Point process analyses of variations in smoking rate by setting, mood, gender, and dependence

The immediate emotional and situational antecedents of ad-libitum smoking are still not well understood. We reanalyzed data from ecological momentary assessment using novel point process analyses to assess how craving, mood, and social setting influence smoking rate, as well as to assess the moderating effects of gender and nicotine dependence. Smokers (N = 304) recorded craving, mood, and social setting using electronic diaries when smoking and at random nonsmoking times over 16 days of smoking. Point process analysis, which makes use of the known random sampling scheme for momentary variables, examined main effects of setting and interactions with gender and dependence. Increased craving was associated with higher rates of smoking, particularly among women. Negative affect was not associated with smoking rate, even in interaction with arousal, but restlessness was associated with substantially higher smoking rates. Women's smoking tended to be less affected by negative affect. Nicotine dependence had little moderating effect on situational influences. Smoking rates were higher when smokers were alone or with others who were smoking, and smoking restrictions reduced smoking rates. However, the presence of others who are smoking undermined the effects of restrictions. The more sensitive point process analyses confirmed earlier findings, including the surprising conclusion that negative affect by itself was not related to smoking rates. Contrary to hypothesis, men's and not women's smoking was influenced by negative affect. Both smoking restrictions and the presence of others who are not smoking suppress smoking, but the presence of others who are not smoking undermines the effects of restrictions. Point process analyses of ecological momentary assessment data can bring out even small influences on smoking rate.