Effect of combined cardiovascular risk factors on individual and population medical expenditures: a 10-year cohort study of national health insurance in a Japanese population.
BACKGROUND
Although obesity is required for some criteria defining metabolic syndrome, clustering of other risk factors also indicates an increased risk of cardiovascular disease. Whether the relationship between cardiovascular risk factor clustering and medical expenditures differs with body mass index (BMI) requires investigation, especially in a population with a low prevalence of obesity such as that in Japan.


RESULTS
A 10-year cohort study of 4,478 Japanese National Health Insurance beneficiaries aged 40-69 years in a community between 1990 and 2001 was carried out in the present study. The clustering of cardiovascular risk factors showed a positive and graded relationship to personal medical expenditures in participants who are overweight (BMI > or =25.0) and normal weight (BMI <25.0). The individual medical expenditures per month were 1.7-fold higher for participants with 2 or 3 risk factors and overweight than for those without these factors (26,782 vs 15,377 Japanese yen). Differences in the geometric means were similarly significant after adjustment for other confounding factors. However, the excess medical expenditures by risk clustering of normal weight categories within the total medical expenditures were higher than those of overweight categories because more participants were of normal weight.


CONCLUSIONS
Cardiovascular risk factor clustering and being overweight can be a useful predictor of medical expenditures in a Japanese population.
Okamura
Tomonori
T
Department of Health Science, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu 520-2192, Japan. tokamura@belle.shiga-med.ac.jp
Nakamura
Koshi
K
Kanda
Hideyuki
H
Hayakawa
Takehito
T
Hozawa
Atsushi
A
Murakami
Yoshitaka
Y
Kadowaki
Takashi
T
Kita
Yoshikuni
Y
Okayama
Akira
A
Ueshima
Hirotsugu
H
D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000191:economics / Q000453:epidemiology / Q000209:etiology*; D016000:Cluster Analysis; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000191:economics* / Q000453:epidemiology; D008875:Middle Aged; D009313:National Health Programs / Q000191:economics; D009765:Obesity / Q000150:complications / Q000191:economics / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors