In the present study, we randomized 5 kitchens of a veteran’s
retired home in northern Taiwan into experimental and control
groups (Figure 1). When a veteran registered into the retired
home, he was assigned into one of 11 squads; each squad was
composed of 200 people, and 2 squads shared one kitchen. Of
5 kitchens (corresponding to 10 squads), 2 kitchens (corresponding
to 4 squads) were randomly assigned to use potassiumenriched
salt. The other 3 kitchens (6 squads) were randomly
assigned to use regular salt. The simplest randomization method,
ie, drawing lots, was used. Bed-ridden veterans were either assigned
to squad 12 or transferred to the veteran’s home located in
northeast Taiwan. Because the veterans in squad 11 shared the
kitchen with those in squad 12, they were excluded from
the study. The residents’ kidney function was examined before
the study. Persons with high serum creatinine concentrations (ie,
3.5 mg/dL) were asked to cook their meals separately and were
excluded from the study. The rest of the veterans ate food prepared
by the cook of the kitchen to which they were assigned. The
salt, which was manufactured by Taiwan Salt Work (Tainan,