Prevalence in disaster survivors

What is prevalence?

Prevalence represents the overall proportion of individuals in a population who have the disorder of interest. It is different from incidence, which represents only the new cases that have developed over a particular time period. Point prevalence is the proportion of individuals in a population who have the disorder at a given point in time (e.g., at one-month post-trauma), while period prevalence is the proportion of individuals in a population who have the disorder over specific time periods (e.g., one to two months post-trauma). Lifetime prevalence is the proportion of individuals in a population who have ever had the disorder and lifetime morbid risk also includes those who had the disorder but were deceased at the time of the survey.

What is the evidence for the prevalence of PTSD in people exposed to disasters?

Moderate to low quality evidence found the mean prevalence of PTSD following public health disasters (SARS outbreaks) to be around 14%, after natural disasters (earthquakes, hurricanes) mean prevalence was around 18%, and after man-made disasters (war, terrorism) mean prevalence was around 24%.

There were vast differences in prevalence rates across studies. The prevalence of PTSD in adults exposed to earthquakes was between 4.1% and 67.7% and between 2.5% and 60% in children exposed to earthquakes. The prevalence of PTSD in children and adolescents after tsunamis was between 6.0% and 70.7%. After hurricanes the prevalence was between 9.0% and 36.7%, after cyclones and tornadoes the prevalence was between 1.0% and 90.0%, after fires the prevalence was between 9.0% and 36.7%, after floods the prevalence was between 2.05% and 37.0%, after ship sinking the prevalence was between 50.0% and 89.5%, and after the 9/11 attack the prevalence was between 2.3% and 35.0%. For adults exposed to earthquakes, being female, having low education level or socio-economic status, prior trauma, being trapped, and experiencing fear, injury, or bereavement were related to greatest risk of PTSD. For children, being older, having higher education, being trapped, experiencing fear, injury or bereavement, and witnessing injury/death during the earthquake were related to greatest risk of PTSD.

August 2021

Image: ©sdecoret – stock.adobe.com

Last updated at: 12:31 am, 6th August 2021
To view documentation related to this topic download the files below
Fact Sheet Technical Commentary

NeuRA Libraries

Title Colour Legend:
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.