Methods: The data used were from the cross-sectional surveys administered via QuestionPro from October 2020 to August 2021 in Texas, Tennessee, and Alabama (N = 1,072). The Impact of Event Scale-6 (IES-6) was used to measure tornado-related posttraumatic stress reactions. IES-6 has six items related to difficulties people sometimes have after a stressful life event, and participants indicated how distressing each difficulty had been for them during the past seven days concerning tornado based on a 5-point Likert scale from 0 = “not at all” to 4 = “extremely”. The sum of the six items ranged from 0 to 24, and higher scores indicated a higher level of posttraumatic stress reactions. Stress with tornado exposure was measured by the question, “Taking everything into consideration, how stressful overall were your experiences with the tornado and its aftermath?” with responses from 0 = “not at all stressful” to 4 = “extremely stressful”. Cognitive impairment was assessed by the Eight-item Informant Interview to Differentiate Aging and Dementia (AD8). AD8 contains eight items that test for the changes in memory, orientation, judgement, and function in the last several years (0 = NO, no change, 1 = YES, a change). The total score ranged from 0 to 8, and a score of 2 or greater indicates impairment in cognition. Finally, cognitive impairment was operationalized into a binary variable based on a cut-off point of 2 (0 = no, 1 = yes). Age was divided into two groups: younger adults aged 18-64 and older adults aged over 65. Control variables included participants’ gender, race, ethnicity, marital status, education, stress level before tornado, and current physical health. Multiple linear regressions were performed using Stata 15.
Results: Participants who experienced more stress from tornado exposure and its aftermath were more likely to report a higher level of posttraumatic stress reactions. Compared to those with normal cognition, people with cognitive impairment tended to have a higher level of posttraumatic stress reactions. The two-way interaction showed that the impact of disaster exposure stress on posttraumatic stress reactions was stronger for persons with cognitive impairment than for those with normal cognition. Furthermore, the vulnerability of people with cognitive impairment was even amplified if they were older adults aged 65 and older, as suggested by the three-way interactions among disaster exposure stress, cognitive impairment, and age.
Implications: These findings suggested that social work practitioners should acknowledge the vulnerability of older adults with cognitive impairment in developing post-disaster PTSD, and develop and implement age-responsible interventions and cognitive therapies to promote mental health recovery following disasters.