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.