['The rate-corrected QT interval (QTc) prolongation is a risk factor for sudden cardiac death and may be induced by antipsychotic drugs.', 'To determine the clinical characteristics associated with QTc prolongation (440\u2009msec or greater) in children and adolescents hospitalized for treatment of psychiatric disorders.', 'We determined the frequency of baseline prolongation of QTc in 811 psychiatric pediatric inpatients (15.5\u2009±\u20092.4 years of age). QTc duration was 440\u2009msec or greater (range 441-481\u2009msec) in 16 patients (1.97%). In a 1:5 nested case-control design, the 16 patients with prolonged QTc were age- and gender-matched with 80 patients with QTc of <421\u2009msec.', 'Patients with normal and prolonged QTc had similar utilization of antipsychotics (43.8% vs. 40.8%) and daily chlorpromazine equivalents (165\u2009±\u2009110 vs. 168\u2009±\u2009218\u2009mg). Hypokalemia (p\u2009=\u20090.009) and obesity (p\u2009=\u20090.032) were more common among patients with prolonged QTc. The correlation between obesity and QTc prolongation was confirmed in logistic regression analysis.'] Does antipsychotic drug administration correlate with prolonged rate-corrected QT interval in children and adolescents : results from a nested case-control study?