THE NEW ZEALAND MEDICAL JOURNAL        NZMJ 11 December 2009, Vol 122 No 1307; ISSN 1175 8716 Page 1 of 144 URL: http://www.nzma.org.nz/journal/122-1307/3925/ ©NZMA CONTENTS This Issue in the Journal 4 A summary of the original articles featured in this issue Editorial 6 Sudden infant death and co-sleeping: stronger warning needed Edwin A Mitchell Original Articles 10 Gender inequality in New Zealand life expectancy: decomposition by age and cause Peter Sandiford 18 Does mortality vary between Pacific groups in New Zealand? Estimating Samoan, Cook Island Mori, Tongan, and Niuean mortality rates using hierarchical Bayesian modelling Tony Blakely, Ken Richardson, Jim Young, Paul Callister, Robert Didham 30 Mum’s the word: factors that influenced young adults’ participation in the New Zealand Meningococcal B immunisation programme Marian Bland, Geraldine M Clear, Adrianna Grogan, Kath Hoare, Jan Waldock 39 Sero-prevalence of leptospirosis in workers at a New Zealand slaughterhouse Jackie Benschop, Cord Heuer, Patricia Jaros, Julie Collins-Emerson, Anne Midwinter, Peter Wilson 48 Acute gastrointestinal illness in New Zealand: information from a survey of community and hospital laboratories Rob Lake, Nicola King, Kerry Sexton, Philippa Bridgewater, Donald Campbell Review Article 55 'Party pill' drugs—BZP and TFMPP Ustana Antia Viewpoints 69 What is the mechanism of sudden infant deaths associated with co- sleeping? Christine G McIntosh, Shirley L Tonkin, Alistair J Gunn