Acute Stress Disorder Scale

Trauma Survivors: (Bryant et al., 2000; n = 82, female = 50 (61%), adults of mean age = 39.91 (15.93) years, survivors of bush fires)

• ≥ 56 was the optimal cut-off score on the ASDS for identifying participants at risk for developing PTSD

Trauma Survivors: (Wang et al., 2010; n = 353, female = 173 (49%), mean age =  29.36 (11.45), age range = 17-68 years, earthquake survivors)

Means, Standard Deviations, and Ranges of the ASDS (n = 353)

Trauma Survivors: (Edmondson et al., 2010; n = 132, male = 56%, mean age = 43 years, age range = 20-80 years, Hurricane Katrina evacuees)

• Mean ASDS score for the entire sample (n = 132): 61.61 (19.38)
• Score range = 19 (lowest possible) to 95 (highest possible)

Trauma Survivors: (Bryant et al., 2000)

• Excellent: test-retest reliability for ASDS total score = 0.94

Trauma Survivors: (Bryant et al., 2000)

• Excellent: Cronbach’s alpha for Total scale = 0.96*

Trauma Survivors: (Wang et al., 2010)

• Excellent: Cronbach’s alpha for Total scale = 0.92*

  *Scores higher than 0.9 may indicate redundancy in the scale questions. 

Predictive validity:

Trauma Survivors: (Bryant et al., 2000)

• Excellent positive predictive power (PPP) of ASDS scores for identifying subsequent posttraumatic stress disorder at the optimal cutoff score of 56 = 0.67 (sensitivity = 0.91, specificity = 0.93, negative predictive power = 0.98, efficiency = 0.93)
• The best method for scoring the ASDS relative to the ADS diagnosis was to consider the dissociative and other clusters separately, i.e. using a cutoff for the dissociative cluster of ≥ 9 combined with a cutoff of ≥ 28 for the cumulative scores on the re-experiencing, avoidance, and arousal clusters. This produced an Excellent positive predictive power of 0.80 (sensitivity = 0.95, specificity = 0.83, negative predictive power = 0.96, efficiency = 0.87)

Concurrent validity:

Trauma Survivors: (Bryant et al., 2000)

• Excellent correlations between the Total, Re-experiencing, and Arousal scores on the ASDS and the Frequency and Intensity scores for Total, Re-experiencing, Avoidance, and Arousal subparts of CAPS-2 (all r’s > 0.60)
• Excellent correlation between the Avoidance subscale of the ASDS and the Total – Frequency subpart of the CAPS-2 (r = 0.96)
• Adequate correlations between ASDS – Dissociation subscale scores and the Frequency and Intensity scores for Total, Re-experiencing, Avoidance, and Arousal subparts of CAPS-2 (r = 0.33 – 0.44)
• Adequate correlations between ASDS – Avoidance subscale scores and the Intensity score for the Total and the Frequency and Intensity scores for Re-experiencing, Avoidance, and Arousal subparts of CAPS-2 (r = 0.38 – 0.47) 

Convergent validity:

Trauma Survivors: (Bryant et al., 2000)

• Excellent correlations between Total ASDS scores and Acute Stress Disorder Interview (ASDI) Total (r = 0.86)

Trauma Survivors: (Wang et al., 2010)

• Confirmatory factor analysis (CFA) revealed a 4-factor model based on DSM-IV clusters (dissociation, re-experiencing, avoidance, and arousal) provided the most parsimonious solution with the lowest root-mean square error of approximation (RMSEA) (0.038) and smallest Akaike information criterion (AIC) value (490.94).

Trauma Survivors: (Edmondson et al., 2010)

• CFA revealed a 2-factor model with the avoidance, re-experiencing, and arousal factors loaded onto a second-order Distress factor that was correlated with dissociation as the best fit to the data (X²(125, n = 132) = 199.89, p < 0.01, RMSEA = 0.06, AIC = 309.88)

Trauma Survivors: (Bryant et al., 2000)

• Five experts in ASD rated the ASDS items on a 5-point scale (1 = “not at all”, 5 = “extremely”) for relevance, specificity, and clarity. Mean ratings across the experts were uniformly high at 4.86 (0.93), 4.44 (0.43), and 4.51 (0.27), respectively.

Trauma Survivors: (Wang et al., 2010)

• Items translated and back-translated; based on the diagnostic criteria for ASD listed on the English and Chinese versions of the DSM-IV