Table 1.

Characteristics of included “intervention” studies

Study	Country	Study design	Study population	Intervention	Method of assessment	Results
Lofthouse et al (2016)	New Zealand	Mixed‐methods pilot study	11 volunteers aged 18–65 y	Low‐salt diet education by dietitians over 4 wk	One 24‐h urine collection A 2‐d nonconsecutive weighed diet record One 24‐h diet recall	Baseline mean urinary sodium was 2342 mg/d and dietary sodium intake 3221 mg/d, shown to decrease on follow‐up by 18% and 53%, respectively. Substantial behavior changes were required to decrease sodium intake.
Do et al (2016)	Vietnam	Repeat cross‐sectional study	509 baseline and 511 follow‐up participants aged 25–64 y living within the wards and communes of Viet Tri city	Communication for Behavioral Impact (COMBI) Intervention, conducted for 1 y (June 2013–June 2014)	Spot urine samples Questionnaire Blood pressure	A small but significant decrease in salt excretion was observed from baseline to follow‐up (8.48 g/d to 8.05 g/d) along with a large significant increase in favorable salt knowledge and behaviors. A statistically significant decrease was also observed for systolic and diastolic blood pressure.
Takada et al (2016)	Japan	Cluster, randomized controlled trial	35 housewives aged 40 y or older (18 intervention, 17 control) and 33 family members aged 20 y or older (18 intervention, 17 control)	2× cooking classes showcasing reduced‐salt cooking practices for intervention housewives. Controls received lectures on general healthy eating.	Spot urine samples Blood pressure	Following intervention there was a small increasein salt intake in the control group (10.00–10.3 g/d) compared with a reduction inthe intervention group (9.57–8.95 g/d), resulting in a mean difference between the groups of −1.19 g/d (P = .034). Changes in blood pressure were not significant.
Park et al (2016)	South Korea	Single‐arm pilot intervention using a pre‐post design	49 restaurant owners or cooks in the business district of Seoul	Education, health examination, and counseling of restaurant personnel	Questionnaire on salt KAB Urine dipstick tests	Participants with lower estimated sodium intake reported more favorable sodium‐related KAB such as “it is necessary to use healthy cooking methods for customers.”
Irwan et al (2016)	Indonesia	Randomized controlled trial	51 participants three groups: control (n = 17), salt reduction training (n = 17), and salt reduction and efficacy maintenance (n = 17). All aged <60 y with diagnosed or undiagnosed hypertension	Two 90‐min educational training sessions over 2 d within 1 wk	12‐item “knowledge of hypertension” questionnaire 7‐statement “attitudes towards self‐care” questionnaire Salinity checker of urinary sodium Salt meter assessment of salt in foods	There was no significant decrease in urinary sodium between the two intervention groups and the control group; however, the intervention groups reported that they added less salt. No significant difference was observed for participants’ knowledge, yet self‐efficacy to decrease salt intake significantly increased in both intervention groups compared with the control group.
Li et al (2016)	China	Cluster randomized trial	2380 adult participants from 120 villages in rural northern China (60 control villages and 60 intervention villages)	Community‐based sodium reduction program. Of the intervention villages, half received a subsidy on a salt substitute	One 24‐h urine collection onfollow‐up Sodium to potassium ratio Questionnaire (KAB) Blood pressure	Intervention group had a statistically significant lower sodium excretion than controls (by 5.5%, 237 mmol/d vs 251 mmol/d; P = .03). There was also a decline in the sodium to potassium ratio of 15%. There was no evident significant change in blood pressure. There was a higher uptake of salt substitute use in the villages with the subsidy compared with those without.
Curtis et al (2016)	United States	Repeat cross‐sectional study	National Salt Reduction Initiative (NSRI) packaged food database. 61 food categories, sales, sodium content, and serving size data in 2009, 2012, and 2014 with 6336, 6898, and 7396 products, respectively	2009 sodium targets published, and companies were asked to publicly commit and meet the 2012 and 2014 targets	Percentage of companies meetingtargets Percentage of products meetingtargets Change in sales‐weighted sodiumdensities overall and in specificfood categories	A quarter of food categories met the 2012 target in 2014, with 3% meeting the 2014 targets. Overall, sales‐weighted mean sodium density decreased from 2009 to 2014 by 6.8% (P < .001).

Abbreviation: KAB, knowledge, attitudes, and behaviors.