Abstract
Objective To find out the predicting factors of early recurrent hypothermia in patients from a mental institute and the role of use of antipsychotics. Design Retrospective cohort study. Setting Accident and emergency department of a regional public hospital in Hong Kong. Method All adult patients transferred from a mental hospital to the study centre presenting with hypothermia from 1st January 2002 to 31st December 2009 were included. Demographic data, medical history, drug history, patient's mobility status, and the ambient temperature of the presenting date were collected as predicting variable and analyzed using Wei, Lin and Weissfeld model, with time to the next hypothermia as outcome variable. Results Forty eight patients with 96 hypothermia episodes were included. The use of typical antipsychotics was associated with a significantly shorter median time to the next hypothermia episode (50.2 to 21 months) (p=0.005 by log rank test). In the Wei, Lin and Weissfeld model, use of typical antipsychotics was the sole significant predicting factor for early recurrent hypothermia (p<0.0001), with hazard ratio of 2.89 (95% CI 1.64-5.10). Conclusion Use of typical antipsychotics is the only significant predictor of early recurrence of hypothermia in institutionalised psychiatric patients.