Comparison between administration via Internet and paper-and-pencil administration of two clinical instruments: SCL-90-R and GHQ-28

Abstract

The objective of this study is to compare the results of the Symptom Check List (SCL)-90-R and the General Health Questionnaire (GHQ)-28 administered on paper with the results of administration via Internet. Forty university students were asked to respond to the two questionnaires, first in one format (Internet or paper), and 1 week later in the other format. For the GHQ-28, no statistically significant differences were found between the two forms of presentation, Internet or paper, except in the social dysfunction subscale. In the case of the SCL-90-R, there were differences in the Positive Symptoms Distress Index (PSDI) and in the somatization and obsession–compulsion subscales. The effect of using the two formats in combination was also analyzed. Internal consistency of the instruments is high for both types of presentation ( α=0.91 in GHQ-28; α=0.97 in SCL-90-R). Correlation between the two formats is also high, with values ranging between 0.76 and 0.92, p<0.001, except in the social dysfunction subscale. Finally, correlation between the GHQ-28 and SCL-90-R is also high, for both the paper and Internet results ( r=0.88, p<0.01 on paper and r=0.83, p<0.01 via Internet). The differences found should be verified in future research with other types of sample.