A family environment which is characterized by parents who sometimes, hardly ever or never monitored their middle school aged children’s whereabouts fell into the lowest quartile of parent monitoring whereas higher quartiles are characterized by parents who monitored their children most or all of the time. For example, 72.6% of subjects in lowest quartile parent monitoring reported sometimes, hardly ever or never left a note for their parents about where they were going, in contrast with only 5.1% of subjects in higher quartiles. About 42.3% of subjects in lowest quartile parent monitoring reported parents sometimes, hardly ever or never knew if they came home an hour late on weekends, in contrast with only 2.8% of subjects in higher quartiles. In addition, we found in our data that the association between levels of parent monitoring and nicotine dependence is not linear. Individuals with the lowest quartile of parent monitoring was associated with a significantly increased risk and there was no gradient in the remaining three quartiles. This is consistent with a prior study showing only the lowest quartile level of parent
