Validation of serostatus of rheumatoid arthritis using ICD-10 codes in administrative claims data

PURPOSE

To determine the accuracy of International Classification of Diseases- Tenth Revision (ICD-10) diagnosis codes for rheumatoid arthritis (RA) serostatus using a U.S. claims database (Optum Clinformatics Data Mart, Optum) and to compare the results to a previous validation study performed in IBM Marketscan Research Database (sensitivity 73%, positive predictive value, PPV, 84%).

METHODS

In Optum (01/01/2016-03/31/2020) linked with laboratory results, we selected RA patients based on ≥2 ICD-10 diagnosis codes for RA (M05 or M06) and at least one dispensing of RA treatments. We included individuals with at least one laboratory result for rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) performed 365 days prior to and including the cohort entry date. An individual was "seropositive" if at least one of the 2 diagnosis codes used to define RA status was M05. "Seronegative" patients were required to have only M06. Secondary analyses were performed using subsets of M05 and M06 diagnosis codes. We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa of M05 and M06 against the prespecified reference standard laboratory data.

RESULTS

We identified 14 490 adult RA patients who had at least 1 RF or anti-CCP result. The number of patients identified for each reference standard definition ranged from 3315 (reference standard definition: high + anti-CCP) to 13 636 (any + RF). PPV for seropositive RA, M05, was 77.1%. The PPV of M06 for seronegative RA was 61.6%. When we applied more restricted definitions of M05 and M06, the PPV for seropositive RA increased to 79.2%. The PPV for seronegative RA also notably increased to 89.5%.

CONCLUSION

ICD-10 codes (M05 and M06) can help identify RA serostatus in claims data, but their limitations should be acknowledged. The PPVs for seropositive and seronegative RA found in the Optum database were lower than those found in MarketScan, perhaps related to database variability or differing patient characteristics and clinical practice. When more restricted definitions of M05 and M06 were used, the PPVs for seropositive and seronegative RA improved to 79.2% and 89.5%, respectively.

Real-world patient characteristics and use of disease-modifying anti-rheumatic drugs in patients with rheumatoid arthritis: a cross-national study

INTRODUCTION

Rheumatoid arthritis (RA) is associated with significant morbidity and economic burden. This study aimed to compare baseline characteristics and patterns of anti-inflammatory drug use and disease-modifying anti-rheumatic drug (DMARD) use among patients with RA in Southern Italy versus the United States.

METHOD

Using Caserta Local Health Unit (Italy) and Optum's de-identified Clinformatics® Data Mart (United States) claims databases, patients with ≥ 2 diagnosis codes for RA during the study period (Caserta: 2010-2018; Optum: 2010-2019) were identified. Baseline patient characteristics, as well as proportion of RA patients untreated/treated with NSAIDs/glucocorticoids/conventional DMARDs (csDMARDs)/biological/targeted synthetic DMARDs (b/tsDMARDs) during the first year of follow-up, and the proportion of RA patients with ≥ 1 switch/add-on between the first and the second year of follow-up, were calculated. These analyses were then stratified by age group (< 65; ≥ 65).

RESULTS

A total of 9227 RA patients from Caserta and 195,951 from Optum databases were identified (two-thirds were females). During the first year of follow-up, 45.9% RA patients from Optum versus 79.9% from Caserta were exclusively treated with NSAIDs/glucocorticoids; 17.2% versus 11.3% from Optum and Caserta, respectively, were treated with csDMARDs, mostly methotrexate or hydroxychloroquine in both cohorts. Compared to 0.6% of RA patients from Caserta, 3.2% of the Optum cohort received ≥ 1 b/tsDMARD dispensing. Moreover, 61,655 (33.7%) patients from Optum cohort remained untreated compared to 748 (8.3%) patients from the Caserta cohort. The subgroup analyses stratified by age showed that 42,989 (39.8%) of elderly RA patients were untreated compared to 18,666 (24.9%) young adult RA patients in Optum during the first year of follow-up. Moreover, a higher proportion of young adult RA patients was treated with b/tsDMARDs, with and without csDMARDs, compared to elderly RA patients (Optum_<65: 6.4%; Optum_≥65: 1.0%; P-value < 0.001; Caserta_<65: 0.8%; Caserta_≥65: 0.1%; P-value < 0.001). Among RA patients untreated during the first year after ID, 41.2% and 48.4% RA patients from Caserta and Optum, respectively, received NSAIDs, glucocorticoids, and cs/b/tsDMARDs within the second year of follow-up. Stratifying the analysis by age groups, 50.6% of untreated young RA patients received study drug dispensing within the second year of follow-up, compared to only 36.7% of elderly RA patients in Optum. Interestingly, more young adult RA patients treated with csDMARDs during the first year after ID received a therapy escalation to b/tsDMARD within the second year after ID in both cohorts, compared to elderly RA patients (Optum_<65: 7.8%; Optum_≥65: 1.8%; Caserta_<65: 3.2%; Casert_a≥65: 0.6%).

CONCLUSIONS

Most of RA patients, with heterogeneous baseline characteristics in Optum and Caserta cohorts, were treated with anti-inflammatory/csDMARDs rather than bDMARDs/tsDMARDs during the first year post-diagnosis, especially in elderly RA patients, suggesting a need for better understanding and dealing with barriers in the use of these agents for RA patients. Key Points • Substantial heterogeneity in baseline characteristics and access to bDMARD or tsDMARD drugs between RA patients from the United States and Italy exists. • Most of RA patients seem to be treated with anti-inflammatory/csDMARD drugs rather than bDMARD/tsDMARD drugs during the first year post-diagnosis. • RA treatment escalation is less frequent in old RA patients than in young adult RA patients. • An appropriate use of DMARDs should be considered to achieve RA disease remission or low disease activity.

Risk of Hospitalization for Serious Infection After Initiation of Ustekinumab or Other Biologics in Patients With Psoriasis or Psoriatic Arthritis

OBJECTIVE

To compare the risk of serious infections requiring hospitalization in patients with psoriasis (PsO) or psoriatic arthritis (PsA) initiating ustekinumab versus other biologics or apremilast.

METHODS

In this multi-database cohort study, we identified patients with PsO/PsA who initiated therapy with adalimumab, apremilast, certolizumab, etanercept, golimumab, ixekizumab, secukinumab, or ustekinumab between 2009 and 2018. The primary outcome measure was hospitalizations due to serious infections, which included bacterial, viral, or opportunistic infections. We estimated hazard ratios (HRs) comparing each study drug to ustekinumab after applying propensity score fine stratification weights for confounding control in each database. Database-specific weighted HRs were combined by meta-analysis.

RESULTS

We identified 123,383 patients with PsO/PsA who initiated one of the study drugs. During a total of 117,744 person-years of follow-up, 1,514 serious infections occurred with a crude incidence of 1.29 per 100 person-years. After propensity score fine stratification and weighting, the incidence rates of serious infection among ustekinumab initiators ranged from 0.59 to 0.95 per 100 person-years. Compared with ustekinumab, the combined weighted HRs (95% confidence interval [95% CI]) for serious infections were 1.66 (95% CI 1.34-2.06) for adalimumab, 1.42 (95% CI 1.02-1.96) for apremilast, 1.09 (95% CI 0.68-1.75) for certolizumab, 1.39 (95% CI 1.01-1.90) for etanercept, 1.74 (95% CI 1.00-3.03) for golimumab, 2.92 (95% CI 1.80-4.72) for infliximab, 2.98 (95% CI 1.20-7.41) for ixekizumab, and 1.84 (95% CI 1.24-2.72) for secukinumab.

CONCLUSION

Other biologics and apremilast were associated with a 1.4- to 3-times higher risk of hospitalization for serious infections in PsO/PsA patients when compared to ustekinumab; this finding should be considered in the safety profile of these therapies when selecting appropriate treatment regimens in patients with PsO/PsA.

Predictors of Treatment Change Among Patients with Rheumatoid Arthritis Treated with TNF Inhibitors as First-Line Biologic Agent in the USA: A Cohort Study from Longitudinal Electronic Health Records

BACKGROUND

Previous observational studies utilizing administrative claims data have largely been unable to consider clinical factors that may be related to patterns of drug use among patients with rheumatoid arthritis (RA).

OBJECTIVE

To understand predictors of treatment changes following initiation of a tumor necrosis factor inhibitor (TNFi) using nation-wide electronic health record (EHR) data in the USA.

METHODS

The Optum Immunology Condition EHR data (01/01/2011-09/30/2019) was used to identify a population of adult patients with RA initiating a TNFi as the first line biologic disease-modifying anti-rheumatic drug (DMARD). The primary outcome was any treatment change during the 1-year post-index period defined as cycling to a different TNFi or switching to non-TNFi biologic or targeted synthetic DMARDs. Secondary outcomes were the individual components of TNFi cycling and switching, examined separately. To identify predictors of DMARD treatment changes, we used a least absolute shrinkage and selection operator (LASSO) regression model. Model c-statistics and odds ratios (ORs, 95% confidence intervals (CIs)) of predictors were reported.

RESULTS

We identified 24,871 patients with RA who initiated a TNFi. The mean age was 55.5 (± 13.7) years and 77.2% were female. Among the TNFi initiators, 22.2% experienced TNFi cycling or switching during the 1-year follow-up time. Predictors that are associated with higher likelihood of TNFi cycling or switching included female gender (OR: 1.26, 95% CI: 1.16-1.36) and glucocorticoid use (OR: 1.30, 95% CI: 1.21-1.40). In contrast, inflammatory bowel disease (OR: 0.62, 95% CI: 0.48-0.78), psoriasis (OR: 0.82, 95% CI: 0.70-0.95), recent use of methotrexate (OR: 0.89, 95% CI: 0.81-0.97), and vitamin D intake (OR: 0.92, 95% CI: 0.85-0.99) were negatively associated with TNFi cycling or switch.

CONCLUSIONS

Gender, glucocorticoid use, inflammatory bowel disease, psoriasis, and vitamin D intake were identified as significant predictors of TNFi cycling or switching for TNFi initiators in the RA population. Predicting treatment change remains challenging even with large detailed EHR data. This study aimed to identify key determinants of treatment changes among patients with rheumatoid arthritis (RA) initiating a tumor necrosis factor inhibitor (TNFi) as their first-line biologic disease-modifying antirheumatic drug (DMARD) in routine care settings using a US nation-wide longitudinal electronic health record (EHR). Among 24,871 patients with RA who initiated a TNFi, 22.2% experienced TNFi cycling or switching during the 1-year follow-up time. Female patients and those who used glucocorticoids were more likely to experience TNFi cycling or switching, whereas inflammatory bowel disease, psoriasis, recent methotrexate use, and vitamin D intake were negatively associated with the outcome. However, predicting treatment change remains challenging even with larger detailed EHR data potentially due to unmeasured factors such as prescriber's preference or patient's belief in the medication.

Patient characteristics associated with use of TNF vs interleukin inhibitors as first-line biologic treatment for psoriatic arthritis

BACKGROUND: Previous studies have examined treatment patterns among patients who use tumor necrosis factor (TNF) inhibitors for psoriatic arthritis (PsA). However, little data exist for a comparison between the TNF inhibitor treatment pattern and that of newly available biologics such as interleukin (IL)-12/23 or 17 inhibitors in the United States. OBJECTIVES: To (a) examine patient characteristics and their association with initiation of TNF inhibitors vs IL-12/23 or 17 inhibitors among PsA patients and (2) compare treatment persistence of PsA patients who initiated TNF inhibitors vs IL-12/23 or 17 inhibitors as first-line biologic treatment in a real-world setting in the United States. METHODS: Using claims data from MarketScan (2013-2017), we identified a cohort of PsA patients who initiated TNF inhibitors or IL-12/23 or 17 inhibitors. The primary outcome was treatment persistence, defined as continuous use of the index drug at 1 year, regardless of refill gaps. The secondary outcome was treatment persistence with high adherence at 1 year (ie, refill gaps ≤ 30 days). Multivariable logistic regression was used to assess the association between patient characteristics and treatment initiation and persistent use of TNF inhibitors vs IL-12/23 or 17 inhibitors. RESULTS: We identified 3,180 TNF inhibitor initiators and 214 IL-12/23 or 17 inhibitor initiators. Initiators of IL-12/23 or 17 inhibitors had more comorbidities than TNF inhibitor initiators. The proportion of patients with treatment persistence was 53.0% in TNF inhibitor initiators and 53.7% in IL-12/23 or 17 inhibitor initiators; 37.1% of TNF inhibitor users and 24.8% of IL-12/23 or 17 inhibitor users were treatment persistent with high adherence. There was no difference in 1-year treatment persistence between the 2 groups after adjusting for baseline characteristics (adjusted odds ratio [aOR] for TNF inhibitors vs IL-12/23 or 17 inhibitors: 0.86, 95% CI = 0.63-1.15). However, use of TNF inhibitors was associated with a greater treatment persistence with high adherence compared with use of IL-12/23 or 17 inhibitors (aOR = 1.61, 95% CI = 1.15-2.26). CONCLUSIONS: PsA patients who initiated an IL 12/23 or 17 inhibitor had a greater comorbidity burden compared with those who initiated TNF inhibitors. Treatment persistence was similar between the 2 groups, whereas medication adherence was higher with TNF inhibitors than with IL 12/23 or 17 inhibitors during the first year of treatment. DISCLOSURES: This study was funded by an investigator-initiated research grant from Pfizer, Inc (grant number: WI235988). The content is solely the responsibility of the authors. The sponsor was given the opportunity to make nonbinding comments on a draft of the manuscript. Publication of the manuscript was not contingent on approval by the sponsor. Kim has received research grants to the Brigham and Women's Hospital from Roche, AbbVie, and Bristol-Myers Squibb for unrelated topics. Merola is a consultant and/or investigator for BMS, AbbVie, Dermavant, Lilly, Novartis, Janssen, UCB, Sun Pharma, and Pfizer. Jin, Chen, Lee, and Landon have nothing to disclose.

Development and Validation of a Pediatric Comorbidity Index

Comorbidity scores are widely used to help address confounding bias in nonrandomized studies conducted within health-care databases, but existing scores were developed to predict all-cause mortality in adults and might not be appropriate for use in pediatric studies. We developed and validated a pediatric comorbidity index, using health-care utilization data from the tenth revision of the International Classification of Diseases. Within the MarketScan database of US commercial claims data, pediatric patients (aged ≤18 years) continuously enrolled between October 1, 2015, and September 30, 2017, were identified. Logistic regression was used to predict the 1-year risk of hospitalization based on 27 predefined conditions and empirically identified conditions derived from the most prevalent diagnoses among patients with the outcome. A single numerical index was created by assigning weights to each condition based on its β coefficient. We conducted internal validation of the index and compared its performance with existing adult scores. The pediatric comorbidity index consisted of 24 conditions and achieved a C statistic of 0.718 (95% confidence interval (CI): 0.714, 0.723). The index outperformed existing adult scores in a pediatric population (C statistics ranging from 0.522 to 0.640). The pediatric comorbidity index provides a summary measure of disease burden and can be used for risk adjustment in epidemiologic studies of pediatric patients.

Association of Opioid Overdose With Opioid Prescriptions to Family Members

IMPORTANCE

Prescription opioid misuse is a public health problem that leads to overdose. Although existing interventions focus on limiting prescribing to patients at high risk, individuals may still access prescription opioids dispensed to family members.

OBJECTIVE

To determine whether opioid prescriptions to family members were associated with overdose for individuals who themselves did not have an opioid prescription.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a 1:4 matched case-control study using health care utilization data from 2004 through 2015 from a large US commercial insurance company. Eligible individuals were required to have at least 12 months of continuous enrollment and 1 or more family members in the database. Individuals who experienced overdose were identified by their first opioid overdose after the baseline period and matched to control participants by time in the database, calendar time, age, sex, and number of individuals in the family unit. Both groups were restricted to individuals with no prior opioid dispensing of their own. Data analysis was conducted from January 2018 to August 2018.

EXPOSURES

Any prior opioid dispensing to a family member, total morphine milligram equivalents dispensed to family members, and the type of opioid product dispensed.

MAIN OUTCOMES AND MEASURES

Individual odds of opioid overdose resulting in an emergency department visit or hospitalization were the primary end point. The primary analysis evaluated the odds of overdose among individuals whose family members had been dispensed an opioid. Sensitivity analyses examined the odds stratified by age and timing relative to the dispensing of opioids to family members.

RESULTS

A total of 2303 individuals who experienced opioid overdose and 9212 matched control individuals were identified. The mean (SD) age was 23.2 (18.1) years; 1158 affected individuals and 4632 control individuals (50.3%) were female. The mean (SD) time in the database before an overdose case was 3.2 (3.3) years. Prior opioid dispensing to family members was associated with individual overdose (odds ratio [OR], 2.89 [95% CI, 2.59-3.23]). There was a significant dose-response association between increasing amounts of opioids dispensed to family members and odds of overdose (>0-<50 morphine milligram equivalents per day: OR, 2.71 [95% CI, 2.42-3.03]; 50-<90 morphine milligram equivalents per day: OR, 7.80 [95% CI, 3.63-16.78]; ≥90 morphine milligram equivalents per day: OR, 15.08 [95% CI, 8.66-26.27]).

CONCLUSIONS AND RELEVANCE

In this analysis, opioid prescriptions to family members were associated with overdose among individuals who do not receive opioid prescriptions. Interventions may focus on expanding access to opioid antagonists, locking prescription opioids in the home, and providing greater patient education to limit fatal overdose among family members.

Fracture Risk After Bariatric Surgery: Roux-en-Y Gastric Bypass Versus Adjustable Gastric Banding

The long-term consequences of bariatric surgery on fracture risk are unclear but are likely to vary by procedure type. In physiologic studies, Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB) have differential effects on rates of bone loss. Therefore, our objective was to compare fracture risk in obese adults after RYGB and AGB procedures. Using claims data from a US commercial health plan, we analyzed rates of nonvertebral fractures within a propensity score-matched cohort (n = 15,032) of morbidly obese adults who received either RYGB or AGB surgery between 2005 and 2013. A total of 281 nonvertebral fractures occurred during a mean follow-up time of 2.3 ± 1.9 years. RYGB patients had an increased risk of nonvertebral fracture (hazard ratio [HR] = 1.43, 95% confidence interval [CI] 1.13-1.81) compared with AGB patients. In fracture site-specific analyses, RYGB patients had increased risk of fracture at the hip (HR = 1.54, 95% CI 1.03-2.30) and wrist (HR = 1.45, 95% CI 1.01-2.07). Nonvertebral fracture risk associated with RYGB manifested >2 years after surgery and increased in subsequent years, with the highest risk in the fifth year after surgery (HR = 3.91, 95% CI 1.58-9.64). In summary, RYGB is associated with a 43% increased risk of nonvertebral fracture compared with AGB, with risk increasing >2 years after surgery. Fracture risk should be considered in risk/benefit discussions of bariatric surgery, particularly among patients with high baseline risk of osteoporosis who are deciding between RYGB and AGB procedures. © 2017 American Society for Bone and Mineral Research.

Effect of Combination Therapy on Adherence Among US Patients Initiating Therapy for Hypertension: a Cohort Study

BACKGROUND

New trial evidence suggests that many patients may require more aggressive pharmacologic management to achieve lower blood pressure goals. Especially when first initiating anti-hypertensive treatment, it is unknown whether starting patients on multiple medications may be better for long-term adherence and persistence compared with starting one medication.

OBJECTIVE

To examine contemporary patterns of anti-hypertensive therapy initiation and compare long-term adherence and persistence among patients initiating fixed-dose combinations and single anti-hypertensive therapies.

DESIGN

Retrospective cohort study.

PATIENTS

Using claims from a large nationwide insurer, we identified all patients initiating oral hypertension treatment from 2009 to 2013. We categorized patients into three categories based on the number and type of anti-hypertensive medications they initiated: a fixed-dose combination, a multi-pill combination or a single therapy.

MAIN MEASURES

The primary outcome was persistence to any anti-hypertensive medication, either the initiated medication or other anti-hypertensive, 12 months after initiation in administrative claims. We also measured adherence to at least one anti-hypertensive in the 12 months after initiation and refilling at least one anti-hypertensive medication as outcomes. Full adherence was defined as having ≥80% of potential days covered with medication. Multivariable modified Poisson regression models were used to examine the association between initiating a fixed-dose combination anti-hypertensive and medication outcomes.

KEY RESULTS

Of the 484,493 patients who initiated oral anti-hypertensives, 78,958 patients initiated fixed-dose combinations, 383,269 initiated a single therapy, and 22,266 initiated multi-pill combinations. Patients initiating fixed-dose combinations were 9% more likely to be persistent (relative risk [RR]: 1.09, 95% CI: 1.08-1.10) and 13% more likely to be adherent (RR: 1.13 95% CI: 1.11-1.14) than those who started on a single anti-hypertensive therapy. Refill rates were also slightly higher among fixed-dose combination initiators.

CONCLUSIONS

Fixed-dose combination pills appear to enhance adherence and persistence to anti-hypertensive medications among commercially insured patients starting treatment compared with single therapy.

Comparative Safety and Effectiveness of Denosumab Versus Zoledronic Acid in Patients With Osteoporosis: A Cohort Study

Limited head-to-head comparative safety and effectiveness data exist between denosumab and zoledronic acid in real-world healthcare. We aimed to examine the safety and effectiveness of denosumab compared to zoledronic acid with regard to risk of serious infection and cardiovascular disease (CVD) and osteoporotic fracture. We conducted a cohort study using claims data (2009-2013) from a US commercial insurance plan database. We included patients aged ≥50 years who were newly initiated on denosumab or zoledronic acid. The primary outcomes were (1) hospitalization for serious infection; (2) composite CVD endpoint including myocardial infarction, stroke, coronary revascularization, and heart failure; and (3) nonvertebral osteoporotic fracture including hip, wrist, forearm, and pelvic fracture. To control for potential confounders, we used 1:1 propensity score (PS) matching. Cox proportional hazards models compared the risk of serious infection, CVD, and osteoporotic fracture within 365 days after initiation of denosumab versus zoledronic acid. After PS matching, a total of 2467 pairs of denosumab and zoledronic acid initiators were selected with a mean age of 63 years and 96% were female. When compared with zoledronic acid, denosumab was not associated with an increased risk of serious infection (HR 0.81; 95% confidence interval [CI], 0.55 to 1.21) or CVD (HR 1.11; 95% CI, 0.60 to 2.03). Similar results were obtained for each component of CVD. The risk of osteoporotic fracture was also similar between groups (HR 1.21; 95% CI, 0.84 to 1.73). This large population-based cohort study shows that denosumab and zoledronic acid have comparable clinical safety and effectiveness with regard to the risk of serious infection, CVD, and osteoporosis fracture within 365 days after initiation of medications. © 2016 American Society for Bone and Mineral Research.

Persistent opioid use following cesarean delivery: patterns and predictors among opioid-naïve women

BACKGROUND

The incidence of opioid-related death in women has increased 5-fold over the past decade. For many women, their initial opioid exposure will occur in the setting of routine medical care. Approximately 1 in 3 deliveries in the United States is by cesarean, and opioids are commonly prescribed for postsurgical pain management.

OBJECTIVE

The objective of this study was to determine the risk that opioid-naïve women prescribed opioids after cesarean delivery will subsequently become consistent prescription opioid users in the year following delivery and to identify predictors for this behavior.

STUDY DESIGN

We identified women in a database of commercial insurance beneficiaries who underwent cesarean delivery and who were opioid naïve in the year prior to delivery. To identify persistent users of opioids, we used trajectory models, which group together patients with similar patterns of medication filling during follow-up, based on patterns of opioid dispensing in the year following cesarean delivery. We then constructed a multivariable logistic regression model to identify independent risk factors for membership in the persistent user group.

RESULTS

A total of 285 of 80,127 (0.36%, 95% confidence interval, 0.32-0.40), opioid-naïve women became persistent opioid users (identified using trajectory models based on monthly patterns of opioid dispensing) following cesarean delivery. Demographics and baseline comorbidity predicted such use with moderate discrimination (c statistic = 0.73). Significant predictors included a history of cocaine abuse (risk, 7.41%; adjusted odds ratio, 6.11, 95% confidence interval, 1.03-36.31) and other illicit substance abuse (2.36%; adjusted odds ratio, 2.78, 95% confidence interval, 1.12-6.91), tobacco use (1.45%; adjusted odds ratio, 3.04, 95% confidence interval, 2.03-4.55), back pain (0.69%; adjusted odds ratio, 1.74, 95% confidence interval, 1.33-2.29), migraines (0.91%; adjusted odds ratio, 2.14, 95% confidence interval, 1.58-2.90), antidepressant use (1.34%; adjusted odds ratio, 3.19, 95% confidence interval, 2.41-4.23), and benzodiazepine use (1.99%; adjusted odds ratio, 3.72, 95% confidence interval, 2.64-5.26) in the year prior to the cesarean delivery.

CONCLUSION

A very small proportion of opioid-naïve women (approximately 1 in 300) become persistent prescription opioid users following cesarean delivery. Preexisting psychiatric comorbidity, certain pain conditions, and substance use/abuse conditions identifiable at the time of initial opioid prescribing were predictors of persistent use.

Patterns of health care utilization related to initiation of amitriptyline, duloxetine, gabapentin, or pregabalin in fibromyalgia

Introduction

Several pharmacologic treatments are available for fibromyalgia, but little is known about the comparative effectiveness of these treatments on health care utilization.

Methods

Using US commercial insurance claims data (covering 2007 to 2009), we conducted a cohort study to examine the comparative effectiveness of amitriptyline, duloxetine, gabapentin, and pregabalin on health care utilization in patients with fibromyalgia. We measured patients’ medication adherence using the proportion of days covered (PDC) and estimated multivariable rate ratios (RRs) for outpatient visits, prescriptions, hospitalization, and emergency department (ED) visits in propensity score (PS)–matched cohorts.

Results

Cohorts of 8,269 amitriptyline, 9,941 duloxetine, and 18,613 gabapentin initiators were compared with their PS-matched pregabalin initiators. During the baseline 180-day period, patients had, on average, seven to nine physician visits, including six to eight specialist visits, and received eight prescription drugs. The mean PDC up to 180 days varied from 38.6% to 67.7%. The number of outpatient visits, prescriptions, and hospitalizations decreased slightly after initiating one of the study drugs, but the number of ED visits increased after treatment initiation. Compared to pregabalin, duloxetine was associated with decreased outpatient visits (RR, 0.94; 95% confidence interval (CI), 0.88 to 1.00), prescriptions (RR, 0.94; 95% CI, 0.90 to 0.98), hospitalizations (RR, 0.75; 95% CI, 0.68 to 0.83), and ED visits (RR, 0.85; 95% CI, 0.79 to 0.91). Little difference in health care utilization rates was noted among amitriptyline and gabapentin initiators compared to those who were started on pregabalin.

Conclusions

Fibromyalgia patients had high health care utilization before and after initiation of amitriptyline, duloxetine, gabapentin, or pregabalin. Medication adherence was suboptimal. Overall, fibromyalgia treatment had little impact on reducing health care utilization, but duloxetine initiators had less health care utilization than those started on pregabalin.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0530-8) contains supplementary material, which is available to authorized users.

Are risk evaluation and mitigation strategies associated with less off-label use of medications? The case of immune thrombocytopenia

Using data from a large commercial health insurer, we studied prescribing of romiplostim (Nplate) and eltrombopag (Promacta), two drugs for primary immune thrombocytopenia (ITP) for which risk evaluation and mitigation strategies (REMS) with elements to assure safe use were initially imposed and then removed. We identified 103 and 117 new users of romiplostim and eltrombopag, respectively. Use was almost exclusively for FDA-approved indications ("on-label") while the REMS with elements to assure safe use were in place. After these elements were lifted, off-label use of eltrombopag among patients with hepatitis C virus (HCV), a subsequently approved indication, increased. The ratio of incidence rate ratios of off-label/HCV to on-label initiation of eltrombopag between the two time periods was significant (13.41; P < 0.001). Our finding of an association with reduced off-label prescribing suggests that REMS with elements to assure safe use can help promote patient safety but may also prevent promising off-label drug uses.

Clinical characteristics and medication uses among fibromyalgia patients newly prescribed amitriptyline, duloxetine, gabapentin, or pregabalin

OBJECTIVE

Fibromyalgia is a common chronic pain disorder with unclear etiology. No definitive treatment is available for fibromyalgia, and treatment with antidepressants or antiepileptics is often used for symptom management.

METHODS

Using US health care utilization data, a large population-based cohort study was conducted to describe clinical characteristics and medication use patterns in patients diagnosed with fibromyalgia who newly started amitriptyline, duloxetine, gabapentin, or pregabalin.

RESULTS

There were 13,404 amitriptyline starters, 18,420 duloxetine starters, 23,268 gabapentin starters, and 19,286 pregabalin starters. The mean age ranged from 48–51 years and 72–84% in each group were women. Back pain was the most frequent comorbidity in all 4 groups (range 48–64%) and hypertension, headache, depression, and sleep disorder were also common. The median daily dose at the start of followup was 25 mg for amitriptyline, 60 mg for duloxetine, 300 mg for gabapentin, and 75 mg for pregabalin, and >60% of patients remained on the same dose throughout the follow up period. Only one-fifth of patients continued the treatment started for ≥1 year. The mean number of different prescription drugs at baseline ranged from 8–10 across the groups. More than one-half of patients took opioids and one-third took benzodiazepines, sleep disorder drugs, and muscle relaxants.

CONCLUSION

Patients who started 1 of the 4 common drugs for fibromyalgia similarly had multiple comorbidities and other fibromyalgia-related medication use, but continued the treatment only for a short time. The dose of the 4 drugs was not increased in most patients during the followup period.