BMI	Body Mass Index
CEAP	Clinical, Etiological, Anatomical, and Pathophysiological Classification
CI/CIs	Confidence Interval/Confidence Intervals
CIVIQ-20	20-item Chronic Venous Insufficiency Quality-of-Life Questionnaire
CIVIQ-20-Ar	Chronic Venous Insufficiency Questionnaire (Arabic version)
COSMIN	Consensus-based Standards for the Selection of Health Measurement Instruments
CVI	Chronic Venous Insufficiency
EFA	Exploratory Factor Analysis
HRQoL	Health-Related Quality of Life
I-CVI	Item-level Content Validity Index
ICC(2,1)	Intraclass Correlation Coefficient (specifically, two-way random intraclass correlation coefficient)
KMO	Kaiser–Meyer–Olkin Measure of Sampling Adequacy
MCS	Mental Component Summary
MDC95	Minimal Detectable Change at a 95% Confidence Level
NHP	Nottingham Health Profile
PCS	Physical Component Summary
PROMs	Patient-Reported Outcome Measures
S-CVI	Scale-level Content Validity Index
S-CVI/Ave	Scale-level Content Validity Index Average Method
S-CVI/UA	Scale-level Content Validity Index Universal Agreement Method
SD	Standard Deviation
SEM	Standard Error of Measurement
SF-36	36-item Short Form Health Survey
SIP	Sickness Impact Profile
SPSS	Statistical Package for the Social Sciences