Review of P-NQLS psychometric validation in U.S. parents of children aged 6-18 years.

Introduction: The Nationwide Quality of Life Scale (NQLS) is a brief, mental-health focused quality of life (QoL) scale with seven items that are non-overlapping with symptom scales. We developed a parent version (P-NQLS), obtained national norms, and calculated psychometric properties for the P-NQLS. Methods: Parents (N=2251) of children aged 6-18 years who were representative of the U.S. population on key demographics completed the P-NQLS along with measures of depression, suicidality, internalizing, externalizing, and attention symptoms. We assessed the P-NQLS's factor structure through exploratory factor analysis (EFA) and evaluated its internal reliability and convergent validity. Age- and sex-specific norms were established using GAMLSS with BCPE distributions and P-spline smoothers, with percentile curves and tables (5th-95th) provided. Results: EFA suggested a one-factor solution for P-NQLS in the national sample. The scale showed good internal consistency (Cronbach's alpha=0.85). P-NQLS total scores (M=20.7, SD=4.7, range=0-28, higher scores indicate higher QoL) were negatively correlated (all p<.0001) with depression (Pearson's r=-0.47), suicidality (r=-0.50), internalizing (r=-0.43), externalizing (r=-0.41), and attention (r=-0.37) symptoms. P-NQLS scores declined steadily with age in both sexes, with the most pronounced decreases (3-5 points) observed at lower percentiles (5th, 10th), suggesting greater age-related decline among children with lower baselines. Females scored slightly higher than males across most ages and percentile levels, though the differences were within one point. Conclusions: The newly created P-NQLS, a 7-item parent-reported QoL scale with one underlying factor, demonstrates strong reliability and validity and has robust national norms for youth aged 6-18.