Forecasting the Local Risk of Type 2 Diabetes and the Effects of Prevention Programs Using Spatial Microsimulation: Development and Use of the TropISM Model

Simulation modelling has become an important tool in social science research, though such models are less commonly used in population health. Spatial microsimulation models provide a unique way to estimate health outcomes at the small area level and forecast the local effects of potential health interventions. Spatial microsimulation models combine geographically rich census data with information rich survey data to generate synthetic small area populations containing the wealth of information available in both types of data. Model outputs can therefore be used to inform the local delivery of health promotion programs. This research developed and validated the Type 2 dIabetes Spatial Microsimulation ("TropISM") model of chronic disease risk factors and outcomes for the 140 neighbourhoods of metropolitan Toronto. The model was developed using Canadian census data from 2006 and the 2005 Canadian Community Health Survey. The five-year incidence of diabetes was estimated using the Diabetes Population Risk Tool (DPoRT 2.0), a population-level risk algorithm that forecasts disease incidence using risk factor information routinely collected in population health surveys, together with the synthetic TropISM population. By leveraging both models, it was possible to evaluate the effects of hypothetical weight loss interventions on potential reductions in diabetes incidence at the neighbourhood level. Synthetic, neighbourhood specific prevalence estimates of diabetes were also used to estimate potential spatial accessibility to diabetes education programs within metropolitan Toronto. Accessibility was estimated using a two-step floating catchment area model, a type of spatial interaction model used to estimate area specific provider-to-population ratios. Results indicate that although the TropISM model accurately replicated demographic characteristics of Toronto's 140 neighbourhoods, it underestimated the true prevalence of type 2 diabetes, hypertension, and heart disease among men. In addition, TropISM captured broad spatial patterns in disease prevalence, but was unable to capture the spatial variability in known prevalence assessed from administrate health databases maintained by the Institute for Clinical Evaluative Sciences. Irrespective of these limitations, when the DPoRT model used synthetic TropISM population to forecast diabetes incidence, the overall five-year forecast incidence was comparable to the true incidence of disease (4.9% vs. 5.8%, respectively; 95% uncertainty interval: 4.2%-5.9%). At the neighbourhood level, the true incidence of diabetes fell within the range of forecast uncertainty in 65 neighbourhoods, while forecast incidence was underestimated in 52 neighbourhoods, most of which were located in Scarborough and Etobicoke. Again, broad spatial patterns in forecast incidence were captured by TropISM even though forecasts did not capture the spatial variability in true incidence rates. When the synthetic TropISM population was used to assess the ex ante effects of population-level weight loss programs on the future incidence of diabetes in silico, the entire population of high-risk, overweight individuals having a body mass index ≥ 25 kg/m² would have to lose 17% of its baseline body weight to produce a reduction in diabetes incidence of just one percentage point across metropolitan Toronto. Greater reductions in incidence were observed in neighbourhoods comprised of larger proportions of visible minorities and immigrants, even though the baseline prevalence of overweight and obesity tended to be slightly lower in these neighbourhoods compared to the metropolitan average (39% vs. 41.2%, respectively). Finally, the two-step floating catchment area model was used with synthetic, neighbourhood-specific counts of type 2 diabetes to conduct an exploratory analysis of spatial accessibility to diabetes education programs located throughout metropolitan Toronto. Results point to a potential mismatch between population demand for services and potential spatial access. In particular, some neighbourhoods within Scarborough had relatively higher prevalence of type 2 diabetes but lower access to diabetes education programs while neighbourhoods within central Toronto tended to have greater spatial access and lower prevalence rates of type 2 diabetes. Disparities in service provision suggest additional resources could be devoted to diabetes management in high-prevalence, low service neighbourhoods. In light of its short-comings, TropISM model results suggest how spatial microsimulation models can be improved to produce more accurate neighbourhood-specific estimates of diabetes prevalence. Importantly, TropISM was able to capture broad spatial patterns in diabetes prevalence and incidence, providing insight into where weight loss programs may contribute to greater reductions in diabetes incidence and identifying factors that might influence those reductions. This information can be used to customize health promotion interventions to the particular needs of specific communities. In conclusion, the TropISM spatial microsimulation model was able to (a) predict the consequences of different weight loss programs on projected diabetes incidence and (b) identify potential mismatches between existing demand for health promotion programs and the geographic availability of those resources. This locally relevant information enables public health planners to better allocate scarce resources to communities of greatest need. This research therefore illustrates how spatial microsimulation modelling can be used as a spatial decision support tool for local public health planning

Contraband Cigarette Purchasing from First Nation reserves in Ontario and Quebec: Findings from the 2002–2014 ITC Canada Survey

Backround: The availability of contraband cigarettes provides incentives for price-sensitive smokers to reduce their monetary costs of smoking. The objectives of this study were to examine whether Canadian smokers’ geographic proximity to First Nations reserves and attempts to quit smoking influenced the likelihood of purchasing lower-cost cigarettes from reserves. Methods: Data were from the International Tobacco Control (ITC) Canada Survey, a prospective survey of Canadian adult smokers conducted from 2002 to 2014 using telephone and online interviewing methods. Analysis was restricted to smokers from Ontario (n=2105) and Quebec (n=1427) participating in at least one survey wave. Smokers’ postal codes were used to calculate distance to the nearest reserve. Weighted logistic generalised estimating equations (GEE) regression examined the linear relationship between distance and the log odds of last purchasing cigarettes on reserve in each province. GEE models also examined the relationship between past-year quit attempts and the log odds of on-reserve purchasing. Results: Controlling for other factors, from 2002–2014, smokers from Ontario who lived 10 km closer to reserves than otherwise similar smokers had significantly higher odds of last purchasing on reserve (OR ranged from 1.16 to 1.65). Distance had little effect on smokers’ purchasing behaviours in Quebec. Moreover, in Ontario, for every 10 km increase in distance, smokers who did not try to quit had significantly greater odds of purchasing from a reserve than smokers who tried to quit (p=0.002). Conclusion: In order for tobacco taxation policies to achieve their maximal benefit, governments must limit potential sources of lower-cost cigarettes. Collaborative governance arrangements can ensure tobacco products sold on reserve to non-Indigenous people are appropriately taxed while allowing First Nations communities to keep the revenue generated by such taxes.US National Cancer Institute || Canadian Institutes of Health Research || Canadian Tobacco Control Research Initiativ

ITC EUREST-PLUS Spain: protocol of a prospective longitudinal study of smokers in Spain

Objective: The ITC EUREST-PLUS Spain Survey is a longitudinal study of a representative sample of Spanish adult (≥18 years old) smokers. This protocol describes the methods of the 2021 follow-up survey. Method: The ITC EUREST-PLUS Survey, a prospective cohort study of a representative sample of smokers in six European countries, was conducted in 2016 (baseline) and 2018 (waves 1 and 2). The 2021 ITC EUREST-PLUS Spain Survey is a continuation of the Spanish cohort with a new interview in 2021 (wave 3). Lost participants were replaced with new smokers recruited using the same multi-stage sampling design. This latest follow-up aims to examine current patterns and transitions of tobacco use and to evaluate the impact of new tobacco-related policies. Comments: The ITC EUREST-PLUS Spain Survey will provide recent information about the impact of tobacco control policies on smoking behaviour

Cross-border purchasing of cigarettes among smokers in Six Countries of the EUREST-PLUS ITC Europe Surveys

Introduction: The availability of lower-cost cigarettes in neighboring countries provides price-sensitive smokers with incentives to purchase cheaper out-of-country cigarettes. This study estimates the prevalence of and factors associated with cross-border purchasing of cheaper cigarettes among smokers from Germany, Greece, Hungary, Poland, Romania, and Spain. The prevalence of cross-border purchasing was estimated by residential location, defined as living in regions bordering a lower-price country (where prices were at least €1/pack lower), regions bordering a similar- or higher-price country, and internal non-border regions. Methods: Data were from a survey of nationally representative samples of adult smokers (n=6011) from Germany, Greece, Hungary, Poland, Romania, and Spain. The primary outcome was purchasing cheaper out-of-country cigarettes in the previous six months. Residential location was defined using The Nomenclature of Territorial Units for Statistics (NUTS2 in Germany and NUTS3 in the other countries). Multivariable logistic regression tested differences in purchasing cheaper out-of-country cigarettes by country and residential location. Results: Residential location was associated with purchasing cheaper out-of-country cigarettes in Germany and Poland (p<0.05): 31% of German and 11% of Polish smokers living in regions bordering lower-price countries reported purchasing cheaper out-of-country cigarettes in the previous six months. Smokers living in regions bordering lower-price countries had 4.21 times greater odds of purchasing cheaper out-of-country cigarettes compared to smokers living in non-border regions. Conclusions: Overall, only a minority of smokers in the six countries purchased cheaper cigarettes outside their country. However, smokers living in regions bordering countries where cigarettes were at least €1/pack lower than their home country had significantly higher odds of purchasing cheaper out-of-country cigarettes. This effect was especially prominent among German smokers. Tax harmonization policies designed to minimize cross-border price differentials can eliminate lower-priced alternatives for price-sensitive smokers

U.S. adult perceptions of the harmfulness of tobacco products: descriptive T findings from the 2013–14 baseline wave 1 of the path study

Introduction: This study is the first nationally representative survey of U.S. adults (18+) to examine perceptions of the relative harms of eight non-cigarette tobacco products. Methods: Data are from Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study Adult Questionnaire, a nationally representative study of 32,320 adults in the United States conducted from September 2013 to December 2014. Results: 40.7% of adults believed that electronic cigarettes were less harmful than cigarettes, and 17.8% of adults believed that hookah was less harmful than cigarettes. Those less knowledgeable about the health risks of smoking were more likely to believe that the non-cigarette products were less harmful than cigarettes. Current non-cigarette tobacco product users were more likely to perceive that product to be less harmful than cigarettes (except filtered cigars). There was a significant positive correlation between beliefs that cigarettes were harmful and the likelihood of using hookah; perceptions of the harmfulness of cigarettes was not associated with the likelihood of using any other product. Conclusions: Perceptions of harmfulness varied widely across non-cigarette tobacco products. E-cigarettes and hookah in particular are seen as less harmful compared to cigarettes

Methods of the ITC Four Country Smoking and Vaping Survey, wave 1 (2016)

AIM: To describe the methods of the 2016 International Tobacco Control (ITC) Four Country Smoking and Vaping (4CV) Survey, conducted in 2016 in Australia (AU), Canada (CA), England (EN) and the United States (US). METHODS: The respondents were cigarette smokers, former smokers (quit within the previous 2 years), and at-least-weekly vapers, aged 18 years and older. Eligible cohort members from the ITC Four Country Survey (4C) were retained. New respondents were sampled by commercial firms from their panels. Where possible, ages 18-24 and vapers were oversampled. Data were collected online, and respondents were remunerated. Survey weights were calibrated to benchmarks from nationally representative surveys. RESULTS: Response rates by country for new recruits once invited ranged from 15.2 to 49.6%. Sample sizes for smokers/former smokers were 1504 in AU, 3006 in CA, 3773 in EN and 2239 in the US. Sample sizes for additional vapers were 727 in CA, 551 in EN and 494 in the US. CONCLUSION: The International Tobacco Control Four Country Smoking and Vaping Survey design and data collection methods allow analyses to examine prospectively the use of cigarettes and nicotine vaping products in jurisdictions with different regulatory policies. The effects on the sampling designs and response quality of recruiting the respondents from commercial panels are mitigated by the use of demographic and geographic quotas in sampling; by quality control measures; and by the construction of survey weights taking into account smoking/vaping status, sex, age, education and geography

Socioeconomic Differences in Exposure to Tobacco Smoke Pollution (TSP) in Bangladeshi Households with Children: Findings from the International Tobacco Control (ITC) Bangladesh Survey

This study assessed the pattern of exposure to tobacco smoke pollution (TSP; also known as, secondhand smoke) in Bangladeshi households with children and examined the variations in household smoking restrictions and perception of risk for children’s exposure to TSP by socioeconomic status. We interviewed 1,947 respondents from Bangladeshi households with children from the first wave (2009) of the International Tobacco Control (ITC) Bangladesh Survey. 43.5% of the respondents had complete smoking restrictions at home and 39.7% were very or extremely concerned about TSP risk to children’s health. Participants with lower level of education were significantly less likely to be concerned about the risk of TSP exposure to children’s health and less likely to adopt complete smoking restrictions at home. Logistic regression revealed that the predictors of concern for TSP exposure risk were educational attainment of 1 to 8 years (OR = 1.94) or 9 years or more (OR = 4.07) and being a smoker (OR = 0.24). The predictors of having complete household smoking restrictions were: urban residence (OR = 1.64), attaining education of 9 years or more (OR = 1.94), being a smoker (OR = 0.40) and being concerned about TSP exposure risk to children (OR = 3.25). The findings show that a high proportion of adults with children at home smoke tobacco at home and their perceptions of risk about TSP exposure to children’s health were low. These behaviours were more prevalent among rural smokers who were illiterate. There is a need for targeted intervention, customized for low educated public, on TSP risk to children’s health and tobacco control policy with specific focus on smoke-free home

The purchase sources of and price paid for cigarettes in six European countries: Findings from the EUREST-PLUS ITC Europe Surveys

Introduction: Tobacco tax policies have been proven to be effective in reducing tobacco consumption, but their impact can be mitigated through price-minimizing behaviours among smokers. This study explored the purchase sources of tobacco products and the price paid for tobacco products in six EU member states. Methods: Data from Wave 1 of the EUREST-PLUS ITC Europe Survey collected from nationally representative samples of adult smokers in Germany, Greece, Hungary, Poland, Romania and Spain (ITC 6E Survey) were used. The ITC 6E Survey sample, conducted in 2016, randomly sampled 6011 adult cigarette smokers aged 18 years or older. Information on purchase sources of tobacco was examined by country. The difference in reported purchase price by purchase location (store vs non-store/other) was analysed using linear regression for each country. Results: Tobacco purchasing patterns and sources varied widely between countries. Non-store/other purchases were very rare in Hungary (0.1%) while these types of purchases were more common in Germany (5.1%) and Poland (8.6%). Reported prices of one standard pack of 20 cigarettes were highest in Germany (4.80€) and lowest in Hungary (2.45€). While non-store purchases were only made by a minority of smokers (>10% in all countries), the price differential was considerable between store and non-store/other sources, up to 2€ per pack in Greece and in Germany. Conclusions: The results suggest a huge variation of purchasing sources and price differentials between store and non-store purchasing sources across the six EU member states examined. While the cross-sectional data precludes any causal inference, supply chain control through licensing as introduced in Hungary and the lack of such measures in the other countries might nevertheless be a plausible explanation for the large differences in the frequency of non-store purchases observed in this study

Perceptions, Predictors of and Motivation for Quitting among Smokers from Six European Countries from 2016 to 2018: Findings from EUREST-PLUS ITC Europe Surveys

The European Tobacco Products Directive (TPD) was introduced in 2016 in an effort to decrease prevalence of smoking and increase cessation in the European Union (EU). This study aimed to explore quitting behaviours, motivation, reasons and perceptions about quitting, as well as predictors (reported before the TPD implementation) associated with post-TPD quit status. A cohort study was conducted involving adult smokers from six EU countries (n= 3195). Data collection occurred pre-(Wave 1; 2016) and post-(Wave 2; 2018) TPD implementation. Bivariate and logistic regression analyses of weighted data were conducted. Within this cohort sample, 415 (13.0%) respondents reported quitting at Wave 2. Predictors of quitting were moderate or high education, fewer cigarettes smoked per day at baseline, a past quit attempt, lower level of perceived addiction, plans for quitting and the presence of a smoking-related comorbidity. Health concerns, price of cigarettes and being a good example for children were among the most important reasons that predicted being a quitter at Wave 2. Our findings show that the factors influencing decisions about quitting may be shared among European countries. European policy and the revised version of TPD could emphasise these factors through health warnings and/or campaigns and other policies