Figure 1
Daily usage of ECs and EC liquid by age groups_
| User behaviour | Age group (years) | X̅ ± SD |
|---|---|---|
| Frequency per day (times/day) | 18 – 29 | 88.3 ± 88.3 |
| 30 – 39 | 83.0 ± 88.1 | |
| 40 – 49 | 64.0 ± 75.2 | |
| Over 50 | 62.0 ± 73.0 | |
| Volume of EC liquid per day (mL/day) | 18 – 29 | 7.2 ± 7.3 |
| 30 – 39 | 6.0 ± 6.0 | |
| 40 – 49 | 3.4 ± 4.4* | |
| Over 50 | 2.5 ± 1.8* |
Smoking cessation among EC users (%)_
| Smoking cessation within | Total (%) | Beijing (%) | Shanghai (%) | Guangzhou (%) | Shenzhen (%) |
|---|---|---|---|---|---|
| ≤ 1 month | 30 (27.9) | 9 (43.8) | 8 (33.3) | 2 (9.5) | 10 (29.0) |
| > 1 ≤ 3 months | 28 (26.7) | 1 (6.3) | 7 (27.8) | 4 (14.3) | 16 (45.2) |
| > 3 ≤ 6 months | 20 (18.6) | 4 (18.8) | 3 (11.1) | 10 (38.1) | 3 (9.7) |
| > 6 ≤ 12 months | 14 (12.8) | 3 (12.5) | 4 (16.7) | 6 (23.8) | 1 (3.2) |
| > 1 ≤ 2 years | 7 (7.0) | 1 (6.3) | 3 (11.1) | 1 (4.8) | 2 (6.5) |
| > 2 ≤ 3 years | 6 (5.8) | 3 (12.5) | 0 (0.0) | 1 (4.8) | 2 (6.5) |
| > 3 years | 1 (1.2) | 0 (0.0) | 0 (0.0) | 1 (4.8) | 0 (0.0) |
Health effects and family response reported by EC users_
| Health effects | Proportion n (%) | |
|---|---|---|
| Irritating to the mouth | Yes | 110 (21.5) |
| No | 381 (74.6) | |
| I don’t know | 20 (3.9) | |
| Adverse respiratory effects (e.g. pharyngitis, cough, irritation, etc.) | Better | 289 (56.6) |
| No change | 218 (42.7) | |
| Worse | 4 (0.8) | |
| Changes in body and body functions (e.g. weight, sleep quality, memory, sense of smell etc.) after using ECs for 3 months | Better | 216 (42.3) |
| No change | 291 (56.9) | |
| Worse | 4 (0.8) | |
| Attitudes of families and friends towards the use of ECs | Supportive | 258 (50.5) |
| Adverse | 25 (4.9) | |
| No opinion | 228 (44.6) | |
The differences of the use patterns among age groups, n (%)_
| Total | Age 18 – 29 years | Age 30 – 39 years | Age 40 – 49 years | Age over 50 years | F | p | ||
|---|---|---|---|---|---|---|---|---|
| Flavor preference | Fruit | 294 (59.9) | 173 (73.3) | 79 (48.2) | 34 (51.5) | 8 (32.0) | 70.487 | < 0.001 |
| Tobacco | 101 (20.6) | 23 (9.7) | 42 (25.6) | 28 (42.4) | 8 (32.0) | |||
| Cigar | 7 (1.4) | 1 (0.4) | 5 (3.0) | 1 (1.5) | 0 (0.0) | |||
| Chocolate | 5 (1.0) | 1 (0.4) | 3 (1.8) | 0 (0.0) | 1 (4.0) | |||
| Menthol | 62 (12.6) | 26 (11.0) | 27 (16.5) | 2 (3.0) | 7 (28.0) | |||
| Others | 22 (4.5) | 12 (5.1) | 8 (4.9) | 1 (1.5) | 1 (4.0) | |||
| Nicotine concentration | 0 mg/mL | 85 (17.3) | 34 (14.4) | 29 (17.7) | 14 (21.2) | 8 (32.0) | 51.874 | < 0.001 |
| Low | 284 (57.8) | 164 (69.5) | 88 (53.7) | 23 (34.8) | 9 (36.0) | |||
| Moderate | 77 (15.7) | 20 (8.5) | 36 (22.0) | 17 (25.8) | 4 (16.0) | |||
| High | 13 (2.6) | 5 (2.1) | 2 (1.2) | 5 (7.6) | 1 (4.0) | |||
| ≥20 mg/mL | 1 (0.2) | 0 (0.0) | 0 (0.0) | 1 (1.5) | 0 (0.0) | |||
| Don’t know | 31 (6.3) | 13 (5.5) | 9 (5.5) | 6 (9.1) | 3 (12.0) | |||
| Duration of use | 3 – 6 months | 75 (15.3) | 42 (17.8) | 17 (10.4) | 14 (21.2) | 2 (8.0) | 34.793 | 0.003 |
| 6 – 12 months | 149 (30.3) | 81 (34.3) | 39 (23.8) | 21 (31.8) | 8 (32.0) | |||
| 1 – 2 years | 172 (35.0) | 73 (30.9) | 78 (47.6) | 14 (21.2) | 7 (28.0) | |||
| 2 – 3 years | 57 (11.6) | 30 (12.7) | 16 (9.8) | 8 (12.1) | 3 (12.0) | |||
| 3 – 5 years | 23 (4.7) | 6 (2.5) | 8 (4.9) | 6 (9.1) | 3 (12.0) | |||
| > 5 years | 15 (3.1) | 4 (1.7) | 6 (3.7) | 3 (4.5) | 2 (8.0) | |||
| Frequency of use in past 30 days | 3 – 4 days/week | 89 (18.1) | 41 (17.4) | 32 (19.5) | 11 (16.7) | 5 (20.0) | 4.731 | 0.579 |
| 5 – 6 days/week | 89 (18.1) | 42 (17.8) | 28 (17.1) | 17 (25.8) | 2 (8.0) | |||
| per day | 313 (63.8) | 153 (64.8) | 104 (63.4) | 38 (57.6) | 18 (72.0) | |||
Basic distribution of EC users, n (%)_
| Characteristics | Classification | Number of participants (%) | ||||
|---|---|---|---|---|---|---|
| Total | Beijing | Shanghai | Guangzhou | Shenzhen | ||
| Age (years) | 18–29 | 243 (47.6) | 38 (46.3) | 42 (34.1) | 44 (29.5) | 119 (75.8) |
| 30–39 | 175 (34.2) | 30 (36.6) | 57 (46.3) | 72 (48.3) | 16 (10.2) | |
| 40–49 | 67 (13.1) | 7 (8.5) | 18 (14.6) | 22 (14.8) | 20 (12.7) | |
| Above 50 | 26 (5.1) | 7 (8.5) | 6 (4.9) | 11 (7.4) | 2 (1.3) | |
| Gender | Male | 463 (90.6) | 76 (92.7) | 104 (84.6) | 131 (87.9) | 152 (96.8) |
| Female | 48 (9.4) | 6 (7.3) | 19 (15.4) | 18 (12.1) | 5 (3.2) | |
| Education | Doctoral | 1 (0.2) | 1 (1.2) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Master | 6 (1.2) | 5 (6.1) | 1 (0.8) | 0 (0.0) | 0 (0.0) | |
| Bachelor | 231 (45.2) | 55 (67.1) | 76 (61.8) | 68 (45.6) | 32 (20.4) | |
| Associate degree | 184 (36.0) | 13 (15.9) | 36 (29.3) | 57 (38.3) | 78 (49.7) | |
| High School | 86 (16.8) | 8 (9.8) | 10 (8.1) | 22 (14.8) | 46 (29.3) | |
| Others | 3 (0.6) | 0 (0.0) | 0 (0.0) | 2 (1.3) | 1 (0.6) | |
| Occupation | General staff | 145 (28.4) | 24 (39.3) | 43 (35.0) | 43 (28.9) | 35 (22.3) |
| Middle or senior level management | 119 (23.3) | 16 (19.5) | 41 (33.3) | 47 (31.5) | 15 (9.6) | |
| Students | 70 (13.7) | 7 (8.5) | 3 (2.4) | 2 (1.3) | 58 (36.9) | |
| Freelancers | 51 (10.0) | 13 (15.9) | 10 (8.1) | 12 (8.1) | 16 (10.2) | |
| Private business owners / Partners | 44 (8.6) | 7 (8.5) | 11 (8.9) | 16 (10.9) | 10 (6.4) | |
| General staff of Government Departments / Institutions | 24 (4.7) | 2 (2.4) | 6 (4.9) | 12 (8.1) | 4 (2.5) | |
| Blue-collar workers in a servicebranch (e.g., restaurants or shops) | 12 (2.3) | 3 (3.7) | 1 (0.8) | 2 (1.3) | 6 (3.8) | |
| Middle or senior level management in Government Departments / Institutions | 11 (2.2) | 2 (2.4) | 3 (2.4) | 1 (0.7) | 5 (3.2) | |
| Owners of small shops / restaurants, etc. | 10 (2.0) | 0 (0.0) | 1 (0.8) | 6 (4.1) | 3 (1.9) | |
| Labourers / blue-collar / manual workers | 10 (2.0) | 2 (2.4) | 1 (0.8) | 4 (2.7) | 3 (1.9) | |
| Middle / senior level professionals (e.g., lawyers, doctors, scientists, etc.) | 9 (1.8) | 3 (3.7) | 2 (1.6) | 3 (2.0) | 1 (0.6) | |
| Retired | 3 (0.6) | 1 (1.2) | 1 (0.8) | 1 (0.7) | 0 (0.0) | |
| Unemployed / laid off | 3 (0.6) | 2 (2.4) | 0 (0.0) | 0 (0.0) | 1 (0.6) | |
Types of e-cigarettes used in the four cities_
| Classification | Number of participants (%) | ||||
|---|---|---|---|---|---|
| Total | Beijing | Shanghai | Guangzhou | Shenzhen | |
| Cartomized | 491 (96.1) | 80 (97.6) | 113 (91.9) | 147 (98.7) | 151 (96.2) |
| Tank | 15 (2.9) | 2 (2.4) | 9 (7.3) | 2 (1.3) | 2 (1.3) |
| Disposable | 5 (1.0) | 0 (0) | 1 (0.8) | 0 (0) | 4 (2.5) |
Usage status of tobacco products, n (%)_
| Product usage | Total | Beijing | Shanghai | Guangzhou | Shenzhen |
|---|---|---|---|---|---|
| EC only | 137 (26.8) | 21 (25.6) | 31 (25.2) | 42 (28.2) | 43 (27.4) |
| Dual usage | 374 (73.2) | 61 (74.4) | 92 (74.8) | 107 (71.8) | 114 (72.6) |
Proportion of dual users before and after using ECs by cigarette “tar” bands, n (%)_
| The number of dual users smoking cigarettes containing different concentrations of “tar” | X2 | p | ||||
|---|---|---|---|---|---|---|
| < 6 | 6 – 8 | 9 – 11 | ||||
| Total | before using ECs | 84 (16.4) | 132 (25.8) | 268 (52.4) | 34.064 | 0.000 |
| after using ECs | 156 (30.6) | 158 (30.9) | 197 (38.5) | |||
| Beijing | before using ECs | 22 (27.1) | 17 (20.8) | 43 (52.1) | 6.650 | 0.036 |
| after using ECs | 34 (41.7) | 21 (25.0) | 27 (33.3) | |||
| Shanghai | before using ECs | 18 (14.7) | 39 (32.0) | 59 (48.0) | 9.996 | 0.007 |
| after using ECs | 34 (28.0) | 49 (40.0) | 39 (32.0) | |||
| Guangzhou | before using ECs | 19 (13.0) | 46 (31.0) | 77 (52.0) | 11.047 | 0.004 |
| after using ECs | 37 (25.0) | 58 (39.0) | 54 (36.0) | |||
| Shenzhen | before using ECs | 25 (15.9) | 29 (18.7) | 88 (56.11) | 9.269 | 0.010 |
| after using ECs | 51 (32.7) | 31 (19.6) | 75 (47.7) | |||
Perception of ECs among the users_
| E-cigarette perception | Proportion n (%) | |
|---|---|---|
| Reasons given for initiating EC use | To quit smoking | 382 (74.8) |
| To reduce the exposure to cigarette smoke of family members | 255 (49.9) | |
| To avoid a smoking ban in public places | 221 (43.2) | |
| Multiple flavors in ECs | 204 (39.9) | |
| For reasons of fashion or curiosity | 198 (38.7) | |
| Economic reasons | 9 (1.8) | |
| To make smoke rings | 2 (0.4) | |
| To pursue a healthy lifestyle | 2 (0.4) | |
| Due to living abroad for a long time | 1 (0.2) | |
| First contact with EC | Introduced by relatives, friends, or colleagues | 355 (69.5) |
| Advertising in print articles or online | 65 (12.7) | |
| EC experience store or EC shop | 60 (11.7) | |
| WeChat friends circle | 24 (4.7) | |
| Outdoor advertising | 7 (1.4) | |
| ECs are less harmful than traditional cigarettes | Yes | 48 (9.4) |
| No | 11 (2.2) | |
| I don’t know | 453 (88.6) | |
| Is there any risk of harm from ECs? | Yes | 38 (7.5) |
| No | 262 (51.3) | |
| I don’t know | 210 (41.1) | |
| Ability to quit smoking by using ECs | I can quit | 309 (60.5) |
| I can’t quit | 69 (13.6) | |
| I don’t know | 132 (25.9) | |
| Does using ECs have an effect on people around you who don't smoke | Yes | 158 (31.0) |
| No | 239 (46.8) | |
| I don’t know | 113 (22.2) | |
| The most persuasive channel for “information on the health effects of ECs” | Consulting professional books or scientific literature | 145 (28.4) |
| Searching for information on the Internet | 140 (27.3) | |
| Introduction by acquaintances | 152 (29.8) | |
| Related materials provided by retail stores | 74 (14.5) | |
| Channels to communicate on products, taste, smoking and other related information with other consumers who use ECs | Friends and colleagues who use ECs | 320 (62.7) |
| EC-related BBS* and WeChat groups | 74 (14.5) | |
| EC experience store | 94 (18.3) | |
| No communication | 23 (4.5) | |
Cig/day of dual users before and after using ECs_
| Cigarettes/day (X̅ ± SD) | t | p | ||
|---|---|---|---|---|
| Before using ECs | After using ECs | |||
| Total | 14.20 ± 8.85 | 8.23 ± 4.95 | 14.08 | < 0.001 |
| Beijing | 18.67 ± 11.19 | 9.27 ± 4.95 | 5.40 | < 0.001 |
| Shanghai | 14.97 ± 8.43 | 8.20 ± 4.95 | 4.65 | < 0.001 |
| Guangzhou | 18.08 ± 8.44 | 9.60 ± 5.29 | 9.95 | < 0.001 |
| Shenzhen | 14.07 ± 7.62 | 8.04 ± 4.42 | 9.16 | < 0.001 |
The history of cigarette smoking for EC-only users and dual users, n (%)_
| User of: | User history/status | Total | Beijing | Shanghai | Guangzhou | Shenzhen |
|---|---|---|---|---|---|---|
| ECs only | Always using ECs only | 101 (19.7) | 12 (14.3) | 32 (25.8) | 43 (28.6) | 15 (9.3) |
| Smoker before using ECs only | 410 (80.3) | 70 (85.7) | 91 (74.2) | 106 (71.4) | 142 (90.7) | |
| Dual usage | Smoker before using ECs | 451 (88.2) | 65 (78.7) | 100 (81.5) | 139 (93.5) | 147 (93.9) |
| Nonsmoker before using ECs | 60 (11.8) | 17 (21.3) | 23 (18.5) | 10 (6.5) | 10 (6.1) |