The Short Health Anxiety Inventory (SHAI) [42 (link),43 (link)] measures health-related anxiety. A cut-off score of 18 has been shown to reliably identify people meeting the DSM-IV hypochondriasis criteria. The scale has good psychometric properties [43 (link),44 ], and in this sample, Cronbach’s alpha was 0.88.
The Patient Health Questionnaire-9 (PHQ-9) [45 (link),46 ] measures depression severity over a two week period [47 (link)]. It has cut-off points of 5, 10, 15 and 20 (interpreted as mild, moderate, moderately severe and severe depression). The scale has good psychometric properties [45 (link),46 ], and in this sample, Cronbach’s alpha was 0.71.
The Generalised Anxiety Disorder-7 (GAD-7) [48 (link),49 ] measures general anxiety. It has cut-off points at 5, 10 and 15 (interpreted as mild, moderate, and severe anxiety). The scale has good psychometric properties [48 (link),49 ], and in our sample, Cronbach’s alpha was 0.92.
The Perseverative Thinking Questionnaire (PTQ) [50 (link)] measures self-reported rumination. The scale has 15 items, a total score that ranges from 0 to 75 and three subscale scores. Only the total score was used in this study. The original PTQ has good psychometric properties [50 (link)] and Cronbach’s alpha was 0.97 in our sample.