Table 2 Table of results of accepted studies referred to in the manuscript, which provide evidence for the impact of pandemics/epidemics on the mental health of healthcare professionals beyond the systematic review of KJ Vyas, EM Delaney, JA Webb-Murphy and SL Johnston [5]

SE Chua, et al. [13]

Difference between HCPs and healthy controls on stress levels (no inferential test)

Stress levels for HCPs (M = 18.6, SD = 4.9) were similar to healthy control subjects (M = 18.3, SD = 5.6), but 50% higher than the normative value for the PSS-10.

Fiksenbaum et al. (2006) [14]

Correlations between contact with SARS patients, and emotional exhaustion and state anger.

Exposure amongst nurses was significantly correlated with emotional exhaustion (r = −.21; p < .001) and state anger (r = −.18; p < .001).

D Ji, et al. [16]

Difference in the psychological dimensions of the SCL-90-R between 1 week after arrival of Chinese medical staff in an outbreak zone (Sierre Leone) and 1 week after withdrawal (either Man Whitney U or t-test)

Obsessive compulsion (M = 1.39, SD = .18 vs M = 1.23, SD = .36; p =. 1421); depression (M = 1.22, SD = .31 vs M = 1.18, SD = .29; p = .5480); hostility (M = 1.09, SD = .13 vs M = 1.09, SD = .18; p = 1.00); paranoid ideation (M = 1.11, SD = .19 vs M = 1.11, SD = .24; p = 1.00) and psychoticism (M = 1.14, SD = .24 vs M = 1.08, SD = .14; p = 1.706).

JS Kim and JS Choi [17]

Group differences between MERS exposed vs not exposed nurses on MERS-related burnout (t-test)

Nurses exposed to infected/−suspected patients had higher MERS-related burnout scores (M = 3.09, SD = 0.48) than non-exposed nurses (M = 2.93, SD = 0.42, p = .013).

WJ Lancee et al. [19]

Group differences between HCPs with vs. without history of mental illness on mental disorder development (Fischer test).

A year after the outbreak, HCPs with a history of mental illness before the outbreak had higher risk of developing a new mental DSM-IV axis 1 mental disorder (18%), compared to healthcare workers without (2%, p = .03).

M Lehmann et al. [22]

Group differences between internal medicine staff, Ebola patient treatment staff and research laboratory staff on anxiety levels (Test unspecified).

Internal medicine staff, Ebola patient treatment staff and research laboratory staff did not significantly differ levels of anxiety.

IWC Mak et al., 2009. [28]

Group differences between infected HCPs and infected non HCPs on PTSD prevalence (Test unspecified).

Thirty months after SARS outbreak, PTSD prevalence was higher among infected HCPs (40.7%) than among infected non HCPs (19%, p = .031).

Z Marjanovic et al. [29]

Correlation between contact with SARS patients, and emotional exhaustion and state anger in nurses.

Multiple regressions for emotional exhaustion and state anger.

Correlation between avoidance behavior, and emotional exhaustion and state anger.

Contact with SARS patient was significantly correlated with emotional exhaustion (r = −.21; p < .001) and state anger (r = −.18; p < .001).

Contact with SARS patients significantly predicted emotional exhaustion (β = −.15, p = .003) but did not predict state anger (β = −.09, p = .068).

Avoidance behavior was significantly correlated with emotional exhaustion (r = .26; p < .001) and state anger (r = .33; p < .001).

RG Maunder, et al. [32]

Group differences between SARS exposed vs not exposed HCPs on burnout prevalence (χ²).

Group differences between SARS exposed vs not exposed HCPs on burnout (t-test or Mann-Whitney U Test)

Group differences between SARS exposed vs not exposed HCPs on face-to-face patient contact (χ²).

Group differences between SARS exposed vs not exposed HCPs on work hours (χ²).

Burnout prevalence is higher in exposed HCPs (30.4%) than HCPS not exposed (19.2, p = .003)

Exposed HCPs had significantly higher burnout scores (Md = 19, IQR = 10–29) than non- exposed HCPs (Md = 16, IQR = 9–23)

Since SARS outbreak, significantly less face-to-face patient contact was reported by exposed HCPs (16.5%) compared to those who were not exposed (8.3%, p = .007).

Since SARS outbreak, significantly less work hours was reported by exposed HCPs (8.6%) compared non exposed HCPs (2.2%, p = .003).

GM McAlonan et al. [33]

During outbreak: Group differences between high vs low risk HCPs on perceived stress (t-test). Comparison of symptom scores to norm (no inferential test)

One year after outbreak: Group differences between high vs low risk HCPs on perceived stress (2-way ANOVA).

Interaction between time and infection level tested with a 2 way ANOVA.

Perceived stress levels did not significantly differ between high vs low risk HCPs (t(164) = − 1.36, p = 0.176) although they were higher than the normative value (13).

Perceived stress levels of high-risk HCPs (M = 18.6, SD = 4.9) were significantly higher than the low-risk HCPs (M = 14.8, SD = 5, p < .05).

Change in perceived stress from 2003 to 2004 was significantly different for the 2 groups (F1,336 = 4.61, P < 0.05), with a general trend toward a decrease over time for low-risk HCPs and an increase for high-risk HCPs.

JS Park et al. [35]

Mediation analysis of the relationship between hardiness and mental health by perceived stress

Mediation analysis of the relationship between stigma and mental health by perceived stress

The relationship between hardiness and mental health was partially mediated by perceived stress (indirect effect 0.251, Boot SE = 0.638). Where increased hardiness led to descrease stress (B = −.31, SE = .05, p < .001), which subsequently led to better mental health symptoms (B = −.81, SE = .13, p < .001).

The relationship between stigma and mental health was mediated by perceived stress (indirect effect = − 0.061, Boot SE = 0.020). Where increased stigma led to increase stress (B = .075, SE = .023, p = .002), which subsequently led to better mental health symptoms (B = −.81, SE = .13, p < .001).

E Poon et al. [37]

Group differences between hospital workers who had contact with SARS patients vs no contact with SARS patients on burnout symptoms (t-test).

Hospital workers who had contact with SARS patients had significantly higher burnout symptoms (M = 7.3, SD = 5.3) than those who did not have contact with SARS patients (M = 5.1, SD = 4.7, p < .001).

K Sim et al. [38]

Group differences between doctors and nurses with versus without psychiatric morbidities on effort coping, in context of SARS outbreak (Mann-Whitney U Test)

Group differences between doctors and nurses with versus without posttraumatic morbidities on effort coping, in context of SARS outbreak (Mann-Whitney U Test).

Group differences were examined between exposed and non exposed medical staff on psychiatric symptoms (Mann-Whitney test) and posttraumatic symptoms (χ²), in the context of a SARS outbreak.

Doctors and nurses with psychiatric morbidities had higher scores on effort coping (M = 49.7, SD = 13.2) than doctors and nurses without psychiatric morbidity (M = 39.7, SD = 10.4, p < .001)

Doctors and nurses with psychiatric morbidities had higher scores on effort coping (M = 53.4, SD = 13.1) than doctors and nurses without psychiatric morbidity (M = 40.6, SD = 10.9, p < .001).

Exposed medical staff showed no difference to non-exposed staff in psychiatric symptoms (M = 2.6, SD = 4.2 vs. M = 2.3, SD = 4.4, p = .28) or presence of posttraumatic symptoms (7.2% vs.10.6%, p = .40).

TW Wong et al. [46]

Group differences between doctors, nurses and healthcare assistants on coping strategies, in context of SARS outbreak (ANOVA with post hoc analyses).

Planning was more likely to be used by doctors (M = 5.33, SD = 1.44) compared to nurses (M = 4.85, SD = 1.44, p < .05) and healthcare assistants (M = 4.42, SD = 1.56, p < .01). Behavioral disengagement was more likely to be used by nurses (M = 2.96, SD = 1.26) than doctors (M = 2.56, SD = 0.91, p < .01). Self-distraction was more likely to be used by healthcare assistants (M = 4.58, SD = 1.92) than doctors (M = 4.11, SD = 1.42, p < .05).

H Xiao et al. [48]

Assessment of the indirect pathway from social support to sleep quality via perceived stress.

The relationship between social support and sleep quality was mediated by perceived stress (B = −.06, SE = .01, p = .002). Where a lack of social support (B = .57, SE = .09, p < .001) led to an increase in perceived stress, which subsequently led to lower sleep quality (B = .26, SE = .01, p < .001).