Lower health literacy predicts smoking relapse among racially/ethnically diverse smokers with low socioeconomic status

For over 90 million U.S. adults, difficulty with health literacy (HL) interferes with the capacity to obtain, process, and understand basic health information needed to make appropriate healthcare decisions [1, 2]. Thus, HL is a conceptually-distinct construct from poor knowledge regarding smoking-related health risks. Individuals with lower HL are more likely to engage in unhealthy behaviors (e.g., unhealthy eating, poor medication adherence), and they have less access to prevention and treatment programs [3, 4]. Compared to individuals with higher HL, those with lower HL are more likely to have poor health status and health outcomes [4]. They are also more likely to be of low socioeconomic status (SES) and racial/ethnic minorities [5]. Because smoking is the leading behavioral risk factor contributing to social disparities in the incidence and mortality of disease [6–10], there is a critical need to understand how difficulty with HL might impact smoking cessation outcomes. It is possible that HL is an important, but overlooked, factor in understanding tobacco-related health disparities.

To date, little is known about the potential impact of low HL on smoking and cessation outcomes. Sudore and colleagues reported a significant relationship between lower HL and current smoking status among elderly adults [11]; however, Baker et al. found no association between lower HL and smoking status in a different sample of older adults [12]. Arnold and colleagues reported no association between HL and smoking status among low-income, pregnant women, yet found that lower HL was significantly associated with lower levels of smoking risk knowledge and fewer negative smoking-related attitudes [13]. A more recent study found that among low-SES, racially/ethnically diverse smokers, lower HL was significantly associated with certain established predictors of smoking relapse (i.e., nicotine dependence, stronger positive and weaker negative smoking outcome expectancies, less smoking health risk knowledge, and lower smoking risk perceptions), even after controlling for demographic and SES-related characteristics known to predict relapse i.e., age, gender, race/ethnicity, education, income, relationship status; [14].

These findings highlight the need for studies to investigate the association between HL and cessation outcomes, particularly among racially/ethnically diverse smokers. Smokers with lower HL are more difficult to recruit and retain in treatment studies e.g., [15]. Furthermore, smokers with lower HL who do enroll in treatment may have trouble understanding oral and written treatment materials, and may fail to tell others about these difficulties due to shame and embarrassment see [16, 17]. Research is needed to gain a better understanding of the association between HL and smoking cessation outcomes and potential mechanisms of this association. Such studies would help to inform and improve smoking prevention and cessation interventions targeting individuals with HL difficulties, and should ultimately contribute to reducing tobacco-related health disparities.

The purpose of the present study was to examine the impact of HL on smoking cessation outcomes among low-SES, racially/ethnically diverse smokers enrolled in cessation treatment. Based on prior research, it was hypothesized that lower HL would be associated with poorer cessation outcomes, even after controlling for demographic (i.e., age, gender, race/ethnicity, relationship status) and SES-related characteristics (i.e., education, income) and nicotine dependence.

To our knowledge, this is the first known investigation of the association between HL and smoking cessation outcomes among low-SES, racially/ethnically diverse smokers enrolled in cessation treatment. As hypothesized, smokers with lower HL were more likely than smokers with higher HL to relapse following cessation treatment. Importantly, this association held after adjusting for established predictors of relapse including nicotine dependence, demographics, and SES (i.e., education, income). Findings provide preliminary support for lower HL as an independent risk factor for smoking relapse among low-SES, racially/ethnically diverse smokers.

Results indicated that lower HL was associated with being Black and having lower education and income. These findings are consistent with the 2003 National Assessment of Adult Literacy [1, 30], which indicated that lower HL was associated with male gender, older age, racial/ethnic minority status, and SES-related characteristics such as lower education and income. They are also in line with results from numerous other studies [11, 14, 31–33]. It is noteworthy that lower (vs. higher) HL smokers in this study were more than three times as likely to relapse, even after controlling for the effects of established predictors of relapse. These results support prior research suggesting that HL is a crucial SES-related factor essential in understanding health disparities [4, 14, 32, 34].

In addition to being associated with a greater likelihood of smoking relapse, prior research has found that lower HL is associated with higher nicotine dependence, more positive and fewer negative expectancies about the consequences of smoking, less knowledge about smoking health risks, and lower smoking risk perceptions [13, 14]. These findings highlight the need for efforts to increase awareness about the impact of HL difficulties on smoking, and potentially other, poor health behaviors. Healthcare providers should be trained to communicate clearly with patients about the health consequences of smoking, and to offer treatments that do not require high HL. Regardless of HL level, providers should utilize plain language, visual aids (e.g., pictographs), and techniques such as the teach-back method to convey smoking health risks [33, 35]. Notably, research is needed to investigate potential mechanisms underlying the association between HL and cessation outcomes among low-SES, racially ethnically diverse smokers. Such findings could be useful in the development of cessation interventions targeting smokers with HL difficulties, and thereby help to reduce tobacco-related health disparities.

The present study has several limitations. First, the larger study required that eligible participants have at least a sixth grade reading level. This eligibility criterion resulted in a range of scores on the REALM that was skewed toward the higher end of the HL continuum, and individuals with the lowest levels of health literacy were not well represented in the study. However, it is notable that this eligibility criterion resulted in the exclusion of only six individuals screened. This phenomenon is consistent with prior research suggesting that smokers with lower HL might be more difficult to recruit and retain in treatment studies e.g., [15]. Due to the restricted range of the REALM, we were unable to use the traditional cut-off points, and dichotomized the REALM based on a median split. Notably, despite this restricted range, a significant association between HL and smoking relapse emerged. Given this restricted range, it is possible that the association between HL and smoking relapse may have been underestimated, and future studies are needed to examine this association among smokers with levels of HL that are lower than those observed in the current study. Nevertheless, it is important to note that the 95% confidence interval was relatively wide (1.15 – 9.26), suggesting that this finding should be interpreted cautiously.

An additional limitation is that long-term cessation outcome data was not collected. Future research should replicate and extend this work, and investigate longitudinal relations of HL and cessation outcomes using longer follow-up periods. Studies should also investigate associations between HL and cessation outcomes using alternate measures of HL, such as the Chew HL items [36]. In addition, such associations should be examined among smokers not enrolled in cessation treatment. Finally, as previously noted, future studies should examine potential mechanisms underlying relations between low HL and poor cessation outcomes. Gaining a better understanding of the mechanisms through which HL influences cessation will help identify treatment targets in this population, improve current cessation interventions, and ultimately reduce tobacco-related health disparities and disease burden.

This is the first study that we know of to investigate the association between HL and smoking cessation outcomes in a sample of low-SES, racially/ethnically diverse smokers enrolled in cessation treatment. Results indicated that lower HL smokers were more than three times as likely to relapse as smokers with higher HL, even after controlling for the effects of established predictors of relapse (e.g., education, income). Findings provide preliminary support for HL as an independent predictor of smoking relapse, and an important factor in understanding tobacco-related health disparities.