THEMATIC ISSUE ON ECONOMICS OF TOBACCO CONTROL IN THE AMERICAS Pan American Journal Review of Public Health Income levels and prevalence of smoking in Latin America: a systematic review and meta-analysis* Ariel Bardach,1 Herney Andrés García Perdomo,2 Ruth Amanda Ruano Gándara,1 and Agustín Ciapponi1 Suggested Citation (Original article) Bardach A, García Perdomo HA, Ruano Gándara RA, Ciapponi A. Niveles de ingreso y prevalencia de tabaquismo en América Latina: revisión sistemática y metaanálisis Rev Panam Salud Publica. 2016;40(4):263-71. ABSTRACT Objective. Determine the relationship between the prevalence of current tobacco use and smoker income levels in Latin America and the Caribbean (LAC). Methods. A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS databases. Studies from LAC published from January 1989 to December 2015 were included and analyzed by subgroups disaggregated by decade of data, country, bias risk, sex, and age group. Results. Of 1,254 studies evaluated by full text, 29 articles were included, of which 25 were chosen for meta-analysis. All included studies were cross-sectional or surveillance, and were primarily from Brazil and Mexico. Low income was associated with a higher prevalence of active tobacco use (odds ratio [OR] 1.62; 95% confidence interval [95% CI] 1.34–1.96 than high income (reference). A dose-re- sponse effect trend was observed: middle income (OR 1.23; 95% CI 1.00-1.52) and low income (OR 1.64; 95% CI 1.17-2.30). This association was greater in men (OR 2.22; 95% CI 1.77- 2.78) than in women (OR 1.6; 95% CI 1.11-2.47). Conclusions. An inverse relationship was observed between income and tobacco use preva- lence. Further efforts are required to determine this relationship in special populations, such as adolescents and pregnant women. This research may be useful to policymakers by improving tobacco control strategies and characterizing public health equity issues. Key words Tobacco use; equity; health economics. Tobacco use is the world’s leading (passive smoking) of cigarettes (1, 2). consumption imposes a significant eco- cause of preventable death. Approxi- From 2010 to 2050, 400 million people are nomic burden: worldwide, the estimated mately six million people die from conse- projected to die from diseases attribut- cost exceeds US$500,000 million a year quences related to smoking, both from able to smoking, particularly lung can- (7), primarily from direct medical costs the direct as well as the indirect use cer, chronic respiratory disease, and and lost productivity. cardiovascular disease (3, 4). It is esti- Tobacco use in low-income populations mated that the majority of deaths will is related to a higher frequency of associ- take place in low- and middle-income ated diseases and patients who have lim- * Official English translation provided by the Pan American Health Organization. In the case of countries (5). In Latin America and the ited access to health services and fewer discrepancy between the two versions, the Caribbean (LAC), the proportion of dis- possibilities for purchasing medicines Spanish original shall prevail. 1 Cochrane Center, Institute of Clinical and ability-adjusted life years (DALY) that (8-10). The greatest incidence of tobacco Sanitary Effectiveness (IECS), Argentina. Send are lost every year as a result of tobacco use (onset of habit) occurs in men from correspondence to Ariel Bardach. E-mail: use is still too high (6). low- and middle- income countries, but [email protected] 2 Del Valle University Hospital, Del Valle In addition to its significant impact in the prevalence of tobacco use is higher in University, Cali, Colombia. terms of death and morbidity, tobacco middle- to high-income countries (8, 9). Rev Panam Salud Publica 40(4), 2016 1 Review Bardachetal.•IncomelevelsandprevalenceofsmokinginLatinAmerica According to a widely cited epidemio- income level, which was determined smoking, percentage prevalence of logical model, in the first stages of the through direct measurements (house- smoking, enrollment dates, odds ratio epidemic, tobacco use and associated hold income, minimum wage units, pov- (OR) for the relationship between in- diseases predominate in men, with lim- erty line). Job status and educational come level and smoking, monetary unit, ited use among women, regardless of the level were excluded as substitute vari- income of the smoker and family, num- type of country (10). Later on, the preva- ables. When more than two categories of ber of cigarettes per day, handling of con- lence in males declines, with a shorter income level were reported in the study, founding and adjusting variables, age delay in the onset of disease in men; an average category was selected for category, the study’s epidemiological de- women follow a similar progression, al- comparison with the highest and lowest sign type, rural or urban scenario, special beit in lower proportions. Based on this income levels. The other criterion was population groups (pregnant women, trend, higher income societies are ini- the reporting of prevalence of current to- workers), sampling type (probabilistic or tially involved, since they are more open bacco use. All definitions used by the au- non-probabilistic), education category, to adopting new habits, with low-income thors were included and subsequently ethnic group, and religion. societies following suit later on. How- categorized in a later stage. Studies on Observational epidemiological, sur- ever, since the dynamic varies by income, both the general population and specific veillance, and quasi-experimental stud- it has been recommended that the epi- groups were considered (regional groups, ies, and experimental control studies demic in developing countries be de- ethnic groups, age group, etc.). were included. The methodological qual- scribed via separate analyses of men and A systematic search was conducted in ity of the studies was evaluated using a women (11). multiple databases, including MEDLINE, tool based on the STROBE checklist (20), In recent decades, a large body of ev- EMBASE, CENTRAL, SOCINDEX, and the Cochrane Handbook for Systematic idence has described an inverse rela- LILACS. Gray literature was evaluated Reviews of Intervention (21), and two tionship between social status and through personal contact with the princi- methodological documents: Sanderson tobacco use (12-16). In these studies, pal authors, tobacco control agencies, spe- et al. (22), and Fowkes and Fulton (23). poverty and tobacco use were mea- cific Web pages, and consultations with An algorithm was prepared to estimate sured using different tools; however, the principal investigators. The strategy the risk of bias in the observational stud- income level was frequently shown to that was used can be found in the online ies. Four major criteria were considered be a factor and was clearly and closely supplementary information. (methods used to select study partici- associated with poverty. pants, methods used to measure expo- In a previous systematic review (17), a Study selection and data extraction sure and variable results, methods to strong inverse relationship was found control for confounding, and compara- between the prevalence of tobacco use The studies were selected using EROS® bility between groups), as well as two and lower income in most geographical (Early Review Organizing Software, In- minor criteria (statistical methods, ex- areas of the world, for both sexes and all stituto de Efectividad Clínica y Sanitaria cept for confounding, and conflict of in- age groups. The review considered stud- [Institute for Clinical Effectiveness and terest). Two independent reviewers ies published since 1990. Furthermore, Health Policy - IECS], Buenos Aires), a evaluated methodological quality. Any tobacco disproportionately impoverishes Web platform designed to facilitate per- disagreements were resolved by consen- the poorest households, which have the forming systematic reviews (19). sus of the entire team. Annex 1, item 2.2 highest prevalence due to the displaced Two independent investigators re- provides additional information on the consumption of basic goods, diminished viewed all of the identified studies by ti- tool used and a detailed methodological capacity to afford healthcare costs, and tle and abstract. Any disagreements were evaluation of each article included. premature deaths of breadwinners. A resolved by consensus of the review previous analysis had demonstrated that team. The full text of all articles that could Statistical analysis low-income smokers had worse results potentially be included was obtained. in terms of tobacco-related diseases and Two independent investigators evaluated For studies that only reported data on that the proportion of spending on to- the full text of the selected articles to de- prevalence, descriptive statistics were bacco was higher among low-income termine whether they met the criteria for used. For studies that reported odds ra- households, with the subsequent impact inclusion. Any disagreements were re- tios (OR) or coefficients (b), a meta-anal- on finances (16). solved by consensus of the review team. ysis was conducted to obtain a summary The principal objective of this study If the data in the included studies were measurement and the respective confi- was to evaluate the relationship between unclear or insufficient, the author was dence intervals. Only the studies that re- the prevalence of smoking and income consulted. If the matter was not resolved ported