Personal and Physical Characteristics

The included studies indicated that certain demographic and physical characteristics, and protective and risk factors, are related to the resilience of disaster rescue workers. Being in a uniformed profession, such as the police officer or firefighting, is considered a protective factor in the resilience of disaster rescuers. Following the 9/11 terrorist attack, professional police responders exhibited more resilience than non-traditional responders after participating in rescue activities.^{Reference Perrin, DiGrande and Wheeler39} Police officers were also at a lower risk of developing PTSD than those in other occupations.^{Reference Perrin, DiGrande and Wheeler39-Reference Pietrzak, Feder and Singh50} The prevalence of PTSD, depression, and psychological distress was lower among firefighters (1.6%, 3.8%, and 2.6%) than among municipal workers (6.6%, 15.9%, and 14.9%) and medical workers (6.6%, 14.3%, and 14.5%).

Risk factors for low resilience among disaster rescuers were being female, single, young, of Hispanic race, and having previously had a traumatic experience. People with these characteristics were more likely to suffer from negative psychological problems after deployment. Female rescuers were shown to be at a higher risk of developing severe PTSD symptoms and burnout within six months after a disaster rescue than male rescuers.^{Reference Armagan, Engindeniz and Devay35,Reference Pietrantoni and Prati59} Rescue workers who were single and younger were more likely to develop Acute Stress Disorder (ASD),^{Reference Fullerton, Ursano and Wang44} characterized by the development of severe anxiety, dissociation, and other symptoms within one month after exposure to an extreme traumatic stressor,^{Reference Steve62} while voluntary rescuers who were married and older were more likely to be regarded as resilient individuals.^{Reference Thormar, Sijbrandij and Gersons51} Hispanic-American rescuers reported more severe symptoms of PTSD than European-American and African-American rescuers.^{Reference Marmar, McCaslin and Metzler38-Reference Pietrzak, Feder and Singh50} Yet another study reported that responders from visible minority groups were more resilient than whites.^{Reference Ai, Richardson and Plummer55} In addition, rescue workers with previous traumatic experiences have been found to be prone to suffering from psychological problems, such as PTSD and depression, after a disaster rescue.^{Reference Marmar, McCaslin and Metzler38,Reference Fullerton, Ursano and Wang44-Reference Gu, Song and Shao63}

Physical fitness is another protective factor affecting the resilience of rescue workers. Chinese soldiers and healthcare rescuers in good physical health had low levels of secondary trauma and burnout after being dispatched to an earthquake site and were regarded as resilient.^{Reference Mao, Loke and Fung26-Reference Chang and Taormina56} Another study involving 1024 military rescue workers revealed a positive association between poorer physical health and severe PTSD symptoms.^{Reference Gu, Song and Shao63} Humanitarian aid workers viewed good physical health as necessary to maintaining physical capacity, which could help them to solve problems in their mission.^{Reference Nolty, Bosch and An52,Reference Ghodsi, Jazani and Sohrabizadeh53} Poor sleep quality was also found to strongly contribute to PTSD symptoms in professional humanitarian aid workers and volunteer rescue workers after a disaster event.^{Reference Marmar, McCaslin and Metzler38,Reference Thormar, Gersons and Juen41,Reference Eriksson, Lopes Cardozo and Foy54}

Personality Traits

Certain personality traits, including hopefulness, extroversion, optimism, altruism, spirituality, and self-confidence, which contribute to the positive handling of traumatic situations are considered characteristics of resilience.

Hopefulness is associated with resilience. A qualitative study found that voluntary rescuers who had a sense of hope had a high level of psychological resilience after a large-scale disaster than those who did not.^{Reference Carlile, Mauseth and Clark43} A study of 1553 humanitarian aid workers indicated that those with a hopeful outlook had a high level of resilience.^{Reference Nolty, Bosch and An52} Another study noted that rescue workers deployed during 9/11 who were without a sense of hope were at a higher risk of developing symptoms of PTSD, anxiety, and depression 6 months after the disaster, compared to non-deployed rescuers.^{Reference Alvarez and Hunt20} A study on 452 members of rescue teams also reported that those who possessed a sense of hope in their disaster rescue work and in their personal life were regarded as resilient.^{Reference Liang and Peng47}

Extraversion is a personality trait that is negatively correlated with symptoms of psychological disorders among disaster rescue workers.^{Reference Liao, Lee and Lee58,Reference Zhou61} A study employing factor analysis found that the personality trait of extraversion contributed to the resilience of rescue workers after they had been exposed to trauma.^{Reference Madeha, Saleem and Mamood48} Another study revealed that, unlike extraversion, introversion is reported to be positively associated with PTSD.^{Reference Gu, Song and Shao63}

The trait of optimism is yet another positive characteristic related to resilience. Two quantitative studies of 159 rescue workers who responded to a plane crash and 21 healthcare rescuers showed that individuals with an optimistic personality reported less distress during a disaster than those with a pessimistic personality.^{Reference Mao, Loke and Fung26,Reference Dougall, Hyman and Hayward57} A cross-sectional study of 554 students who engaged in disaster relief efforts found a negative association between optimism and depression after the devastation resulting from hurricanes Katrina and Rita.^{Reference Ai, Richardson and Plummer55} Semi-structured interviews revealed that resilient rescuers were optimistic about their rescue work during deployment and their future tasks.^{Reference Geiger36,Reference Liang and Peng47}

The personality traits of altruism and spirituality were also associated with resilience^{Reference Isaacs, Mota and Tsai64,Reference Sharma, Marin and Koenig65} Studies have shown that following the Haiti earthquake and Wenchuan earthquake, increased resilience was seen among those who had a desire to help others.^{Reference Mao, Loke and Fung26,Reference Carlile, Mauseth and Clark43,Reference Ai, Richardson and Plummer55} It has also been reported in a qualitative study that having a religious belief can mitigate symptoms of trauma and promote post-traumatic resilience and growth after disastrous events.^{Reference Geiger36} Other studies reported that spirituality contributes to the enhancement of resilience,^{Reference Madeha, Saleem and Mamood48,Reference Ghodsi, Jazani and Sohrabizadeh53} particularly when the focus of spirituality is not only on inner beliefs but also on external practices.^{Reference Nolty, Bosch and An52}

Self-efficacy or self-confidence also improves psychological resilience. A study of 241 military men exposed to the Wenchuan earthquake found a negative correlation between anxiety and self-efficacy.^{Reference Zhang, Zhu and Miao42} Those with self-efficacy were also reported to be more likely to exhibit symptoms of compassion fatigue and burnout.^{Reference Pietrantoni and Prati59} In addition, self-confidence has been found to contribute to the enhancement of resilience among frontline workers, humanitarian aid workers, and volunteers exposed to disastrous events.^{Reference Carlile, Mauseth and Clark43,Reference Madeha, Saleem and Mamood48,Reference Thormar, Sijbrandij and Gersons51,Reference Ghodsi, Jazani and Sohrabizadeh53}

Negative personality traits weaken the resilience of disaster rescue workers and contribute to psychopathologic symptoms. Emotional instability is the most frequently reported predictor of negative personality traits among those suffering from PTSD and psychological stress.^{Reference Zhang, Zhu and Miao42,Reference Huang, Liu and Li46,Reference Liao, Lee and Lee58,Reference Zhou61} Having a psychotic personality is another predictor of PTSD.^{Reference Madeha, Saleem and Mamood48,Reference Zhou61}

Coping Strategies

Coping strategies, including seeking social support, problem-focused coping, avoidance coping, and expressive suppression, were positively correlated with resilience among disaster rescuers. A longitudinal study indicated that greater use of seeking-social-support coping strategies predicts the lessening of stress among rescue workers approximately 2 and 6 months after deployment, whereas problem-focused and avoidance coping strategies are associated with less stress months after a disaster.^{Reference Dougall, Hyman and Hayward57} This finding is consistent with those from the studies of 214 humanitarian aid workers and 21 healthcare rescuers.^{Reference Mao, Loke and Fung26,Reference Eriksson, Lopes Cardozo and Foy54} Another two studies reported that avoidance coping was negatively related to the state of anxiety of rescuers after deployment.^{Reference Zhang, Zhu and Miao42,Reference Eriksson, Lopes Cardozo and Foy54} A mixed-methods study showed that suppression is associated with the lowest levels of job burnout among rescue medical staff, and that these effects were mediated by positive reappraisals.^{Reference Gan, Wen and Wang45}

However, poor coping strategies significantly affect resilience. Two studies showed that poor coping strategies were positively correlated with PTSD after disasters.^{Reference McCanlies, Mnatsakanova and Andrew32,Reference Huang, Liu and Li46} Self-blame and wishful-thinking coping have also been identified as risk factors that reduce resilience.^{Reference Marmar, McCaslin and Metzler38} In addition, wishful-thinking coping has been positively associated with anxiety and PTSD.^{Reference Marmar, McCaslin and Metzler38,Reference Zhang, Zhu and Miao42}

Perceived Resources

Social support, defined as resources from family, friends, colleagues, and work organizations or communities, has frequently been reported as predicting resilience and aiding in the prevention of psychological stress, anxiety, burnout, and PTSD.^{Reference Alvarez and Hunt20,Reference Marmar, McCaslin and Metzler38,Reference Sakuma, Takahashi and Ueda40,Reference Carlile, Mauseth and Clark43,Reference Huang, Liu and Li46,Reference Pietrzak, Feder and Singh50,Reference Thormar, Sijbrandij and Gersons51,Reference Chang and Taormina56,Reference Dougall, Hyman and Hayward57,Reference Zhou61}

Rescue workers who perceive that they have a high level of social support or social acknowledgement are less likely to suffer from negative consequences such as burnout^{Reference Marmar, McCaslin and Metzler38,Reference Thormar, Sijbrandij and Gersons51,Reference Chang and Taormina56} and PTSD^{Reference Huang, Liu and Li46,Reference Pietrzak, Feder and Singh50,Reference Eriksson, Lopes Cardozo and Foy54,Reference Dougall, Hyman and Hayward57,Reference Zhou61} during or after deployment in a disaster area. A qualitative study showed that volunteers with strong social support enjoyed psychological benefits, although volunteers can be regarded as survivors who have experienced considerable material loss after a large-scale disaster.^{Reference Carlile, Mauseth and Clark43} In a longitudinal study, great social support for workers involved in air crashes was negatively linked with concurrently reported distress at 2, 6, 9, and 12 months after the incident.^{Reference Dougall, Hyman and Hayward57} Social support was found to help disaster rescuers balance their emotions to improve their mood,^{Reference Ai, Richardson and Plummer55} and to have motivated them to remain part of the disaster rescue team.^{Reference Mao, Loke and Fung26,Reference Nolty, Bosch and An52,Reference Ghodsi, Jazani and Sohrabizadeh53}

Being Equipped with Special Skills for Disaster Rescue

Being equipped with special preparation and training can enhance the resilience of disaster rescuers. Disaster rescuers without formal training demonstrated lower levels of physical and psychological health when compared with trained rescue personnel such as police officers.^{Reference Hagh-Shenas, Goodarzi and Dehbozorgi37} Canine search and rescue handlers who were certified members of the Federal Emergency Management Agency (FEMA) were less likely to report PTSD symptoms.

It was postulated that their special training and preparedness for disaster gave them a sense of efficacy and a locus of internal control.^{Reference Alvarez and Hunt20} A study also reported that adequate disaster preparedness reduced the prevalence of PTSD among rescue workers.^{Reference Perrin, DiGrande and Wheeler39} It has been suggested that trained disaster rescuers were able to focus on task performance and goal achievement when they served at a disaster scene, and that this ability may have enhanced their resilience.^{Reference Mao, Loke and Fung26,Reference Geiger36,Reference Carlile, Mauseth and Clark43,Reference Ghodsi, Jazani and Sohrabizadeh53}

Had Less Adverse Consequences

The nature of rescue work and the occurrence of disasters are stressors that could have negative psychological consequences on rescue workers dispatched to disaster sites. However, disaster rescuers with the attributes of resilience reported fewer symptoms of ASD or PTSD.^{Reference Alvarez and Hunt20,Reference McCanlies, Mnatsakanova and Andrew32,Reference Armagan, Engindeniz and Devay35,Reference Hagh-Shenas, Goodarzi and Dehbozorgi37-Reference Thormar, Gersons and Juen41,Reference Fullerton, Ursano and Wang44,Reference Huang, Liu and Li46,Reference Madeha, Saleem and Mamood48,Reference Pietrzak, Feder and Singh50,Reference Thormar, Sijbrandij and Gersons51,Reference Eriksson, Lopes Cardozo and Foy54,Reference Zhou61,Reference Gu, Song and Shao63} With resilience, rescue workers would also not be prone to developing anxiety and/or depression,^{Reference Alvarez and Hunt20,Reference McCanlies, Mnatsakanova and Andrew32,Reference Hagh-Shenas, Goodarzi and Dehbozorgi37,Reference Sakuma, Takahashi and Ueda40,Reference Zhang, Zhu and Miao42,Reference Fullerton, Ursano and Wang44,Reference Eriksson, Lopes Cardozo and Foy54,Reference Ai, Richardson and Plummer55,Reference Zhang, Chen and Xia60,Reference Gu, Song and Shao63} fatigue,^{Reference Pietrantoni and Prati59} distress,^{Reference Alvarez and Hunt20,Reference Nishi, Kawashima and Noguchi49,Reference Dougall, Hyman and Hayward57,Reference Liao, Lee and Lee58} burnout,^{Reference Gan, Wen and Wang45,Reference Ghodsi, Jazani and Sohrabizadeh53,Reference Chang and Taormina56,Reference Pietrantoni and Prati59} and lack of work engagement.^{Reference Nishi, Kawashima and Noguchi49,Reference Nolty, Bosch and An52,Reference Eriksson, Lopes Cardozo and Foy54}