The relationship of depression to antiepileptic drug adherence and quality of life in epilepsy.

We sought to examine the impact of depression upon antiepileptic drug (AED) adherence in patients with epilepsy. We administered the Center for Epidemiologic Studies Depression Scale (CES-D), Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), Seizure Severity Questionnaire (SSQ), and Quality of Life in Epilepsy-10 (QOLIE-10) and measured AED adherence by utilizing the medication possession ratio (MPR) in adult patients with epilepsy identified through a pharmacy claims database. From a sampling frame of over 10,000 patients identified in claims, 2750 were randomly selected and contacted directly by mail to participate in the cross-sectional survey. A total of 465 eligible patients completed a survey. Survey data were combined with administrative claims data for analysis. We conducted a path analysis to assess the relationships between depression, adherence, seizure severity, and quality of life (QOL). Patients with depression scored significantly worse on measures of seizure severity (p=.003), QOL (p<.001), and adherence (p=.001). On path analysis, depression and QOL and seizure severity and QOL were related, but only the NDDI-E scores had a significant relationship with medication adherence (p=.001). Depression as measured by the NDDI-E was correlated with an increased risk of AED nonadherence. Depression or seizure severity adversely impacted QOL. These results demonstrate yet another important reason to screen for depression in epilepsy.

Patients' preferences for treatment outcomes of add-on antiepileptic drugs: a conjoint analysis.

To understand the relative importance of the outcomes of add-on antiepileptic drugs (AEDs) and the willingness of patients with epilepsy to accept therapeutic trade-offs between seizure control and tolerability, we administered a Web-enabled, choice-format conjoint survey to patients with a self-reported physician diagnosis of epilepsy and symptoms of partial seizures. Patients answered nine choice questions to evaluate treatment outcomes of two different hypothetical add-on AEDs. Patients were first asked to choose the better of the two medicines and then asked a follow-up question about whether or not they would add the selected AED to their current treatment regimen. Our study demonstrated that patients with epilepsy consider seizure reduction to be the top priority when ranking it against the reduction or elimination of side effects. This study aids in better understanding of patients' AED treatment preferences and may aid in management of epilepsy.

Health care resource utilization and costs associated with restless legs syndrome among managed care enrollees treated with dopamine agonists.

PURPOSE: This study assessed the direct economic burden of restless legs syndrome (RLS) among patients treated with dopamine agonists (DAs) using a large United States managed care database. DESIGN: Retrospective database analysis. METHODOLOGY: Patients were required to have > or =1 prescriptions for a DA (i.e., pergolide, pramipexole, ropinirole) between 1/1/2005 and 12/31/2007 (date of first DA, or "index"); continuous enrollment for > or =6 months before and > or =12 months after index; > or =1 diagnosis of RLS, before and after index; and no diagnosis of Parkinson's disease. Study measures included annual all-cause and RLS-related costs by care setting (hospitalizations, emergency room, office, pharmacy, other, total) and treatment-pattern events (discontinuations, switches, adjunctive treatments, titrations). PRINCIPAL FINDINGS: A total of 7,796 patients met the inclusion criteria. About 70% of patients received ropinirole, and 30% received pramipexole at index. Approximately 91% had >1 RLS-related office visits, and patients filled an average of 6.5 RLS-related prescriptions (DAs, gabapentin, carbidopa/levodopa) during the 1-year follow-up period. Mean (SD) all-cause health care costs were $11,485 ($21,362) per patient, mostly due to multiple medical conditions occurring with RLS. RLS-related costs were 6.7% of total all-cause costs (mean [SD] $774 [$1,504]), consisting of office visits (16%), pharmacy (63%), and other costs (20%). Approximately 58% had a treatment-pattern event suggesting a dopamine-related side effect. Opioids were the most commonly used adjunctive therapy (13% of patients). CONCLUSION: We found relatively low costs associated with RLS treatment. These findings should encourage expanding the coverage of treatment to reduce the suffering and costs associated with RLS.

Risk factors for antiepileptic drug regimen change in patients with newly diagnosed epilepsy.

This study aimed to investigate the evolution of treatment within patients with newly diagnosed epilepsy identified from a large US commercial health care database. Postdiagnosis, patient follow-up was divided into observation units defined by consecutive antiepileptic drug (AED) prescriptions. Consecutive prescriptions were compared to assess whether a change in AED regimen had occurred. Factors associated with a regimen change were explored using a logistic regression model with subject random effects. Among 5930 patients with newly diagnosed epilepsy, there was a median of one regimen change in the first year. However, patients prescribed polytherapy regimens early in the course of disease were at a substantially greater risk of a regimen change (polytherapy vs monotherapy odds ratio=10.2, 95% confidence interval=9.2-11.3). Although a seizure during the preceding 90 days significantly increased the risk of a regimen change, it was beyond the scope of the study to determine the proportion of changes directly attributable to uncontrolled seizures.

Economic burden associated with the use of generic antiepileptic drugs in the United States.

This study quantifies the economic burden associated with generic-versus-branded use of antiepileptic drugs (AEDs) in the United States. Adult patients with epilepsy receiving carbamazepine, gabapentin, phenytoin, primidone, or zonisamide were selected from the PharMetrics database. By use of an open-cohort design, patients were classified into mutually exclusive periods of generic-versus-branded AED use. Annualized cost differences (CDs) between periods were estimated using multivariate regressions. Results were stratified into stable versus unstable epilepsy and newer-generation versus older-generation AEDs. A total of 33,625 patients (52% male, mean age=51 years) were observed. Periods of generic AED treatment were associated with higher medical service costs (adjusted CD [95% CI]=$3186 [$2359; $4012]), stable pharmacy costs ($69 [$-34; $171]), and greater total costs ($3254 [$2403; $4105]) versus brand use. Epilepsy-related costs represented 30% of incremental costs. Similar findings were observed for patients with stable and unstable epilepsy and users of newer-generation and older-generation AEDs. Significantly higher health care costs were observed during generic AED use across seizure control and AED subgroups.

Prevalence and cost of nonadherence to antiepileptic drugs in elderly patients with epilepsy.

Retrospective insurance claims from the United States were analyzed to assess nonadherence to antiepileptic drugs (AEDs) and the association between AED nonadherence, seizures, and health care costs in elderly persons with epilepsy. Inclusion criteria were: age 65, epilepsy diagnosis between 1 January 2000 and 31 June 2006, 2 AED prescriptions, and insurance enrollment for 6 months pre- and 12 months post-AED initiation. Adherence was evaluated using the medication possession ratio (MPR), with MPR<0.8 defining nonadherence. Per-patient outcomes were evaluated over 12 months post-AED initiation. Of 1278 patients identified, 41% were nonadherent. Seizure, defined by epilepsy-related inpatient or emergency department admission, occurred in 12.1% of nonadherers versus 8.2% of adherers (P=0.0212). Nonadherers had higher inpatient (+$872, P=0.001), emergency department (+$143, P=0.0008), other outpatient ancillary (+$1741, P=0.0081), and total health care (+$2674, P=0.0059) costs. AED adherence among elderly patients with epilepsy is suboptimal and associated with increased seizures and health care costs.

Association of antiepileptic drug nonadherence with risk of seizures in adults with epilepsy.

This study evaluated the potential effect of antiepileptic drug (AED) nonadherence on the risk of subsequent seizure. Retrospective insurance claims from the United States were analyzed. Inclusion criteria were: age 21-64 years, diagnosis of epilepsy or nonfebrile convulsions, 2 AED prescriptions, and insurance enrollment for 6 months pre- and 60 days post-AED initiation. Seizure was defined as a hospital or emergency admission associated with epilepsy or nonfebrile convulsions. Observation began 7 days post-drug initiation, ending with the first of the following: seizure, insurance disenrollment, or 365 days post-drug initiation. Adherence was measured using the medication possession ratio (MPR), with MPR <0.8 defining nonadherence. Seizure risk was assessed using an extended Cox proportional hazards model. Of 18,073 subjects identified, 2467 (14%) had 1 seizure. Mean follow-up was 133 days among subjects with event and 305 days for patients without event. Seizure risk was 21% higher among nonadherers (hazard ratio=1.205, P=0.0002) than adherers.

Seizure emergency plans: patient results from a cross-sectional epilepsy survey.

Guidance for seizure emergency plans exists, although their impact and extent of use in patients with epilepsy are undetermined. This study's primary purpose was to measure the estimated use and content of seizure emergency plans. Secondary objectives included measuring: disease severity, quality of life, productivity, and adherence among patients with and without a plan. An online survey was conducted among 408 patients with epilepsy (ages 18-64) who took one or more antiepileptic drugs. Only 30% of patients reported having a plan, which included avoiding injury, notifying a physician, resting/relaxing, and seeking emergency assistance. Those with a plan were more likely to have experienced more seizures in the past year, to have missed school/work, to have incurred injury, to have visited the ER, to have been hospitalized, to fear additional seizures, and to have lost a job. Seizure emergency plans appear to be reserved for adults with more severe disease, but there may be clinical benefits to developing a plan for all adult patients with epilepsy.

Association of non-adherence to antiepileptic drugs and seizures, quality of life, and productivity: survey of patients with epilepsy and physicians.

Non-adherence to epilepsy medications can interfere with treatment and may adversely affect clinical outcomes, although few studies have examined this relationship. This study assessed barriers and drivers to adherence, its impact on quality of life, and the importance of the patient-physician relationship to adherence. Two cross-sectional online surveys were conducted among 408 adult patients with epilepsy and 175 neurologists who treat epilepsy patients. Twenty-nine percent of patients self-reported being non-adherent to antiepileptic medications in the prior month. Non-adherence was found to be associated with reduced seizure control, lowered quality of life, decreased productivity, seizure-related job loss, and seizure-related motor vehicle accidents. Patient-oriented epilepsy treatment programs and clear communication strategies to promote self-management and patients' understanding of epilepsy are essential to maximizing treatment and quality of life outcomes while also minimizing economic costs.

Comparative efficacy and cost of asthma care in children with asthma treated with fluticasone propionate and montelukast.

OBJECTIVE: To assess the comparative efficacy of fluticasone propionate (FP) and montelukast (MON), using administrative claims for pediatric asthma in a clinical setting. STUDY DESIGN: This retrospective observational study used the PharMetrics Integrated-Outcomes Database. Children age 4 to 17 years with an ICD-9-CM 493.xx for asthma, therapy with an inhaled corticosteroid in the 12 months before the index medications, and an index claim for FP or MON between January 2001 and December 2003 were studied. FP- and MON-treated children were propensity-matched based on health care utilization. Asthma-related parameters studied included treatment failure, hospitalizations, and total cost of care. RESULTS: The children treated with MON were more likely to experience treatment failure (odds ratio [OR] = 2.55; 95% confidence interval [CI] = 2.19 to 2.96) and to be admitted to the hospital for asthma-related care (OR = 1.99; 95% CI = 1.15 to 3.44) compared with those treated with FP. Furthermore, the children treated with MON incurred significantly higher asthma-related treatment costs compared with those treated with FP (parameter estimate = 0.418; P < .0001). CONCLUSIONS: In children with asthma, treatment with FP is associated with better outcomes and lower cost than treatment with MON.

The economic consequences of generic substitution for antiepileptic drugs in a public payer setting: the case of lamotrigine.

Generic substitution of antiepileptic drugs (AEDs) may increase pharmacy utilization, thus counterbalancing per-pill savings. The purpose of our study was to analyze the economic impact of government-mandated switching from branded to generic lamotrigine. Patients in a Canadian public pharmacy claims database using branded lamotrigine (Lamictal GlaxoSmithKline, UK) in 2002 converted to generic lamotrigine in 2003 and were observed from July 2002 to March 2006. Patients used branded lamotrigine for >or=90 days pre-generic entry and had >or=1 claim for generic lamotrigine post-generic entry. For the generic period, observed per-patient monthly drug costs were calculated as the sum of costs for lamotrigine, other AEDs, and non-AEDs. Expected per-patient drug costs were estimated assuming lamotrigine dose and other prescription drug utilization in the generic period were identical to those observed during the brand period. Differences between observed and expected costs were compared. Among 1,142 branded lamotrigine users, overall average monthly drug costs per person were expected to decrease by $30.55 due to lower pill costs. Instead, they fell by $11.98 from the brand to the generic periods (p < 0.001). Because of dosage changes, lamotrigine costs decreased by $29.92 instead of the anticipated $33.87 (p < 0.001). Increased pharmacy utilization caused other AED costs to rise by $6.29 versus the expected $0.36 (p < 0.001), while non-AED drug cost increased by $11.64 rather than by $2.95 (p < 0.001). We concluded that conversion to generic lamotrigine resulted in lower than expected cost savings. Further research is necessary to determine whether this is due to reduced effectiveness and/or tolerability. Payers may weigh smaller-than-expected cost reductions against a possible decrease in effectiveness to assess the relevance of mandatory generic switching of lamotrigine.

High-risk individuals' willingness to pay for diabetes risk-reduction programs.

OBJECTIVE: The purpose of this study was to estimate how much at-risk individuals are willing to pay for type 2 diabetes primary prevention programs. RESEARCH DESIGN AND METHODS: An Internet-based, choice-format conjoint survey was presented to individuals at elevated risk for type 2 diabetes. Hypothetical diabetes risk-reduction programs included seven features: diet, exercise, counseling, medication, weight loss goal, risk reduction, and program costs. The sample included 582 individuals aged > or =45 years, two-thirds of whom were obese. Conditional logit models were used to calculate participants' willingness to pay for risk reduction programs. Each respondent's self-assessed risk of developing diabetes was compared with an objective measure based on a diabetes screening tool. RESULTS: Many respondents underestimated their personal risk of developing diabetes. Those with a low perceived risk were less likely to indicate that they would participate in a diabetes prevention program. Individuals had the strongest preference for programs with large weight loss goals, fewer restrictions on diet, and larger reductions in the risk of diabetes. Respondents were willing to pay approximately $1,500 over 3 years to participate in a lifestyle intervention program similar to the Diabetes Prevention Program. Individuals with a high perceived risk were willing to pay more than individuals with lower perceived risk. CONCLUSIONS: Many individuals will be willing to participate in interventions to delay or prevent diabetes if the interventions are subsidized, but most will be unwilling to pay the full program cost. Our results also offer insights for designing risk-reduction programs that appeal to potential participants.

Comparing outcomes in patients with persistent asthma: a registry of two therapeutic alternatives.

OBJECTIVE: Clinical trials have demonstrated improved efficacy of fluticasone propionate/salmeterol (100/50 mcg) in a single device (FSC) compared with montelukast (10 mg) (MON). This study was designed to assess asthma control, asthma-related quality of life, asthma-related emergency department (ED) visit/hospitalization, treatment-related satisfaction, and productivity losses in patients newly started on FSC or MON. RESEARCH DESIGN AND METHODS: Patients who were newly prescribed FSC or MON during a regularly scheduled office visit were enrolled in a prospective observational study by nearly 500 physicians from eight managed care plans. Patient survey data were collected at baseline and at months 1, 3, 6, and 12, to measure study outcomes. ED visits/inpatient stays were reported from commercial claims data. Multivariate analyses assessed 12-month outcomes, controlling for several baseline patient characteristics. RESULTS: A total of 1414 patients >or= 15 years old were enrolled in the registry (FSC, n = 1061; MON, n = 353), 90% of which completed a 12-month survey. FSC patients had significantly greater improvement in both asthma control and quality of life, and reported significantly higher satisfaction with their medication (p = 0.003) and fewer days at work/school with asthma symptoms (p = 0.04) than MON. Other parameters of productivity losses such as missed work/school days due to asthma were not significantly different between the two groups. FSC use was also significantly associated with a lower risk of an asthma-related ED visit/hospitalization compared with MON (odds ratio = 0.35, 95% confidence interval: 0.15-0.92). CONCLUSION: In a 12-month office-based observational study, patients age 15 and older with persistent asthma, newly started on FSC, improved in symptom, quality of life, treatment, and utilization-related outcomes compared with patients newly started on MON. These results should be interpreted in light of the inherent limitations of non-randomized, uncontrolled studies.

Prospective, open-label trial measuring satisfaction and convenience of two formulations of lamotrigine in subjects with mood disorders.

BACKGROUND: Lamotrigine is an anticonvulsant drug indicated for the maintenance treatment of bipolar I disorder and for various types of epilepsy. An orally disintegrating tablet (ODT) of lamotrigine was developed to provide a formulation option that might increase patient convenience and satisfaction. METHODS: Subjects with mood disorders who reported difficulty swallowing currently prescribed lamotrigine immediate-release medication (baseline) were enrolled and treated with lamotrigine ODT for three weeks (end of treatment). Subject satisfaction and convenience were measured using the Treatment Satisfaction Questionnaire for Medication (TSQM). Also measured were global psychopathology using the Clinical Global Impression severity index (CGI-S) and depressive symptoms using the Beck Depression Inventory (BDI-II). RESULTS: Lamotrigine ODT was found to be significantly more convenient to use than lamotrigine immediate-release (change in baseline TSQM convenience score: 23.3, n = 97, P < 0.001). The mean TSQM global satisfaction score was similar at baseline (76.3) and after treatment with lamotrigine ODT (76.0). There were no significant changes on CGI-S and BDI-II. CONCLUSION: Subjects reported that lamotrigine ODT was significantly more convenient than lamotrigine immediate-release, while both formulations were associated with good satisfaction. Lamotrigine ODT may be a treatment option for patients who have difficulty swallowing medication.

Burden of uncontrolled epilepsy in patients requiring an emergency room visit or hospitalization.

OBJECTIVE: To quantify the clinical and economic burden of uncontrolled epilepsy in patients requiring emergency department (ED) visit or hospitalization. METHODS: Health insurance claims from a 5-state Medicaid database (1997Q1-2009Q2) and 55 self-insured US companies ("employer," 1999Q1 and 2008Q4) were analyzed. Adult patients with epilepsy receiving antiepileptic drugs (AED) were selected. Using a retrospective matched-cohort design, patients were categorized into cohorts of "uncontrolled" (≥ 2 changes in AED therapy, then ≥ 1 epilepsy-related ED visit/hospitalization within 1 year) and "well-controlled" (no AED change, no epilepsy-related ED visit/hospitalization) epilepsy. Matched cohorts were compared for health care resource utilization and costs using multivariate conditional regression models and nonparametric methods. RESULTS: From 110,312 (Medicaid) and 36,529 (employer) eligible patients, 3,454 and 602 with uncontrolled epilepsy were matched 1:1 to patients with well-controlled epilepsy, respectively. In both populations, uncontrolled epilepsy cohorts presented about 2 times more fractures and head injuries (all p values < 0.0001) and higher health care resource utilization (ranges of adjusted incidence rate ratios [IRRs] [all-cause utilization]: AEDs = 1.8-1.9, non-AEDs = 1.3-1.5, hospitalizations = 5.4-6.7, length of hospital stays = 7.3-7.7, ED visits = 3.7-5.0, outpatient visits = 1.4-1.7, neurologist visits = 2.3-3.1; all p values < 0.0001) than well-controlled groups. Total direct health care costs were higher in patients with uncontrolled epilepsy (adjusted cost difference [95% confidence interval (CI)] Medicaid = $12,258 [$10,482-$14,083]; employer = $14,582 [$12,019-$17,097]) vs well-controlled patients. Privately insured employees with uncontrolled epilepsy lost 2.5 times more work days, with associated indirect costs of $2,857 (95% CI $1,042-$4,581). CONCLUSIONS: Uncontrolled epilepsy in patients requiring ED visit or hospitalization was associated with significantly greater health care resource utilization and increased direct and indirect costs compared to well-controlled epilepsy in both publicly and privately insured settings.

Restless legs syndrome (RLS) augmentation associated with dopamine agonist and levodopa usage in a community sample.

OBJECTIVE: Assess the rate of augmentation as it occurs during standard long-term dopaminergic treatment of RLS, potential risk factors or predictors of augmentation, the relationship between treatment duration and augmentation, and the clinical impact of augmentation on subjects' health outcomes. METHODS: Two hundred sixty-six patients with dopamine-treated RLS completed a one-time online survey. All subjects were recruited by their PCP/neurologist and were 18 or older. Augmentation was assessed using NIH guidelines and an augmentation classification system was developed through this research. RESULTS: Overall, 20% of the patients were classified as having definitive or highly suggestive clinical indications of augmentation. Five factors were considered likely to reflect increased risk of developing augmentation, including more frequent RLS symptoms pre-treatment, greater discomfort with RLS symptoms before treatment, and longer treatment duration. RLS augmentation occurred at a rate of about 8% each year for at least the first 8 years of dopamine treatment. Subjects reporting definite or highly suggestive clinical indicators of augmentation had an average IRLS score of 23.6, indicating generally inadequate treatment with generally poor clinical outcomes. Only 25% of the patients reported no indications of augmentation and they were the only group to show on average a low (<15) IRLS score and good clinical outcomes. CONCLUSIONS: As currently used, long term dopaminergic treatment for an average ± SD of 2.7 ± 2.4 years produced significant augmentation problems in at least 20% of the patients and only 25% of the patients were totally free of this problem. It is important for physicians to carefully screen patients for changes in RLS symptoms for as long as they are on dopamine agents, with particular attention paid to those patients who present with the most severe RLS symptoms prior to treatment initiation. Given the marked increase in suffering with augmentation, a method for early detection and intervention would be an important contribution to the effective management and treatment of RLS.

The association between antiepileptic drug and HMG-CoA reductase inhibitor co-medication and cholesterol management in patients with epilepsy.

PURPOSE: Pharmacokinetic interactions have been demonstrated in enzyme-inducing antiepileptic drugs (EIAEDs) and statins; however, their clinical significance is not well established. The purpose of this study was to evaluate the association of EIAEDs and non-enzyme-inducing antiepileptic drugs (NEIAEDs) on statin dose adjustments and low-density lipoprotein (LDL) cholesterol levels in patients with epilepsy. METHODS: Retrospective insurance claims from 2000 to 2006 from the Ingenix Impact (formerly Integrated Health Care Information Services) database were analyzed. Two cohorts were compared, EIAEDs+statin and NEIAEDs+statin: 1118 patients were analyzed (58% men; 66% aged >55 years); 506 (45%) initiated with an EIAED. Outcomes assessed included statin dose adjustments and, for a subset of subjects, risk of mean LDL >100mg/dL during the 12-month follow-up period. Descriptive statistics were calculated and regression models estimated. RESULTS: Among the EIAED group, 72% initiated with phenytoin; among the NEIAED group, 57% initiated with gabapentin. For the EIAED group, the risk of upward statin dose adjustments was significantly greater (odds ratio=1.36; P=0.04) compared with the NEIAED group; similarly, the risk of having mean LDL >100mg/dL was significantly greater (odds ratio=41.22; P=0.005) and increased during the follow-up period (+26.6mg/dL; P=0.001) for the EIAED group. DISCUSSION: This study suggests that concomitant use of EIAEDs and statins may be associated with reduced clinical effectiveness of statins. Patients with epilepsy who use EIAEDs and statins concomitantly may require greater vigilance for optimal cholesterol management.

Adolescent and caregiver experiences with epilepsy.

Epilepsy during adolescence can impede the development of psychosocial independence and typical biological maturational processes. We examined in parallel the experiences and perceptions of adolescent patients with epilepsy and their caregivers. Specifically, we focused on frequency and type of seizures, comorbid conditions, adherence to therapies, productivity, clinical and quality of life consequences of seizures, estimated use and content of seizure emergency plans, and the patient-physician relationship. Two cross-sectional online surveys were conducted among 153 adolescent patients with epilepsy and their respective caregivers. A total of 35% of adolescents indicated that they had been nonadherent to antiepileptic medications in the prior month. Adolescents scored significantly lower compared with their peers on quality-of-life measures. Adolescents and caregivers reported similarly on nearly all domains. An adolescent-centered epilepsy management program may help alleviate concerns and also help the adolescent independently manage their epilepsy as they transition into adulthood.

Economic impact of generic substitution of lamotrigine: projected costs in the US using findings in a Canadian setting.

BACKGROUND: Generic substitution may not always save health care costs for antiepileptic drugs (AED). OBJECTIVE: (1) To examine the economic impacts of generic substitution of lamotrigine in Canada; and (2) to convert observed Canadian costs to a United States (US) setting. METHODS: Health claims from Québec's health plan (RAMQ) between 08/2002 and 07/2006 were analyzed. Patients with > or = 1 epilepsy claim and treated with branded lamotrigine (Lamictal) before generic entry were selected. Health care costs ($/person-year) were compared during periods of branded and generic use of lamotrigine. Two cost-conversion methods were employed; one using purchasing power parities, US/Canada service use ratios, and exchange rate, and another employing Canadian health care utilization and US unit costs. RESULTS: 671 patients were observed during 1650.9 and 291.2 person-years of branded and generic use of lamotrigine, respectively. The generic-use period was associated with an increase in overall costs (2006 constant Canadian dollars) relative to brand use (C$7902 vs. C$6419/person-year; cost ratio (CR) = 1.22; p = 0.05), despite the lower cost of generic lamotrigine. Non-lamotrigine costs were 33% higher in the generic period (p = 0.013). Both conversion methods yielded increases in total projected health care costs excluding lamotrigine (2006 constant US dollars) during the generic period (Method 1: cost difference: US$1758/person-year, CR = 1.33, p = 0.01); Method 2: cost difference: US$2516, CR = 1.39, p = 0.004). LIMITATIONS: Study limitations pertain to treatment differences, indicators used for conversion and possible claim inaccuracies. CONCLUSION: Use of generic lamotrigine in Canada was significantly associated with increased overall medical costs compared to brand use. Projected overall US health care costs would likely increase as well.

Factors that affect adherence to bipolar disorder treatments: a stated-preference approach.

BACKGROUND: Medication nonadherence is high among patients with bipolar disorder, and may lead to poor clinical outcomes, decreased quality of life, and increased resource utilization. OBJECTIVE: To investigate the factors associated with nonadherence and to assess the effect of patient-stated preferences on stated adherence to hypothetical medications. RESEARCH DESIGN: A choice-format stated-preference Web survey was administered. In each choice question, patients were asked to choose among 2 or 3 different hypothetical medications. Each choice question was followed by a question asking patients about their likely adherence to the selected medication alternative. SUBJECTS: Patients (N = 469) with self-reported bipolar disorder completed the survey which was programmed and administered to members of a chronic-illness Web panel. MEASURES: Factors associated with stated adherence to current treatment were identified. The effects of socioeconomic characteristics and medication attributes on stated adherence to hypothetical medications were assessed. RESULTS: Patient socioeconomic characteristics affect patients' adherence. Being white and having more education has a significant positive effect on adherence. Self-reported current adherence is a strong factor in predicting adherence for better medications. Medication outcome attributes, especially severity of depressive episodes, strongly influence patients' stated adherence to treatment. Weight gain and cognitive effects of a medication most significantly affected patients' likely adherence to medications for bipolar disorder. CONCLUSIONS: Patients are the final health care decision makers; their satisfaction with a medication is likely to affect whether or not they adhere to the medication prescribed by their physician. In the case of bipolar disorder, this study suggests patients are likely to be more adherent to medications that reduce the severity of depressive episodes and do not cause weight gain or cognitive side effects. By understanding the factors that improve adherence, health care providers can optimize prescribing patterns, which may ultimately lead to more effective management and improvement in the patient's condition.