This analysis revealed that although having lower smoking prevalence than women in the general population, female nurses who smoke may not have an easier time quitting and one should, therefore, not assume, that these healthcare professionals do not need support in quitting. Over three quarters of the nurses who were current smokers had made a quit attempt, higher than the general female population, but less than half had made an attempt within the previous 12 months. The overall prevalence of quit attempts by nurse smokers (76.6%) was higher than previously reported. In a 27-year follow-up (1976-2003) of participants in the Nurses' Health Study, 69% of the nurse who smoked had never made a quit attempt . In the TUS-CPS sample of female smokers, the proportions of nurses and women making a quit attempt in the previous 12 months (43% and 42%, respectively) are slightly lower than the one reported for the general population, i.e., 45% . The lack of difference in recent quit efforts also was surprising given the changes in social acceptability of smoking, especially among healthcare professionals . This is substantially lower than the quit attempt rates of a motivated sample of nurse smokers (92% female) participating in web-based smoking cessation intervention where 73% had made a quit attempt in the previous 12 months .
The difference in the demographics (i.e., age, race, education, marital status, income) between nurses who smoke compared to other female smokers in the TUS-CPS sample has not been previously described. It was expected that nurses would be in the mid-range age groups, and that they would have a higher proportion of Whites and level of income as this mirrors the demographics of the profession [30, 31], and is similar to another sample of nurse smokers .
Female nurses who smoked also differed from other women in the TUS-CPS in smoking characteristics. Nurses had more years of smoking but because of the older age of this group, differences with the general female population would be expected. The categories of number of cigarettes smoked per day also were significantly different with a higher proportion of nurses in the low category (fewer than 10 cigarettes per day) and in the mid-range (11 - 20 cigarettes per day) and fewer smoking more than 20 cigarettes per day. This is similar to the 67% of nurse smokers participating in a web-based smoking cessation program who smoked less than 20 cigarettes per day [19, 32]. A trend toward fewer cigarettes also was noted in 1986 in the Nurse's Health Study, with highest number of cigarettes smoked among the cohort born in 1940-44 . There was no significant difference in the TTFC. More than half of nurses and women in the general population fall into the higher level of nicotine dependence category of smoking within 30 minutes of awakening, an indicator of addiction and of less successful quit efforts . This is similar to a previous report of nurse smokers .
Support for quitting
Nurses have acknowledged that smoking can disrupt workplace relationships and that support for quitting in the workplace would enable quit attempts [19, 33, 34]. In this sample, nurses reported significantly higher levels of worksite cessation support than other women. There were no significant differences in advice from physicians to quit with over a third of nurses and other women not receiving such advice. The proportion of those receiving advice to quit from a healthcare provider was similar to other reports of quit efforts among nurses  and among smokers in general .
In this version of the TUS-CPS there are limited questions about cessation support. We do not have information about use of medications or counseling, the evidence-based recommended strategies for improving quit rates . In a previous report of nurses' quit efforts, a minority of nurses utilized pharmacotherapy and counseling to help them quit smoking . In focus groups of current and former smokers, nurses exhibited similar misconceptions about pharmacotherapy as the general population with reluctance to "replace one addiction with another" and a preference for quitting on their own . Thus, despite being healthcare professionals, nurses who smoke may not be aware of evidence-based methods for quitting. The fact that only a small proportion of the sample ever used a telephone quitline for cessation support emphasizes the need to promote this free and effective resource more broadly. Few smokers seem to take advantage of this resource , including nurses making a quit attempt . A campaign promoting the quitline for nurses and for other female smokers might be warranted. Nurses could take advantage of this private, individualized cessation support.
Correlates of quitting
While smoking the first cigarette within 30 minutes of waking up was not a predictor for nurses making at least one quit attempt in the previous 12 months, it was a predictor for nurses making at least one quit attempt in their lifetime. Compared to other female smokers, nurses who were had lower levels of nicotine dependence (i.e., longer TTFC) were less likely to have made a quit attempt in the previous 12 months. This has not been previously reported. If nurse smokers, as compared to other female smokers, experience fewer symptoms of withdrawal and addiction, could this lead them to minimize health risks of smoking and fewer quit attempts? This clearly is an area needing further study. There are a variety of barriers to quitting reported by nurses. Some nurses who smoke have acknowledged their fear of losing work break if they quit [19, 37] and there are reports of nurses who smoke getting more work breaks . Nurses also have described difficulties in coping with withdrawal symptoms during the work shift and concerns of losing friendships of "smoking buddies"  which may be a concern for other female smokers as well.
Unlike other female professions, the negative impact of smoking on the health of nurses has been well established . The trend in decline of smoking among nurses in the past several decades mirrors changes in smoking among women. However, this study reveals some differences in quitting behaviors that are of concern and points to the need for ongoing programs encouraging nurses to make quit attempts and utilize available resources, such as the telephone quitline. Further, given that smoking among nurses remains a barrier to the provision of smoking cessation intervention to patients, all efforts should be made to promote cessation resources for nurses' own use. Evidence suggests that worksite smoking bans may encourage further quit attempts . As more and more medical campuses become smokefree, this may accelerate quit efforts of all healthcare professionals [39, 40].
When using the TUS-CPS database, there are a number of limitations that must be considered in the interpretation of these findings. Although these are weighted estimates, the sample size of nurses is relatively small. By merging data of RNs and LPNs, this may have resulted in a cohort with higher smoking prevalence and lower education than the RN population alone, but the sample of LPNs was too small to be examined separately. In a related analysis of male and female healthcare providers, LPNs had the highest smoking prevalence (20.6%) and the lowest quit ratio . Thus, we are unable to provide specific directions for either group individually. This analysis focuses on female smokers, however smoking prevalence among male healthcare providers also is a concern. Additionally, we were limited in sub-set analysis because of the sample size.
Smoking status is self-reported and not biochemically confirmed, as recommended . As described, the 2006/2007 version of the TUS-CPS is limited in the number of questions about quitting. Thus, we are unable to describe the range of resources used by women to quit and other variables which might impact their quit such as smoking among household members. No information is available on number of quit attempts although multiple attempts is common [32, 33]. This dataset does not provide information about triggers for quit attempts. Nurses have reported pregnancy, health concerns and illness among family members as incentives to quitting as well as the cost of tobacco products, smokefree work environments, and the social unacceptability of smoking . Additionally, we do not have information on body weight. Being overweight and weight gain after quitting have been suggested as barriers to quit efforts .