Randomised trial on effect of involving media reporters in salt reduction programme to increase media reports and the public’s knowledge, belief and behaviors on salt and health: Changzhi reporters trial

Objective To assess the effects of a novel mass media intervention in increasing media reports on salt and health by involving media reporters in a scientifically well designed salt reduction trial. Methods We recruited and trained 66 media reporters in Changzhi, Shanxi province, China to conduct a randomized controlled trial on blood pressure lowering effect of salt substitute in Dec, 2012 and Jan 2013 among their own relatives or friends (253 from 129 families in the salt substitute arm and 263 from 133 families in the control arm for two months). We shared trial results and other information on salt and health with the reporters within a month after the trial. We monitored all local newspapers for the number of relevant articles in 3 months before, 3 months during and 3 months after the intervention and at the 6th, 12th, 18th, 24th and 48th months after the intervention. Additionally, we conducted two independent surveys on knowledge, belief and behaviours of salt and health among local citizens before and after the intervention. Results As expected, systolic blood pressure was reduced significantly more in the salt substitute than the control group (-4.7±11.0 mmHg vs -2.6±10.3 mmHg, p<0.001) in the randomized trial. The monthly mean number of relevant articles increased from 0.7 before to 1.7 during (p = 0.263), and further to 6.0 after the intervention (p<0.001), and varied from 2 (p = 0.170) to 4 (p = 0.008) from the 6th to 48th month; the awareness of knowledge on salt and health among local citizens improved significantly after the intervention. Conclusions Media reporters’ participation in a well-designed salt reduction trial significantly increased the number of relevant media reports, and the effect was sustained for a prolonged period. Future mass media public health education programs should consider this innovative strategy for better and sustained impacts.


1) Current situation of cardiovascular diseases and hypertension
Both in developed and developing countries, cardiovascular and cerebrovascular diseases have become one of the leading causes of death among residents. According to the China Cardiovascular Disease Report 2007, the estimated number of cardiovascular diseases in China is at least 230 million cases, and 3 million cases die every year from about 40% of the total causes of death of cardiovascular and cerebrovascular nationals, is the number one killer of our residents. There are many risk factors for cardiovascular and cerebrovascular diseases, among which hypertension is the most important risk factor for Chinese residents.
2) Effects of low-salt diet on blood pressure The results of the survey on nutrition and health status of Chinese residents in 2002 showed that the higher the amount of salt, the higher the systolic and diastolic blood pressure levels of the population, compared with 6 g < daily salt intake, 12 g of daily salt intake increased the risk of hypertension by 14%, and 18 g of daily salt intake increased the risk of hypertension by 27%. Many observational studies 5,6 and randomized clinical trials4,7,8,9 have shown that reducing salt intake lowers blood pressure levels. At the same time, the decrease of blood pressure can reduce the risk of cardiovascular and cerebrovascular events 10, 11, 12. Salt is like an invisible killing Hand ", will unconsciously make people suffer from high blood pressure and other cardiovascular and cerebrovascular diseases; low-salt diet is precisely an economic, better effect of prevention of cardiovascular disease measures.

3) The role of mass media in health education
The mass media is the main source of public health information, whether at the individual or the mass level, the health information transmitted by the mass media will affect the public's perception of health. In a sense, the mass media constructs the concept of people's health in daily life, affects the way of life of ordinary people, and changes the bad habits of ordinary people.
Combined "health education" and "mass media" effectively, through the mass media to strengthen the effective dissemination of health policies and health knowledge, enhance people's awareness of health, popularize knowledge of disease prevention, develop good hygiene habits, choose the right health behavior and lifestyle, will play an important role in the prevention of disease (especially with health, living habits and other close relationship between cardiovascular and cardiovascular disease prevention) process. Therefore, integrating health education into the mass media is a long-term, large-scale, strong impact of health education mode 14.
In the past, newspapers and radio were the main means of disseminating information to the public. Nowadays, the emergence and development of new media, such as TV, Internet, mobile phone and so on, make the influence range and strength of mass media more and more, and make effective use of mass media to carry out health education. By repeatedly propagating in the mass media, the Japanese government made people aware the harm of salt in their daily work and life, and effectively changed the bad eating habits according to the method of media propaganda. Compared with the late 1950s, the death rate of stroke in Japan decreased by 80%.

4) Role and influence of journalists in the media
The media reporter is the general name of the media personnel engaged in information collection, compilation and news reporting, is an essential part of the mass media, is the leader of the mass media, and determines the leading direction of the mass media speech.
The main duty of media reporters is to be close to the masses, to life, to reality, to reveal sharp social contradictions from a keen perspective, to pay attention to profound social problems, and to record the social changes bit by bit. The reporter is not only the transmitter of the real information, the watchman of the environment, but also the enlightenment of the people's thought in a certain sense. In old times In the eyes of the surname, the voice of the reporter is the voice of the government, the behavior of the reporter is the right action, and the reporter is the embodiment of justice. Therefore, the influence of journalists' words and deeds is much higher than that of other people. If the reporter can through the mass media platform, combined with a variety of forms, longterm active and active participation in health education, the effect of health education will be far more than the general form of health education, play a multiplier effect with half the effort.

5) The significance of this study
To sum up, the popularization of public health knowledge needs the participation of mass media, and the combination of health education and mass media has become a new inevitable trend. As the main body of mass media, media journalists guide the leading direction of mass media speech, and their attitude to health education knowledge will directly affect the long-term effect of health education. Therefore, how to effectively mobilize the initiative and voluntary participation of media journalists in health education is a topic worthy of discussion. Through this research, we hope to explore the effective ways to stimulate the enthusiasm of media journalists, and provide the basis for the sustainable and efficient development of the health education role of mass media in the future.

RESEARCH PURPOSES
General purpose: The research aims to assess the effects of a novel mass media intervention in increasing media reports on salt and health by involving media reporters in a randomized trial on blood pressure lowering effect of salt reduction.
Specific objectives: 1) Increase the number of media reports on salt and health in the local media over the short and long-term by involving the reporter as a researcher to observe the actual effect of the salt reduction in lowering blood pressure among their own families, neighbours or relatives, .
2) Change the population's knowledge, belief and behaviours on salt intake and health among local citizens.

Study design
We employed a before-and-after comparative study design to evaluate the effects of the intervention. Using the pre-intervention comparison as the main design, we evaluate whether the innovative ideas put forward in this topic (let the reporter as a researcher to observe the actual effect of the salt reduction test to affect the behavior and quantity of their writing and reporting related health knowledge) are effective for the intervention of journalists. The intervention to journalists is actually to invite journalists to participate and be responsible for the implementation of a rigorous randomized opencontrol trial to personally evaluate the effect of low sodium salt on lowering blood pressure. The invited reporter will be responsible for the subjects selected in the randomized controlled experiment, measure the effect of lowering blood pressure, and report the measurement data through the network to obtain the evaluation results of all the subjects.

general route
Collect the content and quantity of the media salting-down reports designated within 3 months before intervention; Street interception survey of 350 people, survey of the Baseline data collection masses of salt reduction related information awareness; Collection of the Basic Information Table for Participating Journalists; Collate the basic information form of participating family that reporter reports.

Low sodium salt intervention
The reporter measured the blood pressure himself and recorded the blood pressure value Intervention Information intervention

Post-interventi on survey
To collect the content and quantity of relevant media reports on desalination within 3 months ,6 months and 12 months after intervention; Street interception survey of 350 people, re-investigating the people on salt reduction related information knowledge Number of reports collecting information before and after intervention The reporter personally measured

1) Selection criteria for media journalists
a. Professional journalists with press cards, health columnists are preferred; b. To reside in the Changzhi region within the next 12 months; c. There are at least four close, accessible families of relatives or friends, and at least two ≥50 year old members of each family eat at home three meals a day; d. Voluntary participants after informed consent.

2) Information interventions
The third month of intervention, the project team through the press conference, email, SMS and other forms, timely feedback of the results of the intervention to the participating journalists. At the same time, through the above form, a lot of knowledge about the relationship between salt reduction and health is disseminated to participating journalists.

Indicator 1: Number of relevant reports on salt reduction knowledge
• Intervention objectives: The amount of salt reduction information reported by relevant media in 3 months after intervention was 100% higher than that in 3 months before intervention.
• Information collection: All news reports on salt-related content require collection, including: a. The prevention and treatment of chronic non-communicable diseases, which contains salt-related elements; b. Report on health effects of low/high salt diet; c. Reports on the classification and characteristics of salts; • Collection scope: Changzhi Daily (including health. Comprehensive section), Evening News (including Health Weekly) • Collection methods: Data are collected every 1 week by specialists using a retrospective recording method.
Check the first week of "Changzhi Daily" and "Shangdang Evening News" electronic version, record the required reports; Order Changzhi Daily and Shangdang Evening News to supplement the missing parts of the electronic version.
• Collection schedule: Stage 1: 3 months before intervention, collect the reports that meet the requirements.
Stage 2: 3 months during intervention, collect the reports that meet the requirements.
Stage 3: 3 months after intervention, collect the reports that meet the requirements.
Stage 4: the sixth month after the intervention, collect the report that the month "Changzhi Daily" and "Shangdang Evening News" meet the requirements.
Stage 5: the 12th month after the intervention, collected the report of the relevant knowledge of Changzhi Daily and Shangdang Evening News in that month.
• Quality control: by the project site responsible personnel, the first five days of each month all related media-related information reported content and quantity.

Indicator 2: Awareness of Salt Reduction Knowledge
For the resident convenience sample surveys, with reference to previous studies [38], we assumed that the proportion of Chinese residents with the knowledge, belief and behaviour on salt intake and health in this part of China was 30%,60% and 30%. We assumed α = 0.05,so a study sample size with 400 individuals in each survey would have 85% power to detect an effect size of 10% change in each of these proportions.On the weekend before and after the intervention ,people who were passing by and willing to be investigated were investigated by means of street interception survey in front of Xiamen and August 1 Square, Changzhi City, where the flow of people was relatively large. e. Voluntary participants after informed consent.

2) Calculation of sample content
As a result of this study, the blood pressure of the intervention group and the control group was compared, considering that the family was the random unit, and the analysis was carried out at the individual level, so the sample size was calculated by using the two sample mean comparison process designed randomly in the PASS11 software group: Assuming that 2 family members per household, with an internal blood pressure correlation coefficient ICC=0.2(no intra-group correlation data between family members is currently available), a minimum of 180 families (90 in each group) are required to obtain a 90% assurance (1-β), at a standard deviation of 13.4 mmHg15 at a significant level of 0.05 to identify 5 mmHg of blood pressure inter-group differences.
Considering the 10 per cent drop-out rate at the end of the study, 200 families were eventually required; each journalist was responsible for 4 families and required 50 journalists.
If the case of ICC=0.4 is considered, a minimum of 216 families (108 per group) is required, and a 10 per cent rate of missing visits is considered, resulting in 240 families and 60 journalists.
Based on the calculation results, it was preliminarily determined that 60 journalists, 240 families and about 480 family members were selected to participate in the study in the local media.

3) Random grouping method
In this study, families were grouped according to the simple random method: Step 1: is to divide the four families chosen by each reporter into two groups according to the principle of age matching, each group of two families; Step 2: Two families in each group were numbered 1 and 2 in the reporting order.
Step 3: Using the random number table, prepare two-digit random numbers for families in turn.
Step 4: The larger group of random numbers was marked as A( defined as the intervention group), and the smaller group was B( defined as the control group). Examples:

4) Intervention -Low Sodium Salt Intervention
The intervention lasted 2 months and was randomly assigned to the families of the intervention group. The low sodium salt for 2 months was presented free of charge by the project department. The low sodium salt must be consumed during the intervention; the control group did not receive any intervention.
Low sodium salt distribution takes the form of direct distribution by designated express delivery companies to the intervention group families.

5) Evaluation indicator -blood pressure
• Subjects: Participation in family members is over the age of 50.
• Blood pressure measurement requirements: Blood pressure measurement work required to participate in the study reporter personally completed and recorded blood pressure values; Morning, fasting blood pressure; sit at least 5 minutes before measuring blood pressure; measure right arm blood pressure, re-test twice, take the average value; if the difference between systolic or diastolic blood pressure readings measured twice >5 mmHg, then measure again after 2 minutes apart, then take the average of 3 readings.
Sphygmomanometer by the project department unified equipment, the measurement method refers to the sphygmomanometer.
• Measurement cycle: Blood pressure was measured twice at the beginning of the intervention, at the end of intervention.
Project managers will be in the corresponding time points, using SMS, e-mail and other forms to remind reporters for blood pressure measurement.
• Data upload: After measuring blood pressure, the reporter should fill in " Table 4, the reporter measures the blood pressure list of the family members involved in the study ", and the blood pressure value measured on the same day through text messages, e-mail and other forms to report to the data manager.

Quality control
The quality control personnel of the project department, within the required time period, extract some family members to measure blood pressure.

Statistical analysis plan
EpiData software was used to establish database, input and manage data; and SPSS 20.0 was used for all data analysis.
1) The difference in number of relevant reports published in the media between pre-and post-intervention were analyzed and compared; 2)The changes of blood pressure of family members in intervention group, control group and intervention group before and after intervention were analyzed and compared; 3)The changes of people's cognition of salt reduction before and after the intervention were analyzed andd and compared

Why do we do this research?
Observe the effect of low sodium salt on blood pressure and improve the bad eating habits of the participants.

Who can participate in this project?
Families close to the reporter, easy to follow-up, at least one family member aged over 50 years old. Nearly 480 people participated in this study.

What do participants do?
At the beginning of this study and at the end of two months, you need to cooperate with your reporter friends to give you free blood pressure measurement.

How long does the project last?
The study will last for 2 months, during which you are free to opt out.

What are the risks of the project?
There is no risk in this study and no loss will be caused to you. And you don't have to bear any costs.

What are the benefits of the project?
During the study, your reporter friend will take your blood pressure regularly.
If in the low sodium salt intervention group, you and your family can also get free low sodium salt for 2 months.

Will my information be kept secret?
Your personal privacy will not be involved in the research, and your personal information will be kept confidential. At the end of this study, your information collected will be deleted and destroyed, and your personal information will not appear in our research report.
Do I have the right to refuse to participate or withdraw?
It is up to you to decide whether to participate in the study. If you want to quit at any time during the study, you are free to leave without giving any reason. If you don't want to, you can refuse to provide any personal information or medical records. Your decision to refuse to participate or quit will not penalize you or lose any of the benefits you have won.

If I have any questions, who can I contact?
If you have any questions about participating in this survey, please contact the project leader in the following ways: