The main objective of this study was to evaluate the policies adopted by the COVID-19 Disease Control Committee (CDCC) in Hamadan Province to control and reduce the risk of SARS-CoV‐2. Similarly, the present study quantitatively assessed the impact of regional government policies and decisions on COVID-19 disease risk using the Bayes network model. Our literature has shown that many studies have been conducted regarding the relationship between drug intervention and COVID-19 risk factors. No studies demonstrating the impact of government policies on reducing prevalence rates through statistical methods have been found. Therefore, this study stands out as a unique and unprecedented contribution. In this study, in addition to determining the magnitude and priority of each policy’s effect on disease risk, we engaged in a set of policies that may have the greatest control effect. Another strong point of this study is that control policies were mentioned according to their priority, while such prioritization was not introduced in any report. The implementation framework of this study can be used as a comprehensive model in other pandemics.
First, we extracted seven core policies based on CDCC reports in Hamadan Province and used the opinion of a group of experts for qualitative assessment. Then, we divided the seven situations into three models based on their conceptual and functional similarity and the modeling carried out. It is evident that the more restrictions are applied to control COVID-19 disease during the pandemic, the lower the risk of contracting the disease.
Unlike China (11) and Japan (8), who were able to prevent the rapid spread of COVID-19 by applying two or three restrictions such as confinement and personal hygiene, but this study showed that if several effective measures are applied simultaneously, we will thus obtain a more favorable result . . In other words, although each of the policies announced in this study can alone control the infection rate, identifying and evaluating a combination of policies and strategies adopted is effective in reducing the infection rate. ‘infection.
In this research, seven Bayes network models were implemented with different combinations of CDCC policies. After careful evaluation, the seventh model was chosen as the most optimal model due to its superior fit index, i.e., RMES, among them. Second, with a slight difference, the sixth model, which includes personal hygiene strategies, mask wearing, vaccination, travel restriction and job closure, was found to be a second predictive model.
To study the effect of implementing the seven policies included in the seventh model on predicting the probability of contracting COVID-19, the amount of each policy was increased to 30%, then the risk of infection was been increased.
The result of the seventh model clearly indicates that CDCC policies are able to reduce the infection risk to 3.72%, when restrictions are increased by 30%. Therefore, observing personal hygiene, wearing a mask, vaccination, travel restrictions, closing jobs, observing social distancing and limiting gatherings can significantly reduce the risk of contracting COVID -19.
In the study conducted, vaccination appeared to be an essential element in effectively reducing the transmission of COVID-19 disease. Although our study was conducted before the fifth peak in Hamadan province and the alpha and beta variants were also disseminated among the population, the expansion of public vaccination was more effective than other CDCC preventive policies. In England, researchers found that with two vaccinations, either BNT162b2 or ChAdOx1nCoV-19, the risk of contracting delta-COVID-19 can be reduced (17). The United States has also shown that when COVID-19 is spreading at a high level in a region, vaccination can increasingly and effectively reduce the spread and resulting deaths (18). Our results, like those of other studies, showed that vaccination is more effective than any other restrictive policy in reducing the spread of the disease. Therefore, it is strongly recommended that in the event of a pandemic emergency, individuals prioritize vaccination activities if a viable vaccine becomes accessible.
Our literature reviews show that social distancing is an effective way to contain the spread of an infectious disease, particularly when little is known about the virus and no vaccine or other drug intervention is available (19). Social distancing and isolation as well as other non-pharmacological measures such as hygiene and mask wearing have a direct impact on infection rates and therefore the spread of the virus (20, 21). In the present study, a notable observation was made regarding the effectiveness of social distancing as the third most crucial measure in disease control.
Social distancing and mask wearing were not identified as the first and second prevention factors in this study because the government was not able to carry out a complete lockdown and on the other hand people have been unable to fully supply masks due to financial issues. A study conducted in January 2021 in Hamadan showed that 13% of people did not wear masks among public passengers and social distancing was lower than the standard measure in Hamadan (22).
Of course, it is worth emphasizing that strict implementation of social distancing can lead to serious economic and psychological damage, as cited in some studies (19).
Adopting such light-touch preventive policies is more suitable for low/middle-income countries and low-income areas than the mandatory home quarantine method, which has occurred in Hong Kong and other high-income countries (23). It is emphasized that home quarantine is very expensive and is impossible for governments in the long term.
In addition to the restrictions mentioned previously, job closures may also play a role in reducing the spread of the virus. In Hamadan province, job closures were implemented according to a divisional schedule and modified according to the increase or decrease in the prevalence of SARS-CoV-2. This action was an appropriate strategy at that time. In Italy, we also found that business closures were carried out periodically, helping to reduce the spread of disease and mortality. In Italy, as in our study, it was noted that although closing businesses is effective in controlling the spread of the respiratory disease COVID-19, it must be carried out selectively and periodically (24).
One of the effective restrictions to reduce the spread of the virus is to limit travel. In China (11), where the implementation of travel restrictions was effective in reducing COVID-19 unlike Hamadan province, which may be due to the following reasons: First, in China, the restrictions were implemented under the form of complete confinement, while in this province, the movement of people has been limited. restrictions were only limited to a few hours of a day and business closures were also selectively enforced by the regional government. To clarify, in this study, commuting and some jobs were maintained due to economic and support issues during the COVID-19 pandemic, and people were traveling there to meet their daily needs and receive some services. Second, there were no family festivals in China and the population was entirely aligned with the government in this regard. But this was not possible due to family celebrations and the lack of cooperation of the population with the regional government. The application of the two policies of travel restrictions and job closures indirectly effects the two policies of observing social distancing and continuing to limit gatherings. In the current study, while social distancing and wearing masks were relatively acceptable in indoor settings, they appeared to be much less so in public passages and streets.
Comparing the policies adopted in this study with countries like China (11), South Korea (ten), Japan (8) and Vietnam (12), which helped prevent SARS-CoV-2 on a large scale, shows that compliance with personal hygiene rules, early detection of carriers and the provision of free sanitary products can quickly prevent the disease. In this study, the level of personal hygiene was estimated to be around 83%, but based on the Bayes network model, it was identified as the last effective policy to prevent COVID-19. Of course, this result is not far from expected. Note that during an infectious pandemic, the most important policy is to break the chain of disease transmission, such as vaccination, quarantine, and business closures. In this research, we found that measures such as vaccination, creating individual restrictions (e.g. staying away from large gatherings, closing jobs and avoiding unnecessary travel), respecting health principles ( for example, physical distancing and wearing a mask) are very important in reducing the prevalence rate of COVID-19.
Boundaries
We had several limitations in this study. First, many decisions were made only once during this period, which did not allow us to calculate a priori probabilities or proportions, and we inevitably had to exclude them from the modeling. For this reason, we were unable to assess the impact of these policies and decisions on reducing disease risk. Second, in Hamadan, there was no mechanism to trace suspicious and sick people. For this reason, we could not compare our results with those of other countries or examine the effect of such mechanisms on reducing the risk of COVID-19. Third, one of our problems was the lack of an accurate and up-to-date registration system. Therefore, a panel of experts was used in the implementation of the Bayes network model. Although we have tried to use experienced people on the panel, their opinion may not be completely accurate. It is suggested to use a fuzzy method (quantitative method) instead of the Delphi method (qualitative) to determine the conditional probabilities. Fourth, in Hamadan there was no possibility of total confinement for this duration. Therefore, it cannot be clearly stated that travel restrictions have a small effect on reducing the prevalence of this disease. Fifth, one of the obstacles to the progression of the Covid-19 disease lies in people’s knowledge. In this study, we did not have the opportunity to measure people’s knowledge.
