Scales Used to Assess Stress Level and Mental Health During the Covid 19 Pandemic: Systematic Review

This systematic review aims to identify the scales used in studies related to the impact of COVID 19 on the increase in mental disorders. Initially, 265 studies that met the review criteria were included. The use of 411 different scales was identified. It was found that only 20% of studies use the same scales. Conclusively, to obtain a more precise value regarding the impact of COVID 19 on mental health, it is necessary that the new studies use similar scales.


COVID-19
At the end of December 2019, the world became aware of the existence of a new virus that was in the city of Wuhan (China), but in a few months, this virus spread in practically all countries on the planet, becoming a global pandemic [1]. In addition to the problems related to the physical health of those who contracted the virus, COVID 19 has become a major cause of problems in the psychological health and well-being of the world population [2].
Recent studies, such as [2], show an exponential increase in people with high stress symptoms, others like Elbay et al. and Ballou et al. showing a significant increase in the number of cases of people with depression and anxiety [3][4][5]. One of the main causes of illness in the mental health of the world population is stress [6]. And it was proven that in the lockdown period, there was a significant increase in the population's stress levels, due to concerns about the economy, access to inadequate information, lack of personal space in the house, boredom, little social life, care not to contracting the virus, anxiety about the appearance of the vaccine and the loss of relatives and friends [7].
Considering the countless psychological problems that COVID 19 caused in the population, researchers from several countries are dedicated to identifying these cases of psychological aging in the population [8,9]. However, in order to obtain a parameter with less stringency, it is important to use validated instruments that are translated into different languages, so that it is possible to have a more uniform global data, as well as the creation of specific instruments for assessing mental health caused by COVID 19, as appoints the following steps: define your purpose, formulate the question, search for literature, evaluate the data, analyze the data and present the results [10][11][12][13].

Information Sources
To search the data, the following databases were used: Cochrane Central Register of Controlled Trials, in the MEDLINE database (Latin American and Caribbean Literature in Health Sciences),

LILACS (Virtual Health Library), SCIELO (Scientific Electronic
Library Online) and PsycINFO.

Searches
For the searches, the following terms will be used as limited vocabulary and thesauri: "COVID 19", "stress", in the Spanish, Portuguese and English languages, with the following combinations ( Figure 1).

Selection of Studies
In order to identify and gather the largest number of relevant works, in the first step, all the publications that contained the keywords in the title, abstract and text were included in the search engines. The second step was the reading and analysis in the integral of the texts that contemplated one of the inclusion criteria.

Data Collection Process Types of Study Methods
Among the various classifications of study methods, those that meet the requirements of this research are experimental, observational, cross-sectional and longitudinal studies, which belong to studies with a unit of analysis or in a group of individuals.

Data Evaluation
In this evaluation, the identified articles were reviewed, classifying them according to the title and abstract, selecting those that met the inclusion criteria and discarding them if it could not be verified that they did not meet them.

Checking Protocol
A protocol was developed whose purpose is to detail the requirements for the selection of articles and to allow the information to be displayed, so that other reviewers can detect ambiguity or application problems. The check protocol is available at https://docs.google.com/spreadsheets/d/1uGFdVoY3uMlSdb4i I35ZCMQVeYCqL3JAs5nVdJNn0w/edit#gid=0

Literature Search
All online publications of journals, university theses and abstract were included, between the period of February 1, 2020 to December 20, 2020. For the searches, the following terms were used as limited vocabulary and thesauri: "COVID 19", "stress", in the Spanish, Portuguese and English languages. The results in the databases ( Table 1). The sum of the results presented was 4272 studies, but most were discarded because they did not meet any of the criteria of this investigation. Of these 4272 studies, 319 articles were selected for full reading, as they met at least 1 of the inclusion criteria. Of these, 8 were duplicates and 46 were excluded because they did not meet all the review criteria, thus subtracting 265 that will be used in this study (Table 2).

Results
As a result, two 265 studies have been analyzed, for which 411 different scales were identified, which were used to measure the level of stress, depression, anxiety, satisfaction with life, wellbeing, social conviviality among other aspects, which were applied in 38 countries. Below follows a list of the scales that were used in more than 1 study.

Discussion
From this analysis, we noticed that only 20% of the studies use the same scales to measure the level of stress, depression and anxiety of the participants. What makes it difficult to carry out meta-analysis and thus have a more precise parameter of the situation of mental disorders in the world. Another problem found in this review is the little use of scales that were created specifically to measure mental health related to COVID 19, considering that the most used scales were not designed to analyze mental health in a pandemic period. We hope that the present study will contribute to standardize the new studies and thus enable a more detailed analysis related to this theme.