Journal of Consulting and Clinical Psychology 1998, Vol. 66, No 6, 1005-1011 Copyright 1998 by the Am n Psychological Association, Inc. 0022-006X/98/S3.0C Relationships Between Stages of Change in Cigarette Smokers and Healthy Lifestyle Behaviors in a Population of Young Military Personnel During Forced Smoking Abstinence Michele Clements-Thompson and Robert C. Klesges University of Memphis Prevention Center Keith Haddock University of Missouri Kansas City Harry Lando University of Minnesota Wayne Talcott Wilford Hall Medical Center This study evaluated the relationships between stages of change and related health behaviors in a population of smokers forced to quit smoking. Participants were 10,136 Air Force recruits who were in basic military training (BMT) and who were not allowed to smoke because of a ban on smoking during BMT. Participants were surveyed about their smoking history, their motivation and readiness to remain smoke free after BMT, and their behavior on 5 target health areas. Results indicated that smoking history best predicted stage of change. Though there were few gender differences, several ethnic differences emerged. These results suggest that, although stages of change involve both a cognitive and behavioral component, removing the behavioral component (smoking) through a smoking ban does not reduce the construct validity of the transtheorelical model. Although smoking has been described as the single most preventable cause of premature disease and disability in the United States, quitting smoking is extremely difficult because of its complex behavioral and addictive nature (U.S. Department of Health and Human Services, 1988). Most programs that help people quit smoking have relatively low success rates, with even intensive programs rarely achieving greater than a 30% sustained cessation (Schwartz, 1987). Participant readiness accounts for a considerable amount of the variable outcomes among smokers. Prochaska, DiClemente, Velicer, and Rossi (1993) have demonstrated that people move through several distinct stages of readiness to change when attempting to modify a behavior. This theory has been successfully applied to smoking cessation and a wide variety of other behaviors, such as beginning an exercise program (Marcus, Rakowski, & Rossi, 1992), weight-reduction efforts, and reducing high-fat diets (Prochaska Michele Clements-Thompson and Robert C. Klesges, Department of Psychology, University of Memphis Prevention Center; Keith Haddock, Department of Psychology, University of Missouri Kansas City; Harry Lando, School of Public Health, University of Minnesota; Wayne Talcott, Wilford Hall Medical Center, San Antonio, Texas. This project was supported by Grant HL-53478 from the National Heart, Lung and Blood Institute. It should be noted that the views expressed in this article are those of the authors and do not reflect the official position of United States Air Force Basic Military Training, the Department of Defense, or the United States Government. Correspondence concerning this article should be addressed to Robert C. Klesges, Department of Psychology, University of Memphis Prevention Center, 5350 Poplar Avenue, Suite 430, Memphis, Tennessee 38119. Electronic mail may be sent to bklesges@cc.memphis.edu. et al., 1994). The transtheoretical model, or stages of change model as it has become known, postulates that people progress through five distinct stages when modifying their behavior (Prochaska et al., 1994). These stages are precontemplation, contemplation, preparation, action, and maintenance. Applied to smoking cessation, the precontemplation stage is the time when a smoker is not thinking about quitting within the next 6 months. The contemplation stage is defined as the period when a smoker is seriously thinking about quitting within the next 6 months. The preparation stage is characterized by smokers who have tried to quit in the past year and are seriously thinking about quitting in the next month. During the preparation stage, smokers may also make small changes in their smoking behavior, such as switching to a lower tar cigarette or cutting back on the number of cigarettes smoked each day. Action is the stage in which smokers actually stop smoking. This period lasts from the time a person stops smoking until 6 months later, if relapse does not occur. The maintenance stage begins 6 months after a person has stopped. Each stage except for the action phase can last different lengths of time for different people. A person might remain in the precontemplation phase for many years before progressing rapidly through the contemplation phase, for example. Also, it is possible for a person to move through the stages in a cyclical pattern. This is usually due to a smoking-cessation attempt and subsequent relapse (Marcus et al., 1992). To test the validity of the transtheoretical model, DiClemente et al. (1991) gave smokers in different stages of change one of four minimal interventions, three of which were individualized to participants' stage of change. No differences were found among precontemplators, contemplators, and prepared participants on age, gender, or education. However, participants in the preparation stage were different from precontemplators and 1005
1006 CLEMENTS-THOMPSON, KLESGES, HADDOCK, LANDO, AND TALCOTT contemplators on a number of variables. Prepared participants were less addicted to nicotine (measured by the Fagerstrom Tolerance Questionnaire), smoked fewer cigarettes per day, derived less pleasure from cigarettes, and had attempted to quit smoking more than either precontemplators or contemplators. Only 1 month after participants began the intervention, differences emerged among smokers in different stages: 56% of prepared participants had made a quit attempt, but only 24% of contemplators and only 8% of precontemplators had made such an attempt. DiClemente et al. cited these data in support of the transtheoretical model applied to smoking cessation. Another study testing the applicability of the transtheoretical model to a population of male smokers was conducted by Pallonen et al. (1994). Participants were mailed stage-matched selfhelp manuals, and subsequent smoking status was monitored for 2 years. These smokers made more quit attempts and quit smoking more often than the control group, which was not mailed the manuals. Also, those who received the manuals progressed more rapidly through the stages than did the control participants. Fava, Velicer, and Prochaska (1995) measured several characteristics of smokers in different stages of change. They found a number of differences among precontemplators, contemplators, and prepared participants. Precontemplators smoked more cigarettes per day (22.0) than contemplators (20.2), who in turn smoked more than prepared participants (17.9). Precontemplators and contemplators smoked sooner after awakening (1 hr) compared with prepared participants (1.5 hr). Precontemplators and contemplators averaged fewer than two quit attempts in the past year, whereas prepared participants had made more than five quit attempts in the past year. Also, precontemplators had made fewer lifetime quit attempts (2.5) than contemplators (4.2), who had made fewer attempts than prepared participants (7.2). One final group difference was significant: age at initiation of smoking. Precontemplators began smoking earlier (16.0 years old) than either contemplators or prepared participants (both 16.7 years old). Fava et al.'s study suggests that there are small but significant differences among smokers in various stages of readiness to change, mostly in the area of previous smoking exposure. In addition to smoking, the transtheoretical model has been shown to be applicable to several other health behaviors. For example, Prochaska et al. (1994) measured stage of change and decision-making processes for 12 behaviors: smoking cessation, quitting cocaine, weight control, intake of high-fat foods, adolescent delinquent behaviors, safer sex, condom use, sunscreen use, radon gas exposure, exercise acquisition, mammography screening, and physicians' preventive practices with smokers. Each participant was measured on only 1 problem behavior. Participants were asked to report the pros and cons of changing the target behavior. Results showed that for a participant to take action to change a behavior, the pros had to outweigh the cons, and participants who were in the precontemplation stage reported that the cons outweighed the pros. In 7 of the 12 behaviors, the critical point at which the pros outweighed the cons of changing the target behavior occurred during the contemplation stage. Although the transtheoretical model has been validated and widely disseminated in smoking, as well as other health behaviors, additional work on the model remains. For example, little is known about the generalizability of the model in special populations; as to date, sample sizes of previous studies have not allowed comparisons, such as between men and women or among ethnic minorities. However, groups of individuals who are experiencing enforced cessation under social controls (e.g., protracted hospital stay, smoke-free jails, and, in this case, basic military training [BMT]) are of strong theoretical and empirical interest. It is becoming increasingly common to see short- and long-term bans on smoking behavior. The transtheoretical model has both cognitive and behavioral components. In terms of the cognitive component, it has been demonstrated that as people report increasing cons of smoking, the probability that they are in more advanced stages increases dramatically (Prochaska et al., 1994). Stated intentions to quit smoking, for example, are a critical component of the model (Prochaska et al., 1994). Smoking behavior, such as smoking cessation attempts in the past and current and past smoking behavior, contributes to the operational definition of which stage one is in (Prochaska et al., 1994). For example, being in the action stage is defined as exhibiting the behavior of smoking cessation, and the contemplation stage is defined as the period when a smoker is seriously thinking about quitting within the next 6 months (Prochaska et al., 1994). However, involuntary cessation "uncouples" the behavioral and cognitive components of the transtheoretical model. That is, all participants are behaviorally in the action stage, because of social controls, but only some are cognitively in the action stage by their own intentions to stay quit once social sanctions are removed. How people who differ in their cognitive readiness to quit smoking react to such enforced cessation (using it as a chance to stay quit vs. intending to return to smoking) is currently unknown; it will not only test the stability of the transtheoretical model in the increasingly common situation of enforced cessation, but it will also guide intervention efforts that could be used as adjuncts to these more policy-oriented bans on smoking. Thus, the purpose of the present investigation was to determine the relationship between cognitive stages of change and related health behaviors to determine the applicability and construct validity of the model under conditions in which smoking behavior is constant (i.e., all smokers are forced to quit) but cognitive readiness varies. Consistent with previous studies in which both the cognitive and behavioral components vary (DiClemente et al., 1991), support for the construct validity of cognitive readiness would be present, for example, if those planning to quit were less addicted to nicotine, smoked fewer cigarettes per day, and had a more active history at attempting cessation compared with those not planning to quit. A secondary aim was to assess the generalizability of the transtheoretical model in diverse populations, namely to evaluate possible gender and ethnic differences in the relationships between readiness and related health behaviors. Method Overview of Parent Grant, Hypotheses, and Design We conducted the study using Air Force recruits who were smokers but who were smoke free at the time of the evaluation because of the Air Force's ban on smoking during BMT, which is 6 weeks in duration. Participants were surveyed about their smoking history and their atti-
STAGES OF CHANGE IN CIGARETTE SMOKERS 1007 tudes and behaviors regarding a number of different health-related topics. Participants were subsequently randomized to receive either the standard stop-smoking program (which is primarily 6 weeks of forced cessation) or an experimental intervention aimed at relapse prevention. All participants were involuntarily in the action phase of smoking cessation and did not progress through a normal sequence of events to become nonsmokers of their own choice. In this unique situation, some participants were more similar to a traditional smoker in the precontemplation phase, whereas others were ready and motivated to stop smoking and more closely resembled a traditional ex-smoker in the action phase. Of this population, 10,142 were smokers until BMT began. We conducted the investigation using data collected during "A Populationwide Smoking Cessation/Prevention Program," a longitudinal study currently being conducted by the University of Memphis, the University of Minnesota, and the United States Air Force. All recruits who entered the Air Force during a 1-year period (August 1995-August 1996) were included in the study. During this period, 32,144 entered BMT, and the present study has complete baseline data on all 32,144. Quality control for the survey was excellent, with fewer than 10 missing data points in the entire data set Instrument A 53-item questionnaire containing five sections was administered to all recruits. The first section contained questions about demographics, including gender, height, weight, ethnic background, marital status, and socioeconomic status. The next section questioned the participant's history of smoking and tobacco use. The third section was completed only by participants who regularly smoked cigarettes (at least one per day) before entering BMT. This section, which contained 17 questions, yielded information that made it possible to determine the extent to which participants were addicted to cigarettes and how heavy a smoker they were before BMT. The Fagerstrom Test for Nicotine Dependence (FTND) is embedded in this section of the measure (Heatherton, Kozlowski, Frecker, & Fagerstrom, 1991). Scores on the FTND range from 0 to 10, with higher scores indicating higher nicotine dependence. The internal consistency of the FTND is.61 (Heatherton et a!., 1991). Despite its modest internal consistency, the FTND is a valid measure of heaviness of smoking as assessed by biochemical markers (Heatherton et al., 1991). Participants were asked about previous quit attempts, whether they planned to start smoking again after BMT, and how confident they were that they would be able to remain nonsmokers permanently. The fourth section was completed by all participants and assessed attitudes about smoking in the Air Force (e.g., whether they agree or disagree that smoking should be prohibited on base). The final section contains questions about other health-related behaviors, such as physical activity, alcohol intake, and risky behaviors. Participants were also asked about their intake of high-fat foods and fruits and vegetables, and their attitudes about illegal drug use and unsafe sex were measured. These latter topics could only be addressed in terms of attitudes, not actual behavior, because endorsements of these items would be grounds for potential dismissal if the Air Force records were ever retained. The particular circumstances of this study required some unique adaptations of the stages of change protocol. This study provides the unique opportunity to independently study the cognitive component of the transtheoretical model, given that social sanctions mandated that all participants be smoke free. By Prochaska's definition (Prochaska et al., 1993), all participants would be behaviorally classified in the action phase but would be cognitively varied in their readiness to maintain their abstinence after the social sanctions were lifted. Therefore, in this unique setting, we assessed cognitive readiness using their responses to the following question: "Once you get out of basic military training, which of these best describes you (a) I plan on staying quit, (b) I am thinking about staying quit, or (c) I do not plan to stay quit?" Participants were classified as cognitively in the action stage if they indicated the first response, in the cognitive contemplation stage if they indicated the second response, and in the cognitive precontemplation stage if they indicated the third response. Approach to Analysis When constructing logistic models that predict membership among levels of a categorical variable, one uses k 1 comparisons, where k is the number of levels of the categorical variable, with one of the levels serving as the reference category (Hosmer & Lemeshow, 1989). Thus, we chose the precontemplation stage as the reference category and developed two logistic models, one comparing individuals in the contemplation stage and the other comparing those in the action stage with those in the precontemplation stage. Note that we could not, by widely accepted statistical constraints, also compare smokers in the contemplation stage with those in the action stage. For both models, all of the variables were simultaneously entered into the model and were used in the interpretation of the data. Because the transtheoretical model has never been tested with smokers forced to quit smoking, several strategies were used to guard against chance findings. First, only partial odds ratios (ORs) were computed, which were adjusted for the effects of other predictors in the model. Second, stringent confidence intervals were created (i.e., 99% confidence intervals), which lowers the likelihood of Type I statistical errors. Third, only subanalyses in which sufficient sample sizes existed were conducted. For instance, although comparing Native American smokers with smokers in other ethnic groups would provide a theoretically interesting contrast, the small number of Native Americans (i.e., 1% of the population) prevented the computation of reliable ORs. Finally, given the unusually large population of smokers studied, in addition to stringent statistical significance criteria, a minimal magnitude difference in OR criteria was established for the interpretation of subgroup analyses. We a priori established a 10% difference in likelihood of category membership (i.e., ORi OR 2 ^ 0.10) as the minimal, meaningful difference between ORs. Sample Characteristics Results As indicated above, although the total sample size was 32,144, only 10,136 were smokers in the year before BMT. Those in the action group (n = 3,966) indicated an intention to remain nonsmokers after BMT. Those in the precontemplation group (n = 1,508) stated a likelihood to resume smoking after BMT Finally, those in the contemplation group (n = 4,662) indicated that they were thinking about continuing cessation following BMT. The demographic characteristics of the smokers were as follows: 83% were Euro-American, 5% were African American, 6% were Hispanic, and 6% were other. The other ethnic category consisted of Asian Americans, Native Americans, and individuals who did not feel that any of the standard ethnic categories represented their ethnic background. Individuals in the other ethnic category were aggregated because of the very small sample size of each of these ethnic categories. Men accounted for 76% of the participants. Most (86%) of the participants were single; 12% were married; and the remaining were separated, divorced, or widowed. All participants had a high school diploma; some had attended college (34%), although only 3% had completed either a 2- or 4-year degree; and less than 1% had attended graduate school or had earned an advanced degree. Considerable variability in family income existed among the
1008 CLEMENTS-THOMPSON, KLESGES, HADDOCK, LANDO, AND TALCOTT participants: 22% of the sample reported an annual family income of less than $20,000, 49% between $21,000 and $50,000, 21% between $51,000 and $80,000, and 8% above $81,000. Predictors of Stage of Change for Continued Smoking Abstinence: Main Effects For both logistic models, predictor variables were grouped into four categories: demographic, health-related behaviors, alcohol use, and smoking history. Table 1 indicates the main effects of each variable entered into each model. The reported ORs represent the increased probability that a participant will fall into a particular category of the dependent variable on the basis of his or her score on the relevant independent variable. In these analyses, an OR below indicates that a participant is more likely to be in the precontemplation stage, whereas an OR above indicates that a participant is more likely to be in the comparison stage (i.e., contemplation or action). Among the demographic variables, Euro-Americans were more likely to be in the precontemplation stage than either the contemplation stage or the action stage. That is, smokers from an ethnic minority background were more ready to continue smoking cessation than their counterparts. Furthermore, married smokers were 51 % more likely to be in the action stage than in the precontemplation stage, whereas women were 26% more likely to be in the contemplation stage than in the precontemplation stage. Among measures of health-related behaviors and alcohol use, only the intake of high-fat foods and risk-taking behavior was related to readiness to continue smoking cessation. For each unit increase in the intake of high-fat foods, smokers were 11 % more likely to be in the precontemplation stage than in the contemplation stage and 16% more likely to be in the precontemplation stage than in the action stage. Similarly, smokers who rated themselves higher on risk-taking behaviors were 16% more likely to be in the precontemplation stage than in the contemplation stage and 29% more likely to be in the precontemplation stage than in the action stage. The most consistent predictors of stage of change were smoking related. For each unit increase on the FTND, smokers were 11 % more likely to be in the precontemplation stage than in the contemplation stage and 19% more likely to be in the precontemplation stage than in the action stage. As a smoker's rating of the percentage of their friends who smoke increased, they were 20% more likely to be in the precontemplation stage relative to smokers in the action stage and 10% more likely to be in the precontemplation stage relative to smokers in the contemplation stage. Similarly, as smokers' ratings of the percentage of Air Force personnel who smoked increased, they were 10% more likely to be in the precontemplation stage than in the contemplation stage and 20% more likely to be in the precontemplation stage than in the action stage. Not surprisingly, indicators that smokers were ready to quit smoking were strongly related to their stage of change. Smokers Table 1 Smokers in Precontemplation Stage Versus Smokers in Contemplation and Action Stages: Main Effects («Pvs. C = 6,170) Pvs. A (, i = 5,472) Variable OR 99% CI OR 99% CI Demographic Marital status (single = 0, married = 1) Ethnic background (Euro- American - 0, minority 1) Gender (male = 0, female = 1) Income Education Health related Intake of high-fat foods Intake of fruits and vegetables Physical activity Risk-taking behavior Seat belt use Alcohol use Alcohol intake (/) 2:8 alcoholic drinks/day (/} Smoking history Nicotine dependence % Air Force participant believes smokes % friends who smoke Successfully quit for s24 hr (no = 0, yes = 1) Switched to low-tar cigarette (no = 0, yes 1) 1.26 1.01 1.71 1.74-1.37 0.63-0.97-1.54-1.13-1.19 - -1.07 - - -1.05 - - 0.86-0.92 0.73- -0.99 1.44-2.03 1.44-2.11 1.51 0.71 0.99 0.71 0.98 2.58 1.76 1.13-2.03 0.56-0.74-1.18-1.10-1.32 0.79-0.97-1.10 0.87-0.65-0.77 0.86-1.05 0.79-0.86-1.11-0.69-0.92 0.72-2.13-3.13 1.43-2.17 Note. Bolded odds ratios indicate a statistically significant difference (p <.01) from (i.e., no association). Odds ratios that are less than indicate that a participant was more likely to be in the precontemplation stage. Odds ratios greater than indicate that a participant was more likely to be in the comparative stage (i.e., contemplation or action). P = precontemplation stage; C = contemplation stage; A = action stage; OR = odds ratio; CI = confidence interval.
STAGES OF CHANGE IN CIGARETTE SMOKERS 1009 who had successfully quit smoking for 24 hr or more in the year before BMT were 1.7 times as likely to be in the contemplation stage than in the precontemplation stage and nearly 2.6 times as likely to be in the action stage than in the precontemplation stage. Furthermore, smokers who had switched to a low-tar cigarette to improve their health were 1.7 times as likely to be in the contemplation stage than in the precontemplation stage and almost 1.8 times as likely lo be in the action stage compared with the precontemplation stage. Moderating Effects of Gender and Stage of Change for Continued Smoking Abstinence One theoretically important analysis was to examine whether gender moderated the association between the predictor variables and stage of change. Table 2 displays all variables and the ORs for men and women on each. In the logistic model contrasting the precontemplation stage with the contemplation stage, gender did not significantly moderate the effect of any of the 16 predictors. Furthermore, only 3 of the 16 (i.e., 19%) potential predictors of stage of change were moderated by gender in the model contrasting the precontemplation stage with the action stage. Two demographic factors (i.e., marital status and ethnic background) and one indicator of readiness to quit smoking (i.e., successful past quit attempt) differently predicted the precontemplation versus action stage of change, all in terms of the magnitude of the effect rather than direction. Specifically, marital status and ethnic background had stronger associations with stage of change for women than for men. For past successful quit attempts, however, the association with stage of change was stronger for men than for women. Moderating Effects of Ethnicity and Stage of Change for Continued Smoking Abstinence We also examined the moderating impact of ethnic background on the predictor variables. African American, Euro- American, and Hispanic participants were tested separately to determine differences between predictor variables for each group. These categories were chosen both because they corresponded to ethnicity classifications used by the federal government and because each resulted in a group with a sufficient sample size. Other ethnic groups (e.g., Asian American and Native American) and smaller subclassifications of ethnicity were not evaluated because the resultant sample size was too small to make meaningful comparisons. In contrast to gender, ethnicity significantly moderated the association between several of the predictor variables and stage of change (31% for the precontemplation stage vs. the contemplation stage; 44% for the precontemplation stage vs. the action stage). Table 3 lists all variables and ORs for the three ethnic groups. For the model contrasting the precontemplation and contemplation stages, none of the 16 potential predictors met the stringent statistical significant criteria for African Americans (likely because of significant variability among scores). For Hispanics, only the intake of high-fat foods was a significant predictor in terms of statistical significant and difference in magnitude from other ethnic groups. In contrast, five factors met both statistical significant and magnitude difference criteria for Euro-Americans, including gender, intake of high-fat foods, percentage of the Air Force the individuals believed smoked, successful past quit attempt, and switching to a low-tar cigarette. Thus, ethnicity appears to play an important role in the ability to discriminate Table 2 Smokers in Precontemplation Stage Versus Smokers in Contemplation and Action Stages: Main Effects P vs. C P vs. A Variable OR for men (n = 4,668) OR for women (ra = 1,502) OR for men (n = 4,255) OR for women (n = 1,217) Demographic Marital status (single = 0, married - 1) Ethnic background (Euro- American = 0, minority = 1 ) Income Education Health related Intake of high-fat foods Intake of fruits and vegetables Physical activity Risk-taking behavior Seat belt use Alcohol use Alcohol intake <J~) ==8 alcoholic drinks/day (/) Smoking history Nicotine dependence % Air Force participant believes smokes % friends who smoke Successfully quit for a24 hr (no = 0, yes = 1) Switched to low-tar cigarette (no = 0, yes = 1) 1.07 1.06 0.85 1.74 1.72 0.67 1.11 1.06 0.97 0.92 1.66 1.79 1.43 0.74 0,97 1.13 1.01 0.70 0.79 2.80 1.76 1.85" 0.60" 1.11 1.10 0.85 0.72 1.93" 1.82 Note. Bolded odds ratios indicate a statistically significant difference (p <.01) from. P = precontemplation stage; C = contemplation stage; A = action stage; OR = odds ratio. " Indicates a difference from the corresponding odds ratio for men by 0.10 or more.
1010 CLEMENTS-THOMPSON, KLESGES, HADDOCK, LANDO, AND TALCOTT Table 3 Smokers in Action Stage Versus Contemptators and Precontemplators: Ethnicity Effects Precontemplation vs. contemplation Precontemplation vs. action Variable OR for OR for OR for OR for OR for OR for Euro-Americans African Americans Hispanics Euro-Americans African Americans Hispanics (n = 5,136) (n = 291) (n = 359) (n = 4,448) (n = 272) (n = 357) Demographic Marital status (single = 0, married ^= 1) Gender (male = 0, female = 1) Income Education Health related Intake of high-fat foods Intake of fruits and vegetables Physical activity Risk-taking behavior Seat belt use Alcohol use Alcohol intake if) ^& alcoholic drinks/day (/) Smoking history Nicotine dependence % Ah" Force participant believes smoke % friends who smoke Smoking behaviors indicating action Successfully quit for ^24 hr Switched to low-tar cigarette 1.32 0.85 1.74 1.82 1.37 0.87 1.30 0.77 1.09 0.68 1.07 0.86 1.33 1.31 n.42 1.05' 1.13 0.76' 0.83 0.71' 1.04 0.97 0.72' 1.83 1.50' 1.49 0.99 0.97 1.09 0.72 0.99 2.57 1.85 2.34 0.74 1.05 1.69 1.17 0.58 0.86 0.72 1.16 2.07 1.82 0.74 1.48 1.01 0.69" 1.15 0.60" 0.61 0.73 0.92 5.51" 1.38' Note. Bolded odds ratios indicate a statistically significant difference (p <.01) from. OR - odds ratio. " Indicates a difference in odds ratios by 0.10 or more among the ethnic categories. smokers in the precontemplation stage versus smokers in the contemplation stage. For the model contrasting the precontemplation and action stages, a similar pattern emerged. Seven of the 16 (i.e., 44%) potential predictors met both statistical and magnitude criteria for Euro-Americans, whereas only 1 factor (i.e., risk-taking behavior) met both statistical significance and magnitude difference criteria for African Americans. Three of the 16 predictors met both statistical and magnitude criteria for Hispanics. Consistent with the other analyses, however, the strongest and most consistent predictor of different stages were smoking behaviors, at least among Euro-Americans. Successfully quitting for 24 hr or more was a strong predictor for Euro-Americans and particularly predictive for Hispanics in predicting the contemplation stage versus the action stage (OR = 5.51). Although not significant, the ORs were in the predicted direction for African Americans as well. Switching to a low-tar cigarette was a strong predictor of higher commitment to quit among Euro-Americans; however, it was not related to increased readiness to quit among either Hispanics or African Americans. Discussion The primary aim of the present investigation was to examine the relationship between the transtheoretical model and healthrelated behaviors in a population of smokers who were forced to quit smoking (behaviorally in the Action stage) but who varied cognitively in their readiness to remain quit. The results indicated that the cognitive variability of readiness is quite consistent with results in the general population where smokers varied in both their cognitive and behavioral readiness to quit smoking. Consistent with Unger (1996), smokers more cognitively ready to maintain abstinence were also likely to be engaged in other health promoting behaviors, including consumption of low-fat foods and self-reports of risk taking. However, also consistent with several investigations, smoking history tends to reliably predict stage of change (DiClemente et al., 1991; Fava et al., 1995). A secondary aim of the study was to evaluate the consistency of the transtheoretical model in heterogeneous populations, namely, those with potential gender and ethnic differences. Consistent with the findings of DiClemente et al. (1991), few gender differences emerged. However, rather strong ethnic differences were observed, including marked differences in cognitive readiness to quit smoking, with ethnic minorities much more likely to be cognitively in the action stage or committed to quit following the lifting of the smoking ban. Several demographic variables predicted cognitive readiness to stay quit. Although marital status did not predict those in the cognitive precontemplation stage versus those in the contemplation stage, it was a strong predictor of those in the action stage versus those in the precontemplation stage, with married participants 51 % more likely to be in the action stage. Gender predicted those in the precontemplation stage versus those in the contemplation stage (women were more likely to be in the contemplation stage) but did not predict those in the precontemplation stage versus those in the action stage. Although some healthrelated behaviors were related to cognitive readiness, the most consistent set of predictors of cognitive readiness was smoking-
STAGES OF CHANGE IN CIGARETTE SMOKERS 1011 history variables. All five smoking-history variables namely, nicotine dependence, perception of the percentage of Air Force personnel that smoke, number of peers who smoke, whether or not they had a history of a smoking cessation attempt of at least 24 hr, and whether or not they had switched to a low-tar or low-nicotine cigarette for health reasons were all consistent predictors of both those in the precontemplation stage versus those in the contemplation stage and those in the precontemplation stage versus those in the action stage. These findings with cognitive staging are consistent with the existing literature on the characteristics of smokers that are both cognitively and behaviorally staged (e.g., DiClemente et al., 1991). Thus, there is evidence that the transtheoretical model generalizes to settings in which social sanctions prohibit smoking. Also consistent with the extant literature (e.g., DiClemente et al., 1991), the present study suggests minimal differences in the predictors of stage of change as a function of gender. Although women were more likely to be in the contemplation stage versus the precontemplation stage, they were no more likely to be in the action stage versus the contemplation stage. Consistent with the overall findings, the factors most related to stage in both men and women were smoking-history variables. This, at least, suggests that the transtheoretical model is equally applicable to both men and women. However, future studies should obtain samples more representative of the general population before this can be concluded with a high degree of certainty. Although minimal differences were noted between men and women, the pattern of results suggests marked ethnic differences in terms of cognitive stages of change. In terms of ethnicity and overall stage, minorities were much more likely to be in a higher stage of change. Specifically, minorities were 22% more likely to be in the contemplation stage compared with the precontemplation stage and 29% more likely to be in the action stage compared with the precontemplation stage. Indeed, preliminary analyses of the longitudinal outcome data suggest that minorities in this population are much more likely to be quit at a 1 year follow-up in general and much more likely to benefit from a smoking-cessation intervention than are nonminorities (Klesges et al., 1998). In terms of predictors of stage of change, the results with Euro-Americans were consistent with the overall findings: Several predictors of stage of change were observed, with the most consistent predictor being smoking history. In contrast, there were few predictors in general and even the smoking-history variables were only sporadically related to stage among minorities in general and African Americans in particular. The exception to this was being successfully quit for 24 hr in predicting Hispanics to be in the action stage, wherein those with this history were over 5.5 times more likely to be in the action stage relative to the precontemplation stage. In contrast, there was no relationship between smoking history and stages of change in African Americans. Whether this lack of relationship means that the transtheoretical model has a different meaning for African Americans hi general or whether the findings are specific to those forced involuntarily to quit is unclear and should be the focus of future research. References DiClemente, C. C., Prochaska, J. O., Fairhurst, S. K., Velicer, W. F, Velasquez, M. M., & Rossi, J. S. (1991). 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