title: Reducing salt intake for prevention of cardiovascular diseases in high-risk patients by advanced health education intervention (RESIP-CVD study), Northern Thailand: study protocol for a cluster randomized trial.
abstract: BACKGROUND
  Decreasing salt consumption can prevent cardiovascular diseases (CVD). Practically, it is difficult to promote people's awareness of daily salt intake and to change their eating habits in terms of reducing salt intake for better cardiovascular health. Health education programs visualizing daily dietary salt content and intake may promote lifestyle changes in patients at high risk of cardiovascular diseases.
  
  
  METHODS
  This is a cluster randomized trial. A total of 800 high-CVD-risk patients attending diabetes and hypertension clinics at health centers in Muang District, Chiang Rai province, Thailand, will be studied with informed consent. A health center recruiting 100 participants is a cluster, the unit of randomization. Eight clusters will be randomized into intervention and control arms and followed up for 1 year. Within the intervention clusters the following will be undertaken: (1) salt content in the daily diet will be measured and shown to study participants; (2) 24-hour salt intake will be estimated in overnight-collected urine and the results shown to the participants; (3) a dietician will assist small group health education classes in cooking meals with less salt. The primary outcome is blood pressure change at the 1-year follow-up. Secondary outcomes at the 1-year follow-up are estimated 24-hoursalt intake, incidence of CVD events and CVD death. The intention-to-treat analysis will be followed.Blood pressure and estimated 24-hour salt intake will be compared between intervention and control groups at the cluster and individual level at the 1-year follow-up. Clinical CVD events and deaths will be analyzed by time-event analysis. Retinal blood vessel calibers of CVD-risk patients will be assessed cross-sectionally. Behavioral change to reduce salt intake and the influencing factors will be determined by structured equation model (SEM). Multilevel regression analyses will be applied. Finally, the cost effectiveness of the intervention will be analyzed.
  
  
  CONCLUSIONS
  This study is unique as it will recruit the individuals most vulnerable to CVD morbidity and mortality by applying the general Framingham CVD risk scoring system. Dietary salt reduction will be applied as a prioritized, community level intervention for the prevention of CVD in a developing country.
  
  
  BACKGROUND
  ISRCTN39416277.
authors.affiliation: Department of Public Health, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan. dr.myonyeinaung@gmail.com
authors.forename: Myo Nyein
authors.initials: MN
authors.lastname: Aung
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Yuasa
authors.forename: Saiyud
authors.initials: S
authors.lastname: Moolphate
authors.forename: Supalert
authors.initials: S
authors.lastname: Nedsuwan
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Yokokawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kitajima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minematsu
authors.forename: Susumu
authors.initials: S
authors.lastname: Tanimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Yoshimune
authors.initials: Y
authors.lastname: Hiratsuka
authors.forename: Koichi
authors.initials: K
authors.lastname: Ono
authors.forename: Sachio
authors.initials: S
authors.lastname: Kawai
authors.forename: Eiji
authors.initials: E
authors.lastname: Marui
mesh_terms: D002318:Cardiovascular Diseases / Q000517:prevention & control*; D002985:Clinical Protocols; D006266:Health Education; D006801:Humans; D012306:Risk; D018401:Sample Size; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D013785:Thailand
chemical_list: D017673:Sodium Chloride, Dietary