Treatment patterns, health care resource utilization, and costs in Japanese adults with attention-deficit hyperactivity disorder treated with atomoxetine

Cardiovascular Safety of Atomoxetine and Methylphenidate in Patients With Attention-Deficit/Hyperactivity Disorder in Japan: A Self-Controlled Case Series Study

OBJECTIVE

To investigate the association between atomoxetine or methylphenidate use and arrhythmia, heart failure (HF), stroke, and myocardial infarction (MI) in attention-deficit/hyperactivity disorder (ADHD) patients mainly focused on the people of working age.

METHODS

In a self-controlled case series study using a Japanese claims database, we identified events of arrhythmia, HF, stroke, and MI among 15,472 atomoxetine new users and 12,059 methylphenidate new users. Adjusted incidence rate ratios (aIRRs) of outcome events were estimated using multivariable conditional Poisson regression.

RESULTS

An increased risk of arrhythmia was observed during the first 7 days after the initial atomoxetine exposure (aIRR 6.22, 95% CI [1.90, 20.35]) and in the subsequent exposure (3.23, [1.58, 6.64]). No association was found between methylphenidate exposure and arrhythmia, nor between atomoxetine or methylphenidate exposure and HF. The limited number of stroke and MI cases prevented thorough analysis.

CONCLUSIONS

Clinicians should consider monitoring for arrhythmia after patients initiating or re-initiating atomoxetine.

Sociodemographic and Clinical Factors Affecting Treatment Adherence in Adults with Attention Deficit and Hyperactivity Disorder

Background

This study aims to explore sociodemographic and clinical factors affecting medication adherence in adults with attention deficit and hyperactivity disorder and elicit dysfunctional domains and comorbidities with a focus on gender differences.

Methods

Patients were recruited from 2 specialty clinics using chart records in a natural treatment design. Adult attention deficit and hyperactivity disorder self-report scale, Diagnostic Interview for attention deficit and hyperactivity disorder in adults, was applied. Adherence is defined if the patient declared ≥80% adherence to medication throughout the last 8-12 weeks.

Results

From 205 attention deficit and hyperactivity disorder patients (male = 112 female = 93 (age (median) min-max = 29 (18-56)), 29% were non-adherent to attention deficit and hyperactivity disorder medication. In the multivariate analysis, having 2 or more comorbid disorders (P = .009), dysfunctions in academic/work (P = .049), and dysfunctions in family and other relationships (P = .047) increased the likelihood of adherence. Adherence rates did not significantly differ between methylphenidate and atomoxetine (P = .405). Women were more likely to have 2 or more comorbid psychiatric disorders (P = .004) and dysfunctions in social relationships (P = .001), free time activities, hobbies (P < .001), self-confidence, and self-image (P < .001).

Results

Nearly one-third of adult patients with attention deficit and hyperactivity disorder did not adhere to medication treatment. Comorbid psychiatric disorders and dysfunctions in life domains appear to increase the likelihood of adherence to attention deficit and hyperactivity disorder medications, possibly through increasing motivation for treatment. The effect of cognitive-behavioral therapy on compliance with attention deficit and hyperactivity disorder medication should further be explored with prospective controlled studies.

Conclusion

We suggest that future longitudinal studies use objective measures of adherence and confirm the role of dysfunctional life domains and comorbid psychiatric disorders as correlates of medication adherence.

Medications for attention-deficit/hyperactivity disorder in Japan: A retrospective cohort study of label compliance

Aim

To assess label compliance in prescription of medications approved for treatment of attention‐deficit/hyperactivity disorder (ADHD) in Japan at the time of this study: methylphenidate (MPH), atomoxetine, and guanfacine.

Methods

Retrospective descriptive study was conducted in prevalent‐user cohorts from the Japan Medical Data Center database. Patients who were prescribed a study drug between January 1, 2013 and September 30, 2018 and were in the database for ≥30 days were included. A prescription was considered compliant if all 4 criteria were satisfied: appropriate age, daily dose not exceeding the approved maximum, no contraindicated concurrent medications, and no contraindicated conditions.

Results

Among 17 418 patients who were prescribed a study drug during 2013‐2018, 73% were male and 53% were children (aged <18 years). Fewer than 2% of prescriptions were for patients outside the approved age, 10%‐13% of patients in the atomoxetine and MPH cohorts received ≥1 prescription exceeding maximum approved dose, no patients were co‐prescribed a contraindicated medication, and 16%–18% of patients in the MPH cohorts had ≥1 contraindicated condition. During their first 500 days of use, for approximately 73%‐86% of patients, all prescriptions were compliant with all label requirements.

Conclusions

Among patients exposed to ADHD medications in Japan during 2013‐2018, nearly all prescriptions for these medications were label‐compliant for age. For >85% of patients, all prescriptions were label‐compliant for dose, and for approximately 80%, all prescriptions were label‐compliant for contraindicated conditions. We did not find evidence of widespread abuse or noncompliant use of prescribed ADHD medications.

To assess label compliance in prescription of medications approved for the treatment of ADHD in Japan at the time of this study (2013‐2018), a retrospective descriptive cohort study was conducted in patients from the JMDC database who were prescribed a study drug (methylphenidate, atomoxetine, or guanfacine) and were in the database for at least 30 days. Among 17 418 patients eligible for the study, nearly all prescriptions were label‐compliant for age; for more than 85% of patients, all prescriptions were label‐compliant for dose, and for approximately 80%, all prescriptions were label‐compliant for contraindicated conditions. We did not find evidence of widespread abuse or noncompliant use of prescribed ADHD medications.

Medication utilization among adult patients with attention-deficit/hyperactivity disorder after reimbursement criteria change

This study analyzed the pattern of attention-deficit/hyperactivity disorder (ADHD) medication initiation in adult patients with ADHD after the reimbursement criteria change and identified the influencing factors associated with it using the claim data. We identified 243 adult patients with ADHD who had not been prescribed ADHD drugs before 1 September 2016. We conducted Kaplan-Meier survival analysis to calculate the time to initial prescription of ADHD medications, and Cox proportional hazard regression analysis to estimate the influencing factors. Approximately one-third of the patients (n = 76, 31.3%) were first prescribed ADHD medications after reimbursement approval, and 40 of them (16.5%) started treatment with osmotic release oral system methylphenidate. The patient's age group (30-39 years) and the status of diagnosis before the index date were associated with early initiation of pharmacotherapy. The odds of starting ADHD medications increased approximately 2.7-fold in the 30-39 age group and 0.2-fold in the case of patients who were diagnosed before the approval. Our findings show that both diagnosis and treatment of adult ADHD remains inadequate despite the change in reimbursement criteria. Improving awareness of adult ADHD among both the public and the professionals is essential to increase its chances of diagnosis and treatment.