Regression parameters in test of Efficacy-Desire Model.

<p>Note: B is the unstandardized coefficient, SE is the standard error, and Prob is the probability of null hypothesis.</p

Examples of warning labels with (A) text on side of pack, (B) picture and text on front of pack, and (C) picture, text and elaboration on front of pack.

<p>Reprinted from <a href="www.fda.gov" target="_blank">www.fda.gov</a> under a CC BY license, with permission from the FDA, copyright 02/24/2012.</p

Predicted relation based on regression model in Table 4 (step 2) between intention and efficacy to quit with frequency of smoking as the parameter.

<p>Predicted relation based on regression model in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054937#pone-0054937-t004" target="_blank">Table 4</a> (step 2) between intention and efficacy to quit with frequency of smoking as the parameter.</p

Parameters of linear regression models for desire to quit smoking, aversion to smoking, and quit efficacy with warning and efficacy as predictors.

<p>Note: Males were coded as 0 and females as 1; Age was coded as 0 for 18–24 and 1 for 25+; Smoke frequency was coded 1 for daily smokers and 0 for less often. B is the unstandardized coefficient, SE is the standard error, and Prob is the probability of null hypothesis.</p

Efficacy-Desire Model of quit intentions showing relations between components of the model as they relate to the reward and control systems of addiction models.

<p><i>Dq</i> and <i>Ds</i> are the desire to quit and smoke, respectively; <i>Eq</i> and <i>Es</i> are efficacies for quitting and smoking respectively. Respective interactions between efficacy and desire lead to <i>Mq</i> and <i>Ms</i>, which directly affect the intention to try quitting (<i>Iq</i>). Dashed paths indicate inverse relations; curved paths are correlations rather than effects.</p

Relations between intention to quit smoking (<i>Iq</i>) and quit efficacy (<i>Eq</i>) by three levels of warning intensity (<i>α</i>) scaled from 0, .5. to 1.0.

<p>Panel A shows the relation using eq. (5) with <i>Es</i> fixed at.5 and <i>β</i> at 3.0. Panel B shows the observed relation using scores predicted by regression model in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054937#pone-0054937-t004" target="_blank">Table 4</a> (step 1).</p

Response distributions of major variables in the study (N = 3297).

<p>Response distributions of major variables in the study (N  = 3297).</p

Predicted relations between three measures and efficacy to quit based on regression models in Tables 2 and 3: (A) desire to quit; (B) probability of smoking frequency; and (C) probability of trying to quit in past 12 months.

<p>Predicted relations between three measures and efficacy to quit based on regression models in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054937#pone-0054937-t002" target="_blank">Tables 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054937#pone-0054937-t003" target="_blank">3</a>: (A) desire to quit; (B) probability of smoking frequency; and (C) probability of trying to quit in past 12 months.</p

Placement of Experimental Warning Labels.

<p>Basic text warnings (left) were placed on the side of cigarettes packages. Graphic warning labels (center) covered approximately 50% of the front of cigarette packages and paired images with basic text statements. Elaborated text warning labels (right) also featured graphic images, but included descriptive text which explained the warning in more detail.</p

Participant Retention Diagram.

<p>Participant recruitment and retention over the course of the trial.</p