In December 2019, a new form of pneumonia of unknown origin was identified in Wuhan, China. On January 12, 2020, Chinese authorities revealed the sequence of a new, hitherto unknown virus called SARS-CoV-2 as the cause of this pneumonia. Shortly afterwards, at the end of February 2020, the virus had already spread rapidly in China, but also in 28 other countries. The pandemic was thus declared on March 11, 2020, when the virus was already circulating on all 5 continents (1).

The United Kingdom was one of the first countries affected in Europe, with the first confirmed cases of COVID-19 detected on January 31, 2020 (2). Following detection, Public Health England, the national public health agency, developed a surveillance system called First Few X for COVID-19 (2). Currently, an estimated 19,820,181 cases have been reported in the United Kingdom since the start of the pandemic and up to 163,095 deaths (3).

The most frequently reported symptoms were fever, fatigue, dry cough, myalgia, and dyspnoea (4). In addition to this, studies have included a worsening of the population’s mental health and increased risk of psychiatric illness in the aftermath of the COVID-19 pandemic (5).

According to various theories such as the one on stress and the one that focuses on perceived risk, negative emotions develop in public emergencies. If these negative emotions are sustained over time, they can even affect the immune function of the population, making them more vulnerable to suffer from the disease which, in this case, is caused by the new virus (6). Therefore, in addition to the organic and physiological effects, the consequences caused by COVID-19 on the physical and mental health of the population have even been defined as ‘coronaphobia’ (7).

The impact that COVID-19 may have on mental health is still being evaluated worldwide, but the associated interventions and services remain largely unstudied. COVID-19 clearly is a health threat identified as a significant stressor (8). Stressful life events, such as those triggered by the COVID-19 pandemic, have a significant influence on an individual’s psychological functioning and well-being, and can act as catalysts for psychological problems including anxiety, confusion, social isolation, and depression (9). Individual differences regarding resilience, coping, and perceptions can influence how a person responds to adverse experiences.

At the start of the first confinement in the United Kingdom on March 23, 2020, rates of psychological distress were found to be significantly higher than in the 6 years prior to the arrival of COVID-19 (10). Another study noted that the rate of psychological distress in the United Kingdom adult population in 2020 was much higher than data collected in 2018, with 18–24 year olds and women being most affected (11). Likewise, one of the main consequences of the pandemic has been an increase in social isolation and feelings of loneliness. This is highly correlated with symptoms of anxiety, depression, and suicidal ideation (12). Fear, understood as a cognitive response to a threat (13), favours human adaptation to certain dangers, but if it remains over time or becomes characteristic of the individual, it can predispose to the appearance of physical illnesses and/or psychological disorders, or aggravate previous pathologies (14). In addition to psychological consequences, long-term mental illnesses and social tension predominate (15).

In pandemic times, people may experience a wide range of psychological states such as fear and anxiety, which may be exacerbated by measures of imposed social isolation and feelings of loneliness (15, 16). Anxiety, which is defined as feelings of tension, worrying thoughts, and physical changes in the body, is the most common psychological problem experienced during a pandemic. In the case of fear, it is defined as a negative emotion accompanied by a high level of nervousness and is evoked by a threat that is considered to have significant consequences for a person (16). When people face challenges during traumatic experiences, their self-esteem, trust in others, self-control, and predictability of the world may be damaged, and this can lead to unpleasant attitudes towards themselves and others. People who experience a high level of fear tend to believe that negative things can happen to them again when confronted with traumatic events (17).

In this pandemic context, it is necessary to create tools that specifically measure the impact on the mental health of people to be able to design future interventions according to population needs. One of the first scales designed specifically for this purpose was the fear of COVID-19 (FCV-19), created by Ahorsu et al. This scale consists of 10 items and has shown to have good psychometric properties in the Iranian population, being subsequently validated in several countries (18). On the other hand, Silva et al. validated the COVID anxiety scale (CAS-19), with 7 items and optimal fit values, to assess the presence of COVID-19 anxiety in the Brazilian population (19).

In the case of Spain, a group of researchers designed and validated a scale that measured not only the fear dimension of COVID-19, but also anxiety. This scale, which was named AMICO (for its Spanish acronym); Escala de Evaluación de la Ansiedad y MIedo a COVID-19, or Scale for the Evaluation of Anxiety and Fear of COVID-19, evaluates the anxiety and fear constructs in a single measurement scale, given the moderate correlation between the two constructs, although different, demonstrated in the literature (20). The questionnaire consists of 16 items, with two factors (anxiety and fear), and proved to be reliable and valid to specifically measure fear and anxiety related to COVID-19 (21).

In the specific case of the United Kingdom, different studies have assessed the presence of COVID-19 anxiety in its population since the beginning of the pandemic, but never used a measurement scale that brought together the constructs of anxiety and fear (9, 17–19). In this context, the present study aims to cross-culturally validate and to conduct the initial psychometric study of the AMICO scale in the United Kingdom, as a screening tool for anxiety and fear of COVID-19 in this population, carrying out the corresponding cross-cultural adaptation.

The aim of the present study was the construct validation of the AMICO_UK scale in the United Kingdom in order to assess the presence of fear and anxiety of COVID-19 in this population group.

The outcomes obtained have provided optimal results in the goodness-of-fit indices for the construct validation of the scale and its overall corrected reliability, and the goodness-of-fit and reliability values were very similar to those obtained in the initial study in Spain (20). Likewise, the present study also provides more refined reliability data, as it considers new calculations using McDonald’s omega (34), and therefore more robust reliability data.

Furthermore, although the items have high weights in both factors, the CFA considering a single factor has been shown to have a worse model fit than the proposed two-factor factor structure.

In addition, the unidimensionality of the scale has been demonstrated by means of a bifactor analysis, which justifies the obtaining of a single final scale score.

In relation to scales measuring fear of COVID-19, the so-called “Fear of COVID-19 Scale” (FCV-19) (14), widely validated in several countries since its creation, was also validated in the United Kingdom and New Zealand population (36).

However, this scale only measures the ‘fear’ construct, unlike the AMICO_UK scale, which also measures anxiety (20). This is the added value of the scale, as it provides information about two different but related constructs that could condition adherence behaviours to safety recommendations issued by governments in terms of public health.

The results of the bivariate analysis may suggest that the impact of the COVID-19 pandemic on mental health could be studied from a social perspective. In this regard, a study from University College London, which started after the COVID-19 pandemic, also concluded that women, young people, socially disadvantaged groups, and people with pre-existing mental health problems have been the most affected by the pandemic in terms of mental health, and confirms these outcomes (37). Similarly, another study on the United Kingdom population also found that young people, women, people with children at home, people with pre-existing mental health problems, and those with low economic status showed high levels of depression and anxiety at the onset of the confinement (21).

The fact that women showed higher anxiety rates than men was also confirmed in the present study with the AMICO scale scores. This could be due to the fact that most of the household care tasks fall on women; this was exacerbated by the alarm and lockdown situation and the consequent school closures, and perhaps women have experienced an increase in the number of tasks (20). Similarly, according to the results of the study by Pierce et al. in the specific case of the United Kingdom, women had higher rates of anxiety than men during the pandemic (11). Another study, albeit on a sample of people from the United States, also concludes that women and non-binary people, as well as people with pre- existing physical and mental health conditions, had higher levels of depression and anxiety after the COVID-19 pandemic was declared (38).

On the other hand, for the economically well-off, the cessation of commuting, changes in education and work activities, and increased time with family may have reduced stress and improved mental health and well-being (39). However, for the more economically vulnerable part of the population, the worsening employment situation might have worsened the mental distress that already existed in this group (11).

Although in the present study age was not a determining factor, it is true that, in general, in the articles reviewed, the rates of mental distress were worse for young people; this was the case in a study that highlights that younger populations tend to have, in general, worse mental health outcomes (40). One explanation for this phenomenon could be that many young students experienced worse academic performance and significant changes in their daily routine during a pandemic (41). In the United Kingdom, anxiety and depression symptomatology has been reported to be highest in young adults (<35 years), improving progressively with increasing age, with the lowest levels found in people aged 60 years and older (42). Similarly, another longitudinal study of United Kingdom households including participants from England, Wales, Scotland, and Northern Ireland, which included pre- pandemic data, also showed that the mental health of the population deteriorated in the early stages of the pandemic, pointing to higher rates of anxiety, depression, stress, suicide risk, and post-traumatic stress disorder (11). Rates of suicidal ideation also increased during the first weeks of confinement, 11% higher than in the previous year.

Weekly rates of suicidal ideation were also higher in the United Kingdom than elsewhere (43).

What is surprising, however, is that rates of self-harm ideation increased at the same time as COVID-19 restrictions decreased (44). This may translate into delayed true effects of the pandemic. However, while other studies have shown an overall increase in mental distress in people aged 16+ in the United Kingdom compared to the previous year (11), it is very difficult to estimate what the long-term mental health effects will be more than 2 years into the pandemic. However, we do have data from other epidemics such as SARS in 2003 (12).

For example, a study in Hong Kong, one of the regions of China most affected by SARS, found that there was a 30% increase in suicide in people aged 65 years and older, that about 50% of those who recovered from SARS remained anxious, and that 29% of health care workers experienced emotional distress. In addition, people who overcame this illness were at risk of post-traumatic stress disorder and depression (45). It is worth noting that the global impact of COVID-19 cannot be compared to that of SARS, and it can be concluded that the data on mental health effects will be much more significant.

For all these reasons, there is a need to continue researching the long-term consequences of COVID-19 on a daily basis in order to be able to offer the population the necessary resources at all times to mitigate the damage at a mental level. In this regard, the present study proposes a scale that measures the constructs of anxiety and fear of COVID-19 unidimensionally, which may be beneficial not only for measuring the prevalence of anxiety and fear of COVID-19 in the United Kingdom, but it can also be used in the experimental study to capture changes in anxiety and fear of COVID-19 that are related to adverse mental health outcomes.

As for the limitations of this study, it is worth highlighting the non-probabilistic sampling through which the individuals in the sample were selected as it may affect the generalisability of the data. Furthermore, since the data collection tool was telematic, there may also be an accessibility bias, as older people and/or those at risk of social exclusion may not have been able to answer the questionnaire. On the other hand, the greater number of women among the sample selected for the study. Therefore, it is necessary to examine, through a new field study, whether the variable “sex” may possibly have such an effect on the validation of the construct of the AMICO_UK scale from a gender perspective. On the other hand, further studies are needed to determine the criterion validity of the scale by calculating ROC curves, and which may also allow for predictive analysis and other regression measures. This is therefore another limitation of the present study.

However, in relation to the impact of the present study and its application to the practice, the validation of this scale could be an appropriate tool to measure the mental health impact that COVID-19 will have on the United Kingdom population in the long term, following the natural evolution of the pandemic. It is therefore positioned as a tool that could allow analysing this long-term impact, as there still are no prospective studies on this issue.

The AMICO_UK scale has adequate construct validity as an instrument to measure the presence of anxiety and fear related to COVID-19 in the United Kingdom population.

The majority of the United Kingdom population had low levels of anxiety and fear at the time the scale was administered. Due to the strong relationship between the impact of the COVID-19 pandemic and the social characteristics of the population, there is a need to assess specific population groups with the AMICO_UK scale with the aim of providing more targeted programmes and helping to improve and restore the mental health of the United Kingdom population.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by Permission to conduct this study was obtained from the National Health Service (NHS) Committee, Ref. 20/HRA/369. The patients/participants provided their written informed consent to participate in this study.

CM-T, RA-C, JF-R, YN-A, JC-R, and JG-S: conceptualization. CM-T, JC-R, and RA-C: data curation. CM-T, RA-C, JG-S, JF-R, JC-R, and YN-A: formal analysis. CM-T, RA-C, JG-S, JC-R, and JF-R: investigation. CM-T, JG-S, RA-C, JF-R, and YN-A: methodology. JG-S and CM-T: project administration. RA-C, JG-S, JC-R, and YN-A: resources. CM-T, RA-C, JG-S, and YN-A: software. JG-S, RA-C, JF-R, JC-R, and YN-A: supervision. RA-C, JG-S, and JF-R: validation. JF-R and JC-R: visualization. RA-C, CM-T, JC-R, and JG-S: writing—original draft. RA-C, JG-S, JF-R, and YN-A: writing—review and editing. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.