HRQoL	Quality of Life
PedsQLI	Pediatric Quality of Life Inventory
HARDSHIP	Headache-attributed restriction, disability, social handicap and impaired participation
SPSS	The Statistical Package for the Social Sciences
EFA	Explanatory Factorial Analysis
KMO	Kaiser-Meyer-Olkin
CFA	Confirmatory factor analysis
CFI	Comparative Fit Index
TLI	Tucker–Lewis Index
RMSEA	Root Mean Square Error of Approximation
ICC	Intraclass Correlation Coefficient
SEM	Structural Equation Modeling
WHO-5	World Health Organization Well-Being Index