Data were abstracted on the following key variables: somatoform disorder
category, sample size, type of intervention, number of and duration of ses-
sions, type of control group, duration of follow-up, outcomes evaluated, and
treatment effect. The following types of patient-centered outcomes were
evaluated: a) symptoms (i.e., the study’s main measure of somatic symptom
count and/or severity); b) functional status (i.e., the study’s main measure of
functional impairment or quality of life); and c) psychological (i.e., either a
domain specific to the disorder, such as hypochondriacal or body dysmorphic
beliefs and behaviors, or a generic measure of depression, anxiety, or psy-
chological distress). For each trial, these three outcomes were assessed as
positive (outcome was better in the treatment group than the control group),
equivocal (there was a trend favoring the treatment group but the group
difference was not statistically significant), negative (the groups did not
differ), or not assessed. Secondary variables for which data were abstracted
include patient demographics (age, gender, educational level, race), and
country as well as type of clinic in which the study was conducted.