Table 3.

The results of meta-analysis for cough score change (WMD).

Score system	Study	No. of placebo	No. of treatment	Pooled score change	P-value	Certainty in pooled estimates
	(n)	(n)	(n)	(95% CI)
P2X3 antagonist
LCQ	7	771	1510	1.637 (0.887, 2.387)	<0.001	High
Awake cough frequency (c/h)	4	162	352	−15.476 (−28.358, −2.594)	0.019	Moderate
Night-time cough frequency (c/h)	4	119	117	−1.782 (−5.813, 2.248)	0.386	Moderate
24 h cough frequency (c/h)	5	182	370	−11.042 (−21.306, −0.778)	0.035	Moderate
Cough severity VAS (mm)	8	761	1069	−11.075 (−17.496, −5.914)	<0.001	High
Urge to cough VAS (mm)	3	107	238	−13.16 (−21.938, −4.381)	0.003	Moderate
CSD total score	6	741	1381	−1.625 (−3.098, −0.151)	0.031	Moderate
TRP modulator
LCQ	2	37	35	−0.285 (−2.353, 1.783)	0.787	Moderate
Day-time cough frequency (c/h)	2	38	38	5.244 (3.405, 7.082)	<0.001	Moderate
24 h cough frequency (c/h)	2	41	41	2.597 (0.393, 4.800)	0.021	Moderate
Cough severity VAS (mm)	2	38	36	5.337 (3.445, 7.229)	<0.001	Moderate
Urge to cough VAS (mm)	3	57	54	0.159 (−3.583, 3.901)	0.933	Moderate
GABA modulator
LCQ	2	54	52	1.347 (0.466, 2.229)	0.003	Moderate
24 h cough frequency (c/h)	2	54	52	−12.929 (−33.858, 8.000)	0.226	Low
Cough severity VAS (mm)	2	52	48	−7.843 (−13.023, −2.663)	0.003	Moderate
Macrolide
LCQ	2	37	37	1.589 (0.245, 2.932)	0.02	Moderate

Abbreviations: WMD, weighted mean difference; CI, confidence interval; LCQ, leicester cough questionnaire; VAS, visual analogue score; CSD, cough severity diary.

Some medicines and outcomes were not available for meta-analysis due to the limited number of literatures.

Pooled score change, the absolute difference between the mean value in medication and placebo.

The certainty in pooled estimate was evaluated by GRADE.