Study | Age | Education | ||||
---|---|---|---|---|---|---|
Age category (years) | Nitrite inhalants users N(%)a | Nitrite inhalants nonusers N(%)a | Education level | Nitrite inhalants users N(%)a | Nitrite inhalants nonusers N(%)a | |
Chen et al. (2016) [24] | 16–20 | 9 (7.4) | 92 (13.1)* | Senior high school and below | 4 (3.3) | 29 (4.1) |
21–25 | 61 (50.0) | 389 (55.3) | College/Bachelors | 79 (64.8) | 457 (65.0) | |
26–30 | 52 (42.6) | 222 (31.6) | Masters or PhD | 39 (32.0) | 217 (30.9) | |
Chu (2013) [17] | ≤30 | 99 (82.5) | 317 (62.8)* | Senior high school and below | 64 (53.3) | 326 (64.6)* |
> 30 | 21 (17.5) | 188 (37.2) | College/Bachelors and above | 56 (46.7) | 179 (35.4) | |
Li (2014) [19] | ≤28 | 417 (66.1) | 1070 (49.2)* | Senior high school and below | 276 (43.7) | 1055 (48.5)* |
> 28 | 214 (33.9) | 1105 (50.8) | College/Bachelors and above | 355 (56.3) | 1120 (51.5) | |
Li et al. (2014) [25] | < 25 | 49 (25.9) | 33 (15.6)* | ≤12 years education experience | 49 (25.9) | 93 (44.1)* |
≥25 | 140 (74.1) | 178 (84.4) | > 12 years education experience | 140 (74.1) | 118 (55.9) | |
Wang et al. (2017) [26] | 18–30 | 109 (71.7) | 193 (53.9)* | Less than college | 53 (34.9) | 200 (55.9)* |
31–70 | 43 (28.3) | 165 (46.1) | College and above | 99 (65.1) | 158 (44.1) | |
Xu et al. (2017) [27] | < 25 | 103 (41.9) | 309 (38.9)* | Less than college | 54 (22.0) | 234 (29.5)* |
25–49 | 139 (56.5) | 441 (55.5) | College and above | 192 (78.0) | 560 (70.5) | |
≥50 | 4 (1.6) | 44 (5.5) |  |  |  | |
Zhang et al. (2016)b [28] | 18–34 | 831 (86.6) | 2007 (76.5)* | Senior high school and below | 191 (19.9) | 818 (31.1)* |
35–75 | 129 (13.4) | 618 (23.5) | College/Bachelors and above | 770 (80.1) | 1809 (68.9) | |
Zhao et al. (2017) [29] | < 20 | 36 (11.9) | 170 (15.2) | Senior high school and below | 66 (21.8) | 303 (27.0) |
20–29 | 203 (67.0) | 695 (62.0) | College/Bachelors | 219 (72.3) | 750 (66.9) | |
≥30 | 64 (21.1) | 256 (22.8) | Masters or PhD | 18 (5.9) | 68 (6.1) |