Cheyenne River Sioux Tribe participants’ serum cotinine concentrations by tobacco-related and demographic variables
| N (%) | Mean (±SD) cotinine (ng/mL) | Median (min; max) cotinine (ng/mL) | P value* | |
| Total | 225 | 89.5 (152.5) | 12.9 (0.4; 859.1) | |
| Age group | ||||
| Younger (18–41 years old) | 118 (52.4) | 79.7 (136.8) | 12.3 (0.4; 650.9) | 0.9779 |
| Older (42–77 years old) | 107 (47.6) | 100.3 (168.1) | 13.1 (0.4; 859.1) | |
| Gender | ||||
| Male | 109 (48.4) | 90.4 (155.8) | 14.8 (0.4; 761.3) | 0.8603 |
| Female | 116 (51.6) | 88.6 (149.9) | 11.5 (0.4; 859.1) | |
| Environmental exposure zone | ||||
| Community centre | 98 (43.6) | 80.5 (146.1) | 11 (0.4; 761.3) | 0.2704 |
| Arsenic zone | 46 (20.4) | 84.1 (118.6) | 17.6 (0.4; 506.3) | |
| Pesticide zone | 56 (24.9) | 115.5 (192.7) | 12.2 (0.4; 859.1) | |
| Mercury zone | 25 (11.1) | 76.4 (130.8) | 10.9 (0.4; 544.7) | |
| Current anglers/fishermen | ||||
| Yes | 164 (72.9) | 96 (162.5) | 14 (0.4; 859.1) | 0.3785 |
| No | 61 (27.1) | 72.1 (120.9) | 9.9 (0.4; 544.7) | |
| Current smoker | ||||
| Yes | 114 (50.7) | 137.5 (168.2) | 79.6 (0.4; 859.1) | <0.0001 |
| No | 111 (49.3) | 40.2 (115.9) | 8.8 (0.4; 761.3) | |
| Current tobacco chewer | ||||
| Yes | 41 (18.2) | 130.5 (205.4) | 19.5 (0.4; 761.3) | 0.0457 |
| No | 184 (81.8) | 80.4 (137) | 11.2 (0.4; 859.1) | |
| Current CoSHS† | ||||
| Yes | 129 (57.6) | 104.6 (161.1) | 15.3 (0.4; 859.1) | 0.0357 |
| No | 95 (42.4) | 69.3 (139) | 10.6 (0.4; 761.3) | |
| Data collection year | ||||
| 2014 | 75 (33.3) | 143.6 (170.4) | 81.2 (0.4; 650.9) | 0.0062 |
| 2015 | 75 (33.3) | 107 (177.9) | 13.1 (0.4; 859.1) | |
| 2016 | 75 (33.3) | 17.9 (35.2) | 10.9 (0.4; 238.4) | |
| Tobacco user, by collection year | ||||
| Tobacco users in 2014 | 48 (21.3) | 203.9 (175.9) | 173.8 (0.4; 650.9) | <0.0001‡ |
| Tobacco users in 2015 | 45 (20.0) | 173.9 (203.2) | 106.7 (0.4; 859.1) | |
| Tobacco users in 2016 | 44 (19.6) | 24.0 (45.1) | 13.5 (8.8; 238.4) | |
| Non-users in 2014 | 27 (12.0) | 36.4 (89.4) | 3.5 (0.4; 356.9) | <0.0001§ |
| Non-users in 2015 | 30 (13.3) | 6.6 (26.1) | 0.4 (0.4; 142.7) | |
| Non-users in 2016 | 31 (13.8) | 9.3 (2.3) | 9.0 (0.4; 17.4) | |
| Childhood SHS (at home)† | ||||
| Yes | 138 (61.6) | 105.5 (167.9) | 14.9 (0.4; 859.1) | 0.0601 |
| No | 86 (38.4) | 64.2 (121.4) | 11.1 (0.4; 650.9) | |
| Tobacco use status¶ | Mean age (years, SD)** | |||
| Non-user without CoSHS | 53 (23.5) | 15.7 (51.9) | 3.5 (0.4; 356.9) | 41.9 (13.2) |
| Non-user with CoSHS | 35 (15.5) | 18.1 (55) | 2.7 (0.4; 247.5) | 43.3 (15.7) |
| Chewer and non-smoker | 23 (10.2) | 130.3 (213.1) | 19.4 (0.4; 761.3) | 37.2 (8.7) |
| Dual user (smoker and chewer) | 18 (8) | 130.8 (201.2) | 21.6 (0.6; 650.9) | 36.9 (7.2) |
| Smoker and non-chewer | 96 (42.6) | 138.7 (162.5) | 90.7 (0.4; 859.1) | 43.1 (14.2) |
*P values were derived from Wilcoxon rank-sum test for two group’s comparison and from Kruskal-Wallis test for three or more groups.
†Missing CoSHS data for one participant.
‡P values for comparing tobacco user subgroups.
§P values for comparing non-tobacco user subgroups.
¶Kruskal-Wallis test for the difference in cotinine concentrations among tobacco use groups was p<0.0001.
**Kruskal-Wallis test for the difference in age among tobacco use groups was p=0.23, demonstrating the age homogeneity of the sample.
CoSHS, composite secondhand smoke; SHS, secondhand smoke.