Age-dependent association of cannabis use with risk of psychotic disorder.

BACKGROUND: Epidemiologic research suggests that youth cannabis use is associated with psychotic disorders. However, current evidence is based heavily on 20th-century data when cannabis was substantially less potent than today. METHODS: We linked population-based survey data from 2009 to 2012 with records of health services covered under universal healthcare in Ontario, Canada, up to 2018. The cohort included respondents aged 12-24 years at baseline with no prior psychotic disorder (N = 11 363). The primary outcome was days to first hospitalization, ED visit, or outpatient visit related to a psychotic disorder according to validated diagnostic codes. Due to non-proportional hazards, we estimated age-specific hazard ratios during adolescence (12-19 years) and young adulthood (20-33 years). Sensitivity analyses explored alternative model conditions including restricting the outcome to hospitalizations and ED visits to increase specificity. RESULTS: Compared to no cannabis use, cannabis use was significantly associated with psychotic disorders during adolescence (aHR = 11.2; 95% CI 4.6-27.3), but not during young adulthood (aHR = 1.3; 95% CI 0.6-2.6). When we restricted the outcome to hospitalizations and ED visits only, the strength of association increased markedly during adolescence (aHR = 26.7; 95% CI 7.7-92.8) but did not change meaningfully during young adulthood (aHR = 1.8; 95% CI 0.6-5.4). CONCLUSIONS: This study provides new evidence of a strong but age-dependent association between cannabis use and risk of psychotic disorder, consistent with the neurodevelopmental theory that adolescence is a vulnerable time to use cannabis. The strength of association during adolescence was notably greater than in previous studies, possibly reflecting the recent rise in cannabis potency.

Youth cannabis use and subsequent health service use for mood and anxiety disorders: A population-based cohort study.

Epidemiologic research suggests a modest association between youth cannabis use and mood and anxiety disorders (MADs). However, current evidence is based mostly on cohort studies using data from the 20th century when cannabis was significantly less potent than today. We linked population-based survey data from 2009 to 2012 with administrative records of health services covered under universal healthcare up to 2017. The cohort included youth aged 12 to 24 years at baseline living in Ontario, Canada with no prior MAD health service use (n = 8,252). We conducted a multivariable Cox model to estimate the association between cannabis use frequency (never,

E-Cigarette Dependence and Depressive Symptoms Among Youth.

INTRODUCTION: Although the relationship between smoking and depression has been well-established, little is known about the association between use of e-cigarette and depression, particularly among youth and young adults. This study proposes that e-cigarette dependence, rather than simply use, serves as a potential stressor and may interact with pre-existing vulnerabilities to contribute to depression in youth, consistent with the diathesis-stress theory. This study examines the longitudinal association of vaping dependence and vaping frequency on depression symptoms among youth and young adults who have never smoked cigarettes. METHODS: People who used e-cigarettes in the past month who reported never smoking a cigarette (N=1,226) aged between 16 and 25 years were followed longitudinally every 3 months for up to 1 year beginning in 2020. The Penn State E-Cigarette Dependence Index at time t was used to predict depression symptoms assessed using the Center for Epidemiologic Studies Depression Scale at time t+1. RESULTS: A total of 32.1% reported vaping in the past month with the Penn State E-Cigarette Dependence Index score (M=8.5) and a Center for Epidemiologic Studies Depression Scale score (M=15.8). Higher vaping dependence scores were significantly associated with increased depression symptoms scores at follow-up among youth and adults (ß=0.08; 95% CI=0.01, 0.15), controlling for baseline depression symptom scores and covariates. Although vaping dependence was highly associated with vaping frequency level, no significant association between the frequency of vaping and depression was found (ß= -0.33; 95% CI= 1.21, 0.54). CONCLUSIONS: These results are consistent with the diathesis-stress model of the relationship between substance use and depression. Vaping dependence but not vaping frequency was associated with increased depressive symptoms among people who never smoked cigarettes.

The impact of COVID-19 on opioid toxicity deaths for people who experience incarceration compared to the general population in Ontario: A whole population data linkage study.

BACKGROUND: To inform preparedness and population health action, we need to understand the effects of COVID-19 on health inequities. In this study, we assess the impact of COVID-19 on opioid toxicity deaths among people who experience incarceration compared to others in the general population in Ontario, Canada. METHODS: We conducted a retrospective cohort study for the period of January 1, 2015 to December 31, 2020. We accessed and linked coronial data on all opioid toxicity deaths in Ontario with correctional data for people aged 18 years and older who were incarcerated in a provincial correctional facility. We used data from the Statistics Canada Census to calculate whole population rates. We used an interrupted time series design and segmented regression to assess for change in the level or rate of increase in deaths due to opioid toxicity coinciding with the COVID-19 pandemic. We compared the impact of COVID-19 on the opioid toxicity death rates for people exposed and not exposed to incarceration. RESULTS: Rates of opioid toxicity death increased with a linear positive slope in both persons exposed to incarceration and those not exposed over the study period. The start of COVID-19 measures coincided with a marked upward shift in the trend lines with modification of the effect of COVID-19 by both sex and exposure to incarceration. For persons exposed to incarceration, the risk ratio (RR) was 1.50 (95%CI 1.35-1.69) for males and 1.21 (95%CI 1.06-1.42) for females, and for persons not exposed to incarceration, the RR was 1.25 (95%CI 1.13-1.38) for males and not significant for females. CONCLUSIONS: COVID-19 substantially exacerbated the risk of opioid toxicity death, impacting males and females who experienced incarceration more than those who had not, with an immediate stepwise increase in risk but no change in the rate of increase of risk over time. Public health work, including pandemic preparedness, should consider the specific needs and circumstances of people who experience incarceration.

Burden of opioid toxicity death in the fentanyl-dominant era for people who experience incarceration in Ontario, Canada, 2015-2020: a whole population retrospective cohort study.

OBJECTIVES: To describe mortality due to opioid toxicity among people who experienced incarceration in Ontario between 2015 and 2020, during the fentanyl-dominant era. DESIGN: In this retrospective cohort study, we linked Ontario coronial data on opioid toxicity deaths between 2015 and 2020 with correctional data for adults incarcerated in Ontario provincial correctional facilities. SETTING: Ontario, Canada. PARTICIPANTS: Whole population data. MAIN OUTCOMES AND MEASURES: The primary outcome was opioid toxicity death and the exposure was any incarceration in a provincial correctional facility between 2015 and 2020. We calculated crude death rates and age-standardised mortality ratios (SMR). RESULTS: Between 2015 and 2020, 8460 people died from opioid toxicity in Ontario. Of those, 2207 (26.1%) were exposed to incarceration during the study period. Among those exposed to incarceration during the study period (n=1 29 152), 1.7% died from opioid toxicity during this period. Crude opioid toxicity death rates per 10 000 persons years were 43.6 (95% CI=41.8 to 45.5) for those exposed to incarceration and 0.95 (95% CI=0.93 to 0.97) for those not exposed. Compared with those not exposed, the SMR for people exposed to incarceration was 31.2 (95% CI=29.8 to 32.6), and differed by sex, at 28.1 (95% CI=26.7 to 29.5) for males and 77.7 (95% CI=69.6 to 85.9) for females. For those exposed to incarceration who died from opioid toxicity, 10.6% died within 14 days of release and the risk was highest between days 4 and 7 postrelease, at 288.1 per 10 000 person years (95% CI=227.8 to 348.1). CONCLUSIONS: The risk of opioid toxicity death is many times higher for people who experience incarceration compared with others in Ontario. Risk is markedly elevated in the week after release, and women who experience incarceration have a substantially higher SMR than men who experience incarceration. Initiatives to prevent deaths should consider programmes and policies in correctional facilities to address high risk on release.

Iron Status and Associated Factors among Canadian Women: Results from the Canadian Health Measures Survey.

BACKGROUND: Iron deficiency and overload may negatively impact women's health. There has been limited assessment of iron status and its associated factors among Canadian women. OBJECTIVES: This study investigated associations of various sociodemographic, lifestyle, medication, and dietary factors with body iron stores among pre- and postmenopausal women in Canada. METHODS: Analyses were conducted using cross-sectional, nationally representative survey and biomarker data from women aged 20-79 y (n = 6362) in the Canadian Health Measures Survey (2009-2017). Body iron stores were assessed by measuring serum concentrations of ferritin (SF). Information on potential correlates was collected during an in-home interview. Multivariable linear regression analyses were performed to evaluate associations with SF concentration, and logistic regression was used to estimate associations with iron deficiency (SF <15 µg/L) or elevated iron stores (SF >150 µg/L). RESULTS: Geometric mean SF concentrations were significantly higher in postmenopausal than in premenopausal women (73.2 versus 33.8 µg/L; P < 0.001). The prevalence of iron deficiency among pre- and postmenopausal women was 16.0% and 4.0%, respectively, whereas that of elevated iron stores was 2.7% and 21.0%, respectively. After simultaneous adjustment for multiple factors, including high-sensitivity CRP (inflammation marker), we found that age, East/Southeast Asian (versus White) race/ethnicity, alcohol, and red meat consumption were positively associated with SF concentration among pre- and postmenopausal women. In addition, aspirin use and dairy consumption were inversely associated with SF concentration among postmenopausal women only. Similar patterns were observed for associations with elevated iron stores among postmenopausal women, whereas higher grain consumption was associated with an increased prevalence of iron deficiency among premenopausal women. CONCLUSIONS: Sociodemographic, lifestyle, medication, and dietary factors are correlated with iron status determined by SF concentration among Canadian women. The findings may have implications for intervention strategies aimed at optimizing body iron stores in pre- and postmenopausal women.

Smoking, e-cigarettes and the effect on respiratory symptoms among a population sample of youth: Retrospective cohort study.

INTRODUCTION: E-cigarettes have been steadily increasing in popularity, both as cessation methods for smoking and for recreational and social reasons. This increase in vaping may pose cardiovascular and respiratory risks. We aimed to assess respiratory symptoms in youth users of e-cigarettes and cigarettes. METHODS: A retrospective survey design was utilized to assess Canadian youth aged 16-25 years. Participants were recruited from the Ontario Tobacco Research Unit Youth and Young Adult Research Registration Panel November 2020 to March 2021. A total of 3082 subjects completed the baseline survey. Of these, 2660 individuals who did not have asthma were included in the analysis. The exposure of interest was pack-equivalent years, a novel measure of vaping exposure equivalent conceptually to cigarette pack years incorporating number of puffs per day, number of days vaped per month, and number of years vaped. Respiratory symptoms were measured using the five-item Canadian Lung Health Test. Poisson regression analyses were performed while adjusting for demographic confounders, stratified by smoking status. A non-stratified model tested the interaction of status and vaping dose and the effect of vaping device used was assessed among ever vapers. Analyses controlled for demographic characteristics, use of cannabis and alcohol, and survey date. RESULTS: Each additional puff year increased the rate ratio (RR) of respiratory symptoms by a factor of 11.36 (95% CI: 4.61-28.00; p<0.001) for never smokers, but among current daily smokers higher pack-equivalent years were not associated with more respiratory symptoms (RR=0.83; 95% CI: 0.23-3.11). Among current vapers, those using pod-style devices were more likely to have more respiratory symptoms (RR=1.25; 95% CI: 1.08-1.45) after adjusting for dose. CONCLUSIONS: Vaping is associated with an increased risk of reporting respiratory symptoms among never smoking youth and non-daily ever cigarette smokers. Use of e-cigarettes among non-smokers should be discouraged.

Machine learning applications in tobacco research: a scoping review.

OBJECTIVE: Identify and review the body of tobacco research literature that self-identified as using machine learning (ML) in the analysis. DATA SOURCES: MEDLINE, EMABSE, PubMed, CINAHL Plus, APA PsycINFO and IEEE Xplore databases were searched up to September 2020. Studies were restricted to peer-reviewed, English-language journal articles, dissertations and conference papers comprising an empirical analysis where ML was identified to be the method used to examine human experience of tobacco. Studies of genomics and diagnostic imaging were excluded. STUDY SELECTION: Two reviewers independently screened the titles and abstracts. The reference list of articles was also searched. In an iterative process, eligible studies were classified into domains based on their objectives and types of data used in the analysis. DATA EXTRACTION: Using data charting forms, two reviewers independently extracted data from all studies. A narrative synthesis method was used to describe findings from each domain such as study design, objective, ML classes/algorithms, knowledge users and the presence of a data sharing statement. Trends of publication were visually depicted. DATA SYNTHESIS: 74 studies were grouped into four domains: ML-powered technology to assist smoking cessation (n=22); content analysis of tobacco on social media (n=32); smoker status classification from narrative clinical texts (n=6) and tobacco-related outcome prediction using administrative, survey or clinical trial data (n=14). Implications of these studies and future directions for ML researchers in tobacco control were discussed. CONCLUSIONS: ML represents a powerful tool that could advance the research and policy decision-making of tobacco control. Further opportunities should be explored.

Household composition and anxiety symptoms during the COVID-19 pandemic: A population-based study.

INTRODUCTION: Household composition may be an important factor associated with anxiety during the COVID-19 pandemic as people spend more time at home due to physical distancing and lockdown restrictions. Adults living with children-especially women-may be particularly vulnerable to anxiety as they balance additional childcare responsibilities and homeschooling with work. The objective of this study was to examine the association between household composition and anxiety symptoms during the COVID-19 pandemic and explore gender as an effect modifier. METHODS: Data were derived from seven waves of a national online survey of Canadian adults aged 18+ years from May 2020 to March 2021, which used quota sampling by age, gender, and region proportional to the English-speaking Canadian population (n = 7,021). Multivariable logistic and modified least-squares regression models were used. RESULTS: Compared to those living alone, significantly greater odds of anxiety symptoms were observed among single parents/guardians (aOR = 2.00; 95%CI: 1.41-2.84), those living with adult(s) and child(ren) (aOR = 1.39; 95%CI: 1.10-1.76), and those living with adult(s) only (aOR = 1.22; 95%CI: 1.00-1.49). Gender was a significant effect modifier on the additive scale (p = 0.0487) such that the association between living with child(ren) and anxiety symptoms was stronger among men than women. CONCLUSION: Additional tailored supports are needed to address anxiety among adults living with children-especially men-during the COVID-19 pandemic and future infectious disease events.

The health impacts of the COVID-19 pandemic on adults who experience imprisonment globally: A mixed methods systematic review.

BACKGROUND: The prison setting and health status of people who experience imprisonment increase the risks of COVID-19 infection and sequelae, and other health impacts of the COVID-19 pandemic. OBJECTIVES: To conduct a mixed methods systematic review on the impacts of the COVID-19 pandemic on the health of people who experience imprisonment. DATA SOURCES: We searched Medline, PsycINFO, Embase, the Cochrane Library, Social Sciences Abstracts, CINAHL, Applied Social Sciences Index and Abstracts, Sociological Abstracts, Sociology Database, Coronavirus Research Database, ERIC, Proquest Dissertations and Theses, Web of Science, and Scopus in October 2021. We reviewed reference lists for included studies. STUDY ELIGIBILITY CRITERIA: Original research conducted in or after December 2019 on health impacts of the COVID-19 pandemic on adults in prisons or within three months of release. STUDY APPRAISAL AND SYNTHESIS METHODS: We used the Joanna Briggs Institute's Critical Appraisal Checklist for Qualitative Research for qualitative studies and the Joanna Briggs Institute's Critical Appraisal Checklist for Studies Reporting Prevalence Data for quantitative studies. We qualitized quantitative data and extracted qualitative data, coded data, and collated similar data into categories. RESULTS: We identified 62 studies. People in prisons had disproportionately high rates of COVID-19 infection and COVID-19 mortality. During the pandemic, all-cause mortality worsened, access to health care and other services worsened, and there were major impacts on mental wellbeing and on relationships with family and staff. There was limited evidence regarding key primary and secondary prevention strategies. LIMITATIONS: Our search was limited to databases. As the COVID-19 pandemic is ongoing, more evidence will emerge. CONCLUSIONS: Prisons and people who experience imprisonment should be prioritized for COVID-19 response and recovery efforts, and an explicit focus on prisons is needed for ongoing public health work including emergency preparedness. PROSPERO REGISTRATION NUMBER: 239324.

The Association Between Self-Reported Non-Injection Cocaine Use and Hepatitis C in the United States: An Analysis of the National Health and Nutrition Examination Survey.

OBJECTIVE: Previous studies conducted on hepatitis C virus (HCV) transmission have focused primarily on its transmission among people who inject drugs. However, there is evidence that transmission may also occur through the sharing of contaminated non-injection implements used to consume drugs nasally, orally, or by inhalation. Studies to date have not conclusively established a relationship between these routes of cocaine use and HCV. We quantified the association between cocaine use and HCV, specifically among individuals who have never injected an illicit substance. METHOD: Data from the 2011-2018 National Health and Nutrition Examination Survey were analyzed. Multivariable logistic regression was used to test for an association between cocaine use and HCV among 10,106 individuals (5,201 females). Covariates included age, race, sex, education, income, and immigrant status. RESULTS: In the unadjusted model, individuals who reported cocaine use had 4.79 (95% CI [2.70, 8.47]) times the odds of ever having HCV compared with those who did not use cocaine. In the adjusted model, individuals who reported cocaine use had 4.48 (95% CI [2.36, 8.50]) times the odds of ever having HCV compared with those who did not use cocaine. CONCLUSIONS: This study highlights that individuals who report non-injection cocaine use have an inflated risk of HCV compared with individuals who report no cocaine use. Harm reduction interventions to reduce the transmission of HCV should therefore be targeted to all people who use drugs, including those who use cocaine orally, intra-nasally, and by inhalation.

Age differences in the association between loneliness and anxiety symptoms during the COVID-19 pandemic.

Loneliness and associated mental health problems are of particular concern during the COVID-19 pandemic due to physical distancing and lockdown restrictions. Loneliness is most common among young adults and women during the pandemic, but it is unclear if the association between loneliness and mental health problems, notably anxiety, is strongest in these groups. The objective of this study was to examine whether the association between loneliness and anxiety differed by age and/or gender during the pandemic. We analyzed data from a multi-wave national online survey of Canadians aged 18+ years from May 2020 to March 2021 (n = 7,021). Multivariable modified least-squares regression was used to examine whether the association between loneliness and moderate to severe anxiety symptoms (GAD-7 10+) differed by age and/or gender on the additive scale, controlling for socio-demographic factors, depression, hopefulness, and survey wave. Age significantly moderated the association between loneliness and anxiety symptoms while gender did not. Loneliness was associated with anxiety symptoms for all age groups, but the association was not as strong among those aged 70+ years compared to other age groups. Evidence-based loneliness interventions that target younger adults are needed to mitigate the mental health effects of infectious disease events such as COVID-19.

Predictors of pod-type e-cigarette device use among Canadian youth and young adults. / Prédicteurs de l'utilisation de la cigarette électronique à capsule chez les jeunes et les jeunes adultes canadiens.

INTRODUCTION: Changes to federal legislation allowed nicotine-based e-cigarettes legal entry into the Canadian market in 2018. This included pod-type e-cigarettes (pods), such as JUUL, that were later found to be associated with steeply increasing prevalence and greater frequency of e-cigarette use among US and Canadian youth. Multiple studies of risk factors of JUUL use and use initiation have been conducted among various population groups in the US, but little evidence exists pointing to similar risk factors of pod use among Canadian youth and young adults. Understanding these risk factors can inform use prevention and intervention strategies in Canadian and other jurisdictions. METHODS: A total of 668 Canadian youth and young adults recruited by the 2018-19 Youth and Young Adult Panel Study were provided a baseline survey 3 months before and a follow-up survey 9 months after the relaxation of federal nicotine e-cigarette regulations. We used multivariable logistic regression to understand and rank importance of baseline predictors of future pod use among respondents. RESULTS: Past-month cannabis use (OR [odds ratio] = 2.66, 95% CI: 1.66-4.21, p < 0.001), established cigarette use (OR = 3.42, 1.53-7.65, p < 0.01), past cigarette experimentation (OR = 2.40, 1.34-4.31, p < 0.01), having many friends who vaped (OR = 2.15, 1.37-3.34, p < 0.001), age below 18 compared to age over 22 (OR = 5.26, 2.63-10.00, p < 0.001) and male sex (OR = 1.69, 1.16-2.50, p < 0.01) were significant and the most influential predictors of future pod use. CONCLUSION: Similar factors drove pod use among Canadian and US youth and young adults. Appropriate preventive strategies can benefit from considering polysubstance use among high school-aged youth.

The association of sex and calendar month with changes in weight: A retrospective cohort study of a community-based weight management clinic.

OBJECTIVE: To assess changes in weight by calendar month and sex in patients enrolled in a weight loss intervention. METHODS: Adults participating in a lifestyle weight loss intervention at the Wharton Medical Clinic from January 1st, 2007 to July 4th, 2019 were examined (N = 19,153). A linear generalized estimating equation was used to examine the association between weight change (baseline, month 1, month 2) and calendar month with adjustment for age, sex and baseline body mass index. A first order interaction between sex and calendar was included to assess if the association between calendar month and weight loss differs by sex. RESULTS: Patients lost 1.3 ± 2.0 kg (1.2 ± 1.8%) of their body weight per month. As compared to the mean monthly weight loss, patients lost slightly less weight in September (mean, 95% confidence interval (CI): -0.3, -0.4 to -0.2 kg) and slightly more weight in October (0.2, 0.1-0.3 kg). With adjustment for age, body mass index and calendar month, men lost 0.4 kg/month (95% CI: 0.3, 0.5 kg/month) than women. There were no other significant differences in the monthly weight change between men and women (sex*calendar month P-value = 0.24). CONCLUSION: While there were slight differences in the amount of weight change achieved by patients in September, and October, it was not of a magnitude that is likely clinically relevant. In addition, men consistently lost more weight than women across all calendar months. Taken together, this suggest that calendar month is not associated with differences in weight loss for men and women enrolled in a structured weight management program.

Adult attention-deficit hyperactivity disorder symptoms and psychological distress, hazardous drinking, and problem gambling: A population-based study.

Recognition of ADHD in the adult population is relatively recent. Epidemiological research examining the mental health impact of ADHD in adulthood is thus limited. The objective of this study was to examine whether adult ADHD symptoms are associated with psychological distress, hazardous drinking, and problem gambling, after controlling for traumatic brain injury and sociodemographic characteristics. We analyzed data from a population-based survey administered in 2015 and 2016 to adults aged 18 years and over in Ontario, Canada (N = 3,817). Logistic regression was used to construct unadjusted and multivariable models for each of the three focal relationships. In the unadjusted models, ADHD symptoms were significantly related to psychological distress (OR = 9.3; 95% CI:6.1, 14.0) and hazardous drinking (OR = 2.1; 95% CI: 1.3, 3.4), but not to problem gambling (OR = 1.5; 0.5, 4.3). After adjustment, ADHD symptoms were significantly related to psychological distress (OR = 7.1; 95% CI: 4.6, 11.1), but not hazardous drinking (OR = 1.4; 95% CI: 0.8, 2.5) or problem gambling (OR = 0.6; 95% CI: 0.2, 2.5). This study further highlights the importance of clinicians assessing for concomitant ADHD and psychological distress in adults.

Excess mortality associated with eating disorders: population-based cohort study.

BACKGROUND: Individuals with eating disorders have a high mortality risk. Few population-based studies have estimated this risk in eating disorders other than anorexia nervosa. AIMS: To investigate all-cause mortality in a population-based cohort of individuals who received hospital-based care for an eating disorder (anorexia nervosa, bulimia nervosa or eating disorder not otherwise specified) in Ontario, Canada. METHOD: We conducted a retrospective cohort study of 19 041 individuals with an eating disorder from 1 January 1990 to 31 December 2013 using administrative healthcare data. The outcome of interest was death. Excess mortality was assessed using standardised mortality ratios (SMRs) and potential years of life lost (PYLL). Cox proportional hazards regression models were used to examine sociodemographic and medical comorbidities associated with greater mortality risk. RESULTS: The cohort had 17 108 females (89.9%) and 1933 males (10.1%). The all-cause mortality for the entire cohort was five times higher than expected compared with the Ontario population (SMR = 5.06; 95% CI 4.82-5.30). SMRs were higher for males (SMR = 7.24; 95% CI 6.58-7.96) relative to females (SMR = 4.59; 95% CI 4.34-4.85) overall, and in all age groups in the cohort. For both genders, the cohort PYLL was more than six times higher than the expected PYLL in the Ontario population. CONCLUSIONS: Patients with eating disorders diagnosed in hospital settings experience five to seven times higher mortality rates compared with the overall population. There is an urgent need to understand the mortality risk factors to improve health outcomes among individuals with eating disorders.

Correction: Variability in patient sociodemographics, clinical characteristics, and healthcare service utilization among 107,302 treatment seeking smokers in Ontario: A cross-sectional comparison.

[This corrects the article DOI: 10.1371/journal.pone.0235709.].

Variability in patient sociodemographics, clinical characteristics, and healthcare service utilization among 107,302 treatment seeking smokers in Ontario: A cross-sectional comparison.

BACKGROUND: Since 2005, the Smoking Treatment for Ontario Patients (STOP) program has provided smoking cessation treatment of varying form and intensity to smokers through 11 distinct treatment models, either in-person at partnering healthcare organizations or remotely via web or telephone. We aimed to characterize the patient populations reached by different treatment models. METHODS: We linked self-report data to health administrative databases to describe sociodemographics, physical and mental health comorbidity, healthcare utilization and costs. Our sample consisted of 107,302 patients who enrolled between 18Oct2005 and 31Mar2016, across 11 models operational during different time periods. RESULTS: Patient populations varied on sociodemographics, comorbidity burden, and healthcare usage. Enrollees in the Web-based model were youngest (median age: 39; IQR: 29-49), and enrollees in primary care-based Family Health Teams were oldest (median: 51; IQR: 40-60). Chronic Obstructive Pulmonary Disease and hypertension were the most common physical health comorbidities, twice as prevalent in Family Health Teams (32.3% and 30.8%) than in the direct-to-smoker (Web and Telephone) and Pharmacy models (13.5%-16.7% and 14.7%-17.7%). Depression, the most prevalent mental health diagnosis, was twice as prevalent in the Addiction Agency (52.1%) versus the Telephone model (25.3%). Median healthcare costs in the two years up to enrollment ranged from $1,787 in the Telephone model to $9,393 in the Addiction Agency model. DISCUSSION: While practitioner-mediated models in specialized and primary care settings reached smokers with more complex healthcare needs, alternative settings appear better suited to reach younger smokers before such comorbidities develop. Although Web and Telephone models were expected to have fewer barriers to access, they reached a lower proportion of patients in rural areas and of lower socioeconomic status. Findings suggest that in addition to population-based strategies, embedding smoking cessation treatment into existing healthcare settings that reach patient populations with varying disparities may enhance equitable access to treatment.

Iron intake, oxidative stress-related genes and breast cancer risk.

Iron has been suggested to contribute to breast cancer development through oxidative stress generation. Our study investigated associations between iron intake and breast cancer risk, overall and by menopausal and estrogen receptor/progesterone receptor (ER/PR) status, and modification by oxidative stress-related genetic polymorphisms (MnSOD, GSTM1 and GSTT1). A population-based case-control study (3,030 cases and 3,402 controls) was conducted in Ontario, Canada. Iron intake (total, dietary, supplemental, heme, nonheme) was assessed using a validated food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from multivariable logistic regression models. Interactions between iron intake and genotypes were assessed among 1,696 cases and 1,761 controls providing DNA. Overall, no associations were observed between iron intake and breast cancer risk. Among premenopausal women, total, dietary and dietary nonheme iron were positively associated with ER-/PR- breast cancer risk (all ptrend < 0.05). Among postmenopausal women, supplemental iron was associated with reduced breast cancer risk (OR>18 vs. 0 mg/day = 0.68, 95% CI: 0.51-0.91), and dietary heme iron was associated with an increased risk, particularly the ER-/PR- subtype (ORhighest vs. lowest quintile = 1.69, 95% CI: 1.16-2.47; ptrend = 0.02). Furthermore, GSTT1 and combined GSTM1/GSTT1 polymorphisms modified some of the associations. For example, higher dietary iron was most strongly associated with increased breast cancer risk among women with GSTT1 deletion or GSTM1/GSTT1 double deletions (pinteraction < 0.05). Findings suggest that iron intake may have different effects on breast cancer risk according to menopausal and hormone receptor status, as well as genotypes affecting antioxidant capacity.

Real-World Effectiveness of Pharmaceutical Smoking Cessation Aids: Time-Varying Effects.

BACKGROUND: There are a limited number of studies that have examined the real-world effectiveness of smoking cessation aids and relapse longitudinally in population-representative samples. This study examines the association between use of nicotine gum, patch, bupropion, and varenicline and time to relapse as well as any changes in the association with increased length of abstinence. METHODS: Data of 1821 current adult smokers (18+) making their first serious quit attempt were compiled from 4504 individuals enrolled in the Ontario Tobacco Survey, a representative telephone survey of Ontario adults, which followed smokers every 6 months for up to 3 years. Use of cessation aids at the time of initial report of a quit attempt was analyzed. A flexible parametric survival model was developed to model length of abstinence, controlling for potential confounders. RESULTS: The best fit model found knots at 3, 13, 43, and 212 days abstinent, suggesting different rates of relapse in the periods marked by those days. Use of the patch and varenicline was associated with lower rates of relapse, but no positive effect was found for bupropion or nicotine gum. The effectiveness of the patch reversed in effect after the first month of abstinence. CONCLUSIONS: This study is one of few reports of long-term quitting in a population-representative sample and demonstrates that the effectiveness of some pharmacological cessation aids (the patch and varenicline can be seen in a population sample). Previous failures in real-world studies of the effectiveness of smoking cessation aids may reflect differences in the products individuals use and differences in the timing of self-reported cessation. IMPLICATIONS: While a large number of randomized controlled trials have shown the efficacy of many pharmaceutical smoking cessation aids, evidence of their effectiveness in observational studies in the real world is ambiguous. This study uses a longitudinal cohort of a representative sample of smokers to show that the effectiveness of pharmaceutical cessation aids can be demonstrated in real-world use situations, but effectiveness varies by product type and has time-varying effects.