Variation in incidence rates of outcomes relevant to vaccine safety monitoring in a US commercially insured population by case identification algorithm

BACKGROUND

Large health insurance claims databases can be used to estimate rates of rare safety outcomes. We measured incidence rates of rare outcomes that could be used to contextualize adverse events among people receiving pneumococcal vaccines in clinical trials or clinical practice. However, algorithms used to identify outcomes in administrative databases are subject to error. Using two algorithms for each outcome, we assessed the influence of algorithm choice on the rates of the outcomes.

METHODS

We used closed administrative medical and pharmacy claims in the Healthcare Integrated Research DatabaseSM (HIRD) to construct a broad cohort of individuals less than 100 years old (i.e., the target cohort) and a trial-similar cohort of individuals resembling those potentially eligible for a vaccine clinical trial (e.g., for a pneumococcal vaccine). We stratified by age and sex and used specific and sensitive algorithms to estimate rates of 39 outcomes including cardiac/cerebrovascular, metabolic, allergic/autoimmune, neurological, and hematologic outcomes. Specific algorithms intended to reduce false positive errors, while sensitive algorithms intended to reduce false negative errors, thereby providing lower and upper bounds for the "true" rates.

RESULTS

We followed approximately 40 million individuals in the target cohort for an average of 3 years. Of 39 outcomes, 14 (36 %) had a rate from the specific algorithm that was less than half the rate from the sensitive algorithm. Rates of cardiac/cerebrovascular outcomes were most consistent (mean ratio of rates from specific algorithms compared to rates from sensitive algorithms = 0.76), while the rates of neurological and hematologic outcomes were the least consistent (mean ratio of rates = 0.33 and 0.36, respectively).

CONCLUSIONS

For many cardiac/cerebrovascular outcomes, rates were similar regardless of the algorithm. For other outcomes, rates varied substantially by algorithm. Using multiple algorithms to ascertain outcomes in claims data can be informative about the extent of uncertainty due to outcome misclassification.

Risk of Anaphylaxis Among New Users of GLP-1 Receptor Agonists: A Cohort Study

OBJECTIVE

To assess risk of anaphylaxis among patients with type 2 diabetes mellitus who are initiating therapy with a glucagon-like peptide 1 receptor agonist (GLP-1 RA), with a focus on those starting lixisenatide therapy.

RESEARCH DESIGN AND METHODS

A cohort study was conducted in three large, U.S. claims databases (2017-2021). Adult (aged ≥18 years) new users of a GLP-1 RA who had type 2 diabetes mellitus and ≥6 months enrollment in the database before GLP-1 RA initiation (start of follow-up) were included. GLP-1 RAs evaluated were lixisenatide, an insulin glargine/lixisenatide fixed-ratio combination (FRC), exenatide, liraglutide or insulin degludec/liraglutide FRC, dulaglutide, and semaglutide (injectable and oral). The first anaphylaxis event during follow-up was identified using a validated algorithm. Incidence rates (IRs) and 95% CIs were calculated within each medication cohort. The unadjusted IR ratio (IRR) comparing anaphylaxis rates in the lixisenatide cohort with all other GLP-1 RAs combined was analyzed post hoc.

RESULTS

There were 696,089 new users with 456,612 person-years of exposure to GLP-1 RAs. Baseline demographics, comorbidities, and use of other prescription medications in the 6 months before the index date were similar across medication cohorts. IRs (95% CIs) per 10,000 person-years were 1.0 (0.0-5.6) for lixisenatide, 6.0 (3.6-9.4) for exenatide, 5.1 (3.7-7.0) for liraglutide, 3.9 (3.1-4.8) for dulaglutide, and 3.6 (2.6-4.9) for semaglutide. The IRR (95% CI) for the anaphylaxis rate for the lixisenatide cohort compared with the pooled other GLP-1 RA cohort was 0.24 (0.01-1.35).

CONCLUSIONS

Anaphylaxis is rare with GLP-1 RAs. Lixisenatide is unlikely to confer higher risk of anaphylaxis than other GLP-1 RAs.

Risk of Death and Cardiovascular Events Following an Exacerbation of COPD: The EXACOS-CV US Study

Purpose

This study estimated the magnitude and duration of risk of cardiovascular events and mortality following acute exacerbations of chronic obstructive pulmonary disease (AECOPD), and whether risks varied by number and severity of exacerbation in a commercially insured population in the United States.

Methods

This was a retrospective cohort study of newly diagnosed COPD patients ≥40 years old in the Healthcare Integrated Research Database from 2012 to 2019. Patients experiencing exacerbations comprised the "exacerbation cohort". Moderate exacerbations were outpatient visits with contemporaneous antibiotic or glucocorticoid administration; severe exacerbations were emergency department visits or hospitalizations for AECOPD. Follow-up started on the exacerbation date. Distribution of time between diagnosis and first exacerbation was used to assign index dates to the "unexposed" cohort. Cox proportional hazards models estimated risks of a cardiovascular event or death following an exacerbation adjusted for medical and prescription history and stratified by follow-up time, type of cardiovascular event, exacerbation severity, and rank of exacerbation (first, second, or third).

Results

Among 435,925 patients, 170,236 experienced ≥1 exacerbation. Risk of death was increased for 2 years following an exacerbation and was highest during the first 30 days (any exacerbation hazard ratio (HR)=1.79, 95% CI=1.58-2.04; moderate HR=1.22, 95% CI=1.04-1.43; severe HR=5.09, 95% CI=4.30-6.03). Risks of cardiovascular events were increased for 1 year following an AECOPD and highest in the first 30-days (any exacerbation HR=1.34, 95% CI=1.23-1.46; moderate HR=1.23 (95% CI 1.12-1.35); severe HR=1.93 (95% CI=1.67-2.22)). Each subsequent AECOPD was associated with incrementally higher rates of both death and cardiovascular events.

Conclusion

Risk of death and cardiovascular events was greatest in the first 30 days and rose with subsequent exacerbations. Risks were elevated for 1-2 years following moderate and severe exacerbations, highlighting a sustained increased cardiopulmonary risk associated with exacerbations.

Comparative safety of conjugated estrogens/bazedoxifene versus estrogen/progestin combination hormone therapy among women in the United States: a multidatabase cohort study

OBJECTIVE

To assess the risk of select safety outcomes including endometrial cancer, endometrial hyperplasia, and breast cancer among women using conjugated estrogens/bazedoxifene (CE/BZA) as compared with estrogen/progestin combination hormone therapy (EP).

METHODS

We conducted a new-user cohort study in five US healthcare claims databases representing more than 92 million women. We included CE/BZA or EP new users from May 1, 2014, to August 30, 2019. EP users were propensity score (PS) matched to users of CE/BZA. Incidence of endometrial cancer, endometrial hyperplasia, breast cancer, and eight additional cancer and cardiovascular outcomes were ascertained using claims-based algorithms. Rate ratios (RR) and differences pooled across databases were estimated using random-effects models.

RESULTS

The study population included 10,596 CE/BZA and 33,818 PS-matched EP new users. Rates of endometrial cancer and endometrial hyperplasia were slightly higher among CE/BZA users (1.6 and 0.4 additional cases per 10,000 person-years), although precision was limited because of small numbers of cases (endometrial cancer: RR, 1.50 [95% confidence interval {CI}, 0.79-2.88]; endometrial hyperplasia: RR, 1.69 [95% CI, 0.51-5.61]). Breast cancer incidence was lower in CE/BZA users (9.1 fewer cases per 10,000 person-years; RR, 0.79; 95% CI, 0.58-1.05). Rates of other outcomes were slightly higher among CE/BZA users, but with confidence intervals compatible with a wider range of possible associations.

CONCLUSIONS

CE/BZA users might experience slightly higher rates of endometrial cancer and endometrial hyperplasia, and a lower rate of breast cancer, than EP users in the first years of use.

Real World Treatment Patterns, Healthcare Resource Utilization, and Cost Among Adults with Pulmonary Arterial Hypertension in The United States

Treatment for pulmonary arterial hypertension (PAH) has evolved over the past decade, including approval of new medications and growing evidence to support earlier use of combination therapy. Despite these changes, few studies have assessed real‐world treatment patterns, healthcare resource utilization (HCRU), and costs among people with PAH using recent data. We conducted a retrospective cohort study using administrative claims from the HealthCore Integrated Research Database®. Adult members with claims for a PAH diagnosis, right heart catheterization, and who initiated PAH treatment (index date) between October 1, 2015 and November 30, 2020 were identified. Members had to be continuously enrolled in the health plan for 6 months before the index date (baseline) and ≥30 days after. Treatment patterns, HCRU, and costs were described. A total of 843 members with PAH (mean age 62.3 years, 64.2% female) were included. Only 21.0% of members received combination therapy as their first‐line treatment, while most members (54.6%) received combination therapy as second‐line treatment. All‐cause HCRU remained high after treatment initiation with 58.0% of members having ≥1 hospitalization and 41.3% with ≥1 emergency room visit. Total all‐cause costs declined from $15,117 per patient per month at baseline to $14,201 after treatment initiation, with decreased medical costs ($14,208 vs. $6,349) more than offsetting increased pharmacy costs ($909 vs. $7,852). In summary, despite growing evidence supporting combination therapy, most members with PAH initiated treatment with monotherapy. Total costs decreased following treatment, driven by a reduction in medical costs even with increases in pharmacy costs.

Development and validation of a predictive model algorithm to identify anaphylaxis in adults with type 2 diabetes in U.S. administrative claims data

PURPOSE

To use medical record adjudication and predictive modeling methods to develop and validate an algorithm to identify anaphylaxis among adults with type 2 diabetes (T2D) in administrative claims.

METHODS

A conventional screening algorithm that prioritized sensitivity to identify potential anaphylaxis cases was developed and consisted of diagnosis codes for anaphylaxis or relevant signs and symptoms. This algorithm was applied to adults with T2D in the HealthCore Integrated Research Database (HIRD) from 2016 to 2018. Clinical experts adjudicated anaphylaxis case status from redacted medical records. We used confirmed case status as an outcome for predictive models developed using lasso regression with 10-fold cross-validation to identify predictors and estimate the probability of confirmed anaphylaxis.

RESULTS

Clinical adjudicators reviewed medical records with sufficient information from 272 adults identified by the anaphylaxis screening algorithm, which had an estimated Positive Predictive Value (PPV) of 65% (95% confidence interval [CI]: 60%-71%). The predictive model algorithm had a c-statistic of 0.95. The model's probability threshold of 0.60 excluded 89% (84/94) of false positives identified by the screening algorithm, with a PPV of 94% (95% CI: 91%-98%). The model excluded very few true positives (15 of 178), and identified 92% (95% CI: 87%-96%) of the cases selected by the screening algorithm.

CONCLUSIONS

Predictive modeling techniques yielded an accurate algorithm with high PPV and sensitivity for identifying anaphylaxis in administrative claims. This algorithm could be considered in future safety studies using similar claims data to reduce potential outcome misclassification.

Real-world safety of palbociclib in breast cancer patients in the United States: a new user cohort study

Background

There is limited real-world safety information on palbociclib for treatment of advanced stage HR+/HER2- breast cancer.

Methods

We conducted a cohort study of breast cancer patients initiating palbociclib and fulvestrant from February 2015 to September 2017 using the HealthCore Integrated Research Database (HIRD), a longitudinal claims database of commercial health plan members in the United States.

The historical comparator cohort comprised patients initiating fulvestrant monotherapy from January 2011 to January 2015. Propensity score matching and Cox regression were used to estimate hazard ratios for various safety events. For acute liver injury (ALI), additional analyses and medical record validation were conducted.

Results

There were 2445 patients who initiated palbociclib including 566 new users of palbociclib-fulvestrant, and 2316 historical new users of fulvestrant monotherapy. Compared to these historical new users of fulvestrant monotherapy, new users of palbociclib-fulvestrant had a greater than 2-fold elevated risk for neutropenia, leukopenia, thrombocytopenia, stomatitis and mucositis, and ALI. Incidence of anemia and QT prolongation were more weakly associated, and incidences of serious infections and pulmonary embolism were similar between groups after propensity score matching. After adjustment for additional ALI risk factors, the elevated risk of ALI in new users of palbociclib-fulvestrant persisted (e.g. primary ALI algorithm hazard ratio (HR) = 3.0, 95% confidence interval (CI) = 1.1–8.4).

Conclusions

This real-world study found increased risks of several adverse events identified in clinical trials, including neutropenia, leukopenia, and thrombocytopenia, but no increased risk of serious infections or pulmonary embolism when comparing new users of palbociclib-fulvestrant to fulvestrant monotherapy. We observed an increased risk of ALI, extending clinical trial findings of significant imbalances in grade 3/4 elevations of alanine aminotransferase (ALT).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07790-z.

Patient Knowledge of Safe Use of ER/LA Opioid Analgesics Following Implementation of the Class-Wide REMS: A Survey Study

BACKGROUND/RATIONALE

The US Food and Drug Administration (FDA) approved a Risk Evaluation and Mitigation Strategy (REMS) for extended release/long-acting (ER/LA) opioids in 2012. The purpose of this study was to assess patient knowledge of the safe use of these products following implementation of the REMS and to determine possible effects of the REMS, including impact on medication access.

OBJECTIVE

To assess patient knowledge of safe use of ER/LA opioids and use of REMS patient education tools such as the Medication Guide (MG) and Patient Counseling Document (PCD).

METHODS

This was a cross-sectional survey of commercially insured (Commercial) and Medicare Advantage-insured (Medicare) adults with ≥1 pharmacy claim for an ER/LA opioid (10/01/2015 - 02/28/2017) in the HealthCore Integrated Research Database and Medicaid-insured (Medicaid) adult members of a research panel, about their knowledge of safe use of ER/LA opioids and receipt/comprehension of the MG and PCD.

RESULTS

Survey respondents consisted of 382 Commercial, 43 Medicare and 40 Medicaid adults. While ≥95% of respondents received and read the MG, fewer were aware of the PCD (Commercial: 47%, Medicare: 65%, Medicaid: 53%). Almost 75% of the knowledge questions were answered correctly by ≥80% of all respondents; fewer respondents recognized that use of opioids as directed can lead to death (Commercial: 73%, Medicare: 56%, Medicaid: 63%), the MG should be read at each dispensing (Commercial: 78%, Medicare: 53%, Medicaid: 75%), opioids should not be stored in the medicine cabinet (Commercial: 77%, Medicare: 79%, Medicaid: 58%), missed doses should not be taken as soon as possible (Commercial: 56%, Medicare: 51%, Medicaid: 50%), and pills should not be crushed (Commercial: 85%, Medicare: 67%, Medicaid: 52%).

CONCLUSION

Although most respondents reported reading and understanding the MG and exhibited knowledge of safe use of ER/LA opioids, providers' use of the PCD and increased understanding of safe use core messages need reinforcement.

Prior presumed coronavirus infection reduces COVID-19 risk: A cohort study

BACKGROUND

Immunological cross-reactivity between common cold coronaviruses (CCC) and SARS-CoV-2 might account for the reduced incidence of COVID-19 in children. Evidence to support speculation includes in vitro evidence for humoral and cellular cross-reactivity with SARS-CoV-2 in specimens obtained before the pandemic started.

METHOD

We used retrospective health insurance enrollment records, claims, and laboratory results to assemble a cohort of 869,236 insured individuals who had a PCR test for SARS-CoV-2. We estimated the effects of having clinical encounters for various diagnostic categories in the year preceding the study period on the risk of a positive test result.

FINDINGS

After adjusting for age, gender and care seeking behavior, we identified that individuals with diagnoses for common cold symptoms, including acute sinusitis, bronchitis, or pharyngitis in the preceding year had a lower risk of testing positive for SARS-CoV-2 (OR=0.76, 95%CI=0.75, 0.77). No reduction in the odds of a positive test for SARS-CoV-2 was seen in individuals under 18 years. The reduction in odds in adults remained stable for four years but was strongest in those with recent common cold symptoms.

INTERPRETATION

While this study cannot attribute this association to cross-immunity resulting from a prior CCC infection, it is one potential explanation. Regardless of the cause, the reduction in the odds of being infected by SARS-CoV-2 among those with a recent diagnosis of common cold symptoms may have a role in shifting future COVD-19 infection patterns from endemic to episodic.

A real-world study on characteristics, treatments and outcomes in US patients with advanced stage ovarian cancer

Background

Detailed epidemiologic descriptions of large populations of advanced stage ovarian cancer patients have been lacking to date. This study aimed to describe the patient characteristics, treatment patterns, survival, and incidence rates of health outcomes of interest (HOI) in a large cohort of advanced stage ovarian cancer patients in the United States (US).

Methods

This cohort study identified incident advanced stage (III/IV) ovarian cancer patients in the US diagnosed from 2010 to 2018 in the HealthCore Integrated Research Database (HIRD) using a validated predictive model algorithm. Descriptive characteristics were presented overall and by treatment line. The incidence rates and 95% confidence intervals for pre-specified HOIs were evaluated after advanced stage diagnosis. Overall survival, time to treatment discontinuation or death (TTD), and time to next treatment or death (TTNT) were defined using treatment information in claims and linkage with the National Death Index.

Results

We identified 12,659 patients with incident advanced stage ovarian cancer during the study period. Most patients undergoing treatment received platinum agents (75%) and/or taxanes (70%). The most common HOIs (> 24 per 100 person-years) included abdominal pain, nausea and vomiting, anemia, and serious infections. The median overall survival from diagnosis was 4.5 years, while approximately half of the treated cohort had a first-line time to treatment discontinuation or death (TTD) within the first 4 months, and a time to next treatment or death (TTNT) from first to second-line of about 6 months.

Conclusions

This study describes commercially insured US patients with advanced stage ovarian cancer from 2010 to 2018, and observed diverse treatment patterns, incidence of numerous HOIs, and limited survival in this population.

Outcome misclassification: Impact, usual practice in pharmacoepidemiology database studies and an online aid to correct biased estimates of risk ratio or cumulative incidence

PURPOSE

It is well documented that outcome misclassification can bias a point estimate. We aimed to understand current practice in addressing this bias in pharmacoepidemiology database studies and to develop an open source application (app) from existing methodology to demonstrate the impact and mechanism of this bias on results.

METHODS

Studies of an exposure and a clinical outcome were selected from all Pharmacoepidemiology and Drug Safety publications during 2017 and any reference to outcome misclassification described. An app to correct risk ratio (RR) and cumulative incidence for outcome misclassification was developed from a published methodology and used to demonstrate the impact of correction on point estimates.

RESULTS

Eight (19%) of 43 papers selected reported estimates of outcome ascertainment accuracy with positive predictive value (PPV) the most commonly reported measure (7 of 8 studies). Three studies (7%) corrected for the bias, 1 by exposure strata, and 5 (12%) restricted analyses to confirmed cases. The app (app http://apps.p-95.com/ISPE/) uses values of PPV and sensitivity (or a range of possible values) in each exposure strata and returns corrected point estimates and confidence intervals. The app demonstrates that small differences between comparison groups in PPV or sensitivity can introduce bias even when accuracy estimates are high.

CONCLUSIONS

Outcome misclassification is not usually corrected in pharmacoepidemiology database studies although correction methods using routinely measured indices are available. Error indices are needed for each comparison group to correct RR estimates for these errors. The app should encourage understanding of this bias and increase adjustment.

Incidence of Opioid Overdose Among Patients Using ER/LA Opioid Analgesics Before and After Implementation of the Class-Wide Opioid Risk Evaluation and Mitigation Strategy

Introduction

The United States (US) Food and Drug Administration (FDA) required a Risk Evaluation and Mitigation Strategy (REMS) for extended-release and long-acting (ER/LA) opioid analgesics on 09 July 2012.

Methods

This study compared the incidence of opioid overdose before (July 2010-June 2012) and after (July 2013-September 2016) the initiation of the Risk Evaluation and Mitigation Strategy (REMS) for extended-release and long-acting (ER/LA) opioid analgesics. We identified patients with ≥1 ER/LA opioid dispensing in either time period in national data from the HealthCore Integrated Research Database^SM (HIRD) and in United States (US) Medicaid claims data from four states. We described each population, calculated the incidence rate (IR) of opioid overdose, and assessed crude and propensity score adjusted incidence rate ratios (IRR) comparing the overdose rate after vs before implementation of the REMS.

Results

A total of 121,229 commercially insured and 11,488 Medicaid patients were included in the analysis. Rates of overdose were substantially higher in Medicaid patients than in the commercially insured patients (IR 192.0, 95% confidence interval [CI] 162.60–225.18 versus 102.60, 95% CI 93.0–112.93 in the active period). The IRRs for opioid overdose were 1.01 (95% CI 0.87–1.17) in the commercially insured population and 0.70 (95% CI 0.52–0.93) in Medicaid.

Conclusion

This leveling off of overdose rates among commercially insured patients and decline among Medicaid patients is encouraging, but it is difficult to disentangle the specific impact of the REMS from many other ongoing initiatives with similar goals.

Testosterone Therapy in Relation to Prostate Cancer in a U.S. Commercial Insurance Claims Database

BACKGROUND

We conducted a study to assess whether testosterone therapy (TT) alters prostate cancer risk using a large U.S. commercial insurance research database.

METHODS

From the HealthCore Integrated Research Database (HIRD), we selected men ages 30 years or greater who were new users of TT during 2007 to 2015. We selected two comparison groups: (i) unexposed (matched 10:1) and (ii) new users of phosphodiesterase type 5 inhibitor (PDE5i). Incident prostate cancer was defined as diagnosis of prostate cancer within 4 weeks following prostate biopsy. Propensity scores and inverse probability of treatment weights were used in Poisson regression models to estimate adjusted incidence rates, incidence rate ratios (IRR), and 95% confidence intervals (CI). Subgroup analyses included stratification by prostate cancer screening, hypogonadism, and follow-up time.

RESULTS

The adjusted prostate cancer IRR was 0.77 (95% CI, 0.68-0.86) when comparing TT with the unexposed group and 0.85 (95% CI, 0.79-0.91) in comparison with the PDE5i group. Inverse associations between TT and prostate cancer were observed in a majority of subgroup analyses, although in both comparisons estimates generally attenuated with increasing time following initial exposure. Among TT users, duration of exposure was not associated with prostate cancer.

CONCLUSIONS

Men who received TT did not have a higher rate of prostate cancer compared with the unexposed or PDE5i comparison groups. The inverse association between TT and prostate cancer could be the result of residual confounding, contraindication bias, or undefined biological effect.

IMPACT

This study suggests that limited TT exposure does not increase risk of prostate cancer in the short term.

Characteristics, treatment patterns, and survival from three cohorts of advanced or metastatic cancer patients using health care claims data in the United States

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Background: Our main objective was to identify, in healthcare claims data, patients with advanced or metastatic: urothelial carcinoma (amUC), gastric cancer (amGC) and non-small cell lung cancer (amNSCLC) and to report on their characteristics, treatments, and survival rates using contemporaneous real-world data. Methods: This cohort study was conducted in the HealthCore Integrated Research Database (HIRD), from January 2010 to January 2018, which contains healthcare claims data from commercial health plans across the US (60 million lives). We applied algorithms, previously validated on registry data, to the HIRD to define 3 cohorts of advanced stage cancer. Cohort characteristics and treatment patterns were described. Patient vital status was captured through probabilistic linkage with the National Death Index (NDI) and survival was assessed using the Kaplan-Meier method. Results: Algorithms to predict advanced stage cancer resulted in the following cohorts: 1,501 amUC, 6,253 amGC and 38,451 amNSCLC cases. Most patients in each cohort were de novo advanced or metastatic, but subsets were diagnosed at early stage and progressed to advanced stage (ranging from 15.1% for amNSCLC to 23.1% for amUC). Patient characteristics, treatments and survival outcomes are described in Table 1. Not all received systemic treatment; Immune Checkpoint inhibitors (ICI) were used in 5.3%, 2.2% and 10.8% of treated amUC, amGC and amNSCLC patients, respectively. Conclusions: In these cohorts of advanced or metastatic cancer patients, median survival time was limited despite most receiving treatment: radiation, systemic therapy or surgery. Treatment with ICI was low despite recent data in amUC and amNSCLC.[Table: see text]

Medical record-based ascertainment of behaviors suggestive of opioid misuse, diversion, abuse, and/or addiction among individuals showing evidence of doctor/pharmacy shopping

Objectives

Doctor/pharmacy shopping, the practice of seeking prescriptions from multiple healthcare sources without their coordination, may be a measure of prescription medicine abuse. This cross-sectional study examined the relationship between a claims-based doctor/pharmacy shopping definition and medical record documented behaviors suggestive of misuse, diversion, abuse and/or addiction.

Methods

Patients with ≥2 opioid dispensings starting in 2012 in a US administrative claims database were grouped into doctor/pharmacy shopping categories by number of providers and pharmacies used over 18 months: no shopping, minimal shopping, moderate shopping and severe shopping. Medical charts of opioid prescribers were reviewed to identify behaviors suggestive of misuse, diversion, abuse and/or addiction.

Results

Among 581,940 opioid users, 78% were classified as no shopping, 11% minimal shopping, 8% moderate shopping and 3% severe shopping. Almost 40% of severe shopping patients had no medical record documented behaviors (positive predictive value: 24.3%). Compared with no shopping, the odds ratio [OR] of ≥3 behaviors was 1.70 (95% confidence interval [CI] 0.50–5.78) for minimal shopping, 1.81 (95% CI 0.54–6.03) for moderate shopping, and 8.93 (95% CI 3.12–25.54) for severe shopping.

Conclusions

Claims-identified severe doctor/pharmacy shopping was strongly associated with behaviors suggestive of misuse, diversion, abuse and/or addiction, but the proportion of medical records documenting these was low.

Development of predictive models to identify advanced-stage cancer patients in a US healthcare claims database

BACKGROUND

Although healthcare databases are a valuable source for real-world oncology data, cancer stage is often lacking. We developed predictive models using claims data to identify metastatic/advanced-stage patients with ovarian cancer, urothelial carcinoma, gastric adenocarcinoma, Merkel cell carcinoma (MCC), and non-small cell lung cancer (NSCLC).

METHODS

Patients with ≥1 diagnosis of a cancer of interest were identified in the HealthCore Integrated Research Database (HIRD), a United States (US) healthcare database (2010-2016). Data were linked to three US state cancer registries and the HealthCore Integrated Research Environment Oncology database to identify cancer stage. Predictive models were constructed to estimate the probability of metastatic/advanced stage. Predictors available in the HIRD were identified and coefficients estimated by Least Absolute Shrinkage and Selection Operator (LASSO) regression with cross-validation to control overfitting. Classification error rates and receiver operating characteristic curves were used to select probability thresholds for classifying patients as cases of metastatic/advanced cancer.

RESULTS

We used 2723 ovarian cancer, 6522 urothelial carcinoma, 1441 gastric adenocarcinoma, 109 MCC, and 12,373 NSCLC cases of early and metastatic/advanced cancer to develop predictive models. All models had high discrimination (C > 0.85). At thresholds selected for each model, PPVs were all >0.75: ovarian cancer = 0.95 (95% confidence interval [95% CI]: 0.94-0.96), urothelial carcinoma = 0.78 (95% CI: 0.70-0.86), gastric adenocarcinoma = 0.86 (95% CI: 0.83-0.88), MCC = 0.77 (95% CI 0.68-0.89), and NSCLC = 0.91 (95% CI 0.90 - 0.92).

CONCLUSION

Predictive modeling was used to identify five types of metastatic/advanced cancer in a healthcare claims database with greater accuracy than previous methods.

Characteristics, treatment patterns, and survival from three cohorts of advanced or metastatic cancer patients using healthcare claims data in the United States

e13082

Background: Our main objective was to identify, in healthcare claims data, patients with advanced or metastatic: urothelial carcinoma (amUC), gastric cancer (amGC) and non-small cell lung cancer (amNSCLC) and to report on their characteristics, treatments, and survival rates using contemporaneous real-world data. Methods: This cohort study was conducted in the HealthCore Integrated Research Database (HIRD), from January 2010 to January 2018, which contains healthcare claims data from commercial health plans across the US (60 million lives). We applied algorithms, previously validated on registry data, to the HIRD to define 3 cohorts of advanced stage cancer. Cohort characteristics and treatment patterns were described. Patient vital status was captured through probabilistic linkage with the National Death Index (NDI) and survival was assessed using the Kaplan-Meier method. Results: Algorithms to predict advanced stage cancer resulted in the following cohorts: 1,501 amUC, 6,253 amGC and 38,451 amNSCLC cases. Most patients in each cohort were de novo advanced or metastatic, but subsets were diagnosed at early stage and progressed to advanced stage (ranging from 15.1% for amNSCLC to 23.1% for amUC). Patient characteristics, treatments and survival outcomes are described in Table. Not all received systemic treatment; Immune Checkpoint inhibitors (ICI) were used in 5.3%, 2.2% and 10.8% of treated amUC, amGC and amNSCLC patients, respectively. Conclusions: In these cohorts of advanced or metastatic cancer patients, median survival time was limited despite most receiving treatment: radiation, systemic therapy or surgery. Treatment with ICI was low despite recent data in amUC and amNSCLC. Characteristics, treatments, and survival from estimated advanced stage date. [Table: see text]

Incidence of outcomes relevant to vaccine safety monitoring in a US commercially-insured population

BACKGROUND

Background incidence rates (IRs) of potential safety outcomes among vaccine eligible individuals can inform assessment of vaccine safety. Vaccine safety surveillance often uses claims databases, but the impact of outcome definitions on background IR estimates is largely unexplored. Using two definitions for each outcome, we estimated background IRs of 32 cardiac, metabolic, allergic, autoimmune, neurologic, hematologic and nephrologic outcomes among individuals eligible to receive pneumococcal vaccination.

METHODS

We defined a cohort of individuals aged 6-100 years in US commercial health plans who had ≥12 months of health plan enrollment between January 2007 and August 2014 and no previous record of conjugate or simple polysaccharide pneumococcal vaccination. We developed a sensitive and a specific definition for each outcome, with the specific definition requiring evidence of additional care consistent with the outcome. IRs per 100,000 person-years for each outcome were presented overall and stratified by age, gender, and invasive pneumococcal disease (IPD) risk category.

RESULTS

We followed 19.9 million individuals for a median of 2.5 years. Wide variation was seen in IRs across different definitions of the 32 outcomes, with 19 (59%) outcomes having a specific definition IR less than half of the sensitive definition IR. IRs were particularly variable by definition for outcomes categorized as either hematologic/nephrologic or neurologic (mean ratio of specific IR to sensitive IR = 0.26 and 0.30, respectively). Across definitions, the IRs of the 32 outcomes were often highest in females, adults ≥65, and those at higher IPD risk.

CONCLUSIONS

Background IRs of safety outcomes relevant to populations indicated for pneumococcal vaccine varied by outcome definitions and population subgroups in this large US commercially-insured population. Given large differences in estimated IRs using sensitive versus specific case definitions, neurologic, and hematologic/nephrologic safety outcomes as compared to allergic and autoimmune outcomes may warrant more refined definitions and medical record validation.

Predictive model algorithms identifying early and advanced stage ER+/HER2- breast cancer in claims data

PURPOSE

Claims databases offer large populations for research, but lack clinical details. We aimed to develop predictive models to identify estrogen receptor positive (ER+) and human epidermal growth factor negative (HER2-) early breast cancer (ESBC) and advanced stage breast cancer (ASBC) in a claims database.

METHODS

Female breast cancer cases in Anthem's Cancer Care Quality Program served as the gold standard validation sample. Predictive models were developed from clinical knowledge and empirically from claims data using logistic and lasso regression. Model performance was assessed by classification rates and c-statistics. Models were applied to the HealthCore Integrated Research Database (claims) to identify cohorts of women with ER+/HER2- ESBC and ASBC.

RESULTS

The validation sample included 3184 women with ER+/HER2- ESBC and 1436 with ER+/HER2- ASBC. Predictive models for ER+/HER2- ESBC and ASBC included 25 and 20 factors, respectively. Models had robust discrimination in identifying cases (c-stat = 0.92 for ESBC and 0.95 for ASBC). Compared with a traditional a priori algorithm developed with clinical insight alone, the ER+/HER2- ASBC-predictive model had better positive predictive value (PPV) (0.91, 95% CI, 0.90-0.93, vs 0.69, 95% CI, 0.66-0.73) and sensitivity (0.54 vs 0.35). Models were applied to the claims database to identify cohorts of 33 001 and 3198 women with ER+/HER2- ESBC and ASBC.

CONCLUSION

We conducted a validation study and developed predictive models to identify in a claims database cohorts of women with ER+/HER2- ESBC and ASBC. The models identified large cohorts in the claims data that can be used to characterize indications in the evaluation of targeted therapies.

Development and Validation of an Algorithm for Identifying Patients with Hemophilia A in an Administrative Claims Database

BACKGROUND

The accuracy with which hemophilia A can be identified in claims databases is unknown.

OBJECTIVE

Develop and validate an algorithm using predictive modeling supported by machine learning to identify patients with hemophilia A in an administrative claims database.

METHODS

We first created a screening algorithm using medical and pharmacy claims to identify potential hemophilia A patients in the US HealthCore Integrated Research Database between January 1, 2006 and April 30, 2015. Medical records for a random sample of patients were reviewed to confirm case status. In this validation sample, we used lasso logistic regression with cross-validation to select covariates in claims data and develop a predictive model to estimate the probability of being a confirmed hemophilia A case.

RESULTS

The screening algorithm identified 2,252 patients and we reviewed medical records for 400 of these patients. The screening algorithm had a positive predictive value (PPV) of 65%. The predictive model identified 18 predictors of being a hemophilia A case or noncase. The strongest predictors of case status included male sex, factor VIII therapy, office visits for hemophilia A, and hospitalizations for hemophilia A. The strongest predictors of noncase status included hospitalizations for reasons other than hemophilia A and factor VIIa therapy. A probability threshold of ≥0.6 resulted in a PPV of 94.7% (95% CI: 92.0-97.5) and sensitivity of 94.4% (95% CI: 91.5-97.2).

CONCLUSIONS

We developed and validated an algorithm to identify hemophilia A cases in an administrative claims database with high sensitivity and high PPV.

Patient and prescriber characteristics among patients with type 2 diabetes mellitus continuing or discontinuing sulfonylureas following insulin initiation: data from a large commercial database

OBJECTIVE

To describe patient and provider characteristics for patients with type 2 diabetes (T2DM) initiating basal insulin and describe basal insulin's impact on sulfonylurea (SU) discontinuation.

METHODS

A retrospective cohort study was conducted using the HealthCore Integrated Research Database. Patients had ≥12 months of continuous coverage prior to initiating insulin, and were utilizing at least one anti-hyperglycemic drug at the time of insulin initiation. Predictors for SU discontinuation were evaluated utilizing Cox proportional hazards models.

RESULTS

Among the 74,334 individuals aged ≥18 years with T2DM who initiated basal insulin from 2006-2015, 30% were taking metformin (MET) and SU when initiating insulin. Among the 22,418 MET/SU patients, 31% discontinued SU within 3 months of insulin initiation and, by 12 months, 55% had discontinued SU. Sulfonylurea discontinuation was similar among many patient and provider characteristics, while being modestly positively associated (p < .05; HRs <1.5) with female gender, more co-morbidities, cardiac revascularization, chronic liver disease, hospitalizations with a T2DM diagnosis, and hypoglycemia prior to insulin initiation. SU discontinuation was modestly inversely associated with receiving an insulin prescription from an endocrinologist (HR = 0.90, 95% CI = 0.85-0.95).

CONCLUSIONS

Roughly half of commercially-insured T2DM patients discontinued SU within 1 year after insulin initiation, and SU discontinuation was not strongly associated with a range of patient and provider characteristics.

Identifying patients according to breast cancer stage and ER/HER2 receptor status using claims data

e13096

Background: Safety analyses of targeted oncology therapies often require cancer stage and receptor status. Automated claims databases offer the largest populations to study rare outcomes, but lack these characteristics. We conducted a validation study of claims data using predictive models to identify two cohorts of women with early-stage and advanced-stage ER+/HER2- breast cancer (ESBC and ASBC, respectively). Methods: Retrospective cohort and validation study using electronic data linkage of a nationwide claims database (HealthCore Integrated Research Database – HIRD) and Anthem’s Cancer Care Quality program (CCQP). The CCQP served as a validation sample. We used claims data to develop two predictive models to estimate breast cancer stage and receptor status. We applied these models to the HIRD to identify ER+/HER2- ESBC and ASBC cohorts. In each cohort we assessed adverse event (AE) rates. Results:: In addition to breast cancer diagnoses, predictive models for ER+/HER2- ESBC and ASBC included 21 and 15 factors, respectively (Table).When compared to an a priori ASBC algorithm developed from clinical experience, the claims-based predictive model for ASBC had better PPV (0.78 v. 0.62) with similar sensitivity (0.39 v. 0.38). For the ASBC cohort, selected AE rates per 100 person-years included: anemia, 26.4; neutropenia, 14.3; pulmonary embolism, 5.7; and leukopenia, 4.0. Conclusions: Identification ofcancer stage and biomarkers using claims data can be improved through predictive modeling. ER+/HER2- ESBC and ASBC cohorts are being utilized for characterizing indications and conducting safety evaluations of targeted therapies. [Table: see text]

The feasibility of using multiple databases to study rare outcomes: the potential effect of long-acting beta agonists with inhaled corticosteroid therapy on asthma mortality

PURPOSE

Long-acting beta agonists (LABAs) when used without concomitant inhaled corticosteroids (ICS) increase the risk of asthma-related deaths, but the effect on asthma-related death of LABA used in combination with ICS therapy is unknown. To address this question, we explored the feasibility of conducting an observational study using multiple US health care data sources.

METHODS

Retrospective cohort study to evaluate the likelihood of getting an upper 95% confidence limit ≤1.4 for the asthma mortality rate ratio and ≤0.40 per 10 000 person-years for the mortality rate difference, assuming no effect of new use of combined LABA + ICS (versus non-LABA maintenance therapy) on asthma mortality. Ten research institutions executed centrally distributed analytic code based on a standard protocol using an extracted (2000-2010) persistent asthma cohort (asthma diagnosis and ≥4 asthma medications in 12 months). Pooled results were analyzed by the coordinating center. Asthma deaths were ascertained by linkage with the National Death Index.

RESULTS

In a cohort of 994 627 persistent asthma patients (2.4 million person-years; 278 asthma deaths), probabilities of the upper 95% confidence limit for effect estimates being less than targeted values, assuming a null relation, were about 0.05. Modifications in cohort and exposure definitions increased exposed person-time and outcome events, but study size remained insufficient to attain study goals.

CONCLUSIONS

Even with 10 data sources and a 10-year study period, the rarity of asthma deaths among patients using certain medications made it infeasible to study the association between combined LABA + ICS and asthma mortality with our targeted level of study precision. Copyright © 2016 John Wiley & Sons, Ltd.

Idiopathic Pulmonary Fibrosis in United States Automated Claims. Incidence, Prevalence, and Algorithm Validation

RATIONALE

Estimates of idiopathic pulmonary fibrosis (IPF) incidence and prevalence from electronic databases without case validation may be inaccurate.

OBJECTIVES

Develop claims algorithms to identify IPF and assess their positive predictive value (PPV) to estimate incidence and prevalence in the United States.

METHODS

We developed three algorithms to identify IPF cases in the HealthCore Integrated Research Database. Sensitive and specific algorithms were developed based on literature review and consultation with clinical experts. PPVs were assessed using medical records. A third algorithm used logistic regression modeling to generate an IPF score and was validated using a separate set of medical records. We estimated incidence and prevalence of IPF using the sensitive algorithm corrected for the PPV.

MEASUREMENTS AND MAIN RESULTS

We identified 4,598 patients using the sensitive algorithm and 2,052 patients using the specific algorithm. After medical record review, the PPVs of these algorithms using the treating clinician's diagnosis were 44.4 and 61.7%, respectively. For the IPF score, the PPV was 76.2%. Using the clinical adjudicator's diagnosis, the PPVs were 54 and 57.6%, respectively, and for the IPF score, the PPV was 83.3%. The incidence and period prevalences of IPF, corrected for the PPV, were 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively.

CONCLUSIONS

Sensitive algorithms without correction for false positive errors overestimated incidence and prevalence of IPF. An IPF score offered the greatest PPV, but it requires further validation.

A common data model to assess cardiovascular hospitalization and mortality in atrial fibrillation patients using administrative claims and medical records

Purpose

Atrial fibrillation/flutter (AF) is frequently associated with cardiovascular comorbidities. Observational health care databases are commonly used for research purposes in studies of quality of care, health economics, outcomes research, drug safety, and epidemiology. This retrospective cohort study applied a common data model to administrative claims data (Truven Health Analytics MarketScan^® claims databases [MS-Claims]) and electronic medical records data (Geisinger Health System’s MedMining electronic medical record database [MG-EMR]) to examine the risk of cardiovascular hospitalization and all-cause mortality in relation to clinical risk factors in recent-onset AF and to assess the consistency of analyses for each data source.

Methods

Cohorts of patients with newly diagnosed AF (n=105,262 [MS-Claims] and n=3,919 [MG-EMR]) and demographically similar patients without AF (n=105,262 [MS-Claims] and n=3,872 [MG-EMR]) were followed from the qualifying AF diagnosis until cardiovascular hospitalization, death, database disenrollment, or study completion. A common data model standardized the data in structure, format, content, and nomenclature to allow for systematic assessment and comparison of outcomes from two disparate data sets.

Results

In both databases, AF patients had greater overall baseline comorbidity and higher incidence rates of cardiovascular hospitalization (threefold higher) and all-cause mortality (46% higher) than non-AF patients. For AF patients, incidence rates of cardiovascular hospitalization and all-cause mortality were increased by the concomitant presence of coronary disease, chronic obstructive pulmonary disease, and stroke at baseline. Overall, the pattern of cardiovascular hospitalization in the MS-Claims database was similar to that in the MG-EMR database. Compared with the MS-Claims database, the use of cardiovascular medications and the capture of certain comorbidities among AF patients appeared to be higher in the MG-EMR data set.

Conclusion

Similar standardized analyses across EMR and Claims databases were consistent in the association of AF with acute morbidity and an increased risk of all-cause mortality. Areas of inconsistency were due to differences in underlying population demographics and cardiovascular risks and completeness of certain data fields.

Occurrence of adverse events among patients with inflammatory bowel disease in the HealthCore Integrated Research Database

OBJECTIVES

Inflammatory bowel disease (IBD) is a chronic condition commonly requiring lifelong care. Both IBD and IBD-related treatments can cause significant morbidity, and it is often difficult to differentiate their relative etiologic contribution to adverse events (AEs). The objectives of this study were to assess the rates of select AEs among patients with IBD as a function of disease severity and of the use of anti-tumor necrosis factor alpha (anti-TNFα) medications.

METHODS

We conducted a retrospective cohort study of IBD patients in the HealthCore Integrated Research Database (HIRD(TM)) between January 2004 and January 2011 to determine rates of AEs in patients with mild and moderate to severe IBD. Key study endpoints were select prespecified malignant neoplasms, infections, and other AEs of interest.

RESULTS

A total of 33,386 IBD patients (52.7% ulcerative colitis; 47.3% Crohn's disease) met the inclusion criteria, and 60% had been followed for ≥1 year. Patients with moderate to severe IBD had increased rates of infections, lymphatic and digestive tract cancers, gastrointestinal (GI) perforations, and myocardial infarctions versus patients with mild IBD. Patients with IBD who used anti-TNFα therapies during the study had increased incidence of many types of infections, certain GI cancers (including rectal and anal cancer), intestinal perforations, and kidney stones compared with patients who had never used anti-TNFα therapies.

CONCLUSIONS

Results from this large US cohort provide descriptive information on AE rates in a population of IBD patients undergoing routine care, estimating background incidence rates of AEs that are not readily available in the published literature. Our study findings may be limited owing to a lack of generalizability and potential for misclassification due to reliance on medical diagnosis and treatment and procedure codes to identify disease, comorbidities, and treatments. Further research and validation of our findings in other populations and databases are needed.

Role of pharmacoepidemiology studies in addressing pharmacovigilance questions: a case example of pancreatitis risk among ulcerative colitis patients using mesalazine

PURPOSE

Well-designed pharmacoepidemiology studies address several limitations of postmarketing spontaneous reports in regard to signal evaluation. This study evaluated a signal of disproportionate reporting of acute pancreatitis cases observed in patients with ulcerative colitis (UC) treated with MMX Multi Matrix System® (MMX®) mesalazine and demonstrated how inherent limitations of postmarketing reports were overcome.

METHODS

Adults with UC who were new users of MMX mesalazine or another branded mesalazine (controlled-release, delayed-release, or extended-release mesalazine; balsalazide disodium; olsalazine sodium; sulfasalazine; or sulfasalazine delayed-release) were identified from a large US administrative healthcare claims database. Acute pancreatitis incidence rates were compared between patients on MMX mesalazine versus comparator therapies. Propensity scores were used to match patients on MMX mesalazine with patients on comparator drugs to achieve a balance of baseline patient factors.

RESULTS

Crude incidence rates [95 % confidence interval (CI)] of acute pancreatitis among patients on MMX mesalazine were similar to those of patients on comparator therapies [8.55 (5.54-13.21) vs 10.05 (7.54-13.41) per 1000 person-years]; the resulting incidence rate ratio (IRR) was [0.85 (0.48-1.47)]. Propensity score-matching had little influence on the IRR [0.84 (0.46-1.55)]; nor did further adjustment by demographic characteristics, daily dose, and causes of acute pancreatitis [0.76 (0.41-1.43)].

CONCLUSION

Findings of no increase in pancreatitis risk with MMX mesalazine demonstrate the value of pharmacoepidemiology studies for evaluating a drug's postmarket safety profile when confronted with spontaneous reporting data suggestive of a safety issue.

Dementia Coding, Workup, and Treatment in the VA New England Healthcare System

Growing evidence suggests that Alzheimer's disease and other types of dementia are underdiagnosed and poorly documented. In our study, we describe patterns of dementia coding and treatment in the Veteran's Administration New England Healthcare System. We conducted a retrospective cohort study with new outpatient ICD-9 codes for several types of dementia between 2002 and 2009. We examined healthcare utilization, medication use, initial dementia diagnoses, and changes in diagnoses over time by provider type. 8,999 veterans received new dementia diagnoses during the study period. Only 18.3% received a code for cognitive impairment other than dementia, most often "memory loss" (65.2%) prior to dementia diagnosis. Two-thirds of patients received their initial code from a PCP. The etiology of dementia was often never specified by ICD-9 code, even by specialists. Patients followed up exclusively by PCPs had lower rates of neuroimaging and were less likely to receive dementia medication. Emergency room visits and hospitalizations were frequent in all patients but highest in those seen by dementia specialists. Dementia medications are commonly used off-label. Our results suggest that, for the majority the patients, no prodrome of the dementia syndrome is documented with diagnostic code, and patients who do not see dementia specialists have less extensive diagnostic assessment and treatment.

Comparative risk of bloodstream infection in hospitalized patients receiving intravenous medication by open, point-of-care, or closed delivery systems

PURPOSE

The impact of i.v. drug delivery via point-of-care (POC)-activated and closed systems versus traditional manual admixture systems on the risk of hospital-acquired bloodstream infection (BSI) is examined.

METHODS

Using data from a proprietary hospital database, a retrospective observational cohort study of patients receiving one or more i.v. drug administrations via POC-activated or closed systems during a three-year period (2007-09) was conducted. Cases of hospital-acquired BSI were identified using diagnosis codes and billing charges for blood cultures and antibiotic use. The risk of BSI in patients with exposure to POC-activated systems, closed systems, or both relative to that of patients exposed to open systems was estimated by odds ratios (ORs) calculated by multivariate logistic regression analysis.

RESULTS

The evaluated data indicated that of the 4,073,864 patients included in the study cohort, 0.5% (n = 20,251) experienced hospital-acquired BSI. After adjusting for selected confounding variables, the use of POC-activated systems was associated with a 16% reduction in BSI risk relative to the use of open systems (OR, 0.84; 95% confidence interval [CI], 0.76-0.93), and the use of closed systems correlated with a 12% risk reduction (OR, 0.88; 95% CI, 0.82-0.96). Patients who received i.v. drugs via both POC-activated and closed systems appeared to derive the greatest relative risk reduction benefit (OR, 0.12; 95% CI, 0.06-0.23).

CONCLUSION

Use of POC-activated and closed systems for i.v. drug delivery was associated with a significantly reduced risk of hospital-acquired BSI compared with exclusive use of open systems in a large population of hospitalized patients.

A new user cohort study comparing the safety of long-acting inhaled bronchodilators in COPD

OBJECTIVE

To investigate a possible increased risk observed in tiotropium clinical trials of stroke and other adverse events.

DESIGN

New users of long-acting anticholinergic therapy (tiotropium HandiHaler®) were compared with new users of long-acting β-agonist (LABA) monotherapy, and propensity scores were used to control confounding.

SETTING

UK healthcare system general practitioner electronic medical record database.

PARTICIPANTS

10 840 patients newly prescribed tiotropium (n=4767) or LABA (n=6073), at least 40 years old, and not having asthma as their only respiratory illness.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incidence rates of total stroke, myocardial infarction, angina and other adverse events.

RESULTS

Tiotropium was associated with increased rates of stroke (HR=1.49, 95% CI 0.91 to 2.45), angina (HR=1.38, 95% CI 0.88 to 2.16) and myocardial infarction (HR=1.26, 95% CI 0.72 to 2.21). Groups had similar rates of chronic obstructive pulmonary disease exacerbation (HR=0.95, 95% CI 0.80 to 1.12) and pneumonia (HR=0.96, 95% CI 0.58 to 1.58). Tiotropium was associated with a lower rate of total mortality (HR=0.70, 95% CI 0.56 to 0.89) and asthma exacerbations (HR=0.46, 95% CI 0.36 to 0.57) than users of LABA.

CONCLUSION

Small increased risks of serious ischaemic cardiovascular events have been reported with inhaled anticholinergic medication from randomised and nonrandomized studies of ipratropium, tiotropium HandiHaler® and tiotropium Respimat®. Additional research is needed to understand the full extent of cardiovascular effects of inhaled anticholinergic medications and the patients who may be most susceptible.

Burden of illness in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis is a life-threatening condition, and few data concerning the impact on healthcare utilization and associated costs are available. The objective of this study was to describe the burden of illness (comorbidity, healthcare resource utilization, and associated costs) in patients with idiopathic pulmonary fibrosis.

METHODS

Two cohorts (patients with idiopathic pulmonary fibrosis and matched controls) were retrospectively identified from US claims databases between January 1, 2001 and September 30, 2008. Cases with idiopathic pulmonary fibrosis were defined by age of 55 years or older and either two or more claims with a code for idiopathic fibrosing alveolitis (ICD-9 516.3), or one claim with ICD 516.3 and a subsequent claim with a code for post-inflammatory pulmonary fibrosis (ICD-9 515). The prevalence and incidence of pre-selected comorbidities, healthcare resource utilization (hospital, outpatient, drugs), and direct medical costs were assessed in each cohort.

RESULTS

A total of 9286 patients with idiopathic pulmonary fibrosis were identified. When compared with age- and gender-matched controls, these patients were at significantly increased risk for comorbidities including pulmonary hypertension and emphysema. The all-cause hospital admission rate (0.5 per person-year) and the all-cause outpatient visit rate (28.0 per person-year) were both ∼2-fold higher than in controls. Total direct costs for patients with idiopathic pulmonary fibrosis were $26,378 per person-year; the incremental costs over controls were $12,124 (2008 value).

CONCLUSIONS

Patients with idiopathic pulmonary fibrosis experience increased comorbidity, healthcare resource utilization, and direct medical costs compared to controls.

Incidence rates for thromboembolic, bleeding and hepatic outcomes in patients undergoing hip or knee replacement surgery

BACKGROUND

Data on clinical outcomes of patients in the general population undergoing knee replacement or hip replacement surgery are sparse.

OBJECTIVES

To conduct an observational study using insurance claims data to assess the incidence of selected clinical events following knee replacement or hip replacement surgery in the USA.

PATIENTS/METHODS

A total of 97,469 knee replacement patients and a total of 45,203 hip replacement patients were included during the period 2004-2008; the median age was 64 years, and 63% of knee replacement patients and 55% of hip replacement patients were women.

RESULTS

During a median follow-up of 70-71 days, the incidence rates in knee replacement patients and hip replacement patients were, respectively: ischemic stroke, 15 and 19 per 1000 person-years; acute coronary syndrome (ACS), 15 and 18 per 1000 person-years; bleeding events, 46 and 47 per 1000 person-years; venous thromboembolism (VTE), 64 and 45 per 1000 person-years; and hepatic events, one and one per 1000 person-years. Approximately 45% of knee replacement and hip replacement patients had no claims for outpatient anticoagulant therapy within 1 week after discharge from hospital.

CONCLUSIONS

Ischemic events such as stroke, ACS and VTE are important adverse events following knee replacement and hip replacement surgery. The results reported here can help in making challenging decisions regarding the clinical management of risks attributable to bleeding events and clotting events.

Estimating effects from randomized trials with discontinuations: the need for intent-to-treat design and G-estimation

BACKGROUND

Randomized trials provide pivotal evidence for evaluation and approval of therapies. Nonetheless, such trials are often plagued by noncompliance, especially in the form of premature discontinuation of treatment. While intent-to-treat (ITT) analysis can provide valid tests of no-effect hypotheses, some trials may make ITT analysis impossible by ceasing follow-up when patients go off assigned treatment. Furthermore, estimates based on ITT, on-treatment, or per-protocol comparisons can seriously understate harm or benefit.

PURPOSE

To show how g-estimation based on randomization status is a natural generalization of ITT null testing to estimating efficacy from trials with important discontinuation or noncompliance.

METHODS

We contrast with an analysis of the effect of a tiotropium inhaler on the occurrence of chronic obstructive pulmonary disease (COPD) events in a six-month double-blind placebo-controlled trial of 1829 patients with good but imperfect compliance.

RESULTS

The covariate-adjusted point estimates, 95% confidence limits (CL), and null P-values comparing expected COPD event times in placebo versus tiotropium patients were: ITT, 1.21, CL = 1.02, 1.43, P = 0.027; on-treatment, 1.27, CL = 1.06, 1.52, P = 0.009; per-protocol, 1.36, CL = 1.13, 1.63, P = 0.001; and g-estimation, 1.31, CL = 1.03,1.72, P = 0.027. Thus g-estimation preserved the ITT test of the null, but exhibited more uncertainty about the size of the tiotropium effect than the other methods. In particular, it allowed for a much larger potential effect than did ITT analysis, but produced a much larger null P than exhibited by per-protocol analysis.

LIMITATIONS

Like ITT analysis, g-estimation requires all patients be followed to the end of the trial protocol, regardless of whether they comply with the protocol. Like on-treatment and per-protocol analyses, it also requires accurate compliance information be recorded.

CONCLUSION

G-estimation should become a standard procedure for the analysis of trials with noncompliance. Software to do so is available in major packages, and the procedure is easily coded for other packages.

Pooled clinical trial analysis of tiotropium safety

BACKGROUND

Marketing approval of pharmaceutical products is often based on data from several thousand subjects or fewer. Evaluation of safety is greatly enhanced by augmenting the safety database with postapproval studies.

METHODS

We conducted a pooled analysis of adverse event data from 19 randomized, double-blind, placebo-controlled trials with tiotropium in patients with obstructive lung disease. We computed incidence rates and rate ratios (RRs) for various reported adverse event end points of interest. Patients contributed person-time to the analysis as long as they were in the study until 30 days after treatment (tiotropium, placebo), or until they had the event of interest, whichever came first. Studies were pooled using the Mantel-Haenszel estimator, and we used 95% confidence intervals (CIs) to assess the precision of effect estimates.

RESULTS

The pooled trial population includes 4,435 tiotropium patients and 3,384 placebo patients contributing 2,159 person-years of exposure to tiotropium and 1,662 person-years of exposure to placebo. Dyspnea, dry mouth, COPD exacerbation, and upper respiratory tract infection were the most commonly reported events. There was a higher relative risk of dry mouth in the tiotropium group (RR, 3.60; 95% CI, 2.56 to 5.05). There was a lower risk of dyspnea (RR, 0.64; 95% CI, 0.50 to 0.81) and COPD exacerbation (RR, 0.72; 95% CI, 0.64 to 0.82) in patients receiving tiotropium compared to patients receiving placebo. Other results of interest are as follows: (1) all-cause mortality (RR, 0.76; 95% CI, 0.50 to 1.16); (2) cardiovascular mortality (RR, 0.57; 95% CI, 0.26 to 1.26); and (3) respiratory mortality (RR, 0.71; 95% CI, 0.29 to 1.74). The relative risk of urinary retention was 10.93 (95% CI, 1.26 to 94.88).

CONCLUSIONS

Pooling of adverse event data from preapproval and postapproval tiotropium clinical trials increase the precision of effect estimates and supports the present safety profile of tiotropium.

Chronic obstructive pulmonary disease severity and cardiovascular outcomes

OBJECTIVE

To identify predictors of chronic obstructive pulmonary disease (COPD) severity and assess the relation between COPD severity and risk of cardiovascular outcomes.

STUDY DESIGN AND SETTING

A cohort of patients with diagnosed and treated COPD was compiled from the Saskatchewan Health longitudinal databases. We used multivariate modeling to identify predictors of hospitalization for COPD as an indicator of COPD severity, and we used the model to characterize patients according to quintiles of COPD severity. These severity levels were used as independent variables in multivariate models of cardiovascular outcomes.

RESULTS

Determinants of COPD severity included emphysema, recent nebulizer use, home oxygen services, corticosteroid use, frequent bronchodilator use, pneumonia and prior COPD exacerbation. The 20% of patients with the highest COPD severity were 1.27 (CI: 1.07-1.50) times more likely to have arrhythmia, 1.25 (CI: 1.07-1.46) times more likely to have ischemic heart disease, 1.38 (CI: 1.11-1.71) times more likely to have angina, 2.28 (CI: 1.95-2.66) times more likely to have congestive heart failure, and 1.63 (CI: 1.22-2.16) times more likely to die of cardiovascular causes than the least severe 20% of patients.

CONCLUSIONS

Patients with more severe COPD, as defined by our model, had higher cardiovascular morbidity and mortality than patients with less severe COPD.

COPD and incident cardiovascular disease hospitalizations and mortality: Kaiser Permanente Medical Care Program

STUDY OBJECTIVES

To determine the relationship between diagnosed and treated COPD and the incidence of cardiovascular disease (CVD) hospitalization and mortality.

DESIGN

Retrospective matched cohort study.

SETTING

Northern California Kaiser Permanente Medical Care Program (KPNC), a comprehensive prepaid integrated health-care system.

PATIENTS OR PARTICIPANTS

Case patients (n = 45,966) were all KPNC members with COPD who were identified during a 4-year period from January 1996 through December 1999. An equal number of control subjects without COPD were selected from KPNC membership and were matched for gender, year of birth, and length of KPNC membership.

MEASUREMENTS AND RESULTS

Follow-up conducted for hospitalization and mortality from CVD end points through December 31, 2000. CVD study end points included cardiac arrhythmias, angina pectoris, acute myocardial infarction, congestive heart failure (CHF), stroke, pulmonary embolism, all of the aforementioned study end points combined, other CVD, and all CVD end points. The mean follow-up time was 2.75 years for case patients and 2.99 years for control subjects. The risk of hospitalization was higher in COPD case patients than in control subjects for all CVD hospitalization and mortality end points. The relative risk (RR) for hospitalization for the composite measure of all study end points was 2.09 (95% confidence interval [CI], 1.99 to 2.20) after adjustment for gender, preexisting CVD study end points, hypertension, hyperlipidemia, and diabetes, and ranged from 1.33 (stroke) to 3.75 (CHF). The adjusted RR for mortality for the composite measure of all study end points was 1.68 (95% CI, 1.50 to 1.88), ranging from 1.25 (stroke) to 3.53 (CHF). Younger patients (ie, age < 65 years) and female patients had higher risks than older and male participants.

CONCLUSIONS

COPD was a predictor of CVD hospitalization and mortality over an average follow-up time of nearly 3 years. The finding of a stronger relationship of COPD to CVD outcomes in patients < 65 years of age suggests that CVD risk should be monitored and treated with particular care in younger adults with COPD.

Cardiovascular disease in patients with chronic obstructive pulmonary disease, Saskatchewan Canada cardiovascular disease in COPD patients

PURPOSE

To measure prevalence, incidence, and mortality of cardiovascular outcomes among persons with chronic obstructive pulmonary disease (COPD) and to assess the extent these outcomes differ from persons without COPD.

METHODS

Retrospective cohort study in longitudinal health care databases maintained by the government of Saskatchewan, Canada. Subjects were persons age 40 years or older who were diagnosed with COPD during 1997-2000 and who received two or more prescriptions for bronchodilators within 6 months of diagnosis. Each subject was matched by age and sex to two controls without COPD or asthma.

RESULTS

Of COPD patients (n = 11,493), 54% were male, and 74% were 65 years or older. Prevalence of all cardiovascular diseases was higher in the COPD group than in the comparison group. After adjusting for cardiovascular risk, odds ratios of prevalence were: arrhythmia 1.76 (confidence interval [CI]: 1.64-1.89), angina 1.61 (CI: 1.47-1.76), acute myocardial infarction 1.61 (CI: 1.43-1.81), congestive heart failure 3.84(CI: 3.56-4.14), stroke 1.11 (CI: 1.02-1.21), pulmonary embolism 5.46 (CI: 4.25-7.02). Risk of hospitalization due to each cardiovascular cause was elevated in the COPD group. The risk ratio for cardiovascular mortality was 2.07 (CI: 1.82-2.36) and all cause mortality was 2.82 (CI: 2.61-3.05).

CONCLUSIONS

Persons with diagnosed and treated COPD are at increased risk for hospitalizations and deaths due to cardiovascular diseases.

The reporting odds ratio and its advantages over the proportional reporting ratio

PURPOSE

The proportional reporting ratio (PRR) is the proportion of spontaneous reports for a given drug that are linked to a specific adverse outcome, divided by the corresponding proportion for all or several other drugs. The PRR is similar to the proportional mortality ratio (PMR), an old epidemiologic measure calculated from death registries and constructed in similar fashion to the PRR. The PMR has important deficiencies, however, which the PRR shares. Miettinen and Wang demonstrated that the PMR could be improved by reformulating it as an odds ratio and applying the principles of a case-control study to the measure. In this paper, we review the problem with the PRR and show how the corresponding odds ratio represents an improvement over the PRR.

METHODS

The method used is discussion and illustration by way of a hypothetical example.

RESULTS

The PRR does not estimate relative risk. If, however, a spontaneous report database is viewed as source data for a case-control study, the reporting odds ratio (ROR) can be used to estimate relative risk. Treating the data as source data for a case-control study allows for further reduction of bias by the judicious choice of controls.

CONCLUSIONS

Calculating the ROR in spontaneous report databases offers advantages over the PRR. It allows for estimation of the relative risk, and focuses attention on which people or reports should be included or excluded from the control series, permitting more deliberate elimination of biases. It also highlights the inherent weaknesses in spontaneous report data, which become more evident in light of the usual principles of control selection in case-control studies.

Risk of serious upper gastrointestinal and cardiovascular thromboembolic complications with meloxicam

PURPOSE

To assess the risk of serious gastrointestinal and thromboembolic complications with approved doses of meloxicam.

METHODS

We pooled data from clinical trials of meloxicam at doses of 7.5 or 15 mg/d. A blinded gastrointestinal adjudication committee used prespecified criteria to identify gastric or duodenal perforation, gastric outlet obstruction, or hemodynamically important upper gastrointestinal bleeding. For analysis of thromboembolic complications, investigator-reported events were analyzed without adjudication.

RESULTS

We analyzed data from 24,196 patients from 28 trials, most of whom had been followed for up to 60 days. Of these patients, 13,118 received meloxicam (10,158 received a daily dose of 7.5 mg and 2960 received 15 mg), 5283 were treated with diclofenac 100 mg, 181 received diclofenac 150 mg, 5371 were treated with piroxicam 20 mg, and 243 received naproxen 500 mg twice daily. Patients who received 7.5 mg of meloxicam daily had a 0.03% risk of serious upper gastrointestinal events, which was significantly lower than the risk in those who received diclofenac, naproxen, or piroxicam (P <0.02). With the 15 mg daily dose of meloxicam, this risk was significantly different only when compared with piroxicam (P = 0.03). The risk of thromboembolic events in patients treated with meloxicam at either dose was lower than with diclofenac, but similar to that observed with piroxicam and naproxen.

CONCLUSION

This pooled analysis of 24,196 patients demonstrates that meloxicam has a favorable gastrointestinal and thromboembolic safety profile. However, only a small number of patients were followed for more than 60 days, and meaningful comparisons were not possible in this subgroup.