Posttraumatic Stress Disorder And Sleep Quality Among Urban Firefighters In Thailand - [Letter].

Dear editor

With great interest we read the study by Khumtong et al on posttraumatic stress disorder (PTSD) and sleep quality amongst a population of urban firefighters in Thailand.1 The authors concluded urban firefighters in Thailand with PTSD were more likely to experience poor sleep quality than those without. Therefore, they importantly recognise that interventions in psychological well-being for this population should be implemented. We would like to offer some insights into their study.

Khumtong et al used the Posttraumatic Stress Disorder Checklist – Civilian Version (PCL-C) in order to identify PTSD within their study population.1 The authors chose a cut-off score of 44. However, there is no universal validated threshold score to make a diagnosis with the PCL-C, as cut-offs vary between 27 and 59.2 Nydegger et al suggested using a score of 50 or more to indicate PTSD in a firefighting population.3 Therefore, it is likely that Khumtong et al are overestimating the presence of PTSD within their sample, decreasing the validity of their results. Furthermore, these results cannot be compared to other studies using the PCL-C if their values for PTSD are different.

A further limitation of the study is the chosen method to collect data on the population’s quality of sleep, using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. This questionnaire focusses on the sleep quality of the individual over the past month.1 As the firefighters were on duty for 24 hrs on ‘3–4 days per week’,1 it’s likely that work-related sleep disturbance was inevitable. This was a confounding factor which was not taken into account. We suggest that future questionnaires distinguish between sleep whilst working versus when not working, in order to see how PTSD can affect sleep in all areas of the firefighters’ lives.

The study looked into only male firefighters, with women being excluded from the study. Evidence shows that PTSD is twice as prevalent in women as in men.2 Although the exact mechanisms behind the development of PTSD are unknown, animal studies have shown there to be gender-specific neurochemical changes following exposure to trauma.4 This unfortunately limits the conclusions of this study to a male-only population. Future studies should include women, regardless of the sample size, as current data is lacking.

Overall, the study by Khumtong et al importantly highlighted the need for psychological help to be available for urban firefighters in Thailand. One such inexpensive and easily accessible method which could be useful is mindfulness. Studies have found this to be a protective factor to prevent the development of PTSD, within urban firefighters in the US.5