Table 3 Transition probabilities* from wave 1 to wave 2 with 95% confidence intervals among adults continuing from PATH wave 1 to wave 2 (n = 26,446)

1. Exclusive cigarette smoker

8613

76.4 (75.3, 77.4)

4.3 (3.8, 4.9)

1.3 (1.1, 1.6)

18.0 (17.0, 19.0)

 1.1. Experimental cigarette smoker

1396

36.7 (34.1, 39.3)

1.3 (0.8, 2.1)

1.8 (1.2, 2.9)

60.2 (57.5, 62.8)

 1.2. Established cigarette smoker without a history of e-cigarette use

6887

84.4 (83.3, 85.4)

4.1 (3.6, 4.7)

1.1 (0.9, 1.4)

10.4 (9.5, 11.4)

 1.3. Established cigarette smoker with a history of e-cigarette use

330

66.4 (60.9, 71.5)

23.1 (18.4, 28.6)

3.7 (2.1, 6.3)

6.8 (4.1, 11.0)

2. Exclusive e-cigarette user

580

12.0 (9.4, 15.4)

10.4 (7.9, 13.5)

45.0 (40.8, 49.3)

32.6 (28.2, 37.2)

 2.1. Experimental e-cigarette user without a history of cigarette smoking

120

7.5¹ (3.9, 13.9)

- ²

10.6¹ (5.7, 18.7)

80.6 (71.7, 87.2)

 2.2. Experimental e-cigarette user with a history of cigarette smoking

94

30.0 (21.1, 40.7)

- ²

14.4 (8.1, 24.3)

51.8 (41.0, 62.4)

 2.3 Established e-cigarette user without a history of cigarette smoking

77

8.2¹ (3.8, 16.6)

- ²

62.2 (49.8, 73.2)

25.9 (15.6, 39.7)

 2.4 Established e-cigarette user with a history of cigarette smoking

289

8.5 (5.8, 12.5)

16.8 (12.7, 21.9)

62.4 (56.7, 67.8)

12.3 (8.3, 17.7)

3. Dual user

2132

54.9 (52.1, 57.6)

28.0 (25.7, 30.3)

6.0 (4.8, 7.5)

11.1 (9.7, 12.7)

 3.1 Experimental dual user

1340

67.2 (64.1, 70.2)

13.4 (11.6, 15.5)

5.1 (3.8, 6.8)

14.3 (12.3, 16.7)

 3.2 Established dual user

792

34.3 (30.2, 38.6)

52.3 (48.0, 56.6)

7.6 (5.9, 9.9)

5.8 (4.3, 7.8)