Trends in the incidence and DALYs of schizophrenia at the global, regional and national levels: results from the Global Burden of Disease Study 2017

Abstract

Aim: Schizophrenia is a serious health problem worldwide. This systematic analysis aims to quantify the burden of schizophrenia at the global, regional and national levels using the Global Burden of Disease Study 2017 (GBD 2017).

Methods: We collected detailed information on the number of incidence cases, disability-adjusted life years (DALYs) and age-standardised incidence rate (ASIR) and age-standardised rate of DALYs (ASDR) during 1990-2017 from GBD 2017. The estimated annual percentage changes (EAPCs) in the ASIR and in the ASDR were calculated to quantify the temporal trends in the ASIR and ASDR of schizophrenia.

Results: Globally there were 1.13 million (95% uncertainty interval [UI] = 1.00 to 1.28) incident schizophrenia cases and 12.66 million (95% UI = 9.48 to 15.56) DALYs due to schizophrenia in 2017. The global ASIR decreased slightly from 1990 to 2017 (EAPC = -0.124, 95% UI = -0.114 to -0.135), while the ASDR was stable. The number of incident cases, DALYs, ASIR and ASDR were higher for males than for females. The incident rate and DALYs rate were highest among those aged 20-29 and 30-54 years, respectively. ASIR and ASDR were highest in East Asia in 2017, at 19.66 (95% UI = 17.72 to 22.00) and 205.23 (95% UI = 153.13 to 253.34), respectively. In 2017, the ASIR was highest in countries with a high-moderate sociodemographic index (SDI) and the ASDR was highest in high-SDI countries. We also found that the EAPC in ASDR was negatively correlated with the ASDR in 1990 (P = 0.001, ρ = -0.23).

Conclusion: The global burden of schizophrenia remains large and continues to increase, thereby increasing the burden on health-care systems. The reported findings should be useful for resource allocation and health services planning for the increasing numbers of patients with schizophrenia in ageing societies.

Keywords: DALYs; incidence; schizophrenia.

Fig. 1.

The incident rate (a) and DALYs rate (b) of schizophrenia of different age group globally. DALYs, disability-adjusted life years.

Fig. 2.

The global disease burden of schizophrenia in 195 countries or territories. (a) The ASIR of schizophrenia in 2017. (b) The relative change in incident cases of schizophrenia between 1990 and 2017. (c) The EAPC of ASIR of schizophrenia from 1990 to 2017. Countries with an extreme number of cases/evolution were annotated. ASIR, age-standardised incident rate; EAPC, estimated annual percentage change.

Fig. 3.

The incident cases and DALYs of schizophrenia at a regional level. The left column in each group is case data in 1990 and the right column in 2017. DALYs, disability-adjusted life years.

Fig. 4.

ASIR (a) and ASDR (b) for schizophrenia by SDI, 1990–2017, and expected value-based SDI. The black line represents the average expected relationship between SDI and incidence (a) or DALYs (b) for schizophrenia based on values from all countries over the 1990–2017 estimation period. ASIR, age-standardised incident rate; ASDR, age-standardised rate of DALYs; SDI, sociodemographic index; DALYs, disability-adjusted life-years.

Fig. 5.

The incident cases (a), ASIR (b), DALYs number (c) and ASDR (d) for schizophrenia from 1990 to 2017 at SDI quintiles level. ASIR, age-standardised incident rate; ASDR, age-standardised rate of DALYs; DALYs, disability-adjusted life-years; SDI, sociodemographic index.

Fig. 6.

The correlation between EAPC of ASIR and ASIR in 1990 (a); EAPC of ASIR and HDI in 2017 (b); EAPC of ASDR and ASDR in 1990 (c); EAPC of ASDR and HDI in 2017 (d) of 195 countries or territories. The size of the circle represents the number of cases in this country in 2017. ASIR, age-standardised incident rate; ASDR, age-standardised rate of DALYs; EAPC, estimated annual percentage change; HDI, human development index; DALYs, disability-adjusted life years.