[1] Univ Otago, Dept Med, Private Bag, Christchurch 4345, New Zealand
[2] Te Whatu Ora Hlth New Zealand, Dept Clin Pharmacol, Christchurch, Waitaha Canterb, New Zealand
[3] Christchurch Hosp, Emergency Dept, Christchurch, New Zealand
[4] Univ Otago, Dept Pathol, Christchurch, New Zealand