Healthcare worker stress, anxiety and burnout during the COVID-19 pandemic in Singapore: A 6-month multi-centre prospective study.

AIM: The long-term stress, anxiety and job burnout experienced by healthcare workers (HCWs) are important to consider as the novel coronavirus disease (COVID-19) pandemic stresses healthcare systems globally. The primary objective was to examine the changes in the proportion of HCWs reporting stress, anxiety, and job burnout over six months during the peak of the pandemic in Singapore. The secondary objective was to examine the extent that objective job characteristics, HCW-perceived job factors, and HCW personal resources were associated with stress, anxiety, and job burnout. METHOD: A sample of HCWs (doctors, nurses, allied health professionals, administrative and operations staff; N = 2744) was recruited via invitation to participate in an online survey from four tertiary hospitals. Data were gathered between March-August 2020, which included a 2-month lockdown period. HCWs completed monthly web-based self-reported assessments of stress (Perceived Stress Scale-4), anxiety (Generalized Anxiety Disorder-7), and job burnout (Physician Work Life Scale). RESULTS: The majority of the sample consisted of female HCWs (81%) and nurses (60%). Using random-intercept logistic regression models, elevated perceived stress, anxiety and job burnout were reported by 33%, 13%, and 24% of the overall sample at baseline respectively. The proportion of HCWs reporting stress and job burnout increased by approximately 1·0% and 1·2% respectively per month. Anxiety did not significantly increase. Working long hours was associated with higher odds, while teamwork and feeling appreciated at work were associated with lower odds, of stress, anxiety, and job burnout. CONCLUSIONS: Perceived stress and job burnout showed a mild increase over six months, even after exiting the lockdown. Teamwork and feeling appreciated at work were protective and are targets for developing organizational interventions to mitigate expected poor outcomes among frontline HCWs.

Aeromedical Decision Making for Military Aircrew with Graves' Disease.

BACKGROUND: Graves' Disease (GD) is a common cause of hyperthyroidism. Although definitive treatment with radioactive iodine (RAI) is preferred for military aircrew, there are cultural and individual differences in receptivity toward RAI, and clinical guidelines that recommend antithyroid drugs (ATD) as the first line therapy. We examined a case series of Republic of Singapore Air Force (RSAF) aviators with GD treated with ATD and the impact of their condition on aeromedical disposition.CASE SERIES: All RSAF aircrew diagnosed with GD and treated with ATD over a 15-yr period were retrospectively identified and analyzed to determine the impact on their fitness for flying duties. The mean age of the 13 aircrew was 33 ± 7.1 yr (range, 25-47 yr), with 11 (84.6%) being males. There were 10 (76.9%) who had ATD as the only treatment while 3 (23.1%) were initially treated with ATD but subsequently underwent RAI or surgery. Of the 10 treated with only ATD, 3 (30.0%) were returned to restricted flying, 6 (60.0%) were returned to unrestricted flying, and 1 (10.0%) is still undergoing ATD titration. There were 10 (76.9%) aircrew who were returned to some form of flying duties while on low doses of ATD.DISCUSSION: This case series suggests that ATD is a viable treatment modality in the aeromedical management of military aviators with GD and it is possible to return military aircrew on a stable maintenance dose of ATD to flying duties. A framework is proposed to support the aeromedical decision-making process for military aircrew in the treatment of GD.Loh EH-T, Soh FW, See B, Tan BBC. Aeromedical decision making for military aircrew with Graves' disease. Aerosp Med Hum Perform. 2021; 92(12):980-986.

Time Course of Simulator Sickness in Asian Military Pilots.

INTRODUCTION: This study sought to determine the incidence, severity, and time-course of simulator sickness (SS) among Asian military pilots following flight simulator training.METHODS: A survey was conducted on Republic of Singapore Air Force pilots undergoing simulator training. Each subject completed a questionnaire immediately after (0H), and at the 3-h (3H) and 6-h (6H) marks. The questionnaire included the simulator sickness questionnaire (SSQ) and a subjective scale to rate their confidence to fly.RESULTS: In this study, 258 pilots with a median age of 31.50 yr (range, 2155 yr) and mean age of 32.61 6.56 yr participated. The prevalence of SS was 48.1% at 0H, 30.8% at 3H, and 16.4% at 6H. Based on a threshold of an SSQ score >10, the prevalence of operationally significant SS was 33.3% at 0H, 13.2% at 3H, and 8.1% at 6H. The most frequent symptoms were fatigue (38.1%), eye strain (29.0%), and fullness of head (19.9%). There was no significant difference in mean scores between rotary and fixed wing pilots. Older, more experienced pilots had greater scores at 0H, but this association did not persist. A correlation was found between SSQ score and self-reported confidence.DISCUSSION: To our knowledge, this study is the first to report the prevalence of operationally significant SS in Asian military pilots over serial time points. Most pilots with SS are able to subjectively judge their fitness to fly. Sensitivity analysis suggests the true prevalence of SS symptoms at 3H and 6H to be closer to 23.8% and 12.0%, respectively.Loi JEQ, Lee MLL, Tan BBC, See B. Time course of simulator sickness in Asian military pilots. Aerosp Med Hum Perform. 2020; 91(11):892896.

Coronary Artery Disease Screening Using CT Coronary Angiography.

BACKGROUND: The increased utility of CT coronary angiography (CTCA) in cardiovascular screenings of aircrew has led to the increased detection of asymptomatic coronary artery disease (CAD). A systematic review of studies relevant to the interpretation of CTCA for the occupational fitness assessment of high-risk vocations was performed, with findings used to describe the development of a pathway for the aeromedical disposition of military aviators with asymptomatic CAD.METHODS: Medline was searched using the terms CT coronary angiogram and screening and prognosis. The inclusion criteria were restricted to study populations ages > 18 yr, were asymptomatic, were not known to have CAD, had undergone CTCA, and with their associations with major adverse cardiovascular events (MACE) and other relevant cardiac outcomes reported.RESULTS: Included in this systematic review were 10 studies. When compared to subjects with no or nonobstructive CAD, those with obstructive CAD on CTCA had hazard ratios (HR) for cardiac events ranging from 1.42 to 105.48. Comparing subjects with nonobstructive CAD and those without CAD on CTCA, a lower HR of 1.19 for cardiac events was found. The annual event rates of subjects with no CAD on CTCA were extremely low, ranging from 0 to 0.5%.CONCLUSIONS: Based on the findings, we suggest that CTCA should only be performed in aircrew with higher cardiac risk profiles. Those found to have no CAD or minimal CAD (i.e., 25% stenosis) in a non-left main coronary artery on CTCA can be returned to flying duties. All other results should be further evaluated with an invasive angiogram.Cheong RWL, See B, Tan BBC, Koh CH. Coronary artery disease screening using CT coronary angiography. Aerosp Med Hum Perform. 2020; 91(10):812817.

Modafinil as a Stimulant for Military Aviators.

INTRODUCTION: Modafinil is a wakefulness-promoting stimulant that has been approved by the Republic of Singapore Air Force (RSAF) as a fatigue countermeasure medication since 2011. Each RSAF aircrew member must undergo a ground test to exclude operationally relevant adverse drug effects prior to consuming the medication for operational reasons. This study describes the RSAF's modafinil ground testing outcomes over a 7-yr period.METHODS: This is a retrospective case series of 243 RSAF aircrew members who underwent modafinil 100-mg test dosing over the 7-yr period from September 2011 to September 2018.RESULTS: The median age was 31 yr (range, 21-53 yr) and mean age was 31.7 yr ± 6.19 yr. Of the aircrew members, 234 (96.3%) were men and all were of Asian ethnicity. Of the subjects, 237 (97.5%) were medically cleared for the operational use of modafinil. Among the six (2.47%) who failed modafinil ground testing, headache (cumulative incidence, 1.65%), anxiety (cumulative incidence, 0.41%), diarrhea (cumulative incidence, 0.41%), and insomnia (cumulative incidence, 0.41%) were reported as the side effects experienced. None of the aircrew members experienced major adverse drug events.DISCUSSION: Our findings suggest a low occurrence of adverse drug effects among military aircrew members who undergo modafinil test dosing prior to using the drug operationally. To our knowledge, this is the single largest published case series of modafinil ground testing outcomes among Asian military aviators.Ooi T, Wong SH, See B. Modafinil as a stimulant for military aviators. Aerosp Med Hum Perform. 2019; 90(5):480-483.

Zolpidem as a Sleep Aid for Military Aviators.

INTRODUCTION: Zolpidem is a short-acting nonbenzodiazepine hypnotic that has been approved by the Republic of Singapore Air Force (RSAF) for aircrew sleep management since 2005. Prior to consuming zolpidem for operational reasons, each RSAF aircrew member is required to undergo a ground test to exclude operationally relevant adverse drug effects. This study describes the RSAF's zolpidem ground testing outcomes over a 12.5-yr period. METHODS: This is a retrospective case series of 578 RSAF aircrew members who underwent zolpidem test dosing from 1 January 2005 to 30 June 2017. RESULTS: The median age was 29 yr (range, 19-54 yr) and the mean age was 30.1 yr ± 6.3 yr. Of the aircrew members, 568 (98.3%) were men and all were of Asian origin; 558 (96.5%) were medically cleared for the operational use of zolpidem. Among the 20 (3.5%) who failed zolpidem ground testing, next-day drowsiness (cumulative incidence, 1.04%), headache (cumulative incidence, 0.87%), and dizziness (cumulative incidence, 0.35%) were the most common causes of failure. None of the aircrew members reported abnormal sleep behaviors or major adverse drug events from zolpidem ingestion. DISCUSSION: Our results suggest a low occurrence of adverse effects among military aircrew members who undergo zolpidem test dosing prior to using the drug operationally. To our knowledge, this is the single largest published case series of zolpidem ground testing outcomes among Asian military aviators.Kew GS, See B. Zolpidem as a sleep aid for military aviators. Aerosp Med Hum Perform. 2018; 89(4):406-408.

Photorefractive keratectomy in young Asian aviators with low-moderate myopia.

INTRODUCTION: The high prevalence of myopia among Asians led the Republic of Singapore Air Force (RSAF) to introduce photorefractive keratectomy (PRK) as a means of enlarging its pilot recruitment pool at the end of 2005. This study aims to address the efficacy and safety of PRK performed on young Asian patients with low-moderate myopia, as well as audit the RSAF's corneal refractive surgery (CRS) program. METHODS: This is a retrospective case series of 149 eyes of 76 consecutive patients that underwent PRK as part of the RSAF CRS program over the 5-yr period from 1 January 2006 to 31 December 2010. RESULTS: The median patient age was 21 yr (range, 18-26 yr) and the mean preoperative spherical equivalent (SE) refraction was -3.39 - 1.19 D. Of the patients, 96.1% were men and all were of Asian origin. At the 12-mo follow-up, 98.5% of eyes had an uncorrected distance visual acuity (UDVA) of < or = 0.00 LogMAR, 100.0% of eyes had an SE refraction of within + 0.50 D of intended correction, and 2.300% of eyes had a loss of corrected distance visual acuity (CDVA) of 0.20 LogMAR. The cumulative incidence of retreatments was 6.7% and cumulative incidence of grade II or worse corneal haze requiring retreatment was 6.0%. Refractive stability was achieved at 3 mo postsurgery. CONCLUSION: The results of this study suggest that PRK performed within the context of a stringent and structured CRS program on young Asian eyes with low-moderate myopia is both efficacious and safe, with refractive stability achieved by 3 mo.