Table 2

Associations of trial characteristics with the effects of salt substitute on blood pressure in univariable metaregressions

	Modelled trial characteristic	Trials (n)	Participants (n)	Coefficient (95% CI)	P value
SBP	Higher mean age per 10 years	19	29 528	−0.84 (−2.10 to 0.41)	0.188
	Higher proportion male per 10%	19	29 528	0.76 (−0.90 to 2.42)	0.369
	Higher mean body mass index per kg/m²	16	26 630	0.13 (−0.77 to 1.03)	0.771
	Higher mean SBP per mm Hg	18	29 672	−0.06 (−0.15 to 0.03)	0.223
	Higher mean DBP per mm Hg	18	29 672	−0.07 (−0.25 to 0.12)	0.483
	Higher mean 24-hour urinary sodium per 1 g	12	25 378	−1.00 (−3.23 to 1.23)	0.380
	Higher mean 24-hour urinary potassium per 1 g	12	25 378	−0.57 (−2.75 to 1.61)	0.610
	Lower proportion NaCl in salt substitute per 10%	18	29 328	−1.53 (−3.02 to −0.03)	0.045
	Higher proportion KCl in salt substitute per 10%	18	29 328	−1.50 (−3.51 to 0.51)	0.143
	Longer duration of intervention per month	19	29 528	0.08 (−0.00 to 0.17)	0.057
DBP	Higher mean age per 10 years	19	29 528	0.09 (−0.72 to 0.90)	0.827
	Higher proportion male per 10%	19	29 528	−0.06 (−1.03 to 0.92)	0.909
	Higher mean body mass index per kg/m²	16	26 630	−0.14 (−0.71 to 0.42)	0.611
	Higher mean SBP per mm Hg	18	29 672	−0.01 (−0.06 to 0.04)	0.647
	Higher mean DBP per mm Hg	18	29 672	−0.04 (−0.14 to 0.07)	0.514
	Higher mean 24-hour urinary sodium per 1 g	12	25 378	−0.14 (−1.43 to 1.16)	0.834
	Higher mean 24-hour urinary potassium per 1 g	12	25 378	−0.92 (−1.99 to 0.15)	0.093
	Lower proportion NaCl in salt substitute per 10%	18	29 328	−0.95 (−1.78 to −0.12)	0.025
	Higher proportion KCl in salt substitute per 10%	18	29 328	−1.23 (−2.54 to 0.08)	0.065
	Longer duration of intervention per month	19	29 528	0.03 (−0.02 to 0.08)	0.253

Note: Metaregressions were done using a Sidik-Jonkman random-effects metaregression.
DBP, diastolic blood pressure; SBP, systolic blood pressure.