A better but persistently low health status in women with fibromyalgia during the COVID-19 pandemic: a repeated cross-sectional data analysis

Multiple overlapping and complementary theoretical arguments suggest that the COVID-19 pandemic could worsen health in fibromyalgia. The aim of this study was to determine mental and physical health in women with fibromyalgia before and during the pandemic. In a 3-sample, repeated cross-sectional design, we analyzed questionnaire data from Dutch women with fibromyalgia, collected in three independent samples: before the COVID-19 pandemic (2018; n = 142) and during the first acute (2020; n = 304) and prolonged (2021; n = 95) phases of the pandemic. Eight dimensions of mental and physical health were assessed using The RAND 36-Item Short Form Health Survey (RAND SF-36). Compared to norm group data, both before and during the pandemic, women with fibromyalgia showed high levels of fatigue and pain and low levels of general health, social functioning, physical functioning, role physical functioning (d > 1.2, very large effect sizes), role emotional functioning, and mental health (0.71 < d < 1.2, medium to large effect sizes). Contrary to theoretical expectation, levels at five health variables before vs. during the pandemic did not differ (p > 0.05), and levels of pain (p < 0.001), role physical functioning (p < 0.001), and physical functioning (p = 0.03) (0.014 ≤ pη(2) ≤ 0.042, small effect sizes) reflected a healthier status during than before the pandemic. These findings indicate a somewhat better but persistently low health status in women with fibromyalgia during the pandemic. This suggests that the pandemic may include changed circumstances that are favorable for some women with fibromyalgia.