Internet-delivered Cognitive Behavior Therapy for Adolescents With Functional Gastrointestinal Disorders: a Pilot Study

Measured with a self-report scale, GSRS-IBS, that have 13 items about weekly gastro-intestinal symptoms like bloating, hard stool, abdominal pain etc. It is a seven-point Likert scale, from 1 ("no trouble at all") to 7 ("very severe discomfort"). The GSRS-IBS has excellent psychometric properties with internal consistency between α = .74 (for abdominal pain) to α = .85 (for satiety).

Measured with a self-report scale, pain reactivity scale (PRS), that have 5 items about reactivity to and worry about pain. Three items are about emotional reactions to current pain. Two items affect frequency of worry about not being able to do things now, and in the future because of the pain. Questions are answered on a 6-point scale from 0 ("not at all") to 6 ("very much"). PRS has been reported to have satisfactory psychometric properties (Wicksell et al, 2011).

Measured with a self-report scale, pain interference index (PII), that have 6 items about interference on various activities because of pain. Questions are answered on a 6-point scale from 0 ("not at all") to 6 ("very much"). According to preliminary analysis, the instrument has satisfactory psychometric properties (Wicksell et al., 2011)

Measured with a self-report scale, functional disability index (FDI), with 15 items on daily activities. Questions are related to specific activities such as climbing stairs, running 100 meters and to go shopping, and general activities such as eating meals and being in school all day. The scale ranges from 1 (no problem at all) to 5 (impossible). It is validated for children and adolescents with chronic abdominal pain with high internal consistency, α = .86 for boys and α = .91 for girls (Claar and Walker, 2006). FDI is the scale that is recommended in pediatric pain studies to measure the influence of pain on function (McGrath et al., 2008).

Measured by a self-report scale called Childhood Anxiety Sensitivity Index (CASI) with 18 items. It is a 3-point scale (1-3), which measures sensitivity to internal sensations that could be symptoms of anxiety. The questions include items such as "I get scared when I feel shaky" or "I get scared when my heart beats fast" but also items that could be gastro-intestinal symptoms, such as "When my stomach hurts, I worry that i might be really sick "(Silverman, Fleisig, Rabian, & Peterson, 1991). CASI has been reported to have high reliability, α = .84 (Silverman et al. 1991).

Measured by the self-report scale Child depression Inventory (CDI) that consists of 27 items on a 3-graded scale (0-2). The scale's psychometric properties have been validated in a study by Smucker, Craighead and Green (1986), which found that the internal consistency measured by Cronbach's alpha was acceptable, between α = .83 and α = .89.

Measured by a four-item short version of a self-report scale, Percieved Stress Scale (PSS-4). PSS-4 consists of four statements about the feeling of being able to control and sort out problems that need to be managed. Responses are rated from 0 ("never") to 4 ("very often"). Reliability for the version with 4 items is α = .72 (Cohen et al., 1983).