Degree Name

Doctor of Philosophy


School of Psychology


Background: The prevalence of cigarette smoking has decreased considerably in many developed countries over the past few decades. However, in Australia, the rate of the decrease has been slowing, and between 2013-2016, appeared to stall. This is important because cigarette smoking remains a major public health issue, and is – for example – the leading cause of cancer-related mortality in Australia.

The slowing decline in smoking prevalence has prompted calls to address the interrelated issues of hardening and hard-core smoking. The hardening hypothesis proposes that, as smoking rates decline, the remaining smokers will become hard-core (i.e., more resistant to quitting). This group of hard-core smokers may require more tailored approaches to cessation and/or product-based tobacco harm reduction (THR). Although hardening and hard-core smoking are often discussed and investigated, the literature is plagued by inconsistencies in how these terms are defined and operationalised. As a result, many aspects of the nature of hardening and hard-core smoking remain unclear.

Alternate nicotine delivery systems (ANDS), such as e-cigarettes, have been proposed as an option to achieve further reductions in smoking prevalence rates in Australia. This is because ANDS may support hard-core smokers to quit or (as a form of THR) transition smokers away from combustible cigarettes. The Australian regulatory environment for ANDS, together with a robust tobacco control environment, means that hard-core smoking and hardening research conducted in other countries may not be transferable to the Australian context. As such, there is a significant knowledge gap about the contemporary nature of hard-core smoking in Australia.

This thesis aims to examine the existence and nature of hardening and hard-core smoking in an Australian context. In doing so, this thesis will also address important theoretical issues relating to the definitions and operationalisations of these concepts. This includes the application of the Precaution Adoption Process Model as a theoretical framework to understand hard-core smoking. This thesis is comprised of three empirical studies and two policy focused commentary papers which address the gaps in the literature to account for: i) contemporary evidence supporting claims of hardening amongst Australian and international smokers (Paper1); ii) identification of the extent of hard-core smoking rates in Australia (Paper 2); iii) an understanding of the characteristics of hard-core smokers (Papers 2 and 3); iv) exploration of a stage-based behaviour change model that may account for smokers who do not want to change their smoking behaviour (Paper 3); v) a review of the status of smoke-free spaces in Australia as a key component of non-product-based THR (Paper 4); and v) a review of Australian tobacco dependence treatment policy (Paper 5).

Method: Paper 1 was a systematic review to identify and summarise studies on hard-core smoking and hardening to: i) determine the degree of variability in definitions of hard-core smoking and hardening; ii) assess the evidence for claims that smokers are becoming increasingly hardened; and iii) identify the determining characteristics of a hard-core smoker. We searched five electronic databases from 1970 to mid-April 2018 using the search term “smok* AND hard* AND (tobacco OR cigar* OR nicotin*)”. We included studies if they included a definition of hard-core smokers and/or hardening and provided a prevalence rate for hard-core smokers or empirical evidence for hardening.

Paper 2 tested the hardening hypothesis by analysing the rates of hard-core smoking in the Australian smoking population between 2010 and 2016. Data were drawn from three waves of the National Drug Strategy Household Survey (NDSHS) in 2010, 2013 and 2016. Two different definitions were used to assess hard-core smoking to arrive at an upper and lower rate. Logistic regression models assessed hard-core smoker characteristics for both definitions of hard-core smoking.

Paper 3 applied the Precaution Adoption Process Model (PAPM) to a community-based sample of smokers (n=336) to determine whether it provides a useful approach to identifying hard-core smokers. Australian smokers were recruited through social media and an online data collection agency.

Paper 4 and Paper 5 reviewed the status of smoke-free spaces and tobacco dependence treatment as key THR approaches in Australia and outlined the need for renewed focus on implementing comprehensive, robust and evidence-based tobacco control polices to reduce population level harm and drive cessation in the face of lobbying by industry for widespread availability of ANDS products.

Results: Paper 1 indicated there is considerable variability in how hard-core smoking is defined and operationalised in the literature. This variability was associated with inconsistencies in reported prevalence rates of hard-core smoking. The three empirical papers indicated there was little evidence of a crisis of hard-core smokers posing a credible threat to achieving further smoking prevalence reductions in Australia. Paper 1 suggested that hardening was not evident in the general smoking population, although there was evidence of softening occurring in smoking populations. In Paper 2, the most inclusive definition of hard-core smoking (i.e. a smoker with no plan to quit) showed a significant decline in hard-core smoking between 2010 and 2016 (5.49%–4.85%). The prevalence of hard-core smoking using the most stringent definition (i.e. a current daily smoker of at least 15 cigarettes per day, aged 26 years or over, with no intention to quit, a lifetime consumption of at least 100 cigarettes, and no quit attempt in the past 12 months) did not change significantly between 2010 and 2016. In Paper 3, 11.9% of smokers were in Stage 4 of the PAPM – i.e. had decided not to quit. These smokers were more resistant to quitting and exhibited similar characteristics to hard-core smokers.

Conclusions: The present thesis demonstrates that the Australian smoking population is not hardening, nor are Australian smokers becoming increasingly hard-core. As such, further reductions in smoking prevalence are achievable by further strengthening and funding a comprehensive approach to tobacco control. This should include improvements in the delivery of tobacco dependence treatment (TDT) to improve quit outcomes amongst the majority of Australian smokers who are motivated to quit. ANDS may be of benefit to some smokers who have been unable to quit using evidence-based combination pharmacotherapy and behavioural support. However, they may create population level harm if they increase rates of youth smoking.

FoR codes (2008)




Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.