The Theory of Planned Behavior as Applied to Preoperative Smoking Abstinence

Abstinence from smoking on the morning of surgery may improve outcomes. This study examined the explicatory power of the Theory of Planned Behavior (TPB) to predict smoking behavior on the morning of surgery, testing the hypothesis that the constructs of attitude, subjective norm, and perceived behavioral control (PBC) will predict intent to abstain from smoking the morning of surgery, and that intent will predict behavior. TPB constructs were assessed in 169 pre-surgical patients. Smoking behavior on the morning of surgery was assessed by self-report and CO monitoring. Correlations and structural equation modeling (SEM) were used to determine associations between measures and behavior. All TPB measures, including intent as predicted by the TPB, were correlated with both a lower rate of self-reported smoking on the morning of surgery and lower CO levels. The SEM showed a good fit to the data. In the SEM, attitude and PBC, but not subjective norm, were significantly associated with intent to abstain, explaining 46% of variance. The effect of PBC on CO levels was partially mediated by intent. The amount of variance in behavior explained by these TPB constructs was modest (10% for CO levels). Thus, attitude and perceived behavioral control explain a substantial portion of the intent to maintain preoperative abstinence on the morning of elective surgery, and intent and perceived behavioral control explain a more modest but significant amount of the variance in actual smoking behavior. Trial Registration: Clinical Trials.gov registration: NCT01014455