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. Author manuscript; available in PMC: 2010 Nov 3.
Published in final edited form as: J Consult Clin Psychol. 2002 Aug;70(4):880–886. doi: 10.1037//0022-006x.70.4.880

Table 3.

Therapy Completer Sample: A Comparison of Explained Variances (R2) for Mean PTSD Symptom Cluster and Total Scores With a Linear Versus Quadratic Fit for Prolonged Exposure (PE) and Cognitive-Processing Therapy (CPT)

Treatment R2 (%) df F Sig F b0 (Sig t) b1 (Sig t) b2 (Sig t)
PE: Reexperiencing
    Linear 49 3 2.94 .18 8.16 (0.01) −0.73 (0.18)
    Quadratic 94 2 17.12 .05 4.04 (0.07) 2.80 (0.09) −0.59 (0.06)
CPT: Reexperiencing
    Linear 63 3 5.14 .11 8.35 (0.01) −0.88 (0.11)
    Quadratic 96 2 21.77 .04 4.61 (0.05) 2.32 (0.11) −0.53 (0.06)
PE: Avoidance
    Linear 88 3 23.11 .02 15.83 (0.01) −1.78 (0.02)
    Quadratic 98 2 66.79 .01 12.28 (0.01) 1.26 (0.27) −0.51 (0.07)
CPT: Avoidance
    Linear 94 3 51.56 .01 14.93 (0.01) −1.74 (0.01)
    Quadratic 98 2 54.01 .02 12.89 (0.01) 0.00 (1.00) −0.29 (0.18)
PE: Arousal
    Linear 83 3 14.67 .03 12.08 (0.01) −1.18 (0.03)
    Quadratic 99 2 69.80 .01 9.04 (0.01) 1.42 (0.13) −0.43 (0.04)
CPT: Arousal
    Linear 87 3 20.19 .02 11.97 (0.01) −1.22 (0.02)
    Quadratic 100 2 325.04 .01 9.23 (0.01) 1.13 (0.05) −0.39 (0.01)
PE: Total PSS
    Linear 79 3 11.46 .04 36.05 (0.01) −3.69 (0.04)
    Quadratic 98 2 52.18 .02 25.38 (0.01) 5.45 (0.12) −1.52 (0.05)
CPT: Total PSS
    Linear 87 3 20.25 . 02 35.22 (0.01) −3.85 (0.02)
    Quadratic 98 2 68.16 .01 26.95 (0.01) 3.23 (0.22) −1.18 (0.06)

Note. PTSD = posttraumatic stress disorder; Sig = significant; PSS = PTSD Symptom Scale.