Our results demonstrate that the cessation rate among women in WIHS was lower than in US population-based studies. Non-Hispanic Blacks, users of crack, cocaine, or heroin, women with less education, and women smoking more cigarettes on a daily basis were less likely to quit smoking. There were similar rates of sustained smoking cessation among HIV-infected and at-risk HIV-uninfected women.
We used 12 months of tobacco cessation as our primary outcome; this duration of cessation has been recommended as a stringent criterion approximating lifelong abstinence.25
This recommendation is based upon data from the California Tobacco Survey. Former smokers identified at a baseline interview were re-interviewed after 18 months. Those who reported duration of cessation at the baseline interview of at least 12 months and as long as more than 10 years had a likelihood of 98% for the subsequent status of cessation (95% continuous and 3% with relapse and subsequent quit), while cessation less than 12 months had a likelihood of 66% for the subsequent status of cessation (42% continuous cessation and 24% with relapse and subsequent quit).26
While smoking prevalence is regularly tracked,19
population-based cessation is infrequently reported. There are two recent publications describing US population-based cessation rates. Messer20
analyzed four waves of the Tobacco Use Supplement of the Current Population Survey between 1992 and 2002. The analysis, restricted to non-Hispanic Whites aged 20 to 64 years, reported 12-month sustained cessation. The average annual cessation rate was 3.4%. Overall there was increasing cessation during the 1990s with the most pronounced acceleration among young smokers. The cessation rates in California, New York, and New Jersey were higher (3.6 to 4.7% per year) compared to the tobacco growing states (Kentucky, Tennessee, North Carolina, South Carolina, Virginia, and Georgia) (2.8 to 4.2% per year). Gender-specific rates were not reported. The rates of cessation in the WIHS cohort, applying a similar definition of sustained cessation during this largely overlapping time period, were lower overall (1.8%) for non-Hispanic Whites (2.1%), and for the California and New York centers (1.6 to 2.7%).
In a second study, Messer21
reported 6-month sustained cessation rates in the 2003 Current Population Survey. This analysis of 18 to 64 year olds included all race and ethnic groups. It reported cessation by age, with rates of 8.5%, 7.0%, 5.0%, and 5.1% for the age groups of 18–24, 25–34, 35–49, and 50–64, respectively. Women (1.16), African Americans (0.63), and Hispanics (0.86) had non-significant adjusted odds ratios of cessation. In WIHS, the rate of 6-month sustained cessation was lower at 2.2%.
While several predictors of cessation were identified in this study, cessation rates were low even among those identified as likely to quit, including Hispanic women (2.4%), women with more than high school education (2.3%), and those without crack, cocaine, or heroin use (2.9%). In our study, HIV status did not predict cessation, likely due to the similar socio-demographic characteristics of the HIV-infected and HIV-uninfected women in WIHS. It appeared that the rate of initiation of the sustained cessation among HIV-infected women was not different during the pre-HAART and early HAART eras. Having a usual source of medical care did not predict cessation.
The low rates of sustained cessation add support to calls for increased attention to smoking cessation services in medical care settings for women with HIV and at risk for HIV.1,2,6
For this service development, we should consider how gender, race/ethnicity, and social class influence smoking cessation,27–29
including knowledge of cessation benefits,24
social and environmental support for cessation,30
and awareness of and access to integrated counseling and pharmacotherapy.31,32
In addition, we believe that the clinical implication of drug use warrants consideration as a predictor of poor cessation outcomes. Histories of substance use are common among individuals who smoke and are HIV-infected or at risk (in this study there were 84% with current or former illicit drug use). There is an emerging consensus that smoking cessation programs for individuals in substance use treatment or recovery are effective and may enhance substance use treatment.33,34
However, there are limitations to the research studying tobacco cessation and substance use. Published studies of smoking cessation and substance use outcomes are set in treatment programs for dependence disorders. The studies of smokers with remote substance use are limited to recovering alcoholics. We are unaware of smoking cessation outcomes research studying individuals with a variety of substances used and with current and/or prior dependent and non-dependent use of substances to guide primary care of smoking cessation.
Furthermore, our analyses suggest that public health strategies, such as the California Tobacco Control Program, started in 1989 and focusing on changing population-wide social norms, knowledge, and public policy,35
may not have penetrated this demographic of women, as we did not find differences in cessation based upon the participants’ state of residence. It may be important to determine how social marketing strategies may alter smoking acceptability among those with HIV risk. As we come to understand the importance of social networks on cessation,36
it is plausible that women who are HIV-infected or at risk are not part of social networks in which family members, friends, or co-workers have quit smoking.30
There are limitations to our findings. There were demographic and smoking-related differences between those with and without follow-up data, limiting the generalizability of the findings. The loss of follow-up is mostly due to the large number of women who had only a baseline study interview and secondarily due to women who died during the 10 years of follow-up. We had complete data on 89% of 841 surviving women with any follow-up data. Given that WHIS enrollees who were not included in this study were heavier and longer duration smokers, we believe that it is unlikely that women lost to follow-up had higher rates of sustained smoking cessation. Their loss to follow-up should not detract from our conclusion that HIV-infected and at-risk women have lower cessation rates than the US population. A second limitation of the study is that we used only baseline data as predictors of cessation. It is conceivable that there were time varying effects of variables that influenced cessation not captured by this analysis. We used only the year-10 cessation as the outcome variable. There may have been some women who quit smoking for more than 12 months and subsequently relapsed who were classified in the group that did not achieve sustained cessation.
While we assessed having a usual source of medical care as a predictor of cessation and the WIHS study centers advised and encouraged cessation and referred all participants to primary care providers, in this analysis, we are unable to determine if medical care remained stable over time or if utilization affected cessation. This analysis covers the period of time immediately before and during the dissemination of HAART therapy. It is conceivable that simpler, contemporary HAART regimens may have changed the dynamic of smoking cessation among HIV-infected women in ways that we were unable to measure. Finally, there may be unmeasured mediators of cessation.31
The care of women with HIV and at risk for HIV is complex, with numerous medical, behavioral, and psychosocial dimensions related to their needs for substance use treatment, safe sex practices, stable housing, depression treatment, and medication adherence. It is possible that the low cessation rates reflect this difficult and competing set of needs for patients and their providers. While sustained cessation is lower among the women in WIHS than the general population, we do not know if they made fewer cessation attempts and if their cessation efforts were more likely to result in relapse. Future analyses using time varying longitudinal techniques, extending the analyses beyond the first 10 years of WIHS, and that assess short-term cessation and relapse are likely to help us understand the chain of events with respect to cessation in WIHS and define barriers to initiating and maintaining cessation.
Forty years after the first Surgeon General’s report on smoking and health,37
there has been a multi-faceted anti-smoking campaign throughout the United States. We have witnessed the dissemination of clinical interventions, medications, and public health policies and programs that aid cessation. Among adult women, the rate of smoking declined from 34% in 196438
to 17% in 2007.19
However, for women with and at high risk for HIV infection, the current rates of smoking dwarf those of US women in the 1960s, the smoking-related risk are increased in the presence of HIV, and the rate of cessation among HIV-infected and at-risk women is well below that of the population at large. To avert predictable smoking-related morbidity and mortality, it is imperative that we intensify efforts to help these high-risk women quit smoking.