Statistical analyses were undertaken using STATA, version 9.2 (2004; Stata Corporation, College Station, TX, USA). Exploratory data analysis was conducted using frequency distributions for categorical variables. In the logistic model, a binary coding of psychological distress was used in which high psychological distress was a combination of 'high' + 'very high' levels of psychological distress = 1 (i.e. K10 scores of 22 or greater) and low psychological distress was a combination of 'low' + 'moderate' levels of psychological distress = 0 (i.e. K10 scores of 21 or less). Simple binary logistic regression and backward stepwise multiple logistic analyses were performed to identify factors influencing high psychological distress. All variables were entered into the model initially, with the least significant variables removed one at a time until only significant variables associated with values of p ≤ 0.05 remained. All statistical tests were two-tailed.