Distress in EMS workers. The Journal of Consulting and Clinical Psychology (June 1995) reported on a study of emergency service (EMS) rescue workers who responded to the I-880 freeway collapse during a San Francisco earthquake. The goal of the study was to identify the predictors of symptomatic distress in the workers. One of the distress variables studied was the Global Symptom Index

(GSI). Several models for GSI (y) based on the following independent variables were considered:

x1 = Critical Incident Exposure scale 1CIE2 x2 = Hogan Personality Inventory@Adjustment scale 1HPI@A2 x3 = Years of experience 1EXP2 x4 = Locus of Control scale 1LOC2 x5 = Social Support scale 1SS2 x6 = Dissociative Experiences scale 1DES2 x7 = Peritraumatic Dissociation Experiences Questionnaire, self@report 1PDEQ@SR2

a. Write a first-order model for E(y) as a function of the first five independent variables, x19x5.

b. The model from part

a, fitted to data collected on n = 147 EMS workers, yielded the following results:

R2

= .469, F = 34.47, p@value 6.001. Interpret these results.

c. Write a first-order model for E(y) as a function of all seven independent variables, x19x7.

d. The model from part c yielded R2

= .603. Interpret this result.

e. The t-tests for testing the DES and PDEQ-SR variables both yielded a p-value of .001. Interpret this result.