key: cord-1011512-a15b8q7k
authors: Ljubić, Toni; Banovac, Ana; Buljan, Ivan; Jerković, Ivan; Bašić, Željana; Kružić, Ivana; Kolić, Andrea; Kolombatović, Rino Rivi; Marušić, Ana; Anđelinović, Šimun
title: Effect of SARS-CoV-2 antibody screening on participants' attitudes and behaviour: a study of industry workers in Split, Croatia
date: 2020-12-07
journal: Public Health
DOI: 10.1016/j.puhe.2020.12.001
sha: 81ac7d408b51a26eb786c3b777be98b66ccb5c67
doc_id: 1011512
cord_uid: a15b8q7k

Objectives To investigate the changes in personal attitudes and behaviour before and after negative serological test results for severe acute respiratory syndrome coronavirus 2. (SARS-CoV-2) antibodies. Study Design Cross-sectional questionnaire survey. Methods A survey questionnaire was conducted with 200 industry workers (69% males and 31% females) who had previously tested negative for SARS-CoV-2 antibodies. The survey examined participants' self-reported general attitudes towards coronavirus disease 2019 (COVID-19), their sense of fear, as well as their behaviour towards protective measures before and after the testing. Results Participants perceived the disease as a severe health threat and acknowledged that the protective measures were appropriate. Respondents reported a high level of adherence to measures and low level of fear, both before and after the testing. Although these indicators were statistically significantly reduced after the test (p < 0.004), they did not result in irresponsible non-adherence behaviours. Almost all respondents attributed their application of personal protection measures to factors other than the results of serological screening. Conclusions Serological tests do not contribute to irresponsible non-adherence behaviours in an environment where protective measures are efficient. However, they may help reduce fear within society and working environments.

Since November 2019, severe acute respiratory syndrome coronavirus 2 (SARS- infection, resulting in coronavirus 2019 (COVID- 19) , has been spreading around the globe. As of 15 May 2020, the COVID-19 pandemic has resulted in >4.5 million recorded cases and >300,000 deaths globally 1 . Countries worldwide are testing their populations to estimate the number of people with active virus infection and the number of those who have recovered from it. It is highly recommended that reverse transcription polymerase chain reaction (RT-PCR) testing is prioritised in hospitalised patients, healthcare facility workers, workers in congregate living settings, first responders, residents in long-term care facilities and in the general population with symptoms of (potential) COVID-19 infection 2 . To estimate the number of people who have previously been exposed to and/or infected with the virus, serological immunoassay tests are currently the best option, especially because of their low cost and short amount of time needed to obtain the results 3 .

The first case of COVID-19 in the Republic of Croatia was reported in late February 2020. To prevent the spread and exponential growth of the disease, restrictive measures were introduced by the Croatian Government on 19 March 2020 4, 5 . From 23 March 2020, leaving the place of residence was also prohibited 6 metres in closed areas), wearing face masks and maintaining personal hygiene. In addition to national measures 4-6 , many companies introduced additional measures to further protect the health of their employees and to allow their businesses to continue functioning. Such is the case for the DIV Group, a company specialising in shipbuilding and the production and trade of screws and mechanical parts, which introduced serological testing for employees, using rapid serological immunoassay, as a health protection element within their corporate security system 8, 9 . protective or restrictive measures necessary for the containment of disease 12 . This can be especially devastating as some health experts worry that testing populations and providing them with the knowledge of their health and/or immunity status regarding COVID-19 could lead to psychological and behavioural changes 13 .

The psychological and behavioural effects of receiving negative test results have already been investigated in various screenings for different conditions. There is concern that after receiving negative test results, individuals may perceive they have a lower risk of developing the disease they were tested for and may subsequently be less likely to take the necessary protective precautions 14, 15 . A systematic review that included eight screening programmes for diseases linked to lifestyle behaviours (type 2 diabetes, breast, bowel, lung and cervical cancer, and abdominal aortic aneurysm) investigated the post-screening changes in behaviours, attitudes and emotions. The study showed that negative screening results are unlikely to cause changes in observed characteristics or have a negative impact on behaviour 16 . Nevertheless, since COVID-19 is a novel disease whose spread is most effectively prevented by maintaining social distancing, community consciousness, personal protection and hygiene practices, 17 behaviours that are dependent on the conscientiousness and self-control of individuals, it is of utmost importance to examine the behaviours and attitudes of people who receive negative test results.

Furthermore, these factors are vital in specific working environments, where interpersonal contact cannot be avoided entirely due to production characteristics. In these settings, changes in behaviour and attitudes of workers could impact the general psychological environment and, most importantly, the health of company workers and their families.

Thus, this study aims to investigate the changes in personal attitudes and behaviour of the DIV Group industry workers before and after receiving negative serological test results for SARS-CoV-2 antibodies.

J o u r n a l P r e -p r o o f

A cross-sectional survey was conducted with the DIV Group industry workers in Split, Dalmatia County, Croatia, who had previously tested negative for SARS-CoV-2 antibodies by rapid immunoassays. The survey was conducted between the 10th and 15th of May, 2020, which corresponds to 12-22 days after serological screening (23-28 April, 2020). The serological testing comprised 1316 participants and was the first mass testing in the Republic of Croatia, and, to the authors' knowledge, was one of the first and largest studies, on a corporate level, in the world at that time 9 . Of 1316 participants, results revealing that only 0.99% of participants (95% confidence interval [CI] 0.53 to 1.68) were positive for SARS-CoV-2 antibodies 9 . All 1316 individuals who took part in the serological screening were invited to participate in this cross-sectional survey.

The DIV Group facility in Split employs about 2200 people, which makes them the second largest employer in the county. The Split facility employee structure includes those working in production, as well as management and administration 8, 9 . To examine if the test results had an impact on participants' attitudes and behaviour, a short questionnaire was designed and employees were surveyed, with the permission of the management of the company. The companies' occupational safety officers distributed the questionnaire to employees in the different company departments (i.e. management, administrative and production) who had participated in the serological screening. Completion of the survey was on a voluntary basis. As only a small proportion (0.99%) of employees tested positive for SARS-CoV-2 antibodies, the current study only includes individuals with negative test results.

The questionnaire included the following six sections: (1) information of the study and informed consent; (2) general demographic data and test results; (3) participants' general attitudes towards COVID-19; (4) participants' protective behaviour and fear of the disease prior to testing; (5) participants' protective behaviour and fear of the disease after the testing; and (6) factors related to compliance with personal protection measures.

The general and demographic questions included gender, age, test results (negative / IgG positive/ IgM positive / IgM + IgG positive) and level of education. Other personal data were not included to ensure the participants' anonymity.

The third section of the questionnaire included questions on participants' perception of COVID-19 and its severity, as well as their attitudes towards the protective and restrictive measurements given at the national and company level. There were seven statements that participants rated on a five-level Likert scale for agreement (1 = strongly disagree; to 5 = strongly agree).

In sections four and five of the questionnaire, participants were asked about their anxiety and fear of COVID-19, compliance with restrictive measures and application of protective equipment before and after the testing. These sections were each composed of two sub-sections. The first included nine statements regarding the participants' fear and perception of their environment; participants rated these on a five-level Likert scale for agreement (1 = strongly disagree; to 5 = strongly agree). In the second sub-section, participants were asked to rate their frequency of obeying the restrictive measurements and applying personal protective equipment. It included four statements with responses on a five-level Likert scale for frequency (1 = never; to 5 = very often).

In the final section of the questionnaire, participants were provided with four statements about factors that influence their adherence to the restrictive and protective measures, including the serological test results and level of actual restrictive measures and recommendations. They were asked to select one of the four statements that best suited their views. 

Categorical variables, including the gender, education level and factors influencing adherence to the protective measures, are given as frequencies and percentages. For the remaining variables, we provided the mean values with 95% CIs. Differences in categorical variables were examined using the chi-squared test with the assumption that each category needs to have a similar number of respondents, while the differences in participants' responses before and after the testing were J o u r n a l P r e -p r o o f examined using a paired-samples t-test. Due to the increased number of multiple comparisons (n = 14), statistical significance was set at p ≤ 0.004 (Bonferroni correction). All analyses were performed using JASP 0.12.1 (JASP Team, 2020).

The sample comprised 200 participants (68% men; median age = 43 years, interquartile range of age = 21 years). The majority of respondents had an undergraduate or graduate education (47.7%) or had completed secondary education (32.7%), while fewer participants completed non-university college or professional studies (18.6%). There were two participants with only primary education (1%) and one answer was missing.

Most participants perceived COVID-19 as a dangerous disease and reported that restrictive measures and protective guidelines at the national and company level were efficient and appropriate (see Table 1 ).

On average, participants had low levels of fear of becoming infected ( Table 2 , statements 4 and 6) or infecting others with COVID-19 ( Table 2 , statements 3 and 5); these results were observed both before and after the testing. Participants' perception of other people adhering to protective measures was also high pre-and post-testing (Table 2, statements 7-9). Nonetheless, changes in participants' behaviour and attitudes before and after testing were statistically significant for most variables. Suspicions that a person or people in their physical vicinity were infected were significantly reduced ( Participants, on average, showed a high frequency of adherence to protective measures and restrictions (Table 3 ). When they were asked about their pre-test and post-test adherence frequencies, they reported maintaining the application of personal protective equipment at almost the same level, but a lower adherence to social distancing was seen (Table 3 , statements 2-4).

Although participants reported changes in behaviour and attitudes before and after receiving the test results, the majority of participants did not attribute their behaviour to the test itself, but rather to the level of company and national protective measures (Table 4) .

The results of the present study show changes in the behaviour and attitudes of participants after receiving negative serological test results, but not to the extent that would lead to irresponsible or dangerous behaviours. Moreover, participants did not report that their adherence to personal protection measures was related to serological test results. To the best of the authors' knowledge, this is the first study to investigate the changes in behaviours and attitudes to COVID-19 before and after receiving negative serological test results.

The results of this study indicate that the levels of fear of being infected or infecting others with COVID-19, as well as behaviours regarding adherence to protective measures, changed significantly after receiving negative test results. However, the fear of becoming infected and/or infecting others was initially at a low-moderate to low level and dropped even lower after receiving negative test results. At the end of February 2020, although COVID-19 was emerging as a pandemic disease and was relatively unexplored, the situation at the DIV Group was under control and protective measures had already been introduced. The company's decision to implement these measures at an early stage was influenced by the experience of their partners in China and Italy, which were, at the time, global pandemic hotspots. The company measures, along with national protective measures, introduced by the second half of March 2020 4-6 , are likely to have had a beneficial impact on the low level of fear seen in the study participants.

The frequency of positive behaviour related to social distancing reduced after the testing, but still remained high. In contrast, results indicate no significant changes in behaviour related to wearing protective equipment, masks and gloves, which remained highly adherent. Both of these findings could be attributed to the promoting environment of the company and society, which raised awareness of the need for protective and restrictive measures. In addition, there were no changes in the perception of colleagues' compliance with protective measures pre-and post-testing, which highlights participants' responsibility and conscientiousness, regardless of their test results.

Most importantly, only 1% of participants attributed their application of personal protection measures to the results of serological testing, rather than other factors. This implies that the antibody testing itself was not likely to generate changes in behaviour. Although the current study could not precisely provide causality of observed changes, it is worth noting that most Studies on screening for various diseases, such as different types of cancer, sexually transmitted diseases (STDs) and diabetes, have been conducted to determine their psychological and behavioural impacts, but also the perception of ones' health and future risk of getting sick [18] [19] [20] [21] [22] . A recent review on these types of studies showed a small decrease in perceived risk of the disease screened for, slightly lower levels of anxiety or worry in the screen-negative group and highlighted that only 5 of 28 studies showed an unfavourable change in the negatively screened groups' health-related behaviours 16 .

Although the present study findings indicate changes of similar direction and extent, it is difficult to compare its results to the abovementioned studies. This is due to the very nature of COVID-19, which is an infectious disease spread primarily by human contact and interaction. With the exception of STDs, the other diseases that populations are usually screened for are not transmittable [18] [19] [20] [21] [22] . It is also not possible to compare STD screening with COVID screening, as the transmission of STDs is usually restricted to the most intimate of human interactions and thus comparisons are limited. In the absence a viable vaccine, stopping the spread of infectious diseases, such as COVID-19, is impossible without necessary changes in human interactions and behaviour, which must be applied to all members of society.

A limitation of this study is that all data were collected after the serological testing took place, in the single survey questionnaire, thus potentially introducing reporting bias. To obtain pre-test measurements, participants would have been required to complete an initial survey on the day of voluntary serological testing; however, this was not feasible for practical reasons. From the organisational and protective standpoint, it was of utmost importance to minimise the time participants spent at the testing station 9 . If an additional survey had been introduced, this would result in not only the prolonged absence of participants from their workplace, but also potentially increased exposure to the virus. Since the period between serological testing and completing the survey questionnaire was a maximum of 22 days, we relied on participants' ability to recall recent behaviours and attitudes. While other studies on the impact of negative-screening results repeated measurements after several months or years 16 In conclusion, the current study indicates that COVID-19 serological tests do not contribute to irresponsible non-adherence behaviours in an environment where protective measures are efficient. However, serological tests may help reduce fear within society and working environments.

As study participants were recruited from just one company, in one location, the findings may not be fully generalisable. Therefore, future research should include different target and general populations to reveal more details on the changes in attitudes and behaviour following serological testing. To obtain more comprehensive understandings, corroborating quantitative study findings with qualitative studies is suggested. J o u r n a l P r e -p r o o f J o u r n a l P r e -p r o o f

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The authors would like to thank DIV Group company and Tomislav Debeljak, along with all study participants. We are especially thankful to Boško Ramljak, Marija Čečuk, and Ivica Sinovčić for their assistance in organisation and data collection.

The survey was approved by the University Department of Forensic Sciences Ethics Committee 

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

None declared.

This article does not represent in whole or in part the views of the authors' institutions. However, it does express those of the authors.J o u r n a l P r e -p r o o f