Incidence in disaster survivors

What is incidence?

The incidence of PTSD refers to how many new cases there are per population in a specified time-period after exposure to a traumatic event. It is different from prevalence, which represents how many overall cases exist. This topic presents the evidence on incidence rates in people exposed to disasters. Please also see the related prevalence and risk factor topics.

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

Moderate quality evidence finds the incidence rate of PTSD after a flood is around 16%. Incidence rates are highest within six months after exposure and in people who experience severe flood intensity.

The incidence rate of PTSD after an earthquake is around 24%. Incidence rates are highest within nine months after exposure, in females, in people with lower educational levels, in people who had damage to their houses, in bereaved people, in people who had injury to their bodies, and in people who witnessed death.

August 2021

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Last updated at: 12:29 am, 6th August 2021
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Fact Sheet Technical Commentary

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