Household income relationship with health services utilization and healthcare expenditures in people aged 75 years or older in Japan: A population-based study using medical and long-term care insurance claims data.

BACKGROUND: This study aimed to determine whether there are disparities in healthcare services utilization according to household income among people aged 75 years or older in Japan.

METHODS: We used data on medical and long-term care (LTC) insurance claims and on LTC insurance premiums and needs levels for people aged 75 years or older in a suburban city. Data on people receiving public welfare were not available. Participants were categorized according to household income level using LTC insurance premiums data. The associations of low income with physician visit frequency, length of hospital stay (LOS), and medical and LTC expenditures were evaluated and adjusted for the five-year age group and LTC needs level.

RESULTS: The study analyzed 12,852 men and 18,020 women, among which 13.3% and 41.5% were respectively categorized as low income. Participants with low income for both genders were more likely to be functionally dependent. In the adjusted analyses, lower income was associated with fewer physician visits (incidence rate ratio: 0.90 (95% confidence interval 0.87-0.92) for men and 0.97 (0.95-0.99) for women), longer LOS (1.98 (1.54-2.56) and 1.42 (1.20-1.67)), and higher total expenditures (1.09 (1.01-1.18) and 1.09 (1.05-1.14)).

CONCLUSIONS: This study suggests older people with lower income had fewer consultations with physicians but an increased use of inpatient services. The income categorization used in this study may be an appropriate proxy of socioeconomic status.