Table 2.

Life quality scale's psychometric indicators of chronic venous disease.

Scale	Reliability	Validity
SF-36	Cronbach's α is 0.72–0.88, and the retest reliability is 0.66–0.94.[21]	Factor analysis produces 2 principal components with a cumulative variance contribution rate of 56.3% and good validity.[21]
EQ-5D	Cronbach's α is 0.89, and the retest reliability is 0.93.[23]	No report
AVVQ	Cronbach's α is 0.72–0.76, and the retest reliability is 0.86.[9,20,24]	Exploratory factor analysis extracts 6 common factors and ultimately retains 4 common factors. Compared with SF-36, it has higher correlation and better validity.[20]
CIVIQ-20	Cronbach's α is 0.65–0.90, and the retest reliability is 0.85–0.98.[10]	The factor analysis has good structural validity and the variance interpretation is 46.9%.[10]
VEINES-QoL/Sym	Cronbach's α is 0.88–0.91, and the retest reliability is 0.87.[25]	Four common factors were extracted and named as symptoms, physiological functions, physiological capacity, mental health, cumulative variance contribution rate of 69.85%, S-CVI of 0.97, and I-CVI of 0.8–1.00 for each questionnaire.[25]
CCVLUQ	Total Cronbach's α is 0.93, and the retest reliability is 0.84.[25]	Factor analysis extracts 7 common factors, and retains 4 common factors according to expert opinions. The load factor of each item is between 0.40 and 0.83. With SF-36 as the calibration, the correlation coefficient r is 0.32–0.70.[25]
DVTQOL	Cronbach's α is 0.79–0.93.[8]	No report
VLU-QoL	Cronbach's α > 0.80 in each dimension, and the retest reliability r value is 0.83–0.86.[17]	Exploratory factor analysis extracted 3 common factors, each item factor load coefficient was greater than 0.4; with SF-36 as the calibration, the correlation coefficient r value was 0.46–0.64[17]
SPVLU-5D	Cronbach's α is 0.93.[18]	No report
CIVIQ-14	The total Cronbach's α is 0.92, the Cronbach's α ≥ 0.80 in each dimension, and the average correlation coefficient between the scale items is 0.45, and the dimensions are 0.45–0.67, respectively.[19]	The factor analysis has good structural validity, KMO = 0.93, and the variance interpretation is 59%.[19]