Warwick 1996

Methods	Participant blinding: no Therapist blinding: not stated Assessor blinding: yes Analysis: available case Country: England Ethics approval: not stated
Participants	Number: active ‐ 16; control ‐ 16; total ‐ 32 (14 female; 18 male) Mean age in years: total ‐ 37; range 20‐53 Diagnostic criteria: DSM‐III‐R hypochondriasis Recruited from: primary care and secondary care Mean length of illness: total ‐ 7.16 years; range 0.5‐33 years Exclusion criteria: 1. primary affective or psychotic disorder; 2. age <18 or >60 years; 3. not British nationality; 4. physical illness which would account for health concerns; 5. previous treatment with cognitive behaviour therapy; 6. not willing to accept random allocation Language restrictions: English Comorbidity: not stated Number of drop‐outs: active ‐ 1; control ‐ 0; total ‐ 1
Interventions	Active treatment: Cognitive Behaviour Therapy Control treatment: waiting list Treatment setting: secondary care outpatients Discipline of therapists: psychiatrists Number and duration of sessions: 16; duration not stated Interval between sessions: 1 week Total exposure: not stated
Outcomes	Length of follow up: 3 months Primary outcome measure: none stated Secondary outcome measures: Patient‐rated Visual Analogue Scales: global problem severity disease conviction when anxious disease conviction when calm need for reassurance time spent worrying about health health anxiety frequency of checking behaviours frequency of avoiding behaviours Therapist‐rated Visual Analogue Scales: global problem severity need for reassurance health anxiety disease conviction Independent assessor rated Visual Analogue Scales: global problem severity disease conviction when anxious disease conviction when calm time spent wanting reassurance strength of need for reassurance frequency of reassurance‐seeking time spent worrying health anxiety frequency of checking behaviour frequency of avoidance Beck Depression Inventory Beck Anxiety Inventory
Notes	unclear selection bias ‐ randomisation not described possible performance bias ‐ participants not blinded; only one therapist ‐ blinding status not stated attrition bias unlikely detection bias unlikely Overall quality: moderate (QRS score = 22)
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear