Increased medical utilization and psychiatric comorbidity following a new diagnosis of methamphetamine use disorder

ABSTRACT

Background: Evidence of patterns of medical utilization and distribution of comorbidities among individuals using methamphetamine remains limited

Objective: This study aims to investigate changes in medical utilization and comorbidities before and after a diagnosis of methamphetamine use disorder.

Methods: A total of 3321 cases (79% were male) of methamphetamine use disorder between January 1, 1996, and December 31, 2012, were identified from Psychiatric Inpatient Medical Claims database in Taiwan. Information was collected on demographics, diagnoses, and medical utilizations. The date of newly diagnosed with methamphetamine use disorder was defined as the baseline. Mirror-image study design was used to compare changes in medical utilization and comorbidities between the pre-baseline period (within 1 year before diagnosis) and the post-baseline period (within 1 year after diagnosis). Conditional logistic regression was used to estimate changes in medical utilization and comorbidities.

Results: Most cases (77%) were first identified in a psychiatric department. There is a significant increase (P < .001) in psychiatric admission (odds ratio[OR] = 2.19), psychiatric emergency visits (OR = 1.31), and psychiatric outpatient visits (OR = 1.15) after diagnosis. Multivariable analysis revealed significantly increased risks (P < .001) of non-methamphetamine drug induced mental disorders (adjusted OR[aOR] = 29.47), schizophrenia (aOR = 2.62), bipolar disorder (aOR = 2.14), organic mental disorder (aOR = 1.82), and upper respiratory tract infection (aOR = 2.03) after diagnosis.

Conclusions: We found significant increases of medical utilization and psychiatric comorbidities after diagnosed with methamphetamine use disorder. These findings may reflect the problem of delayed diagnosis and treatment. Enhancement of early identification of methamphetamine use disorder in general practice is required for early intervention and decreased subsequent morbidities.

KEYWORDS:

• Methamphetamine
• medical utilization
• psychiatric comorbidity
• mirror-image study

Author contributions

WCL, HMC, and CJK conceived and designed the study. CJK acquired the data. SSS performed the statistical analysis. MCH, SYT, and CCC provided administrative and material support. WCL and CJK drafted the manuscript. CHP made critical revisions to the manuscript for critical intellectual content, and SYT and CCC supervised the study.

Acknowledgements

The authors wish to thank Wallace Academic Editing for their assistance with the manuscript’s preparation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This research was supported by grants from the Ministry of Science and Technology, Taiwan [MOST 105-2314-B-532-006-MY3; MOST 108-2314-B-532-005] and Taipei City Hospital [TPCH-109-64]. The funding sources had no involvement in the study design, data collection, analysis, interpretation of data, writing of the report, or the decision to submit the paper for publication.