Measures
The assessment of cardiopulmonary endurance was adapted from the
upstairs experiment,[8] and the cardiopulmonary
endurance before COVID-19 infection was divided into five levels, from
”very relaxed, not panting at all, basically no feeling” to ”feeling
very tired, short of breath and some difficulty, and needing a long time
to rest to calm down”. The degree increased step by step, and the
cardiopulmonary endurance also got worse. After infection, the
expression ”unable to walk up five floors at a normal pace” was added to
the cardiorespiratory endurance evaluation, considering the elderly
population and some people with poor physical fitness.
The evaluation of psychological state adopts 7 Generalized anxiety
disorder scale (generalized Anxiexy Disorde-7,
GAD-7),[9] the scale has been verified and tested
in clinical environment, the problem is short and has a certain
recognition rate on anxiety, easy to diagnose and treatment. GAD-7 is a
self-rating scale, which assesses the psychological state in the recent
two weeks, score range is 0-21. According to the score of the scale,
anxiety can be divided into no anxiety (0-4 points), mild anxiety (5-9
points), moderate anxiety (10-14 points) and severe anxiety (15-21
points). Higher scores indicate more severe anxiety.
Sleep quality was assessed from a module of the Pittsburgh Sleep Quality
Index[10] (PSQI), focusing as much as possible on
sleep disturbances caused by COVID-19 infection, such as going to the
bathroom at night and feeling cold or hot, in order to reduce the burden
on respondents. Each component was rated on a 0-3 scale, with higher
scores indicating poorer sleep quality.