Closer examination revealed a tendency for nonsmoking selleck chemicals llc mothers to report higher levels of reported exposure than expected based on levels of cotinine. Figure 1. Cotinine versus 3-day average cigarette exposure from all sources according to the reporting parent’s/guardian’s smoking status. In order to examine whether parents could provide valid reports of the child’s PSE, Spearman’s correlations between average daily parent-reported exposure with children’s urine cotinine levels over a 3-day period were calculated according to smoking status of the reporting parent. These results are provided in Table 3. Reports from smoking parents yielded correlations of .35 for exposure from self and .54 for exposure from all sources.

The proportion of shared variance between cotinine and 3-day parent-reported exposure increased by an absolute difference of 15% (Pearson’s r2=.13�C.28) when other sources of exposure (other parent, relatives, friends) are considered over and above exposure by the reporting smoking parent. The mean urine cotinine level for patients whose reporting parent was a smoker was 5.1 ng/ml (IQR=1.9�C13.6 ng/ml). Table 3. Spearman’s correlations between average daily parent-reported exposure and child urine cotinine levels over 3 days Lower correlations were found between child cotinine levels and 3-day exposure reported by nonsmoking parents. Spearman’s correlations were .16 for exposure from the smoking spouse alone and .38 for exposure from all sources. Also, the proportion of shared variance between cotinine and 3-day parent-reported exposure increased by an absolute difference of 13% (Pearson’s r2=.

04�C.17) when other sources of exposure are considered over and above the smoking spouse/partner when that report was provided by the nonsmoking parent. The mean cotinine level for patients whose reporting parent was a nonsmoker was 2.0 ng/ml (IQR=0.7�C5.2 ng/ml). To examine how well 3-day parent reports of all PSE sources could be predicted from the child’s urine cotinine levels, the SE of estimate (SEE) or root mean square was obtained. Nonsmoking parent reports (n=33) were excluded from the analysis, as they were not strongly correlated with cotinine and we wanted to examine the most precise predictions. Cilengitide The SEE or root mean square was 0.70 on the log scale for predicting exposure from urine cotinine, and the 95% prediction intervals for 3-day exposure at the average value of 1.5 cigarettes/day ranged from 0 to 41.8 cigarettes. That is, if urine cotinine was used to predict the child’s exposure at an average 3-day reported exposure of 1.5 cigarettes/day as reported by smoking parents, 95% of these predictions of exposure would fall between 0 and 41.8 cigarettes.