Efficient screening of current smoking status in recruitment of smokers for population-based research

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.

Association Between Socioeconomic Status and Access to Care and Quitting Smoking With and Without Assistance

Introduction

Socio-economic disparities in smoking rates persist, in Ontario, despite public health care and universal tobacco control policies. Mechanisms for continuing disparities are not fully understood. Unequal access or utilization of assistance for cessation may contribute. The objective of this research was to use longitudinal data on smokers to examine the associations between socioeconomic status (SES) and access to care measures and assisted and unassisted quit attempts.

Methods

Data were taken from 3578 smokers with at least one follow-up interview participating in the Ontario Tobacco Survey (OTS). Multinomial regression models with imputed missing values were run for each measure of SES and access to care to assess the association with quitting behavior and use of assistance, unadjusted and while adjusting for smoking history and demographic covariates.

Results

Adjusted analyses found smokers living in areas with the lowest ethnic concentration were more likely to make an assisted quit attempt compared to unassisted quitting (RR = 1.64; 95% CI = 1.08-2.50) or making no quit attempt (RR = 1.65; 95% CI = 1.15-2.37). Smokers who reported visiting a doctor in the previous 6 months were more likely to quit with assistance versus unassisted compared to those not visiting a doctor, whether they were advised (RR = 1.89, 95% CI = 1.43-2.48) or not advised to quit (OR = 1.32, 95% CI = 1.01-1.74). Similar results were seen when comparing assisted quit attempts with no quit attempts.

Conclusions

Adjusted analyses showed that quitting with assistance was unrelated to measures of SES except ethnic concentration. Physician intervention with patients who smoke is important for increasing assisted quit attempts.

Implications

For most measures of SES there were no significant associations with either assisted or unassisted quitting adjusting for demographic and smoking history. Smokers who live in areas with the lowest ethnic concentration were most likely to use assistance as were smokers who visited their doctor and were advised to quit smoking. Interventions to increase the delivery of effective quitting methods in smokers living in areas with high ethnic concentrations and to increase physician compliance with asking and advising patients to quit may increase assisted quit attempts.

Health professional advice, use of medications and smoking cessation: A population-based prospective cohort study

INTRODUCTION

The mediating role of cessation medications in the association between health professional advice and quitting behaviors is unclear.

METHODS

Data were from the Ontario Tobacco Survey longitudinal study, collected between July 2005 and June 2011 in Ontario, Canada. The analytic sample included 3437 baseline smokers who were seen by health professionals during follow-up. Logistic regression with generalized estimating equations and mediation analysis techniques were used to examine the impact of advice and medications on quitting outcomes (making a quit attempt, short-term quitting 1-6months and long-term quitting>6months).

RESULTS

Those who received advice to quit smoking were more likely to use cessation medications than those who did not receive advice (21% vs. 13%, P<0.001). Receiving advice was associated with making a quit attempt (adjusted odds ratio (OR) 1.25, 95% confidence interval (CI) 1.10-1.41) and long-term quitting (adjusted OR 1.49, 95% CI 1.10-2.02), but not with short-term quitting. Use of cessation medications was associated with making a quit attempt (adjusted OR 11.83, 95% CI 9.93-14.08), short-term quitting (adjusted OR 3.69, 95% CI 2.90-4.68), and long-term quitting (adjusted OR 2.73, 95% CI 1.95-3.82). Using prescription medications was associated with a higher likelihood of quitting short-term (adjusted OR 2.43, 95% CI 2.59-3.74) and long-term (adjusted OR 2.27, 95% CI 1.23-4.17) than using NRT. Use of cessation medications was a significant mediator in the pathway from receiving advice to quitting.

CONCLUSION

Health professionals should advise smokers to quit and encourage them to use cessation medications, especially prescription medications when trying to quit.

Duration of nicotine replacement therapy use and smoking cessation: a population-based longitudinal study

In the present study, we examined the association between duration of nicotine replacement therapy (NRT) use and smoking cessation using data from the Ontario Tobacco Survey longitudinal study (3 waves of data collected between July 2005 and December 2009). We used logistic regression with generalized estimating equations to examine the association between NRT use (any use and <4 weeks, 4.0–7.9 weeks, 8.0–11.9 weeks, and ≥12 weeks of use compared with nonuse) and quitting smoking (≥1 month). Using NRT was not associated with quitting when use duration was not taken into account (adjusted odds ratio (OR) = 1.08, 95% confidence interval (CI): 0.86, 1.35). Compared with abstaining from NRT when attempting to quit smoking, using NRT for less than 4 weeks was associated with a lower likelihood of quitting (adjusted OR = 0.51, 95% CI: 0.38, 0.67); however, using NRT for 4 weeks or longer was associated with a higher likelihood of cessation (for 4.0–7.9 weeks of NRT use, adjusted OR = 2.26, 95% CI: 1.58, 3.22; for 8.0–11.9 weeks of NRT use, adjusted OR = 3.84, 95% CI: 2.24, 6.58; and for ≥12 weeks of NRT use, adjusted OR = 2.80, 95% CI: 1.70, 4.61). Thus, use of NRT for less than 4 weeks was associated with reduced likelihood of cessation, whereas NRT use for longer periods of time was associated with a higher likelihood of cessation.

Transitions in smoking status over time in a population-based panel study of smokers

INTRODUCTION

Few studies have examined the transitions of smokers in the general population through multiple periods of daily, occasional smoking, or abstinence over time. Transitions from daily to occasional smoking are particularly of interest as these may be steps toward cessation.

METHODS

The Ontario Tobacco Survey panel study followed 4,355 baseline smokers, semiannually for up to 3 years. Probabilities of all possible changes in smoking status more than 6 months were estimated using 13,000 repeated measures observations generated from sets of 3 consecutive interviews (n = 9,932 daily smokers, 1,245 occasion smokers, and 1,823 abstinent for at least 30 days, at Time 1).

RESULTS

For initial daily smokers, an estimated 83% remained daily smokers more than 2 follow-ups. The majority of those who had been abstinent for 30 days at 1 interview, were also former smokers at the following interview. In contrast, occasional smoking status was unstable and future smoking status was dependent upon smoking history and subjective dependence. Among daily smokers who became occasional smokers 6 months later, an estimated 20% became a former smoker, at the next interview, but 50% returned to daily smoking. Daily, turned occasional smokers who rebounded back to daily smoking were more likely to describe themselves as addicted at Time 1. Continuing occasional smokers were somewhat less likely to intend to quit, or have tried, despite considering themselves less addicted.

CONCLUSIONS

Reducing to occasional smoking can be a stepping stone toward cessation but entails a greater risk of return to daily smoking, compared with complete abstinence.

Are occasional smokers a heterogeneous group? An exploratory study

BACKGROUND

Occasional smokers represent an important segment of all smokers and have been described to be a heterogeneous group in terms of past experience and likelihood of maintaining nondaily smoking behavior.

METHODS

In the prospective Ontario Tobacco Survey, 408 occasional smokers were followed for a year. Characteristics of subgroups of occasional smokers, as suggested by previous literature, were studied for personal and smoking behavior group differences. Agglomerative hierarchical clustering was also used to empirically identify subgroups of occasional smokers using average linkage. Smoking status at 1-year follow-up was examined overall and by the identified subgroups to determine if any were useful predictors of persistent status as nondaily smoking and likelihood of smoking cessation.

RESULTS

Significant differences were seen among the subgroups of occasional smokers suggested in previous studies including the number of quit attempts, setting a firm quit date, and whether or not participants cared others knew they smoked in descriptive analyses. Exploratory cluster analysis suggested 4 clusters of occasional smokers based on differences in age, perceived addiction, and history of daily smoking. Subgroups based on participants' history of smoking, self-reported addiction level, and empirically identified cluster subgroups resulted in significant differences of smoking status at 1-year follow-up.

CONCLUSIONS

This study suggests that occasional smokers may be a heterogeneous group with different subgroups characterized by age, accumulated smoking experience and smoking pattern, as well as factors associated with the likelihood of quitting altogether, over time, and perceived addiction.