Table 4.

Improvement of cough over time with no treatment (placebo)

Publication	Control Treatment	Time point, days	Patients analysed	Outcome definition	Baseline, mean (95% CI)	Follow-up, mean (95% CI)	Change from baseline (95% CI)	MID
Wang et al, 2014²⁶	Placebo	14	Baseline: 139 Follow-up: 139^a	Change in the Leicester Cough Questionnaire	10.10 (9.6 to 10.6)^b	NR	3.6 (2.9 to 4.3)^c	1.3
Wang et al, 2014²⁶		28	Baseline: 139 Follow-up: 139^a		10.10 (9.64 to 10.57)^b	NR	5.9 (5.1 to 6.7)^c	1.3
Zanasi et al, 2014²⁷	Placebo	10	Baseline: 46 Follow-up: 42	The change in both daytime and nighttime cough severity	Daytime: 3.49 (3.28 to 3.70)^{^b,^d} Nighttime: 1.38 (0.99 to 1.77)^{^b,^d}	Daytime: 2.14 (1.73 to 2.55)^b Nighttime: 0.74 (0.49 to 0.99)^b	NR	NR
Zanasi et al, 2014²⁷		20	Baseline: 46 Follow-up: 42		Daytime: 3.49 (3.28 to 3.70)^{^b,^d} Nighttime: 1.38 (0.99 to 1.77)^{^b,^d}	Daytime: 0.64 (0.38 to 0.90)^b Nighttime: 0.17 (0.04 to 0.30)^b	NR	NR
Woodcock et al, 2010²⁸	Placebo	5	Baseline: 30 Follow-up: 30	Change in cough severity scores	2.01 (NR)	1.52 (NR)	−0.49 (NR)	NR
Ponsioen et al, 2005³⁰	Placebo	14	Baseline: 68 Follow-up: 68	Cough score	3.8 (3.56 to 4.04)^b	1.9 (NR; SEM 0.1)	NR	NR
Pornsuriyasak et al, 2005³¹	Placebo	14	Baseline: 15 Follow-up: 15	Symptom score	9.8 (8.59 to 11.02)^b	4.27 (2.58 to 5.96)^b	NR	NR
Pornsuriyasak et al, 2005³¹		28	Baseline: 15 Follow-up: 12		9.8 (8.59 to 11.02)^b	2.66 (1.00 to 4.32)^b	NR	NR

↵a Missing data imputed by study authors using last observation carried forward: 14 days: 17; 28 days: 29.
↵b 95% CI calculated by us from standard deviation.
↵c Higher Leicester Cough Questionnaire score indicates higher quality of life; that is, the result is in favour of the control. For all other cough scores lower values indicate fewer cough symptoms.
↵d Values extracted from figure. MID = minimally important difference. NR = not reported. SEM = standard error of mean.