Using CTT: confirmatory factor analysis
RESIDUAL
Confirmatory factor analysis (CFA, using maximum likelihood as an estimator) was performed to verify the two a priori scales of the HidroQoL. According to the COSMIN initiative, the structural validity of an instrument is rated as sufficient if one of the following requirements is met: either the Comparative Fit Index (CFI) or Tucker–Lewis Index (TLI) is > 0.95 or the Root Mean Square Error of Approximation (RMSEA) is < 0.06 or the Standardized Root Mean Square Residual (SRMR) is < 0.08 [