Trends in uptake of cancer screening among people with severe mental illness before and after the COVID-19 pandemic in Japan: A repeated cross-sectional study

Aim: The aim of this study was to investigate trends in cancer screening participation among people with severe mental illness (PSMI) from periods before and after the COVID-19 pandemic.
Methods: In this repeated cross-sectional study, we used anonymized datasets on municipal cancer screening participation among PSMI in Okayama City. The data covered fiscal year (FY) 2018 to FY2022; we used the municipal cancer screening database and Medical Payment for Services and Supports for Persons with Disabilities. PSMI were defined as those with schizophrenia or related psychotic disorders (F20-29) or bipolar disorder (F30 or F31), identified using International Classification of Diseases, Tenth Revision, codes. The analysis included men and women aged 40-69 years for colorectal and lung cancer screening; men and women aged 50-69 years for gastric cancer screening; women aged 40-69 years for breast cancer screening; and women aged 20-69 years for cervical cancer screening. Municipal cancer screening rates among PSMI were calculated for each FY.
Results: For all cancer types, cancer screening rates for PSMI in FY2020 (colorectal: 9.0%; lung: 11.6%; gastric: 4.9%; breast: 6.2%; and cervical: 6.1%) were lower than the rates in FY2019 (11.5%, 14.0%, 6.5%, 9.3%, and 8.3%, respectively). In FY2022, the rates (9.9%, 12.9%; 5.3%; 8.0%, and 6.9%, respectively) recovered, but remained low.
Conclusion: This study showed that cancer screening rates among PSMI were very low, both before and after the COVID-19 pandemic. Efforts to encourage participation in cancer screening in this population are urgently needed.