. 2021 Mar 23;16(3):687–696. doi: 10.1007/s11739-021-02674-3

Table 2.

Comparison of controls and HTP users at baseline, 12-, 24- and 36-month follow-up visits

	Baseline	12-month follow-up	p value^c	24-month follow-up	p value^c	36-month follow-up	p value^c	Overall between group p value from baseline
COPD controls (n = 19)
Post-BD FEV1^a (L)	1.46 (1.19, 1.68)	1.41 (1.17, 1.68)	0.614	1.36 (1.18, 1.67)	0.872	1.47 (1.18, 1.62)	0.643	0.469
Post-BD FVC^a (L)	2.36 (2.1, 2.61)	2.27 (2.2, 2.71)	0.135	2.31 (2.16, 2.81)	0.251	2.3 (2.08, 2.57)	0.149	0.385
%FEV1/FVC^b	60.5 (± 6.8)	59.4 (± 6.7)	0.631	59.2 (± 6.8)	0.575	60.8 (± 8.7)	0.594	0.239
Cig/day^b	20.6 (± 3.7)	20.2 (± 3.8)	0.764	19.8 (± 5.0)	0.657	19.6 (± 4)	0.650	< *0.001*
CAT score^a	19 (17.5, 24)	20 (18, 22)	0.284	20 (15.5, 24.5)	0.520	20 (18, 23)	0.709	*0.008*
COPD exacerbations^b	2.2 (± 1.1)	2.2 (± 1)	0.878	2.1 (± 1.1)	0.833	2.1 (± 0.9)	0.728	*0.024*
6MWD^a,d	250 (202.5, 361.8)	270 (210.5, 368.8)	0.872	263.5 (225.5, 374.8)	0.182	270 (216, 362)	0.155	*0.001*
COPD HTP users (n = 19)
Post-BD FEV1^a (L)	1.27 (0.98, 1.78)	1.33 (0.99, 1.77)	0.120	1.39 (1.05, 1.72)	0.064	1.30 (1.02, 1.79)	0.257
Post-BD FVC^a (L)	2.59 (2.07, 2.7)	2.6 (2.07, 2.76)	0.277	2.57 (2.02, 2.91)	0.296	2.55 (2.03, 2.93)	0.376
%FEV1/FVC^b	57.2 (± 10.1)	57.1 (± 10.5)	0.980	58.1 (± 10.2)	0.798	57.3 (± 10.3)	0.984
Cig/day^b	20.5 (± 3.4)	1.5 (± 2)	< 0.001	1.2 (± 1.8)	< 0.001	1.2 (± 1.8)	< 0.001
CAT score^a	20 (17, 24.5)	16 (14.5, 20)	<0.001	17 (14.5, 19)	0.001	15 (13, 21)	0.006
COPD exacerbations^b	2.1 (± 0.9)	1.4 (± 0.8)	0.012	1.2 (± 0.8)	0.002	1.3 (± 0.8)	0.004
6MWD^a,d (m)	281 (185, 344)	310 (219.5, 370)	0.004	333 (224, 370)	0.003	350 (249, 396)	0.005

Significant differences are noted in bold

Bolditalic indicates significant comparison

COPD chronic obstructive pulmonary disease, HTP heated tobacco product, n number, BD bronchodilator, L litre, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, Cig conventional cigarettes, CAT COPD assessment tool, 6MWD 6-minute walk distance, m metres

^aMedian (interquartile range)

^bMean (± standard deviation)

^cWithin-group p value vs baseline

^d11 subjects in the COPD HTP user group and 11 in the COPD control group at all 3 follow-up visits