The prevalence of hypertension among Chinese residents is high while the control rate is low. It has been suggested by numerous epidemiologic studies that reducing salt intake could reduce blood pressure level. Therefore, it is significant for health management of residents and reducing social burden to explore determinants of salt-reduction behavior among residents.

To explore the predisposing, reinforcing and enabling factors of salt-reduction behavior among Shandong residents based on the PRECEDE model, and provide scientific suggestions for the subsequent salt-reduction campaign.

This study was a mixed methods research. A total of 114 residents were interviewed in 2016 and 2018 by using purposive sampling method. The interview guide mainly contained attitudes to salt control, difficulties encountered and assistance received during salt control. The quantitative data were obtained from the database of terminal survey of Shandong and Ministry of Health Action on Salt and Hypertension (SMASH), and the sample of eastern as well as central-southern Shandong from the database was selected into this research. The part related to hypertension among this survey was selected from the database, and a total of 6 697 research objects were finally selected.

The results of multinomial Logistic regression showed that gender, occupation and education level have an impact on the compliance of salt reduction behavior controlling for the effect of other variables (P<0.05). Personal taste, salt reduction knowledge and attitude towards low-salt diet have an impact on salt reduction behavior compliance while controlling for the effect of personal general conditions (P<0.05). Physician intervention could reinforce salt-reduction behavior in residents. The health education of medical personnel could not only enhance the salt-reduction behavior and awareness of hypertensive patients, but also strengthen the supervision of family members. Through enhancing family members' salt-reduction behavior and awareness, and finally promoting salt reduction among residents. Supervision by family members in daily life can strengthen salt-reduction behavior of the residents. SMASH had formulated policies involved in the project promoting, catering industry, food industry and health education about salt-reduction, which playing very important role in creating strong salt-reduction environment. The salt-restriction spoon was the most important low-salt product in affecting residents' salt-reduction behavior, while the impact of low-salt food and low-sodium salt in reducing salt intake was weakened because of the poor accessibility. Mass media promotion was the main way for residents to obtain information on salt reduction. Television and promotion in public places were the more visible forms of mass communication currently.

Attitude towards low-salt diet and knowledge are predisposing factors of residents' salt-reduction behavior. Exhortation of doctors and reminding from family members were reinforcing factors, which can help residents to start out reducing salt intake and also reinforcing salt-reduction behavior. The salt-reduction environment was created by policies regarding salt-reduction and mass communication, products regarding salt restriction were essential tools for reducing salt intake, which are enabling factors.