probable cases of SJS (PPV = 6.00%, 95%CI = 3.14%-10.25%). CONCLUSION: These findings demonstrate the difficulties associated with identifying rare disorders, which lack specific diagnostic criteria, within administrative claims databases. They underscore the challenges of using claims data to monitor ill-defined clinical conditions as well as the need to validate claims-identified cases with information from other sources, such as medical charts. Copyright © 2012 John Wiley & Sons, Ltd.

Early steps in the development of a claims-based targeted healthcare safety monitoring system and application to three empirical examples.

BACKGROUND: Several efforts are under way to develop and test methods for prospective drug safety monitoring using large, electronic claims databases. Prospective monitoring systems must incorporate signalling algorithms and techniques to mitigate confounding in order to minimize false positive and false negative signals due to chance and bias. OBJECTIVE: The aim of the study was to describe a prototypical targeted active safety monitoring system and apply the framework to three empirical examples. METHODS: We performed sequential, targeted safety monitoring in three known drug/adverse event (AE) pairs: (i) paroxetine/upper gastrointestinal (UGI) bleed; (ii) lisinopril/angioedema; (iii) ciprofloxacin/Achilles tendon rupture (ATR). Data on new users of the drugs of interest were extracted from the HealthCore Integrated Research Database. New users were matched by propensity score to new users of comparator drugs in each example. Analyses were conducted sequentially to emulate prospective monitoring. Two signalling rules--a maximum sequential probability ratio test and an effect estimate-based approach--were applied to sequential, matched cohorts to identify signals within the system. RESULTS: Signals were identified for all three examples: paroxetine/UGI bleed in the seventh monitoring cycle, within 2 calendar years of sequential data; lisinopril/angioedema in the second cycle, within the first monitoring year; ciprofloxacin/ATR in the tenth cycle, within the fifth year. CONCLUSION: In this proof of concept, our targeted, active monitoring system provides an alternative to systems currently in the literature. Our system employs a sequential, propensity score-matched framework and signalling rules for prospective drug safety monitoring and identified signals for all three adverse drug reactions evaluated.

Factors associated with the initiation of proton pump inhibitors in corticosteroid users.

PURPOSE: Proton pump inhibitors (PPIs) and corticosteroids are commonly prescribed drugs; however, each has been associated with fracture and community-acquired pneumonia. How physicians select patients for co-therapy may have implications for potential additive or synergistic toxicities. METHODS: We conducted a retrospective cohort study of 13 749 incident corticosteroid users with no prior PPI exposure using the HealthCore Integrated Research Database(SM) . We used logistic regression to evaluate the association between PPI initiation in the first 30 days of steroid therapy and corticosteroid dose, clinical risk factors including comorbid diseases, and medication use including prescription nonsteroidal anti-inflammatory drugs (NSAIDs). RESULTS: A new PPI prescription within 30 days of starting corticosteroids was filled by 1050 patients (7.6%). PPI use was associated with the number of baseline comorbid conditions (OR = 1.21 for each additional condition, 95%CI = 1.13-1.28), recent hospitalization (OR = 4.71, 95%CI = 4.02-5.52), prednisone dose higher than 40 mg/day (OR = 1.87, 95%CI = 1.45-2.41), history of gastroesophageal reflux or gastric ulcer disease (OR = 1.54, 95%CI = 1.24-1.91), renal insufficiency (OR = 2.06, 95%CI = 1.73-2.46), and liver disease (OR = 1.82, 95%CI = 1.45-2.28). The concomitant use of prescription NSAIDs was also associated with PPI use (OR = 1.89, 95%CI = 1.32-2.70); however, the total use of PPIs in this group was low (6.3%, 95%CI = 4.4-8.2%). CONCLUSIONS: Overall, PPI therapy among corticosteroid users was uncommon, even among those with risk factors for gastrointestinal toxicity. PPI use was significantly more common among patients who had recently been hospitalized, had a greater burden of comorbid illness, or were receiving high daily doses of corticosteroids.

Anticonvulsant medications and the risk of suicide, attempted suicide, or violent death.

CONTEXT: In 2008, the US Food and Drug Administration mandated warning labeling for anticonvulsant medications regarding the increased risk of suicidal thoughts and behaviors. The decision was based on a meta-analysis not sufficiently large to investigate individual drugs. OBJECTIVE: To evaluate the risk of suicidal acts and combined suicidal acts or violent death associated with individual anticonvulsants. DESIGN: A cohort study of the risk of suicidal acts and combined suicidal acts or violent death in patients beginning use of anticonvulsant medications compared with patients initiating a reference anticonvulsant drug. SETTING AND PATIENTS: Patients 15 years and older from the HealthCore Integrated Research Database (HIRD) who began taking an anticonvulsant between July 2001 and December 2006. MAIN OUTCOME MEASURES: Cox proportional hazards models and propensity score-matched analyses were used to evaluate risk of attempted or completed suicide and combined suicidal acts or violent death, controlling for psychiatric comorbidities and other risk factors, among individual anticonvulsants compared with topiramate and secondarily carbamazepine. RESULTS: The study identified 26 completed suicides, 801 attempted suicides, and 41 violent deaths in 297,620 new episodes of treatment with an anticonvulsant (overall median follow-up, 60 days). The incidence of the composite outcomes of completed suicides, attempted suicides, and violent deaths for anticonvulsants used in at least 100 treatment episodes ranged from 6.2 per 1000 person-years for primidone to 34.3 per 1000 person-years for oxcarbazepine. The risk of suicidal acts was increased for gabapentin (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.11-1.80), lamotrigine (HR, 1.84; 95% CI, 1.43-2.37), oxcarbazepine (HR, 2.07; 95% CI, 1.52-2.80), tiagabine (HR, 2.41; 95% CI, 1.65-3.52), and valproate (HR, 1.65; 95% CI, 1.25-2.19), compared with topiramate. The analyses including violent death produced similar results. Gabapentin users had increased risk in subgroups of younger and older patients, patients with mood disorders, and patients with epilepsy or seizure when compared with carbamazepine. CONCLUSION: This exploratory analysis suggests that the use of gabapentin, lamotrigine, oxcarbazepine, and tiagabine, compared with the use of topiramate, may be associated with an increased risk of suicidal acts or violent deaths.

Validation of claims-based diagnostic codes for idiopathic thrombotic thrombocytopenic purpura in a commercially-insured population.

It was the purpose of the present study to validate administrative claims codes for idiopathic thrombotic thrombocytopenic purpura (TTP) in a commercially-insured US population. Patients with at least one medical claim with ICD-9 code 446.6X between 1/1/2001 and 5/31/2008 were identified in the HealthCore Integrated Research Database (HIRD). A chart abstraction form was developed to enable case determination for patients identified by the claims code. Two clinical experts, not involved in the design of the study, reviewed the abstracted medical record data and determined whether definite evidence supporting the diagnosis of TTP was present. The positive predictive value (PPV) of the claims coding algorithm for cases assessed by both reviewers was computed. The claims algorithm was further refined and the PPV of the refined algorithm was computed. One hundred eighty-nine abstracted charts were reviewed by two clinical experts; 86 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 45.5% [86/189; 95% confidence interval (CI), 38.3-52.9%]). Refinement of the claims algorithm first included the use of plasma exchange treatment, resulting in 103 potential cases, of which 67 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 65.0%; 95% CI, 55.0-74.2%). Further refinement of the claims algorithm ruled out alternative diagnoses that may mimic TTP; 34 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 72.3% [34/47; 95% CI, 57.4-84.4%]).Our findings demonstrate the difficulty of confirming the diagnosis of rare disorders that lack definite diagnostic criteria, and indicate that more complex claims coding algorithms are necessary for identifying these disorders.

Clopidogrel use and clinical events after drug-eluting stent implantation: findings from the HealthCore Integrated Research Database.

BACKGROUND: Relationships between long-term use and level of dual antiplatelet therapy and outcomes after drug-eluting stent implantation are not well established. METHODS: This is a retrospective cohort study of 9,256 patients receiving drug-eluting stents between January 2003 and August 2006. We classified patients according to tertiles of clopidogrel use during the 12 months after stent implantation. We used inverse probability weighting to account for differential selection into levels of clopidogrel use and logistic regression to estimate propensity scores for levels of clopidogrel use. We used Cox proportional hazards models to estimate effects of level of clopidogrel use on risk of bleeding events, death, and death or nonfatal myocardial infarction. RESULTS: There were 3,102 patients in the high-use group, 3,069 in the medium-use group, and 3,085 in the low-use group. Compared with the high-use group, risk of death or nonfatal myocardial infarction was greater in the medium-use group (hazard ratio [HR] 1.46, 95% CI 1.09-1.99, P = .01) and the low-use group (HR 1.59, 95% CI 1.18-2.14, P = .002). The risk of bleeding events was lower in the medium-use group (HR 0.84, 95% CI 0.71-0.98, P = .03) and the low-use group (HR 0.77, 95% CI 0.65-0.90, P = .002). CONCLUSIONS: Higher clopidogrel use 12 months after drug-eluting stent implantation was associated with a greater risk of subsequent bleeding events. Lower use was associated with a greater risk of death or nonfatal myocardial infarction.

Validation of claims-based diagnostic and procedure codes for cardiovascular and gastrointestinal serious adverse events in a commercially-insured population.

PURPOSE: To validate administrative claims codes with medical chart review for myocardial infarction (MI), ischemic stroke, and severe upper gastrointestinal (UGI) bleed events in a large, commercially-insured US population. METHODS: These validation studies were part of a larger study examining the risk of MI, ischemic stroke, and severe UGI bleeds in patients receiving a new prescription of selective cyclooxygenase (COX)-2 inhibitors (coxibs) and non-over-the-counter (OTC) non-steroidal anti-inflammatory drugs (NSAIDs), between 1 July 2002 and 30 September 2004. Patients from the study cohort and other health plan members from the HealthCore Integrated Research Database(SM) (HIRD) experiencing these events were selected for these studies. The positive predictive value (PPV) of each of the claims code algorithms, using medical chart review as the gold standard, was calculated. RESULTS: Two hundred charts per event were abstracted. The PPV for MI was 88.4% (177/200; 95%CI, 83.2-92.5%); PPV for ischemic stroke was 87.4% (175/200; 95%CI, 82.0-91.7%); PPV for severe UGI bleed was 56.5% (109/193; 95%CI, 49.2-63.6%). Refining the ischemic stroke claims algorithm resulted in a PPV of 95.5% (95%CI, 91.0-98.2%); refining the claims algorithm for severe UGI bleed resulted in a PPV of 87.8% (95%CI, 78.7-94.0%). CONCLUSION: The results suggest that, for certain adverse events, claims data can serve as the basis for pharmacoepidemiology research and drug safety surveillance in the US.

Disparities in medical care among commercially insured patients with newly diagnosed breast cancer: opportunities for intervention.

BACKGROUND: African-American women have increased breast cancer mortality compared with white women. Diagnostic and treatment gaps may contribute to this disparity. METHODS: In this retrospective, longitudinal cohort study, Southern US health plan claims data and linked medical charts were used to identify racial disparities in the diagnoses, treatment, and mortality of commercially insured women with newly diagnosed breast cancer. White women (n = 476) and African-American women (n = 99) with newly diagnosed breast cancer were identified by breast cancer claims codes (International Classification of Diseases, Ninth Revision, Clinical Modification codes 174, 233.0, 238.3, and 239.3) between January 2000 and December 2004. Race, diagnoses (breast cancer stage, estrogen/progesterone receptor [ER/PR]-positive status), treatment (breast-conserving surgery, antiestrogen therapy, and chemotherapy interruption or reduction), and all-cause mortality were assessed from medical charts. Multivariate regression analyses were adjusted for age, geography, and socioeconomic status to test the association of race with diagnoses/treatment. RESULTS: White women were older (P < .001) and had higher rates of diagnosis at stage 0/I (55.2% vs 38.4%; P < .05) than African-American women. More white women had positive ER/PR status (75% vs 56% African-American; P = .001) and received antiestrogen therapy if they were positive (37.2% vs 27.3% African-American; P < .001). White women received slightly more breast-conserving surgery and chemotherapy dose modification than African-American women (P value nonsignificant). African-American women had a higher mortality rate (8.1%) than white women (3.6%; P = .06). In adjusted analyses, African-American women were diagnosed at later stages (odds ratio, 1.71; P = .02), and white women received more antiestrogen therapy (odds ratio, 2.1; P = .03). CONCLUSIONS: Disparities in medical care among patients with newly diagnosed breast cancer were evident between African-American women and white women despite health plan insurance coverage. Interventions that address the gaps identified are needed.