Evaluation Of The Effect Of Salt-reduction Intervention In Population Level

Objective:To compare the changes of salt reduction knowledge,salt reduction attitudes and salt reduction behaviors in four cities(districts)of Shandong Province and Jiangsu Province,and to evaluate the effects of salt reduction KAP by salt reduction intervention in population level,to analyze the effects of salt reduction knowledge,salt reduction attitudes and salt reduction behaviors.Analyze the influencing factors of salt reduction knowledge,salt reduction attitudes and salt reduction behaviors,and summarize the intervention experience,provide scientific basis to formulate salt reduction intervention measures in line with China’s national conditions.Methods:This study is a community intervetion trial which using a multi-stage cluster random sampling method sample 9,600 people from four counties in Shandong and Jiangsu provinces(Gaomi and Fushan located at Shandong Province,Xinyi City and Ganyu located at Jiangsu Province),and each county sampled 2,400 people.Baseline survey was conducted in two counties of Shandong Province as intervention group and two counties in Jiangsu Province as control group.The intervention time was 4 years.The final survey was conducted in October 2017.Questionnaire survey and physical measurement survey were used including the general situations,disease history,living habits,and salt-reduction KAP.Those indicators were used to describe by the X±SD,median and quartile frequency(rate).When comparing the difference between two groups,t test.Wilcoxon rank sum test,x2 test and Fisher’s exact probability analysis was used.In the evaluation of intervention effect,the total score of salt reduction knowledge,belief and practice and its influencing factors were analyzed by PSM-DID combined with median regression;.the high level of salt reduction KAP,the items of salt reduction knowledge,belief and practice,the changes of intervention process indicators and the influencing factors of salt reduction KAP indicators were analyzed by PSM-DID combined with logistic regression,and to explore the relationship between the knowledge,attitude and intervention measures of salt reduction.Results:There were 9600 people in baseline surveys,and 9573 were qualified.After 4 years of intervention,6268 people were followed up.The follow-up rate was 65.54%.The follow-up population was more females than males in the two groups.The average age of the control group was(46.88±13.55)years old and the intervention group was(51.08±12.15)years old,and the difference between the two groups was statistically significant(t=-12.64,P<0.0001).The occupation,BMI,education level,and hypertension were different in the two groups(P<0.05).PSM-DID method found that adjusting the age,gender,occupation,education level,hypertension,regional and BMI,smoking,drinking,exercise,the net effect of intervention increased the total scores of salt-reduction knowledge by 13.22(10.83-15.62).The probability of a high level of knowledge awareness increases by 21.15%.The net effect of the intervention group was higher than the control group,and the results in most of the models were statistically significant.And in all models,the net effect of intervention on salt recommended intake standards was not statistically significant.PSM-DID analysis found that the net ef’fect of intervention increased the probability of the intervention group holding a high level of salt reduction by 9.14%after adjusting the age,gender,occupation,education level,hypertension,regional and BMI,smoking,drinking,exercise.The net effect of the intervention also made the possibility of holding the low-salt diet not affecting the taste of food by 14.45%,and it also increased the probability of "who don’t think that I don’t need a low-salt diet as long as I am not sick" by 16.10%.PSM-DID analysis of the implementation of salt reduction behaviors,after adjusting the basic conditions such as age,gender and BMI,smoking,drinking,exercise and other adjustment variables,the net effect of intervention increased the total score of salt-reduction behaviors by 28.73(26.27-31.19).The net effect of intervention increases the probability of a high level of salt reduction behaviors by 23.44%.It was also found that among the knowledge of salt reduction,"hearing about low sodium salt","knowing the use of quantitative salt spoon"and"knowing food nutrition label on food packaging" and attitude of salt reduction,"propagating low salt diet among the people" and "propagating low salt diet" and"propagating low salt diet" and intervention methods,"medical personnel" and "news media" had the stronger influence on salt reduction behavior.Influencing factors analysis found that age,gender,occupation,education level,region and exercise were all associated with salt reduction behaviors and the total score and high level of salt reduction knowledge.Among them,older people contribute to the increase of salt reduction behavior,while younger people contribute-to the increase of the overall level of salt reduction knowledge.And we found that junior middle school level is more conducive to the increase of salt reduction knowledge and the possibility of high level occurrence of salt reduction behavior than senior high school level or above.Men,farmers,forestry,animal husbandry,fishermen,elementary schools and below,non-hypertension,non-smoking and non-exercise all decreased the possibility of holding a high level of salt reduction attitudes.Conclusions:On the whole,the intervention measures for salt reduction in Shandong indicated that the increase of salt reduction knowledge,salt reduction attitude and salt reduction behaviors,and the intervention effect was significant.Knowledge of salt reduction,most salt reduction attitudes and education about low-salt diets was conducive to the implementation of the total score of salt reduction and the possibility of taking active salt reduction measures.The older men are more conducive to the increase of salt reduction behavior than the younger ones,but inhibit the increase of knowledge of salt reduction.The intervention net effect has less effect on the knowledge of recommended salt intake,the attitude of the intention to eat less salt and the behavior of eating low-sodium salt.Therefore,salt reduction intervention,for example,the use of quantitative salt spoon,low sodium salt and the propaganda of salt reduction knowledge related to nutrition label,can promote the holding of attitude of "low salt diet does not affect the taste" and "in favor of promoting low salt diet in the population".Strengthen health education for junior high school students and promote salt reduction activities for the elderly.