BACKGROUND: Work ability is an important component of occupational health assessments and reflects how a persons' physical and mental health affect their ability to perform their job. However, little is known about factors relating to the work ability status of flight attendants. The aim of this study was to investigate the physical, mental, and work-related factors that affect flight attendants’ work ability.METHODS: A questionnaire-based cross-sectional study and simple random sampling was conducted with participants employed at a Taiwan-based airline for longer than 1 yr. Analysis of variance and Pearson correlation tests were carried out to analyze work ability according to the flight attendants’ social demographics, physical and mental health, and work-related factors. Multiple regression analysis was used to predict the flight attendants’ work abilities.RESULTS: A total of 472 flight attendants were recruited and the response rate was 78.67%. The work ability of the flight attendants ranged from ‘moderate’ to ‘excellent’ (WAI score, 34.1 ± 1.8 to 45.1 ± 1.5). In a regression analysis, work ability was positively associated with gender, age, and good eating habits; in contrast, insomnia and work-related burnout were negatively associated with work ability (R² = 32.4%).DISCUSSION: Insomnia, work-related burnout, and eating habits had a significant impact on flight attendants’ work abilities. Hence, it is important to address insomnia and high workloads and maintain a healthy lifestyle in the workplace.Hu C-J, Hong R-M, Yeh G-L, Hsieh I-C. Insomnia, work-related burnout, and eating habits affecting the work ability of flight attendants. Aerosp Med Hum Perform. 2019; 90(7):601–605.

BACKGROUND: From a population-based perspective, reports in the peer-reviewed medical literature suggest an increase in the overall prevalence of asthma in recent decades. Applicants for military aviation training with a current or past history of asthma are generally excluded in the United Kingdom.METHODS: In order to assess the impact of the prevalence of asthma on the available pool of military service candidates, the authors collected data on annual live births between 1916 and 2016 as well as peer-reviewed publications that provided insight into asthma prevalence trends within the United Kingdom across the last century (covering birth-year population cohorts ranging from 1924 to 1995). Regression techniques were used to estimate the prevalence of individuals who could reasonably expect to be found unfit for military aviation service due to asthma-like conditions within the birth-year cohorts between 2001 and 2016.RESULTS: Between 1916 and 2016, the number of live births in the United Kingdom has averaged approximately 802,000 per year. The reported prevalence of asthma, based on the assimilated data points, ranged from 2.3 cases per 1000 individuals among the 1924 birth-year cohort, to 29.8 cases per 1000 individuals among the 1990 birth-year cohort.DISCUSSION: Based on the data and analysis presented above, asthma continues to constitute a significant public health issue in the United Kingdom. Military services must base risk mitigation decisions on accurate and precise diagnostic categorizations, and prudently balance the benefits of allowing affected individuals to participate in military service with the potential for mission degradation or compromise.Porter WD, Powell-Dunford N, Wilde GD, Bushby AJR. Asthma and rotary-wing military aircrew selection. Aerosp Med Hum Perform. 2019; 90(7):606–612.

INTRODUCTION: High-gravity (G) training is used to educate trainee pilots about anti-G straining maneuvers (AGSM) in an environment similar to that of a real fighter aircraft, and to enhance their G tolerance. The success or failure of high-G training could be multifactorial, but most previous studies have only focused on the effect of pilots’ physical condition.METHODS: A total of 138 male trainee pilots participated in this study. All trainee pilots had received AGSM training from experienced instructors and then underwent centrifuge high-G training. Participants completed questionnaire surveys about body size, lifestyle, self-reported AGSM proficiency, resilience (Connor-Davidson Resilience Scale, CD-RISC), and depression level (Center for Epidemiologic Studies Depression Scale, CES-D).RESULTS: Of the 138 subjects, 100 (72.5%) successfully completed high-G training without experiencing G-induced loss of consciousness (G-LOC) within two trials; these were allocated to the success group. The remaining 38 (27.5%) subjects who completed the training after three or more attempts, or who failed to complete the training at all, were allocated to the failure group. Multivariate analyses revealed that the success of centrifuge training was positively associated with age and self-reported AGSM proficiency, and negatively associated with depression level.DISCUSSION: The success of high-G training was significantly associated with self-reported AGSM proficiency and depression level. Instructors should emphasize the importance of AGSM proficiency and offer practice-based learning to trainee pilots. In addition, they should pay attention to not only trainee pilots’ physical condition, but also their psychological status.Yun C, Oh S, Shin YH. AGSM proficiency and depression are associated with success of high-G training in trainee pilots. Aerosp Med Hum Perform. 2019; 90(7):613–617.

BACKGROUND: In order to determine the minimum flight crew number and show compliance with airworthiness regulations, the workload of flight crew should be measured in various flight scenarios both in a simulator and in flight tests demonstrating compliance. However, the complexity, environment, and safety considerations of flight tests require pilots to take more responsibility and be more careful with decisions and actions with higher stress, and it might be inappropriate to carry out flight tests in a high-risk abnormal situation. Therefore, it is necessary to assess workload measures in a simulator to predict workload experienced during a flight test.METHODS: Two subjective workload measurements and three psychophysiological measurements were compared both in a simulator and in a flight test among three flight scenarios. The scenarios were carried out in an ARJ21-700 full-flight simulator and a corresponding aircraft, and a total of 17 pilots participated.RESULTS: Both flight scenarios and flight environment had a significant influence on NASA-TLX, eye blink rate, and heart rate. Additionally, the NASA-TLX (R = 0.864) and heart rate differences (R = 0.840) presented strong correlations between the simulator and flight test.DISCUSSION: NASA-TLX and heart rate could be used in simulators and flight tests as consistent measures of workload. Furthermore, in order to reduce the quantity and risk of compliance during a flight test, the best strategy is to combine the results of the NASA-TLX scales and HR-D together in a flight simulator to predict workload experienced in a flight test.Zheng Y, Lu Y, Jie Y, Fu S. Predicting workload experienced in a flight test by measuring workload in a flight simulator. Aerosp Med Hum Perform. 2019; 90(7):618–623.

BACKGROUND: Voice analysis offers an unobtrusive approach for psychological monitoring. We demonstrate the relationship between voice parameters and cognitive performance in: 1) a task with psychological test character, and 2) performance in an operational, mission-relevant task. The central methodological aim was to verify the usefulness of voice commands and counting in providing anchor values for the step-function model of voice pitch.METHODS: During a 22-yr period, 42 cosmonauts participated in the Russian space experiment “Pilot”, which was a hand-controlled docking maneuver. As reference the experiment included the cognitive task “Manometer.” This task was controlled through voice commands. These voice commands were stored and are the basis for the present analysis.RESULTS: Cosmonauts differed in their working style and respective performance during the Manometer task. Clustered groups can be assumed to represent different effort. Importantly, these groups differed in the changes of voice pitch among mission phases and among task repetitions. However, there were no differences between these motivation groups and performance in the professional task.DISCUSSION: The differing effort is the effect of different motivation of cosmonauts for experimental test tasks vs. mission-relevant professional tasks. Latter ones provide a more reliable chance to assess the real actual state and skills of a cosmonaut. Voice pitch measurement seems to be reliable and useful under space conditions for monitoring this volitional effort.Johannes B, Bronnikov SV, Bubeev JA, Kotrovskaya TI, Shastlivtseva DV, Piechowski S, Hoermann H-J, Rittweger J, Jordan J. Operational and experimental tasks, performance, and voice in space. Aerosp Med Hum Perform. 2019; 90(7):624–631.

INTRODUCTION: Armed conflicts tend to be unpredictable to such an extent that the fact that seamen also have to fight for their survival on land cannot be excluded. The aim of the study was to determine the degree of changes in selected coordination motor abilities in the course of a 36-h military survival training of Naval Academy cadets.METHODS: There were 14 Polish Naval Academy cadets, ages 20–27 yr, who were examined 4 times: pretraining, after 24 h, posttraining, and after a 12-h rest. Tests related to the following issues were carried out: divided attention, shooting performance, strength of forearm muscles and ability of its differentiations, body balance, and running motor adjustment. During the training soldiers had to perform the following tasks: first aid in the battlefield, building, water crossing to the enemy base, marching to the azimuth, operations in the recon team, and conducting observations.RESULTS: The maximum strength of forearm muscles during the training decreased from 7–10% during each and every measurement. The ability to differentiate the strength of the forearm muscles after the night part of the training deteriorated (about 9%). There was a systematic deterioration of the ability to maintain balance (between P1 and P4 by 24%).CONCLUSION: A 36-h training at a survival school varied the selected coordination motor abilities. Training should include exercises that develop an ability to differentiate muscle strength, motor adjustment, and balance. These exercises fall within the scope of coordination exercises that can be performed during obligatory physical education classes.Tomczak A, Różański P, Jówko E. Changes in coordination motor abilities of naval academy cadets during military survival training. Aerosp Med Hum Perform. 2019; 90(7):632–636.

INTRODUCTION: Despite the large number of U.S. military members who conduct parachuting operations, its inherent safety risks, and the introduction of a new military parachute in 2010, little has been published in the last decade on U.S. military parachute fatalities.METHODS: Parachute fatality investigative records maintained by the U.S. Army Combat Readiness Center were reviewed for U.S. Army fatalities resulting from military parachuting operations from January 1, 2010, through December 31, 2015. De-identified data on cases were collected, including causes, lethal injuries, and demographic, environmental, and missional factors. A descriptive analysis was performed.RESULTS: There were 13 cases which met study inclusion criteria. Most occurred during static-line operations and were jumps from a C-17 aircraft using a T-11 parachute. The two most common assigned accident codes were “improper or abnormal exit” and “unstable or improper body position,” which combined accounted for 33% of cases. Also noteworthy at 11% each were “entanglement,” “parachute malfunction,” and “dragged on the drop zone,” and at 6% each were “static line injury,” “lost or stolen air,” and “drop zone hazard.” In 69% of cases blunt force trauma was the cause of death.DISCUSSION: Incident factors included human actions, equipment failure, and the environment. Death from blunt force trauma upon impact with the ground as the most frequent lethal injury was expected for parachute operations. This descriptive study provides awareness to military leaders of circumstances in which fatalities occur. Future investigations should include data on the total number of jumps to provide a more comprehensive analysis of risk.Johnson ES, Gaydos SJ, Pavelites JJ, Kotwal RS, Houk JE. U.S. Army parachute mishap fatalities: 2010–2015. Aerosp Med Hum Perform. 2019; 90(7):637–642.

INTRODUCTION: Joint Base Charleston’s C-17 Globemaster III mission is executed by 400 active-duty members from three operational and support wings. Aircrew and mission-essential personnel travel to locations with endemic diseases which are mostly eradicated in the United States. Recently, two members contracted malaria after missions in Africa which required advanced hospital care. Personnel were provided chemoprophylaxis, but the members who contracted malaria were among several who chose not to take it. This preliminary survey assessed aircrew malaria prophylaxis adherence and examined potential factors contributing to nonadherence.METHODS: JB Charleston aircrew members who visited the Flight and Operational Medicine Clinic between January and April 2018 were administered a retrospective, online survey. Researchers performed descriptive statistics and Chi-squared analysis.RESULTS: Most respondents were pilots under 30 yr of age and were prescribed malaria chemoprophylaxis while on a mission. More than two-thirds of respondent aircrew members did not take the medication as prescribed or did not take it at all. Of those, over half of respondents stated too many pills/too many days and medication side effects as the main reasons for nonadherence. Furthermore, almost 70% of adherent members experienced negative medication side effects such as nausea and heightened dreams. There was no statistical relationship between crew position, age, side effects, and prophylaxis adherence.DISCUSSION: Numerous factors contribute to poor prophylaxis regimen compliance among aircrew members. This study highlighted the need for risk-based policy validation, improved patient education, prophylaxis enforcement, process improvements to facilitate adherence, and evaluation of perceived vs. actual risk.Rutherford AE, Yale RS, Finn MF. Malaria prophylaxis adherence among aircrew members. Aerosp Med Hum Perform. 2019; 90(7):643–646.

INTRODUCTION: Research on the mortality of space explorers has focused exclusively on U.S. astronauts and Soviet and Russian cosmonauts. However, other nations have organized space programs over the last 40 yr and the European Space Agency, the Canadian Space Agency, the China National Space Administration, and the Japan Aerospace Exploration Agency all offer an opportunity for further study of the mortality of space explorers.METHODS: We used biographical and vital data abstracted from public sources for European, Canadian, Chinese, and Japanese astronauts. Using general population mortality rates from the Human Mortality Database and mortality rates derived from the cohort of U.S. astronauts, we computed standardized mortality ratios.RESULTS: The groups displayed different preferences in selection of astronauts. As there were no deaths in any of the four groups, the point estimates for standardized mortality ratios were all 0. However, the European cohort experienced a statistically significant reduction in all-cause mortality risk in comparison to the European general population as well as in comparison to U.S. astronauts.DISCUSSION: The healthy worker effect predicts that all study cohorts should have lower all-cause mortality risk in comparison to their general populations. The general population of Japan has mortality rates low enough that any reduction in mortality risk may remain undetectable in the Japanese cohort. Continued surveillance of these populations in the coming decades will make them a useful addition to the evidence base for astronaut mortality.Reynolds RJ, Day SM. Mortality among international astronauts. Aerosp Med Hum Perform. 2019; 90(7):647–651.

BACKGROUND: Physicians rely on intuition and pattern recognition to rapidly evaluate and treat patients. While the realities of our medical system require liberal use of these heuristics to efficiently make clinical decisions, such thinking patterns are error-prone—leaving the clinician at the whims of their cognitive biases.CASE REPORT: We describe a case of Lyme disease in which a pilot’s rash and radicular pain were misdiagnosed on two separate occasions until, nearly a month after initially seeking medical care, the pilot was appropriately diagnosed and treated.DISCUSSION: This case highlights Lyme disease’s mimicry of other common diseases and underscores the need to use slower, more deliberate evaluation in conjunction with pattern recognition and intuition to provide optimal care to flyers.Saul S, Tanael M. Rash, radiculopathy, and cognitive biases. Aerosp Med Hum Perform. 2019; 90(7):652–654.

BACKGROUND: The evaluation of how air rarefaction can affect a loudspeaker performance at altitude implies the need for characterization of earphones during hypobaric conditions. The aim of this study was phonometric analysis at different altitudes of the acoustic output of a widely used earphone model, along with its consequences on audiological investigations conducted under such environmental conditions.METHODS: The transfer function of a TDH-39P earphone was analyzed with an artificial ear under nine different altitude levels, from sea level up to 35,000 ft, inside a hypobaric chamber. A specific phonometric system not sensitive to environmental pressure changes was used. Other potentially confounding factors, such as environmental temperature and humidity, were continuously monitored.RESULTS: No relevant temperature or humidity changes were detected. The sound pressure level generated by the earphone under hypobaric conditions was found considerably affected by air density changes. These data produced a correction table aiming at recalibrating the earphone’s output at each audiometric octave test frequency within the 250–8000 Hz range. Quite different characteristics of response were observed at different audiometric frequencies. Such findings were particularly evident for altitudes exceeding 12,000 ft.DISCUSSION: The development of a frequency-selective and altitude-related correction factor for acoustic stimuli is an essential aspect when hearing threshold measurements in hypobaric environments are performed.Lucertini M, Botti T, Sanjust F, Cerini L, Autore A, Lucertini L, Sisto R. High altitude performance of loudspeakers and potential impact on audiometric findings. Aerosp Med Hum Perform. 2019; 90(7):655–659.

Navel DM. You’re the flight surgeon: dengue fever. Aerosp Med Hum Perform. 2019; 90(7):660–663.