TABLE 1.

Characteristics of population-based cross-sectional studies.

Population based studies
Cross-sectional
Author/s	Year	Country	N	Age when SC measured	Age when mental health measured	SC measure/s	Results
Möricke et al. (22)	2013	The Netherlands	6,330	14.84 (SD = 2.19) months	14.84 (SD = 2.19) months	Utrecht Screening Questionnaire based on factor analysis (non-stand.; par.)	Latent class analysis identified a latent class (5.7%) with high scores on non-typical communication, negative emotionality, demanding behavior, social anxiety, advanced social interaction problems, and sleep problems; another latent class (16.4%) had high scores on non-typical communication and specific problems in language and communication.
Ketelaars et al. (24)	2010	The Netherlands	1,364	4.11 years (SD = 4 months)	4.11 years (SD = 4 months)	CCC (stand.; teach.)	Children with pragmatic language impairment scored two to three times the sample mean on all subscales of the SDQ and had a risk ratio for high/very high difficulties (total score) of 11.3 for boys and 12.3 for girls. In a regression analysis, structural language explained 14.8% of total problem behavior. After adding pragmatic competence and autistic behavior, the model explained 61.6% of the SDQ total difficulties score. Pragmatic competence was the most important predictor.
Theriault et al. (25)	2001	Canada	157	19.78 years	19.78 years	Pragmatic Language Inventory (Non-stand.; self)	The lack of pragmatic language abilities (mostly the presence of verbal impulsivity) almost completely explained the relationship between ADHD symptoms and relationship aggression.

ADHD, attention deficit hyperactivity disorder; CCC, Children’s Communication Checklist; non-stand., non-standardized; par., parent reported; SDQ, Strengths and Difficulties Questionnaire; self, self-assessment; stand., standardized; teach., teacher reported.