Prodromal questionnaire (PQ-16) dimensionality among Colombian adolescent school students

The study aimed to determine the dimensionality of the Spanish version of the PQ-16 among Colombian adolescent school students.

A validation study was designed with the participation of 334 Colombian adolescent students aged between 13 and 17 (M = 15.2, SD = 1.1); 171 (52.1%) were girls, and 163 (47.9%) were boys, 229 (68.6%) were ninth-grade students and 105 (31.4%) were tenth-grade students. Confirmatory factor analysis was performed, internal consistency was calculated with the Kuder-Richardson and McDonald's omega tests, and correlation with suicide ideation was computed with the Kendall correlation (r).

The confirmatory factor analysis showed that the PQ-16 adequately fit a unidimensional structure: RMSEA = 0.05 (90%CI 0.04-0.06), CFI = 0.91, TLI = 0.90, SRMR = 0.05, chi-squared = 193.18 (df = 102, p < 0.001) and normalized chi-squared = 1.89. This factor presented high internal consistency: Kuder-Richardson test and McDonald's omega of 0.83. The correlation between the PQ-16 and suicide ideation was r = 0.45 (p < 0.001).

The PQ-16 is a one-dimensional tool with high internal consistency and correlation with suicide ideation among schooled adolescents. Further research should explore the PQ-16 performance against a structured clinical interview.