Income level associated with mental health inequities

Researchers in Finland reported that household income may be a significant risk factor for first hospital-treated mental disorders across income levels, according to results of a population-based open cohort study published in JAMA Psychiatry.

“The association between poverty and mental health issues is well known globally,” Kimmo Suokas, MD, of Tampere University in Finland, told Healio Psychiatry. “In the present study, we observed the income gradient in the incidence rates of first hospital-treated mental disorders persisting at all levels of income deciles in the adult population in Finland. Second, the reduction in the use of inpatient care has taken place during the entire period in the richest deciles, contrary to the lowest deciles.”

According to Suokas and colleagues, Finland has seen annual population rates of psychiatric hospital care decrease from 6.2 to 4.7 per 1,000 inhabitants. Although first psychiatric hospital admission rates are rarely reported, the researchers noted that they provide insight into the annual emergence of severe mental health conditions and allow for comparisons between income groups. To determine the incidence rates of first psychiatric hospital admissions, the researchers obtained nationwide linked registry data from Finnish Hospital Discharge and Statistics Finland population registers. They analyzed data for all Finnish citizens (n = 6,258,033) who lived in the country between 1996 and 2014 and contributed to 96,184,614 person-years at risk for first inpatient treatment for mental disorders.

Suokas and colleagues reported that a total of 186,082 first psychiatric inpatient treatment episodes occurred, with 50.2% of these among men. Overall age-standardized incidence rates per 1,000 person-years varied from 1.59 (95% CI, 1.56-1.63) in 2014 to 2.11 (95% CI, 2.07-2.15) in 2008. They reported that among the highest income deciles, there was a continuous mean decrease per year of 3.71% (95% CI, 2.82-4.59) in men and 0.91% (95% CI, 0.01-1.8) in women throughout the study period. Among the lowest deciles, trends increased 1.31% (95% CI, 0.62-2.01) in men from 1996 to 2007 and 5.61% (95% CI, 2.36-8.96) in women from 1996 to 2001. Further, they observed an income gradient all levels of household income in the adult population. Lower income deciles were associated with higher adjusted IRRs compared with the highest decile. The gradient did not persist at the highest income deciles in other age groups. Schizophrenia and related psychotic disorders had the steepest diagnosis-specific income gradient.

“Being relatively poor, even in a country with relatively low income inequality and universal welfare policies, is associated with a higher risk for first hospital-treated mental disorders,” Suokas said. “Inequalities in first psychiatric hospitalizations have persisted in the era of deinstitutionalization. On the health care policy level, the finding that individuals with low income are overrepresented in first hospitalizations highlights the importance of accessibility and affordability of community-based mental health care.”

In a related editorial, Vikram Patel, MRCPsych, PhD, FMedSci, of the department of global health and social medicine at Harvard Medical School, noted that these findings may appear “counterintuitive,” since Finland was ranked as the happiest country in the world for 2019.

“One thing is certain: being poor is harmful for one’s mental health, no matter how rich or happy the country where you live,” Patel wrote. “Furthermore, living in a happy country does not guarantee better mental health compared with less happy countries.” – by Joe Gramigna

Disclosures: Patel reports being a cofounder of Librum, a mental health consulting firm. Suokas reports receiving grants from the Jalmari and Rauha Ahokas Foundation and Finnish Psychiatric Association, as well as personal fees from H. Lundbeck A.S. Please see the study for all other authors’ relevant financial disclosures.