Abstract
Emergency first responders, including paramedics, firefighters (urban and rural), State Emergency Services (SES), and specialist communication centre operators, face intense, high-pressure situations, compounded by prolonged hours and disrupted sleep. These operational demands contribute to a challenge of ongoing fatigue within this workforce. To address the complexity of fatigue in this workplace a structured framework is essential. The International Risk Management Framework consists of five steps: Establishing the context, Identify Risks, Analyse Risks, Evaluate Risks, and Treat Risks.This framework is adaptive and provides pragmatic approaches to addressing risks. By applying this framework in Emergency Services Organisations, fatigue can be systematically assessed and targeted, evidence-based mitigation strategies can be implemented.
The first step in the framework is to establish the context, which involves defining fatigue and separating it into its various types. While there are numerous variable definitions, the International Civil Aviation Organisation defines fatigue as " A physiological state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, circadian phase, and/or workload (mental and/or physical activity) that can impair a person’s alertness and ability to perform safety related operational duties”.
Fatigue can manifest in six different forms: cognitive, physical, burnout, emotional, visual, and vocal. Among these, cognitive and physical fatigue are thought to impair occupational performance the most by negatively influencing the ability to think clearly and move efficiently. Cognitive fatigue typically manifests as slowed reaction time and delayed information processing, both of which affect decision making and task execution. Physical fatigue is characterised by reduced neuromuscular function, which can limit co-ordination, endurance and strength.
Each type of fatigue is affected by a complex interplay of both intrinsic and extrinsic factors. Intrinsic factors can include sleep deprivation, circadian misalignment, disruptions of the ultradian sleep cycle and homeostatic sleep pressure, alongside broader health issues such as PTSD, self-medication and sleep disorders. Extrinsic factors can range from acute and chronic workload demands irregular shift patterns, and environmental stressors such as noise, lighting, temperature and workplace culture. Given their influence, particularly on cognitive and physical fatigue, it is essential to clearly identify the main contributors to occupation-induced fatigue in emergency first responders.
To further the establishment of the context and the foundation of this research, a systematic review was conducted to identify the key contributors to occupation induced fatigue. The review encompassed 43 studies, involving a total of 6,372participants and assessed 186 distinct outcome measures. The findings consistently highlighted that emergency first responders face prolonged working hours, including overnight shifts, conditions associated with sleep deprivation substantial physical and mental demands. These conditions lead to elevated levels of both cognitive and physical fatigue. As a consequence of these occupational demands, responders exhibited slower reaction times and impaired decision-making abilities. Physically, they exhibited reduced balance and diminished rapid force production. Together, these impairments contributed to increased safety-compromising behaviours and a higher risk of injuries among responders.
Despite the multitude of outcome measures assessed, 186 in total, it was not possible to specify which were most effective for assessing cognitive or physical fatigue. This was due to the considerable variability in measurement approaches across the included studies. Despite this, the Pittsburgh Sleep Quality Index was the most frequently reported measure, appearing in nine studies. However, it primarily evaluates sleep quality rather than fatigue specifically, limiting its utility in distinguishing between fatigue types. The findings highlighted a significant gap in consensus on appropriate outcome measures for distinguishing between the types of fatigue in emergency first responders. Addressing this gap is of key importance for developing targeted fatigue assessments and informing future mitigation strategies.
To further establish the context, a second review of the literature was conducted to identify the most common and accessible objective and subjective measures of cognitive and physical fatigue. For the objective measurement of cognitive fatigue, the Psychomotor Vigilance Task (PVT) was determined to be the most specific tool. It is a simple reaction-time test available on handheld devices capable of detecting lapses in attention. If equipment or time is limited, pairing subjective measures of cognitive fatigue such as the Samn-Perelli Fatigue Scale, provide a rapid assessment of an individual’s current alertness levels. When a longer-term profile of sleep-related functioning is required, the Pittsburgh Sleep Quality Index offers insight into sleep quality over the preceding month. Some studies also supporting its comparability to the PVT, suggesting a relationship between subjective perceptions of sleep quality and objectively measured fatigue affected performance.
For the detection of physical fatigue, the vertical jump test is proposed to offer a rapid and practical objective measure which captures the loss of power and rate of force development in under a minute. With the availability of smartphone-based applications, this tool is now more accessible and feasible for organisations. However, when live testing may not be practical, monthly subjective measures such as the Chalder Fatigue Scale or the Occupational Fatigue Exhaustion Recovery Scale (OFERS) can provide insight into an individual’s ability to recover physically and cognitively. These are particularly effective when used in conjunction with the objective testing of physical fatigue. While objective and subjective measures help identify existing fatigue, understanding the context of cognitive and physical fatigue requires knowledge of which occupational demands most significantly contribute to elevated physical and cognitive fatigue in emergency first responders.
To complete the contextual framework, a targeted survey was conducted to identify which occupational demands were the strongest contributors to cognitive and physical fatigue. Paramedics were selected due to their elevated injury rates within the emergency first responder workforce. A total of 22 responses were collected. The results indicated that the most cognitively demanding tasks were clinical decision-making and patient care, while the most physically demanding tasks included manual handling and carrying the responder bag. Most respondents (73%) reported experiencing cognitive and physical fatigue toward the end of their shifts, and all (100%) indicated that they continued to feel fatigued on their days off. Nearly a third (32%) of respondents reported having sustained an injury within the past six months. Among those who reported injuries, the majority (86.5%) believed that fatigue contributed to their injuries. The paramedics also rated their chronic fatigue levels as moderate to high and high acute fatigue, with low recovery levels between shifts. These findings underscore the role of both cognitive and physical fatigue in elevating paramedics injury risk and reinforce the need for targeted fatigue mitigation strategies.
Step Two of the Risk Management Framework (RMF) focusses on identifying risks, specifically those associated with fatigue in operational contexts. Physical injuries are well-documented and frequently linked to fatigue related factors. To assist in identifying risk, injury records were sourced from an Australian State Emergency Services Agency. This dataset was systematically evaluated to profile the common injuries suffered within this organisation.
Between 2012 and 2022, the ESA recorded 2,703 physical injuries across five groups: Paramedics, Fire and Rescue, Rural Fire, State Emergency Services, and the Communications Centre personnel. Paramedics reported the greatest number of injuries with1,570 (57.5% of the total; 566 per 1,000 FTE). Fire and Rescue followed with 705 injuries (26%; 184 per 1,000 FTE). Rural Fire and the State Emergency Services (predominately volunteer based), each reported just over 200 injuries (7.4% and 7.2% of the total), but at much higher rates (1,295and 2,054 per 1,000 FTE, respectively), while the Communications Centre’s desk-based staff suffered 31 total injuries (1.1%; 754/1,000 FTE).
Soft-tissue strains emerged as the most prevalent injury type across all emergency service groups. Paramedics predominately injured their lower backs, wrists/hands and shoulders when lifting and moving stretchers or patients. Fire and Rescue personnel experienced hand/wrist and knee strains often attributed to the physical load of heavy operational gear. Rural firefighters most injured their hands, head/face and ankles due to slips, trips and falls on rugged terrain conditions. SES volunteers, tasked with carrying stretchers and rescue equipment, mirrored the soft tissue injury profile to both the upper and lower limb, due to sustained heavy manual tasks. Even Communications Centre operators, despite their office-based roles, reported injuries such as acute hearing damage (acoustic shocks) alongside occasional wrist, hand and back strains from prolonged headset use.
Step three and four of the risk management framework is associated with analysing and evaluating risk, respectively. This chapter combines step three and four which seeks to explore the link between self-reported fatigue and injury among emergency service paramedics, revealing that individuals who sustained injuries in the past six months reported significantly higher levels of chronic fatigue, suggesting a cumulative strain effect that isn't captured by acute or shift specific fatigue metrics. Despite consistent perceptions of fatigue on rest days and a shared belief that fatigue contributes to injury, these factors did not significantly differ between injured and non-injured groups, nor across genders. These findings point to chronic fatigue as a subtle yet critical risk factor that may operate independently of self-awareness or demographic variables.
The final step of the risk management process is to treat the risk. While fatigue will always be an inherent part of this profession, feasible and actionable recommendations are made to mitigate the effects of both cognitive and physical fatigue. This thesis identifies several evidence-based strategies to mitigate fatigue risk. One key strategy is optimizing shift cycles by aligning work schedules with circadian rhythms and ensuring adequate rest between shifts. Allowing more than 16 hours of rest has been shown to reduce fatigue significantly. Improving sleep hygiene through education and awareness of behavioural and environmental factors has improved sleep quality and reduced fatigue among EFR. Additionally, cold water immersion is proposed as a feasible recovery method, and it has been shown to decrease athletes' physical fatigue and can be adapted to EFR settings via showers.
Lastly, regular exercise is critical in offsetting occupational fatigue, improving fitness and job performance, and reducing injury rates, especially in female and older personnel with higher vulnerability. Furthermore, research has shown that dedicated exercise in EFR improves lower body power and grip strength and improves occupational-relevant fitness assessment times. However, exercise should not compromise sleep. Some report barriers to exercise as lack of time and energy, which should be addressed to make exercise more viable.
Collectively, these strategies offer practical, low-cost approaches to reduce cognitive physical fatigue in EFR populations.
The present thesis explores occupational fatigue and its contributors by enhancing the broader understanding of cognitive and physical fatigue within Emergency First Responders (EFR). Furthermore, the thesis has established how fatigue affects cognition and function, which poses the most direct risks to occupational safety. The highlighted gaps in measuring fatigue give further call to action for combining objective and subjective tools as a proactive approach to RMF. The alarming injury rates, particularly among paramedics and SES personnel, reinforce the critical need for physical fitness standards but also highlight the demanding work conditions and poor recovery. The prioritisation of impactful interventions such as improved shift cycles, sleep hygiene, cold-water immersion, and exercise can help to minimise fatigue. Together, these insights provide a robust platform for developing tailored fatigue risk management strategies to safeguard the health, safety, and effectiveness of EFR personnel.
| Date of Award | 2026 |
|---|---|
| Original language | English |
| Supervisor | Ben Schram (Supervisor), Rob Orr (Supervisor) & Elisa Canetti (Supervisor) |