Loneliness, social isolation, and pain following the COVID-19 outbreak: data from a nationwide internet survey in Japan

The aim of cross-sectional study was to investigate the association between loneliness, increased social isolation, and pain following the COVID-19 outbreak. A total of 25,482 participants, aged 15-79 years, were assessed using an internet survey; the University of California, Los Angeles Loneliness Scale (Version 3), Short Form 3-item (UCLA-LS3-SF3) was used to assess loneliness, and a modified item of the UCLA-LS3-SF3 was used to measure the perception of increased social isolation during the pandemic. The outcome measures included the prevalence/incidence of pain (i.e., headache, neck or shoulder pain, upper limb pain, low back pain, and leg pain), pain intensity, and the prevalence of past/present chronic pain. Pain intensity was measured by the pain/discomfort item of the 5-level version of the EuroQol 5 Dimension scale. Odds ratios of pain prevalence/incidence and past/present chronic pain prevalence according to the UCLA-LS3-SF3 scoring groups (tertiles) and the frequency of the perceived increase in social isolation (categories 1-5) were calculated using multinomial logistic regression analysis. The mean pain intensity values among different loneliness and social isolation levels were tested using an analysis of covariance. Increased loneliness and the severity of the perceived social isolation were positively associated with the prevalence/incidence of pain, pain intensity, and the prevalence of past/present chronic pain.