The FTND showed impressive validity relative to other assessment instruments in terms of its ability to predict quitting success amongst a large sample of individuals enrolled in several smoking cessation trials that were conducted in different cities and involved different cessation treatments. While other nicotine dependence scales also predicted quitting success, the FTND showed the largest effect sizes of any single instrument. Moreover, the FTND yielded accurate predictions in both individuals receiving active pharmacotherapy and those receiving placebo (although some pharmacotherapies may moderate the predictive relation, cf.
Fagerstrom & Schneider, 1989;
Shiffman & Paton, 1999). Further analyses revealed that the first item (TTFC) showed the strongest predictive relations with quitting success both early (1 week) and late (6 months) in the follow-up period. This relation was also apparent in large nationally representative samples gathered in four countries.
Survival analyses showed that response to FTND TTFC predicted not only time to relapse, but also the latency from the quit-day for individuals to try a first cigarette (lapse latency) and the latency between a lapse and ultimate relapse (lapse-relapse latency). In general, responses showed linearity between latency to smoke in the morning and the lapse, relapse, and lapse-relapse latencies. Increases across each response category (smoking within 5 minutes, 6-30 minutes, 31-60 minutes, and after 60 minutes) tended to be associated with meaningful increases in lapse and relapse latencies. These data show that FTND TTFC reflects both a vulnerability to sample an initial cigarette and also to resume frequent use. This suggests that FTND TTFC response is associated with a vulnerability that manifests across the relapse process (cf.
Shiffman et al., 1996,
1997). Thus, its validity cannot be attributed to a phase-specific element in the relapse process (e.g., discouragement or loss of self-efficacy after a lapse; see
Gwaltney, Shiffman, Balabanis & Paty, 2005).
One important finding is that the FTND shared predictive validity with an item that elicited information about home smoking policy. Specifically, if an individual is not allowed to smoke in the house s/he is less likely to be smoking at follow-up. It appears that some of the predictive validity of FTND TTFC might be attributed to the fact that restrictive smoking policies may both discourage smoking early in the morning and encourage long-term abstinence. However, even with this smoking policy item in a prediction model, FTND TTFC still retained considerable predictive validity, indicating that the relation between FTND TTFC and quitting success is not merely an artifact of home smoking policy.
Concurrent validation analyses revealed that FTND TTFC was correlated fairly strongly with only two WISDM subscales (i.e., Tolerance and Automaticity), subscales that assess smoking without awareness and smoking heavily. FTND TTFC was
not associated strongly with other smoking motives tapped by the WISDM. Consistent with this pattern of associations, FTND TTFC response was significantly related to self-reported cigarettes smoked per day and CO level, but was not strongly related to magnitude of the withdrawal syndrome. The lack of association with withdrawal raises doubts about the original interpretation of the FTQ, which focused on withdrawal produced by overnight deprivation (
Fagerström, 1978).
FTND TTFC accounted for significant predictive validity in other variables that provide further insight. For instance, FTND TTFC response accounted statistically for the predictive validities of the following variables: education, age of first smoking, WISDM-Automaticity, WISDM-Tolerance, NDSS-Stereotypy, and baseline CO level. It is difficult to explain its association with education and age. However, its relations with the other variables suggest that the reason that FTND TTFC predicts relapse is that it taps a construct that produces a pattern of heavy, frequent smoking that generalizes across time and place (see
Lessov et al., 2004). This is suggested by items such as the NDSS-Stereotypy Item, “I smoke consistently throughout the day,” and the WISDM-Tolerance Item, “I can only go a couple of hours between cigarettes.” FTND TTFC also accounted for the predictive validity of the WISDM-Automaticity scale. This scale assesses the extent to which smoking occurs without awareness or cognitive control (Curtin et al., 2006; Tiffany, 1991). Thus, even among a group of relatively heavy smokers seeking formal cessation treatment, smokers differed in the extent to which they saw their smoking as occurring outside awareness; the extent to which they did so predicted their likelihood of relapse, and FTND TTFC accounted for this relation statistically.
FTND TTFC did not account for the predictive validities of other types of variables. For instance, it did not account for the relations of stress and social support with outcome. This suggests that such items that tap an individual's psychosocial “context” may constitute somewhat independent contributions to relapse risk.
It is important to note that the validity of FTND TTFC may be due, in part, to the fact that it asks about a tangible, specific dimension of smoking that has a similar meaning across individuals (i.e., time). Smokers are asked to report a specific time at which they smoke their first cigarette in the morning. This sort of response option may be less susceptible to response style biases than are other type of options (such as rating “need” or “desire” to smoke in the morning) where thresholds for response options may differ markedly from one person to another.
In terms of theoretical significance, this research suggests that tobacco/smoking dependence, at least as manifested by relapse vulnerability, is related to a pattern of pervasive smoking, one that occurs throughout the day and that does not seem dependent upon an
awareness of interoceptive or exteroceptive cueing. This is not to say that these individuals would not respond to smoking cues in the environment, but rather that their smoking is less contingent upon such cues. In fact, for these smokers cues may be so ubiquitous that their smoking may appear independent of any delimited set of cues. It is also possible that for these individuals control over smoking has shifted to internal cues of which they are unaware (
Baker et al., 2004; Curtin et al., 2006).
Supporting evidence, as noted above, is the content of the questionnaires with which early morning smoking was associated (e.g., the WISDM-Automaticity and the NDSS-Priority subscales). In addition, it is noteworthy that early morning smoking was not highly related to subscales such as the WISDM-Cue Exposure/Associative Processes or the WISDM-Social Environmental Goads subscales – subscales that target smoking in response to environmental cues. In addition, such smoking was not strongly related to scales designed to reflect awareness of smoking in response to internal cues such as distress cues (e.g., WISDM-Negative Reinforcement). Findings by
Lessov et al., (2004) are congruent with this conclusion. In the context of biometric twin research, these investigators found that FTND TTFC loaded most heavily on a factor that seemed to reflect sheer volume of smoking; it did not load on a factor that included withdrawal magnitude, consciously perceived quitting difficulty, or smoking despite experiencing smoking-related problems. Further evidence that suggests that highly dependent smoking is associated with a lack of contextual dependency was provided by
Shiffman and Paty (2006). They recently reported that chippers, light smokers who regularly use tobacco without developing dependence, differ from other smokers in that the chippers are highly cue-dependent (
Shiffman & Paty, 2006). Of course, other factors may also account for the relation of FTND TTFC with abstinence status.
This research may also have practical significance in that it suggests that a single item from the FTND can assess nicotine dependence as it is reflected in relapse vulnerability, and as it is reflected in other measures such as other WISDM and NDSS scales. The use of a single item may be important for epidemiologic or surveillance research where respondent burden is highly important. Moreover, in this research, FTND TTFC produced superior prediction of relapse than did the entire FTND questionnaire. Thus, researchers should be aware that, to the extent that they view relapse as an important endpoint, they may actually degrade their assessment of relapse vulnerability by employing the whole instrument; this is consistent with the variable inter-item correlations (). Finally, it should be noted that the present paper assessed the validity of dependence instruments against only a single criterion: quitting success. Investigators certainly would wish to consider other dependence measures to the extent that they wished to predict a broader array of dependence criteria (e.g., withdrawal; see
Piper et al., 2006).
The FTND TTFC may have important clinical applications. Our data suggest that this item provides a very brief measure of relapse susceptibility. Thus, this measure could be used as a baseline screening item to target smokers beginning treatment. For instance, TTFC is already used to assign dose of nicotine lozenge therapy (
Shiffman et al., 2002), and it is possible that this item could also prove useful in assigning smokers to other treatments. Finally, recent research suggests that TTFC has high heritability relative to other dependence measures (e.g.,
Haberstick et al., 2007;
Lessov et al., 2004). Therefore, it may be well suited to serve as a phenotypic measure for genetic mapping.
Interpretive caveats
Readers should recognize that this paper, and its interpretations, rest upon self-report items. Thus, it has limited ability to shed light on such processes or phenomena as automatic information processing. In addition, it is the case that the relative validities of items and instruments may vary across different samples of smokers. For instance,
West (2005) has reported findings in which other FTND items had relations with abstinence status that were as high, or higher, than the TTFC item. It is also unclear the extent to which one can generalize from the current results to instances where smoking latency data are gathered using a different response format (e.g., continuous measure of time to first cigarette). Finally, if investigators wish to use FTND TTFC as a measure of dependence, they must recognize that a meaningful portion of its predictive validity is related to its association with a secular phenomenon: a restrictive home smoking policy. Thus, in any attempt to isolate the extent to which this item assesses dependence per se, the investigators may wish to control this relation either through sample selection or through statistical means. This would be important, for instance, if investigators wished to use this item in genetics research: a portion of the variance in this item might merely reflect smoking policy rather than dependence.
Summary
The present research shows that FTND TTFC is a strong and consistent predictor of short- and long-term cessation success. Thus, this measure might be useful for both research purposes as well as for treatment planning. Because this measure is sensitive to the motivational forces that drive cessation failure, it may elucidate the nature of nicotine dependence. Construct validation efforts suggest that this item reflects smoking that is relatively heavy and noncontingent with external and internal cues.
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