Disparities in age of smoking initiation and transition to daily smoking in New Zealand September 2019 ISBN: 978-0-478-44986-0 Prepared for the Health Promotion Agency/Te Hiringa Hauora (HPA) by: Niveditha Gurram and Greg Martin, Research and Evaluation Unit, Health Promotion Agency. Citation: Gurram, N., & Martin, G. (2019). Disparities in age of smoking initiation and transition to daily smoking in New Zealand. Wellington: Health Promotion Agency. Copyright The copyright owner of this publication is HPA. HPA permits the reproduction of material from this publication without prior notification, provided that fair representation is made of the material and HPA is acknowledged as the source. This document is available at: http://www.hpa.org.nz/research-library/research-publications Any queries regarding this report should be directed to HPA at the following address: Health Promotion Agency PO Box 2142 Wellington 6140 New Zealand www.hpa.org.nz [email protected] September 2019 CONTENTS Executive summary 5 Acknowledgements 7 1. Introduction 8 1.1 Background 8 1.2 Current study Objectives 9 2. Methods 9 2.1 Survey 9 2.2 Variables 9 2.3 Analyses 10 3. Results 11 3.1 Age of smoking initiation 11 3.2 Age of daily uptake of smoking 12 3.3 Transition duration from smoking initiation to daily uptake 13 4. Discussion 14 4.1 Strengths 15 4.2 Limitations 15 5. Conclusion 16 6. References 17 Appendix: Trends in the age of smoking initiation and daily uptake 2010-2018 19 List of Tables Table 1: 2018 HLS sample characteristics 11 Table 2: Mean age (in years) of smoking initiation among ever smokers who participated in the 2018 HLS 12 Table 3: Mean age of daily uptake of smoking and transition duration (in years) among ever daily smokers who participated in the 2018 HLS 13 Table 4: Unadjusted mean age (in years) of smoking initiation among ever smokers, 2010- 2018 19 Table 5: Unadjusted mean age (in years) of smoking daily uptake among ever daily smokers, 2010-2018 20 Table 6: Unadjusted mean transition age (in years) from smoking initiation to daily uptake of smoking among ever daily smokers, 2010-2018 21 EXECUTIVE SUMMARY INTRODUCTION Understanding trends and disparities related to the age of smoking initiation and transition to daily smoking is important for monitoring the progress of tobacco control strategies. The purpose of this study was to examine the age of smoking initiation and transition into daily smoking using a nationally representative sample of New Zealanders aged 15 years and over by age, sex, ethnicity and deprivation status. This study also compares these results over time. METHODS The Health and Lifestyles Survey (HLS) is a biennial survey of New Zealand adults aged 15 years and over. The survey used multistage, stratified, clustered and random probability sampling and collected information through computer assisted face to face in-house personal interviews. The HLS was completed by 2,725 participants in 2018. KEY FINDINGS In 2018, the mean ages of smoking initiation and daily uptake were 15.3 years and 17.6 years respectively. Māori (14.1 years) and current smokers (14.8 years) were more likely to start smoking at a younger age. Males (15.3 years) were more likely to start smoking at a younger age when compared to females (16.1 years). Māori (16.7 years) were more likely to take up daily smoking at a younger age. Pasifika and Asian people were less likely to initiate first and daily smoking at a younger age. The mean transition duration from smoking initiation to daily uptake was 2.5 years for all smokers, although only 1.4 years for Asian people. Overall, there has been no significant increase in the mean age of smoking initiation between 2012 and 2018, and there has been no significant increase in mean age of uptake of daily smoking between 2010 and 2018. In 2018, Pasifika people were more likely to start smoking and take up daily smoking at a later age when compared to Pasifika people in 2012 and 2010 respectively. DISCUSSION Generally, smoking uptake occurs during adolescence. Despite the changing regulatory environment with regard to tobacco control the mean age of smoking initiation and daily uptake are still under 18 years. We found significant disparities in the age of smoking initiation and daily uptake among the predominant ethnic groups in New Zealand. Māori are initiating smoking and becoming daily smokers at a younger age than the general population. To achieve the Government’s ‘Smokefree 2025’ goal, it is important that policy makers and practitioners are aware of this age disparity in order to ensure this priority population is appropriately engaged. ACKNOWLEDGEMENTS The authors would like to thank the HLS participants for taking the time and effort to answer the questionnaire. We would also like to thank CBG Health Research Ltd for conducting the pilot testing of the questionnaire and undertaking the fieldwork. We also acknowledge Sarah Rendall for managing the HLS with the support of Denise Grealish and for the work she undertook with Wa Anwar to check and clean the data and Richard Ung for reviewing the analyses for this report. 1. INTRODUCTION 1.1 BACKGROUND In March 2011, the New Zealand (NZ) government set an aspirational goal of becoming smokefree by 2025, where less than 5% of the population smokes (The New Zealand Government, 2011). To achieve this goal it is important to understand and monitor the age of smoking initiation and transition into daily smoking. Internationally, there is substantial evidence that most smokers initiate smoking before the age of 18 (Everett et al., 1999; Giovino, 2002; U. S. Department of Health and Human Services, 2012). Several studies have shown that earlier onset smoking is strongly associated with future smoking behaviour and outcomes, including daily smoking, intensity of smoking, addiction to nicotine and difficulty in quitting (Everett et al., 1999; Fernandez et al., 1999; Reidpath, Ling, Wellington, Al- Sadat, & Yasin, 2012; Wilkinson, Schabath, Prokhorov, & Spitz, 2007). Understanding trends and disparities related to the age of smoking initiation and transition to daily smoking is important for monitoring progress of tobacco control strategies. Smoking prevalence in NZ has declined significantly over time. In 2018, 12.8% of adults (15 years or over) smoked daily compared to 16.8% in 2010. However, ethnic disparities continue to exist with 29.9% of Māori adults and 19.1% of Pasifika adults smoking daily (Health Promotion Agency, 2019a). In 2018, less than two percent of young people aged 14 and 15-years-old reported daily smoking, although rising to 5.2% of Māori and 2.9% of Pasifika (Action on Smoking and Health, 2018). In NZ, smoking initiation largely occurs among older youth and young adults (Edwards, Carter, Peace, & Blakely, 2013). Results from the 2012/13 New Zealand Health Survey show that Māori were earliest to initiate smoking at 14.1 years and Pasifika adults had the shortest transition time between initiation and daily uptake when compared with smokers of other ethnic groups (2.7 years) (Ministry of Health, 2014). There are weaknesses with the data available on age of smoking initiation and transition into daily smoking. Firstly, as gender and deprivation status are also associated with smoking prevalence (Tu, Newcombe, Edwards, & Walton, 2016), there is a lack of studies examining the age of smoking initiation and daily uptake by gender and deprivation status. Secondly, there are no further studies available monitoring these results across years. Given the decline in the smoking prevalence in NZ, more updated analyses of age of smoking initiation and daily uptake are required to determine where prevention initiatives might best be targeted. 1.2 CURRENT STUDY OBJECTIVES The aim of this paper is to explore the age of smoking initiation and transition into daily smoking using a nationally representative sample of New Zealanders aged 15 years and over (the 2018 Health and Lifestyles Survey, HLS). This study examines the mean age of smoking initiation and transition into daily uptake for adults as a whole and by age, gender, ethnicity, deprivation status and smoking status. This study also explores trends over time using data from previous waves of HLS data collection (2010, 2012 and 2016). 2. METHODS 2.1 SURVEY The 2018 HLS is a nationally representative survey of 2,725 New Zealanders aged 15 years and over. The survey used multistage, stratified, clustered and random probability sampling and collected information on various health related topics, including tobacco use, alcohol, gambling harm, health education, mental health, immunisation, skin cancer, nutrition and physical activity. Interviews were conducted face-to face in-house using Computer Assisted Personal Interviewing (CAPI). The unweighted response rate for the 2018 HLS is 75%. A full description of the 2018 HLS methodology can be found on the HPA website (Health Promotion Agency, 2018). Participation in the 2018 HLS was voluntary and informed consent was obtained. Ethics approval for the 2018 HLS was obtained from the New Zealand Ethics Committee (Application Number: 2018_15). To compare the results over time, we also used the data from 2010, 2012 and 2016 HLS. Fully detailed methodology reports for each survey year are available elsewhere (Devlin, 2011; Health Promotion Agency, 2013, 2017). 2.2 VARIABLES 2.2.1 Smoking status All survey participants were asked whether they had ever smoked a cigarette (even just a few puffs). Participants who answered ‘yes’ were classified as ever smokers and those who answered ‘no’ were classified as non-smokers. All ever smokers were asked whether they had smoked daily for a week. Those who answered ‘yes’ were categorised as ever daily smokers. All ever smokers were asked how often they smoke tobacco now.