Att 3_Overview of Protocol

Overview of Data Collection Protocol for the Salt Sources Study

Data will be collected through:

1. an observational study of sources of sodium intake among all participants aged 18-74 years (N=450 participants, 150 per site); and

2. a sub-study on 1/3 of the participants in the observational study (N=150 participants aged 18-74 in the observational study [50 per site]).

For each participant who is screened by telephone and consents to participate, data will be collected during an 11-day period according to the scheme shown in the table below.

Activity	Baseline visit	T 1	FUV 1a, c	T 2	FUV 2a	T 3	FUV 3a	T 4	FUV 4a
Consent	X
24-hour recall instructionsb /recall appts scheduled	X
Survey	X
24-hr diet recalls, food record and duplicate salt sample collectionc		X		X		X		X
Urine collection instructions/kits distributed a	X		X		X		X
Return 24-hr urine samplesa			X		X		X		X
Study salt distributeda,d			X		X		X
Study salt returneda					X		X		X
Incentives disbursede			X		X		X		X

T = telephone diet interview; FUV = follow up visit

^a Only for those participating in the sub-study.

^b Includes providing food amount booklet; duplicate salt collection kits.

^c Food recording and duplicate salt sample collection and recording will take place the day before the 24-hour dietary recall is scheduled.

^d Provide the study salt supplement to participants enrolled in the sub-study beginning at FUV 1

^e The incentive for completing the 24-hour dietary recalls will be mailed to those not participating in the sub-study.