@article{oai:nagasaki-u.repo.nii.ac.jp:00000078,
 author = {Yamanashi, Hirotomo and Nobusue, Kenichi and Nonaka, Fumiaki and Honda, Yukiko and Shimizu, Yuji and Akabame, Shogo and Sugimoto, Takashi and Nagata, Yasuhiro and Maeda, Takahiro},
 issue = {4},
 journal = {Family Practice},
 month = {Aug},
 note = {BACKGROUND: Multimorbidity is the presence of two or more chronic diseases and is associated with increased adverse outcomes, including hospitalization, mortality and frequency of use of medical institutions. OBJECTIVE: This study aimed to describe multimorbidity patterns,determine whether multimorbidity was associated with high medical expenditure, and determine whether mental diseases had an interaction effect on this association.METHODS: We conducted a claims data-based observational study. Data were obtained 
for 7526 individuals aged 0-75 years from a medical claims data set for Goto, Japan, 
over a 12-month period (2016-17). Annual medical expenditure was divided into quintiles; 
the fifth quintile represented high medical expenditure. Multimorbidity status was defined 
as the occurrence of two or more health conditions from 17 specified conditions.
 Odds ratios (OR) and 95% confidence intervals (CI) for high medical expenditure were calculated 
by number of comorbidities. RESULTS: In total, 5423 (72.1%) participants had multimorbidity. 
Multimorbidity was significantly associated with high medical expenditure,
 even after adjustment for age, sex and income category (OR: 10.36, 95% CI: 7.57-14.19; P < 0.001).
 Mental diseases had a significant interaction effect on the association between multimorbidity 
and high medical expenditure (P = 0.001). CONCLUSIONS: Multimorbidity is associated 
with high medical expenditure in Japan. Mental diseases may contribute to increased medical costs., Family Practice, 37(4), pp.453-458; 2020},
 pages = {453--458},
 title = {The role of mental disease on the association between multimorbidity and medical expenditure},
 volume = {37},
 year = {2020}
}