The psychometric properties of the 16-item version of the Prodromal Questionnaire (PQ-16) as a screening instrument for perinatal psychosis.

Psychiatric illness can pose serious risks to pregnant and postpartum women and their infants. There is a need for screening tools that can identify women at risk for postpartum psychosis, the most dangerous perinatal psychiatric illness. This study used exploratory factor analysis (EFA) and Rasch item response theory (IRT) models to evaluate the psychometric properties and construct validity of the Spanish language version of the 16-item Prodromal Questionnaire (PQ-16) as a screening tool for psychosis in a population of pregnant Peruvian women. The EFA yielded a four-factor model, which accounted for 44% of the variance. Factor 1, representing "unstable sense of self," accounted for 22.1% of the total variance; factor 2, representing "ideas of reference/paranoia," for 8.4%; factor 3, representing "sensitivity to sensory experiences," accounted for 7.2%; and factor 4, possibly representing negative symptoms, accounted for 6.3%. Rasch IRT analysis found that all of the items fit the model. These findings support the construct validity of the PQ-16 in this pregnant Peruvian population. Also, further research is needed to establish definitive psychiatric diagnoses to determine the predictive power of the PQ-16 as a screening tool.

Low Apgar scores and risk of childhood attention deficit hyperactivity disorder.

OBJECTIVE: To examine whether low Apgar scores at 5 minutes are associated with increased risks of attention deficit hyperactivity disorder (ADHD). STUDY DESIGN: We conducted a nationwide population-based cohort study of all 980 902 singletons born in Denmark from 1988 to 2001. All children were monitored from 3 years of age until a first International Classification of Diseases diagnosis of hyperkinetic disorder, a first medication for ADHD, migration, death, or the end of 2006, whichever came first. We used Cox regression models to examine the association between Apgar scores at 5 minutes and ADHD. RESULTS: Apgar scores were inversely associated with risk of ADHD (hazard ratio 0.92; 95% CI: 0.88-0.96, P trend < .001). Compared with children with Apgar scores of 9 or 10 at 5 minutes, the risk for ADHD was 75% higher in children with Apgar scores of 1 to 4 (hazard ratio 1.75; 95% CI: 1.15 to 2.11) and 63% higher for those with Apgar scores of 5 to 6 (95% CI: 1.25 to 2.11). CONCLUSIONS: A low Apgar score was associated with an increased risk of ADHD in childhood. Low Apgar scores and ADHD may share common causes or a low Apgar score reflects at least one causal pathway leading to ADHD.