Mental healthcare expenditure in the Netherlands by urbanicity and neighbourhood socioeconomic status and interactions with age over the period 2015–2020

BACKGROUND: We previously reported that young adults and young women in particular account for an increasing share of mental healthcare expenditure in the Netherlands. Here we aim to explore temporal patterns of mental healthcare expenditure over the period 2015-2020 by urbanicity and neighbourhood socioeconomic status (SES), as well as their interaction with age. METHODS: We used comprehensive data from health insurers in the Netherlands at the 4-number postal code level. We used postal-code-clustered weighted linear regression to examine temporal patterns of mental healthcare expenditure by urbanicity and SES. Additionally, we analysed interactions with age group (18-34 vs 35-65) by adding the interaction between age, year, and either urbanicity or neighbourhood SES to the model. All models were adjusted for urbanicity, neighbourhood SES, sex, and age. RESULTS: We found a gradient in mental healthcare costs by urbanicity and neighbourhood SES in the Netherlands, which was stable over time. The standardized regression coefficient for transformed total mental healthcare costs in the highest urbanicity group was 0.51 (95%-CI = 0.47;0.56) and -0.58 (95%-CI = -0.61;-0.54) in the highest neighbourhood SES group. The association younger age (18-34) with mental healthcare costs was less strong in urban areas and neighbourhoods with lower SES. CONCLUSIONS: To understand mental healthcare usage the intersection of sociodemographic factors such as age, urbanicity and SES should be taken into account. This can aid initiatives for prevention and improving access to care.