Social isolation and its psychosocial factors in mild lockdown for the COVID-19 pandemic: a cross-sectional survey of the Japanese population

ObjectiveThis study investigated the sociodemographic, behavioural and psychological characteristics of socially isolated individuals during the ‘mild lockdown’ period of COVID-19 in Japan.DesignA cross-sectional study.SettingThe seven prefectures where the emergency declaration was first applied in Japan.ParticipantsWe collected data on 11 333 individuals (52.4% women, 46.3±14.6 years) living in the seven prefectures where the emergency declaration was first applied. The online survey was performed between 11 May and 12 May 2020, in the final phase of the state of emergency.Primary outcome measuresLubben Social Network Scale (LSNS-6)ResultsWe found that male sex (95% CI 1.60 to 1.98), middle age (95% CI 1.55 to 1.93) and lower income (eg, annual household income ConclusionsWe identified the sociodemographic and psychological characteristics associated with social isolation under mild lockdown. These results are expected to be a useful resource for identifying which groups may require intervention to improve their social interactions in order to preserve their mental health during the pandemic.