Socioeconomic patterns of smoking cessation behavior in low and middle-income countries: Emerging evidence from the Global Adult Tobacco Surveys and International Tobacco Control Surveys

Introduction
Tobacco smoking is often more prevalent among those with lower socio-economic status (SES) in high-income countries, which can be driven by the inequalities in initiation and cessation of smoking. Smoking is a leading contributor to socio-economic disparities in health. To date, the evidence for any socio-economic inequality in smoking cessation is lacking, especially in low- and middle-income countries (LMICs). This study examined the association between cessation behaviours and SES of smokers from eight LMICs.
Methods
Data among former and current adult smokers aged 18 and older came from contemporaneous Global Adult Tobacco Surveys (2008–2011) and the International Tobacco Control Surveys (2009–2013) conducted in eight LMICs (Bangladesh, Brazil, China, India, Mexico, Malaysia, Thailand and Uruguay). Adjusted odds ratios (AORs) of successful quitting in the past year by SES indicators (household income/wealth, education, employment status, and rural-urban residence) were estimated using multivariable logistic regression controlling for socio-demographics and average tobacco product prices. A random effects meta-analysis was used to combine the estimates of AORs pooled across countries and two concurrent surveys for each country.
Results
Estimated quit rates among smokers (both daily and occasional) varied widely across countries. Meta-analysis of pooled AORs across countries and data sources indicated that there was no clear evidence of an association between SES indicators and successful quitting. The only exception was employed smokers, who were less likely to quit than their non-employed counterparts, which included students, homemakers, retirees, and the unemployed (pooled AOR≈0.8, p<0.10).
Conclusion
Lack of clear evidence of the impact of lower SES on adult cessation behaviour in LMICs suggests that lower-SES smokers are not less successful in their attempts to quit than their higher-SES counterparts. Specifically, lack of employment, which is indicative of younger age and lower nicotine dependence for students, or lower personal disposable income and lower affordability for the unemployed and the retirees, may be associated with quitting. Raising taxes and prices of tobacco products that lowers affordability of tobacco products might be a key strategy for inducing cessation behaviour among current smokers and reducing overall tobacco consumption. Because low-SES smokers are more sensitive to price increases, tobacco taxation policy can induce disproportionately larger decreases in tobacco consumption among them and help reduce socio-economic disparities in smoking and consequent health outcomes.

引言
在高收入国家，吸烟行为在社会经济地位（Socio-economic Status, SES）较低人群中更为普遍，这一现象或源于吸烟起始与戒断环节中的不平等。吸烟是引发健康领域社会经济差异的首要因素。截至目前，尚无充分证据表明吸烟戒断存在社会经济不平等，这一证据缺口在中低收入国家（Low- and Middle-Income Countries, LMICs）中尤为显著。本研究针对8个中低收入国家的吸烟者，探讨了其戒断行为与社会经济地位之间的关联。

方法
本研究的研究对象为18岁及以上的既往吸烟者与当前吸烟者，数据来源于8个中低收入国家（孟加拉国、巴西、中国、印度、墨西哥、马来西亚、泰国及乌拉圭）同期开展的《全球成人烟草调查》（Global Adult Tobacco Surveys，2008–2011年）与《国际烟草控制调查》（International Tobacco Control Surveys，2009–2013年）。研究以社会人口学特征与烟草产品平均价格作为控制变量，采用多变量逻辑回归（multivariable logistic regression），估算了基于各类社会经济地位指标（家庭收入/财富、受教育程度、就业状态、城乡居住地）的过去一年成功戒断烟草的校正后优势比（Adjusted Odds Ratios, AORs）。此外，采用随机效应荟萃分析（random effects meta-analysis），整合各国及各国对应两项同期调查的校正后优势比合并估计值。

结果
不同国家的吸烟者（包括每日吸烟者与偶发吸烟者）的估算戒断率差异显著。针对各国及不同数据来源的校正后优势比进行的荟萃分析显示，并无明确证据表明社会经济地位指标与成功戒断烟草存在关联。唯一的例外是就业吸烟者：其成功戒断的概率低于非就业人群（包括学生、家庭主妇、退休人员及失业者），合并校正后优势比约为0.8，p<0.10。

结论
在中低收入国家中，未发现较低社会经济地位对成人戒烟行为存在明确影响的证据，这提示社会经济地位较低的吸烟者，其戒烟成功率并不低于社会经济地位较高的吸烟者。具体而言，未就业状态或与戒烟行为相关：对于学生而言，未就业意味着更年轻的年龄与更低的尼古丁依赖；对于失业者与退休人员而言，则意味着更低的个人可支配收入与更低的烟草负担能力。
提高烟草产品税负与价格以降低其可负担性，或可成为推动当前吸烟者戒断、降低整体烟草消费的关键策略。鉴于社会经济地位较低的吸烟者对价格上涨更为敏感，烟草税收政策可使该群体的烟草消费量出现更大幅度的下降，从而有助于缩小吸烟相关的社会经济差异及其后续健康结局差异。