Comparative Analysis of Alternate Measures of Readiness to Quit Smoking: Stages of Change and the Contemplation Ladder

Abstract

Purpose: Two methods of operationalizing readiness to quit smoking have been used extensively in prior research. An algorithm derived from the transtheoretical model classifies current smokers in distinct stages of precontemplation (not intending to quit in next 6 months), contemplation (serious intent to quit within 6 months), and preparation (serious intent to quit within 30 days). The Contemplation Ladder (CL) is a single-item continuous (0-10) rating. The current study, a secondary analysis of a clinical trial testing a method of inducing quit attempts, examined the convergent validity, one-month retest reliability, and predictive validity (for quit attempts) of the CL and the stages of change algorithm. Patients and Methods: Adult daily smokers (≥10 cigarettes/day; N = 278) completed the CL and stage of change algorithm measures and underwent an experimental manipulation intended to induce quit attempts. Four weeks later they completed the same measures and reported on whether they had attempted to quit smoking in the interim. Results: The CL and the staging algorithm showed strong convergent validity, with intercorrelations of 0.50 and 0.51 at baseline and follow-up assessments. Retest reliability was similar for each measure (CL r = 0.52; stage of change r = 0.57). Each showed predictive validity in that smokers who went on to make a quit attempt had scored significantly higher at baseline in readiness to quit. Conclusion: Researchers and clinicians can reasonably choose either measure of readiness to quit smoking with confidence that the results would parallel what would have been obtained with the other.