Maintenance and Concomitant Therapy Use with Chlormethine Gel Among Patients with Stage IA/IB Mycosis Fungoides-Type Cutaneous T-Cell Lymphoma (MF-CTCL): A Real-World Evidence Study.

INTRODUCTION: Chlormethine (CL) gel is a skin-directed therapy approved for treatment of stage IA/IB mycosis fungoides-type cutaneous T-cell lymphoma (MF-CTCL) in the USA. MF-CTCL has a chronic clinical course, requiring long-term maintenance therapy with one or more therapies. This analysis describes real-world patterns of maintenance therapy and use of concomitant therapy with CL gel among patients with stage IA/IB MF-CTCL. METHODS: In a US-based registry, MF-CTCL patients treated with CL gel were enrolled between 3/2015 and 10/2018 across 46 centers and followed for up to 2 years. Patient demographics, clinical characteristics, CL gel treatment patterns, concomitant treatments, clinical response, and adverse events (AEs) were collected from medical records. Descriptive statistics are reported. RESULTS: Of the 206 patients with stage IA/IB MF-CTCL, 58.7% were male, and average age was 60.7 years with 4.6 years since diagnosis. Topical steroids, phototherapy, and topical retinoids were used concomitantly with CL gel in 62.6%, 26.2%, and 6.3% of patients, respectively. Most concomitant therapies (up to 85%) were started before CL gel initiation and, in about half of the cases (up to 57%), were used concurrently for ≥ 12 months. Overall, 158 (76.7%) patients experienced partial response (PR) and 144 continued with maintenance therapy. After achieving PR, most patients (74.3%) kept the same maintenance therapy schedule, most commonly once daily. Of patients who had any skin-related AE (31.6%) or skin-related AEs associated with CL gel (28.2%), nearly half experienced CL gel treatment interruption and ~40% had a dosing reduction. The observed real-world treatment patterns were concordant with National Comprehensive Cancer Network (NCCN) guidelines. CONCLUSION: The study results suggest that continuing CL gel maintenance therapy and combining treatments with CL gel are common practice in the real-world setting, with most maintained on a stable dosing schedule. Careful management of AEs may help patients maintain long-term optimal dosing with less treatment interruptions and dosing reductions.

Effectiveness and safety of anticoagulants for the treatment of venous thromboembolism in patients with cancer.

Anticoagulation is used to treat venous thromboembolism (VTE) in cancer patients, but may be associated with an increased risk of bleeding. VTE recurrence and major bleeding were assessed in cancer patients treated for VTE with the most currently prescribed anticoagulants in clinical practice. Newly diagnosed cancer patients (first VTE 1/1/2013-05/31/2015) who initiated rivaroxaban, low-molecular-weight heparin (LMWH), or warfarin were identified from Humana claims data and observed until end of eligibility or end of data availability. VTE recurrence was a hospitalization with a primary diagnosis of VTE ≥7 days after first VTE. Major bleeding events on treatment were identified using validated criteria. Cohorts were compared using Kaplan-Meier rates at 6 and 12 months and Cox proportional hazards models. Cohorts were adjusted for their differences at baseline. A total of 2428 patients (rivaroxaban: 707; LMWH: 660; warfarin: 1061) met inclusion criteria. Patient characteristics were well balanced after weighting. There was a trend for lower VTE recurrence rates in rivaroxaban users compared to LMWH users at 6 months (13.2% vs. 17.1%; P = .060) and significantly lower at 12 months (16.5% vs. 22.2%; P = .030) [HR: 0.72, 95% CI: (0.52-0.95); P = .024]. VTE recurrence rates were also lower for rivaroxaban than warfarin users at 6 months (13.2% vs. 17.5%; P = .014) and 12 months (15.7% vs. 19.9%; P = .017) [HR: 0.74, 95% CI: (0.56-0.96); P = .028]. Major bleeding rates were similar across cohorts. This real-world analysis suggests cancer patients with VTE treated with rivaroxaban had significantly lower risk of recurrent VTE and similar risk of bleeding compared to those treated with LMWH or warfarin.

Long-term Systemic Corticosteroid Exposure: A Systematic Literature Review.

PURPOSE: While corticosteroids are relatively inexpensive and commonly used as treatment for a variety of conditions, long-term use is known to be associated with certain toxicities. Prior systematic reviews have revealed an increased risk for costly adverse events (AEs), including bone fracture, infection, and gastrointestinal bleeding. The objective of this study was to conduct a systematic literature review of recent publications on the burden of long-term corticosteroid exposure, specifically, to summarize the AEs and economic impact of long-term corticosteroid use and to reveal data gaps for additional research. METHODS: The Ovid search platform was used to access scientific literature databases. The search strategy targeted the use of corticosteroids and economic outcomes research. Articles were restricted to those published between 2007 and 2016 to cover publications since prior reviews; conference abstracts and articles assessing pediatrics were excluded. Titles and abstracts resulting from inclusion criteria were screened, and reviewers independently extracted relevant information from the relevant full-text articles. FINDINGS: The literature review included 32 articles, with 75% focusing on autoimmune diseases, asthma, or lung diseases. Included articles were 14 database analyses, 6 simulations, 6 clinical trials, 3 systematic literature reviews, 2 patient surveys, and 1 chart review. Commonly-cited AEs associated with long-term corticosteroid exposure included hypertension (prevalence >30%); bone fracture (21%-30%); cataract (1%-3%); nausea, vomiting, and other gastrointestinal conditions (1%-5%); and metabolic issues (eg, weight gain, hyperglycemia, and type 2 diabetes; cases had 4-fold the risk of controls). Association of dose and duration with increased AE risk is not well-quantified. AEs like peptic ulcer and myocardial infarction are particularly costly to payers (1-year cost of $21,825 and $26,472, respectively, in year-2009 USD). The few articles assessing the economic impact of corticosteroid use have found dose-related increases in health care resource utilization and costs, with per-annum incremental costs relative to nonusers ranging from $5700 in low-dose users (<7.5 mg/d) to $29,000 in high-dose users (>15 mg/d). Adherence to treatment guidelines on avoiding AEs (eg, prescribing of oral bisphosphonates, calcium, and vitamin D) remains low. IMPLICATIONS: Although doses of long-term corticosteroids have fallen over the past several decades in response to AEs, dose reduction may not be a sufficient solution. Numerous AEs, some very costly, persist among long-term corticosteroid users, suggesting a need for further research to fill current data gaps, as well as a potential need for alternative treatment options.

Healthcare costs associated with rivaroxaban or warfarin use for the treatment of venous thromboembolism.

INTRODUCTION: Rivaroxaban has been shown to have similar efficacy but less major bleeding than warfarin in randomized trials of patients experiencing venous thromboembolism (VTE). This report sought to assess healthcare costs up to 12-months following an index VTE in patients prescribed either rivaroxaban or warfarin. MATERIALS AND METHODS: This study analyzed claims from the MarketScan Commercial Claims and Encounters Database from November 2011-July 2015. It selected adults newly-diagnosed with VTE (deep vein thrombosis [DVT] or pulmonary embolism [PE]) if they had an outpatient prescription claim for rivaroxaban or warfarin within 7-days of the index event. Warfarin users were 2:1 propensity-score matched to rivaroxaban users and followed until the end of insurance coverage, end of data availability or 12-months of follow-up. Total per patient healthcare costs, including inpatient, outpatient, and overall pharmacy costs, were compared using a multivariable generalized linear model. RESULTS: In total, 10,929 rivaroxaban patients were matched to 21,858 warfarin patients. Mean follow-up for rivaroxaban and warfarin patients was 317- and 321-days for those experiencing an index DVT, and 313- and 318-days for those with PE. Mean overall treatment costs per patient were lower for rivaroxaban vs warfarin users (-$1,116, p = .0016). This cost difference was driven by lower inpatient (-$622) and outpatient (-$1,156) treatment costs, and the higher pharmacy costs ($661) were, therefore, fully offset. Results were similar when analysis was restricted to DVT patients. No significant difference in total costs was observed in patients experiencing an index PE. LIMITATIONS: Claims databases are subject to inaccuracies and missing data. Prescription claims may not fully reflect actual medication utilization. Despite propensity-score matching and regression, residual confounding cannot be excluded. CONCLUSIONS: Rivaroxaban was associated with significantly lower total per patient VTE treatment costs, despite higher pharmacy costs. These savings are the result of decreased inpatient and outpatient healthcare utilization costs associated with rivaroxaban.

Medication persistence and discontinuation of rivaroxaban and dabigatran etexilate among patients with non-valvular atrial fibrillation.

OBJECTIVE: To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and dabigatran in the US. METHODS: A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF on rivaroxaban or dabigatran between October 2010 and March 2013. The index date was the date of the first prescription of rivaroxaban or dabigatran. All patients had ≥6 months of data prior to the index date and were followed until the earliest of inpatient death, end of continuous enrollment, or end of the study period. Rivaroxaban patients were matched 1:1 with dabigatran patients using the propensity score matching technique. Cox proportional hazards models were employed to estimate the adjusted hazard ratios (aHRs) of non-persistence and discontinuation. Persistence was defined as absence of a refill gap of ≥60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. RESULTS: A total of 30,337 NVAF patients on rivaroxaban or dabigatran met the study criteria. All 7259 rivaroxaban patients were matched 1:1 to dabigatran patients. Compared with dabigatran users, rivaroxaban patients were 11% less likely to become non-persistent with therapy (aHR: 0.89, 95% CI 0.84-0.95) and 29% less likely to discontinue therapy (aHR: 0.71, 95% CI 0.66-0.77). LIMITATIONS: Claims data are subject to miscoding and inaccuracies. Refill data may not fully reflect actual medication taken. Confounding may remain even after propensity score matching and additional adjustments in model. Longer follow-up may produce more precise estimates of persistence and discontinuation. CONCLUSIONS: This matched cohort analysis indicated that, compared to dabigatran, rivaroxaban was associated with better persistence and lower rates of discontinuation.

Effects of rivaroxaban versus warfarin on hospitalization days and other health care resource utilization in patients with nonvalvular atrial fibrillation: an observational study from a cohort of matched users.

PURPOSE: Compared with warfarin, the new target-specific oral anticoagulant agents may have advantages, such as shorter hospital length of stay, in patients with nonvalvular atrial fibrillation (NVAF). The objective of the present study was to assess, among patients with NVAF, the effects of rivaroxaban versus warfarin on the number of hospitalization days and other health care resource utilization in a cohort of rivaroxaban users and matched warfarin users. METHODS: Data from health care claims dated from May 2011 to December 2012 from the Humana database were analyzed. Adult patients newly initiated on treatment with rivaroxaban or warfarin, with ≥2 diagnoses of AF (ICD-9-CM code 427.31), and without valvular AF were identified. Based on propensity score methods, warfarin recipients were matched 1:1 to rivaroxaban recipients. The end of the observation period was defined as the end of data availability, the end of insurance coverage, death, the date of a switch to another anticoagulant agent, or day 14 of treatment nonpersistence. The total number of hospitalization days and other health care resource utilization parameters (numbers of hospitalizations, emergency department [ED] visits, and outpatient visits) were evaluated using the method by Lin et al. FINDINGS: Matches for all rivaroxaban recipients were found, and the characteristics of the matched groups (n = 2253 per group) were well balanced. The mean age of both cohorts was 74 years; 46% were female. The estimated mean total numbers of hospitalization days were significantly less in rivaroxaban users compared with those in warfarin users (all-cause, 2.71 vs 3.87 days [P = 0.032]; AF-related, 2.11 vs 3.02 days [P = 0.014]). The numbers of outpatient visits were also significantly less (all-cause, 25.26 vs 35.79 visits [P < 0.001]; AF-related, 5.48 vs 9.06 visits [P < 0.001]). Rivaroxaban users had a lesser estimated mean number of all-cause hospitalizations compared with warfarin users (0.55 vs 0.73; P = 0.084), and a significantly lesser estimated mean number of AF-related hospitalizations (0.40 vs 0.57; P = 0.022). The difference in the estimated mean numbers of all-cause ED visits was not statistically significant between the rivaroxaban and warfarin users. IMPLICATIONS: In this study conducted in clinical practice, the estimated mean numbers of hospitalization days, outpatient visits, and AF-related hospitalizations associated with rivaroxaban were significantly less than were those associated with warfarin in these patients with NVAF. The corresponding estimated difference in all-cause ED visits was not statistically significant.

Hospital length of stay of nonvalvular atrial fibrillation patients who were administered Rivaroxaban versus Warfarin with and without pretreatment parenteral anticoagulants therapies.

BACKGROUND: Warfarin has been the only anticoagulant used for decades to prevent strokes and systemic embolisms in nonvalvular atrial fibrillation (NVAF) patients. Compared with rivaroxaban, warfarin has a narrow therapeutic range and many genetic and food-drug interactions that could potentially prolong hospital length of stay (LOS). OBJECTIVE: To compare hospital LOS between NVAF patients who were administered rivaroxaban versus warfarin with and without pretreatment of parenteral anticoagulant agents in a population of rivaroxaban-treated patients. METHODS: A retrospective matched-cohort analysis was conducted using the Premier Perspective Comparative Hospital Database from November 2010 to September 2012. Adult patients were included in the study if they had a hospitalization for NVAF. Rivaroxaban users were matched with up to 4 warfarin users based on propensity score analyses. Patients with and without pretreatment of parenteral anticoagulant agents were evaluated separately. Hospital LOS was compared between treatment groups using generalized estimating equations. RESULTS: The matched cohorts' characteristics were well balanced. Among the matched rivaroxaban and warfarin users who were administered parenteral agents, the mean age of the cohorts was 70 years and 47% of patients were female, whereas in the sample of patients who were not administered parenteral agents, the mean age was 72 years and 50% of patients were female. In the sample of patients who were administered parenteral agents, rivaroxaban users had significantly shorter hospital LOS (LOS difference: 1.38 days, P < 0.001) compared with warfarin users among rivaroxaban-treated patients. No significant difference in LOS was found in the sample of patients who were not administered parenteral anticoagulant agents (P = 0.169). CONCLUSION: In the study sample of NVAF patients who were administered parenteral anticoagulant agents, rivaroxaban was associated with a significantly shorter hospital LOS compared with warfarin. The difference in LOS was not statistically significant in the sample of patients who were not administered parenteral anticoagulant agents.

Medication persistence and discontinuation of rivaroxaban versus warfarin among patients with non-valvular atrial fibrillation.

OBJECTIVES: To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and warfarin in the US. RESEARCH DESIGN AND METHODS: A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF treated with rivaroxaban or warfarin from 1 July 2010 through 31 March 2013. Index date was the date of the first prescription of rivaroxaban or warfarin. All patients were followed until the earliest of inpatient death, end of continuous enrollment, or end of study period. Rivaroxaban patients were matched 1:1 by propensity scores. Medication persistence was defined as absence of refill gap of ≥ 60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. Cox proportional hazards models were estimated to examine the adjusted hazard ratios (aHRs) of rivaroxaban vs. warfarin on non-persistence and discontinuation. RESULTS: A total of 32,886 NVAF patients on rivaroxaban or warfarin met the study inclusion criteria. Each of the 7259 rivaroxaban patients identified were matched 1:1 to warfarin patients. Patients on rivaroxaban had a significantly better rate of persistence (aHR: 0.63, 95% CI 0.59-0.68) and lower rate of discontinuation (aHR: 0.54, 95% CI 0.49-0.58) compared to warfarin recipients. LIMITATIONS: Claims data may have contained inaccuracies and miscoding. Confounding may remain even after propensity score matching and additional adjustments in model. Refill data may not fully reflect actual medication use. Longer follow-up may produce more precise estimates of persistence and discontinuation. CONCLUSION: This matched cohort analysis indicated that rivaroxaban was associated with significantly higher medication persistence and lower discontinuation rates compared to warfarin.

Is rivaroxaban associated with lower inpatient costs compared to warfarin among patients with non-valvular atrial fibrillation?

BACKGROUND: Warfarin has been the mainstay treatment used by patients with a moderate-to-high risk of stroke due to non-valvular atrial fibrillation (NVAF). Unlike rivaroxaban, laboratory monitoring to allow the attainment of the prothrombin time international normalized ratio goal is required with warfarin, thereby potentially increasing a patient's hospitalization costs. OBJECTIVE: To compare hospitalization costs between hospitalized NVAF patients using rivaroxaban versus warfarin in a real-world setting. METHODS: A retrospective claims analysis was conducted using the Premier Perspective Comparative Hospital Database from November 2010 to September 2012. The study included adult patients hospitalized for NVAF after November 2011. Patients using rivaroxaban during hospitalization were matched with up to four warfarin users by propensity score analyses. Hospitalization costs were compared between the matched cohorts using generalized estimating equations. A sub-analysis was performed for patients who were first administered their treatment on day three or later of their hospital stay. Sensitivity analyses were conducted on matched cohorts with a primary diagnosis of AF. RESULTS: The matched cohorts' (2809 rivaroxaban and 11,085 warfarin users) characteristics were well balanced. The mean age of cohorts was 71 years and 49% of patients were female. The average hospitalization cost of rivaroxaban users was $11,993 compared to $13,255 for warfarin users. The cost difference was significantly lower by $1284 (P < 0.001). Patients who were administered rivaroxaban treatment on day three or after incurred significantly lower hospitalization costs (cost difference: $4350; P < 0.001) compared to warfarin users. Rivaroxaban users with a primary diagnosis of AF also had significantly lower costs compared to warfarin users. LIMITATIONS: These included possible inaccuracies or omissions in diagnoses, completeness of baseline characteristics, and a study population that included patients newly initiated on and patients who continued anticoagulant therapy. CONCLUSION: Hospitalization costs for rivaroxaban were significantly lower than those for warfarin in NVAF patients treated with rivaroxaban.

Real-world comparative effectiveness and safety of rivaroxaban and warfarin in nonvalvular atrial fibrillation patients.

BACKGROUND: Rivaroxaban was shown to be effective in reducing the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (AF) in a randomized controlled trial setting. OBJECTIVE: To assess real-world safety, effectiveness, and persistence associated with rivaroxaban and warfarin in nonvalvular AF patients. METHODS: Healthcare claims from Symphony Health Solutions' Patient Transactional Datasets from May 2011 to July 2012 were analyzed. Adult patients newly initiated on rivaroxaban or warfarin, with ≥2 AF diagnoses (ICD-9-CM: 427.31) and a CHADS2 score ≥1 during the 180 day baseline period were included. Cohorts were matched 1:4 using propensity score methods. Study outcomes were major bleeding, intracranial hemorrhage (ICH), gastrointestinal (GI) bleeding, composite stroke and systemic embolism, and venous thromboembolism (VTE) events. Cox proportional hazard models were used to compare event and persistence rates. RESULTS: The matched sample included 3654 rivaroxaban and 14,616 warfarin patients. Matching was adequate, with all standardized differences in patient characteristics <10%. No significant differences were observed for bleeding and composite stroke and systemic embolism outcomes, although rivaroxaban users were associated with significantly fewer VTE events (hazard ratio [HR] = 0.36, 95% confidence interval [CI]: 0.24-0.54, p < 0.0001) compared to warfarin users. Rivaroxaban was also associated with a significantly lower risk of treatment non-persistence (HR = 0.66; 95% CI: 0.60-0.72, p < 0.0001). LIMITATIONS: Claims data may have contained inaccuracies, and mortality and laboratory data were not available. Confounding may still have been possible even after propensity score matching. Early use pattern of medications may have changed over time. CONCLUSION: This analysis suggests that rivaroxaban and warfarin do not differ significantly in real-world rates of composite stroke and systemic embolism and major, intracranial, or GI bleeding. Rivaroxaban, however, was associated with significantly fewer VTE events and significantly better treatment persistence compared with warfarin.

Hospital length of stay: is rivaroxaban associated with shorter inpatient stay compared to warfarin among patients with non-valvular atrial fibrillation?

BACKGROUND: Warfarin has been the mainstay treatment for prevention of stroke among patients with non-valvular atrial fibrillation (NVAF). Unlike rivaroxaban, warfarin requires laboratory monitoring to allow the attainment of the prothrombin time (PT) international normalized ratio (INR) goal, thereby potentially prolonging a patient's hospital length of stay (LOS). OBJECTIVE: To compare hospital LOS between hospitalized NVAF patients using rivaroxaban versus warfarin in a real-world setting. METHODS: A retrospective claims analysis was conducted using the Premier Perspective Comparative Hospital Database from 11/2010 to 9/2012. Adult patients were included in the study if they had a hospitalization for NVAF. Patients using rivaroxaban during hospitalization were matched with up to four warfarin users by propensity score analyses. Patients who were first administered their oral anticoagulants on day 3 or later of their hospital stay were also evaluated. Comparison of hospital LOS was assessed using generalized estimating equations. RESULTS: The characteristics of the matched cohorts were well balanced. Among the matched rivaroxaban and warfarin users (2809 and 11,085 patients, respectively), the mean age of the cohorts was 71 years and 49% of patients were female. The average (median) hospital LOS for rivaroxaban patients was 4.46 (3) days, compared to 5.27 (4) days for the warfarin cohort. The mean difference in hospital LOS of 0.81 days (19.44 hours) was found to be significant at P < 0.001. Patients who were administered rivaroxaban on day 3 of their hospital stay or later also had a significantly lower LOS compared to warfarin users. LIMITATIONS: These included inaccuracies or omissions in diagnoses, completeness of baseline characteristics, and a study population that included patients newly initiated on and patients who continued anticoagulant therapy. CONCLUSION: The study sample of NVAF patients receiving rivaroxaban was associated with a significantly shorter hospital length of stay compared to the sample of patients receiving warfarin.

Laboratory evaluation of potassium and creatinine among ambulatory patients prescribed spironolactone: are we monitoring for hyperkalemia?

BACKGROUND: Serum potassium and creatinine evaluation is recommended in patients prescribed spironolactone, yet the proportion of ambulatory patients chronically dispensed spironolactone receiving evaluation is not well understood. OBJECTIVE: To estimate the rate of potassium and creatinine evaluation and identify factors associated with conducting these tests among ambulatory patients dispensed spironolactone. METHODS: A retrospective cohort study was designed to evaluate patients at 10 health maintenance organizations with ongoing spironolactone dispensing for one year (N = 2257). Potassium and creatinine evaluation were determined from administrative data. Associations between patient characteristics and laboratory testing were assessed, using logistic regression modeling. RESULTS: Serum creatinine and potassium were evaluated in 72.3% of patients during a 13 month period. The likelihood of potassium and creatinine monitoring was greater among patients who were older (OR 1.28; 95% CI 1.17 to 1.41 per decade of life); male (OR 1.25; 95% CI 1.01 to 1.54); had diabetes (OR 1.63; 95% CI 1.31 to 2.03); received concomitant therapy with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (OR 2.23; 95% CI 1.74 to 2.87), potassium supplements (OR 1.96; 95% CI 1.51 to 2.54), or digoxin (OR 2.10 95% CI 1.48 to 2.98); or had more outpatient visits (OR 1.31; 95% CI 1.19 to 1.44). Among patients with heart failure (n = 790), factors associated with the incidence of laboratory testing were diabetes (OR 1.64, 95% CI 1.14 to 2.34), outpatient visits (OR 1.20; 95% CI 1.02 to 1.41), and digoxin therapy (OR 2.26; 95% CI 1.38 to 3.69). CONCLUSIONS: Three-fourths of ambulatory patients dispensed spironolactone receive recommended laboratory evaluation, with monitoring more likely to be completed in patients prescribed concomitant therapy with drugs that increase hyperkalemia risk, older patients, and those with diabetes.

Adherence to paroxetine CR compared with paroxetine IR in a Medicare-eligible population with anxiety disorders.

There are many challenges in the pharmacologic management of elderly patients with anxiety disorders, including an increased sensitivity to drug effects, reduced drug metabolism, and socioeconomic barriers leading to poor medication adherence. As such, the purpose of this study was to evaluate differential rates of adherence between paroxetine controlled release (CR) and paroxetine immediate release (IR) in the treatment of anxiety disorders in a Medicare-eligible population. Patients aged 65 years or older initiating therapy with paroxetine CR or paroxetine IR with a diagnosis of anxiety were identified from the Integrated Healthcare Information Services National Managed Care Benchmark database from July 2001 to February 2004. Logistic regression models were used to assess differences in 6-month adherence rates, controlling for differences in multiple background characteristics. Adherence was defined as having a minimum medication possession ratio of 80% over 180 days without evidence of a 15-day gap before 90 days of therapy. Of the 604 patients included in the study, 18% received paroxetine CR and 82% received paroxetine IR; comorbid anxiety and depression were present in 37.3% of patients. Overall, only 37.3% of patients adhered to therapy, with a greater percentage of patients adhering to paroxetine CR (45.0%) compared with paroxetine IR (35.6%). After controlling for background characteristics, patients receiving paroxetine IR were 38.7% less likely to adhere to therapy compared with patients receiving paroxetine CR (P = .0328). When stratified by those with comorbid anxiety and depression, patients receiving paroxetine IR were 55.1% less likely to adhere to therapy compared with patients receiving paroxetine CR (P = .0292). This study demonstrates that antidepressant nonadherence is common in patients older than 65 years of age, with overall rates of nonadherence at 62.7% and patients receiving paroxetine IR having the lowest levels of adherence. Future work should assess differences in all available selective serotonin reuptake inhibitors while also directly assessing the economic impact of nonadherence in the elderly population.

Baseline laboratory monitoring of cardiovascular medications in elderly health maintenance organization enrollees.

OBJECTIVES: To identify correlates of laboratory monitoring errors in elderly health maintenance organization (HMO) members at the initiation of therapy with cardiovascular medications. DESIGN: Cross-sectional study in 10 HMOs. SETTING: United States. PARTICIPANTS: From a 2 million-member sample, individuals aged 65 and older who received one of seven cardiovascular medications (angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), amiodarone, digoxin, diuretics, potassium supplements, and statins) and did not have recommended baseline monitoring performed during the 180 days before or 14 days after the index dispensing. MEASUREMENTS: The proportion of members receiving each drug for whom recommended laboratory monitoring was not performed. Laboratory monitoring error rates stratified by sex, age group, chronic disease score, and HMO site were examined, and logistic regression was used to identify predictors of laboratory monitoring errors. RESULTS: Error rates varied by medication class, ranging from 23% of patients receiving potassium supplementation without serum potassium and serum creatinine monitoring to 58% of patients receiving amiodarone who did not have recommended monitoring for thyroid and liver function. Highest error rates occurred in the youngest elderly for ACE inhibitors, ARBs, digoxin, diuretics, and potassium supplements, although in patients receiving amiodarone and statins, errors were most frequent in the oldest elderly. Errors occurred more frequently in patients with less comorbidity. CONCLUSION: Laboratory monitoring errors occurred frequently in elderly HMO members at the initiation of therapy with cardiovascular medications. Further study must examine the association between these errors and adverse outcomes.