Main findings

To our knowledge, this is the first multicentre study that has examined the prevalence of psychological outcomes among healthcare workers during the evolution of the COVID-19 pandemic in the Asia-Pacific region. Our study demonstrated the discrepancy between the volume of confirmed COVID-19 cases per day/1 million population and the prevalence of adverse psychological outcomes in the participating countries. Despite having the lowest volume of cases per day/1 million population, Vietnam displayed a higher prevalence of PTSD related to COVID-19 among healthcare workers compared with India. In contrast, Singapore reported the highest number of cases per day/1 million population, but had a lower prevalence of depression and anxiety among its healthcare workers, when compared with the Malaysian cohort. Our study highlights that all healthcare workers were vulnerable to psychological adversity regardless of the volume of confirmed COVID-19 cases. In fact, it would be crucial to focus efforts on addressing the independent predictors of psychological adversity, such as healthcare workers with the presence of physical symptoms, presence of prior medical conditions and those who are not medically trained.

Comparison with findings from other studies

During the early stages of the COVID-19 pandemic, Wang et al investigated the psychological impact of the COVID-19 pandemic on the general public in China using the DASS-21 scale, and found that 16.5%, 28.8% and 8.1% of its respondents reported moderate-severe depressive, anxiety and stress levels, respectively.^{Reference Wang, Pan, Wan, Tan, Xu and Ho12} However, given the differences in sampling approach, measurement and methodology, it poses a challenge for direct comparison with our present study cohorts’ prevalence of depression (1.5%), anxiety (3.0%) and stress (0.09%). We speculate that the prevalence of adverse psychological outcomes may improve across the COVID-19 pandemic trajectory, as there will have been an additional amount of time and effort in countries in building their readiness through resource allocation, emergency implementation of drastic infection control measures and mental preparedness.^{Reference Young, Ong, Kalimuddin, Low, Tan and Loh13,Reference Wong, Leo and Tan14}

Our earlier study reported depression rates among non-medical and medical healthcare personnel to be 10.3% and 8.1% respectively, as compared with the overall 4.7% depression rate displayed in the present study.^{Reference Tan, Chew, Lee, Jing, Goh and Yeo5} This trend was similar for the rates of anxiety in the early phases of the pandemic (20.7% in non-medical and 10.8% in medical healthcare workers, versus the overall 3.6% in the present study).^{Reference Tan, Chew, Lee, Jing, Goh and Yeo5} It is important to note that it is difficult to make accurate longitudinal conclusions when comparing the two studies because of the different population cohorts. Nevertheless, there is a trend towards better psychological preparedness and resilience for impending widespread transmission when the spread of the pandemic is already known, as compared with the uncertainty during the earlier stages of the pandemic.^{Reference Huang, Han, Luo, Ren and Zhou15}

Impact of differing strategies in different countries

Each of the participating countries has adopted strategies to curb the spread of COVID-19 and ensuring confidence in its healthcare workers through preventive strategies. The world witnessed the largest COVID-19 national lockdown in India, which led to the desired effect of flattening the epidemic curve. India's population of 1.3 billion with its widening socioeconomic disparities pose unique challenges in the pandemic. Moreover, India's young general population (65% of the population are less than 35 years of age) may serve as a determining factor for psychological resilience as evident by the lower levels of adverse psychological outcomes in this study.^{Reference Lancet16} This characteristic is reflected in the present study's Indian cohort with a lower mean age with fewer prior medical conditions as compared with their counterparts.

The most effective lockdown was seen in Vietnam. The country tightened its border immediately after the first death in Wuhan. Vietnam's approach was never based on mass testing, which may possibly account for its strikingly low number of confirmed cases. Its stringent infectious control has been backed up by the country's military and public security forces.^{Reference Black17} Despite their low levels of detected cases, an interesting finding of our study is Vietnam's high prevalence of PTSD, and relative higher rates of anxiety and depression as compared with their India and Singapore counterparts.

Singapore adopted a multipronged aggressive surveillance strategy among various patient groups (for example all patients with pneumonia) that allowed clinician's discretion to order a test based on clinical suspicion, even if the case definition was not met.^{Reference Ng, Li, Chua, Chaw, Zhao and Er18} This strategy led to an increase in detected COVID-19 cases, many of which may not have been detected if the case definition was strictly followed. Although, it reported a high volume of confirmed cases, most were asymptomatic or mildly symptomatic.^{Reference Ng, Li, Chua, Chaw, Zhao and Er18} Perhaps, this accounted for the lower prevalence of anxiety, depression and PTSD related to COVID-19 among healthcare workers.

Similarly, Malaysia adopted an aggressive testing strategy, in which its tests per million capita far exceed its Association of South-East Asian Nations counterparts, resulting in higher reported confirmed cases but of milder severity and lower mortality.¹⁹ However, despite its lower rates of confirmed cases as compared with Singapore, we found a higher prevalence of depression, anxiety and stress among Malaysian healthcare workers.

Indonesia's declaration of a public health emergency on 21 March led to large-scale social distancing and movement restriction.^{Reference Sutrisno20} Despite its higher death rates per 1 million population, the prevalence of depression and anxiety remain comparable with its counterparts. Therefore, there is no clear correlation between the volume of confirmed cases per day per million capita and the prevalence of adverse psychological outcomes. Perhaps the risk of psychological distress among healthcare workers goes beyond the country's COVID-19 disease burden, and may also be contributed to by other societal and cultural factors specific to different nations.

Differences between medical and non-medical healthcare workers

Our study demonstrated that non-medically trained healthcare workers were at higher risk of adverse psychological outcomes as compared with their medically trained counterparts. This is in agreement with our recent study on healthcare workers during the start of the pandemic in Singapore, as well as a recent study in China that demonstrated that front-line nurses had significantly decreased vicarious traumatisation scores in comparison with non-front-line nurses and the general public during the COVID-19 pandemic.^{Reference Tan, Chew, Lee, Jing, Goh and Yeo5,Reference Li, Ge, Yang, Feng, Qiao and Jiang21} This difference between medical and non-medical healthcare workers may be attributed to the relative lack of accessibility to first-hand medical information on the pandemic and less formal training and confidence in infectious control measures.^{Reference Tan, Chew, Lee, Jing, Goh and Yeo5}

Role of physical symptoms

Our current findings demonstrate that the presence of physical symptoms was an independent predictor of adverse psychological outcomes. This is in line with our previous study that reported this significant association during the earlier stages of the pandemic.^{Reference Chew, Lee, Tan, Jing, Goh and Ngiam22} We postulated a bidirectional association between physical symptoms and psychological stress, in which somatic symptoms may represent a way of communicating emotions.^{Reference Puri, Hall and Ho23} However, healthcare workers displaying physical symptoms may face a sense of fear, stigmatisation and ostracism from co-workers, which may exacerbate the psychological pain.^{Reference Nezlek, Wesselmann, Wheeler and Williams24–Reference Matua and Van Der Wal26}

Role of prior medical conditions

We found that healthcare workers with prior medical conditions were at risk of adverse psychological outcomes. Studies have shown that vulnerable groups, namely those who are immunocompromised, with underlying medical conditions are at higher risk of life-threatening illness from COVID-19.^{Reference Zhang, Lu, Zeng, Zhang, Du and Jiang27,Reference Richards, Anderson, Carter, Ebert and Mossialos28} The knowledge of this increased risk may have worked as an additional stressor for our healthcare workers with pre-existing illnesses. Perhaps more efforts can be made to address the concerns of this vulnerable group of healthcare workers through ensuring that their exposure to COVID-19 patients are adjusted accordingly to their health risk status.

Implications

Our present findings demonstrate that regardless of the volume of cases or deaths, healthcare workers from all countries are vulnerable to psychological distress from the COVID-19 outbreak. Therefore, as the pandemic reaches its peak, it calls for urgent clinical and policy strategies for identifying healthcare workers at risk, i.e. those who are not medically trained, those with physical symptoms and prior medical conditions. Passive psychoeducation through educational pamphlets, emails or website can be relatively easy and inexpensive to implement, and may serve as a readily available resource for those experiencing psychological distress. Education on the natural history of the virus, and the appropriate use of infection control measures, especially for the non-medically trained hospital workers, may be helpful. A meta-analysis has shown that brief passive psychoeducational interventions targeting high-risk groups can be effective, although the extent of benefit remains unknown.^{Reference Donker, Griffiths, Cuijpers and Christensen29} Early psychological interventions in the form of cognitive–behavioural therapy, have also been proven to reduce psychological distress.^{Reference Mcnally, Bryant and Ehlers30} Therefore, improved accessibility to formal psychological support for healthcare workers (in the form of counselling, internet-based cognitive–behavioural therapy) is of paramount importance.^{Reference Tan, Chew, Lee, Jing, Goh and Yeo5} These dedicated interventions will help allay the fear of COVID-19 transmission between colleagues and improve the confidence of our healthcare workers.^{Reference Wang, Pan, Wan, Tan, Xu and Ho12,Reference Chew, Lee, Tan, Jing, Goh and Ngiam22}

Limitations

We acknowledge certain limitations of the study. First, it is cross-sectional in nature, which does not allow us to assess the causality of the different psychological outcomes. We also did not examine the prevalence of psychological symptoms before COVID-19, and did not examine the participants longitudinally for progression or improvement in their symptoms. Second, questionnaires were self-administered because of the strict infection control measures in all participating institutions. Hence, the information obtained could not be verified by a medical professional. Furthermore, all surveys were administered in English. Although English had been the primary language of communication in all the hospitals in which the survey had been administered, varying levels of proficiency with the English language may also have contributed to bias and inaccuracy in the survey findings.

In terms of sampling, larger tertiary centres within the countries were studied. The findings thus may not be generalisable and reflective of smaller regional or rural centres. Although the response rate was greater than 88%, participants with greater mental health concerns may be more likely to respond to the study, which may slightly overestimate the prevalence of mental health disorders. A larger sample size that is more representative of healthcare workers across the study region would be needed to estimate the true prevalence of mental disorders in this population. Follow-up studies are required to evaluate the progression of the psychological impact on healthcare workers during the aftermath of the COVID-19 pandemic, as there have been concerns regarding the ‘rebound effect’ where high-risk healthcare workers may experience various neuropsychiatric manifestations once the imminent threat of the infectious disease subsides, along with the protective positive attitude of collegiality and bravery.^{Reference Maunder, Lancee, Balderson, Bennett, Borgundvaag and Evans31}

In conclusion, we reported a varied, albeit high, prevalence of psychological distress in healthcare workers regardless of the individual countries’ burden of confirmed COVID-19 cases and deaths, as well as the different infectious control strategies adopted by the various countries. Our study suggested that vulnerable groups of healthcare workers may include those who are not medically trained, and those with physical symptoms and prior medical conditions. Targeted psychological interventions may be beneficial for this group of healthcare workers.