For the items and responses, see Appendix B. Items not included in the final questionnaire did not contribute selleck chemical meaningful predictive validity relative to the other items already in the final item set. This includes seemingly important items addressing self-appraisal of addiction, self-efficacy/outcome expectancy, smoking reinforcement appraisal/expectancies (multiple dimensions), withdrawal severity (multiple dimensions), and depression history, for example (see Appendix A). Therefore, each item was tested against the entire pool of other items. The items not included were not significantly related to outcomes, or their predictive validity overlapped considerably with that of other items. Another analysis was used to determine a strategy for scoring the items.

The magnitude of the logistic regression coefficients for three items, specifically, FTND items regarding time to first cigarette and cigarettes per day, and the demographic item related to education level, relative to their item score range, were generally higher than those of the other items. Thus, to maximize the predictive power of the total sum score across items, these three items were effectively weighted more heavily by introducing a wider range of score values to these three items. FTND items 1 and 4 were scored using the same traditional scoring as on the FTND (0�C3), whereas the education level item was scored as 0, 1, or 2, corresponding to education levels of less than a high school degree (2), high school degree or equivalent (1), and some college experience (0).

The education level item is scored in reverse direction GSK-3 to be consistent with its predictive effects on relapse. The remaining four items were scored as binary (see Appendix B). Cross-validation analyses To evaluate the effectiveness of the WI-PREPARE constructed using the exploratory analyses and the derivation sample, a series of cross-validation analyses were conducted using the second sample of 703 respondents. In this validation sample, the average WI-PREPARE score was 6.16 (SD=2.29). The predictive validity of the WI-PREPARE was compared against that of the FTND. Because two of the FTND items are included in the WI-PREPARE, the comparison performed here was ultimately concerned with the relative value of the five non-FTND items introduced to the WI-PREPARE against the four FTND items not included in the WI-PREPARE (i.e., FTND items 2, 3, 5, and 6). The FTND items not included in the WI-PREPARE are displayed in Table 2. Table 2. FTND items 2, 3, 5, and 6 Table 3 reports results from logistic regression analyses predicting abstinence from smoking 1 week, 8 weeks, and 6 months postquit as a function of either the FTND total score or the WI-PREPARE total score in the cross-validation sample.