Boz 2003.

Methods	Single‐centre, open‐label, randomised parallel study: sertraline vs amitriptyline Control for symptomatic/analgesic medications use
Participants	Country: Turkey N = 90; Sex: 11 male, 79 female Mean age: 37.8 (SD 12.2) sertraline, 40.4 (SD 11.4) amitriptyline Diagnosis: Chronic tension‐type headache according to the International Headache Society Criteria (IHS 1988) Exclusion criteria: presence of major depression or depression symptoms, antidepressant use in the previous year, score > 15 Hamilton Depression Scale or > 13 Beck Depression Inventory I‐II Scale, severe concomitant neurological and medical disorders, breast feeding and pregnancy Recruitment: first visit at the outpatient clinic
Interventions	N = 46 amitriptyline to a maximum of 25 mg/day N = 44 sertraline 25 mg/day Active treatment: 12 weeks
Outcomes	1. Headache frequency (number of attacks/28 days) 2. Duration (hours/day) 3. Headache severity (scored on a 10‐point visual analogue scale) 4. Headache index (headache frequency * average severity * duration/28 days) 5. Number of patients with more than a 50% reduction in the headache index 6. Symptomatic/analgesic drug consumption
Notes	22 patients met the criteria for co‐existing migraine (8 in Sertraline and 14 in Amitriptyline) 6 dropouts (7%): amitriptyline: 3 (2 for side effects, 1 for worsening condition) sertraline: 3 (1 for side effects, 2 for worsening condition) Per protocol analyses No sample size calculation
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated (supplemental communication by authors)
Allocation concealment (selection bias)	High risk	Patients sequentially allocated depending on time of presentation
Blinding (performance bias and detection bias) All outcomes	High risk	Open‐label design
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low dropout rate, balanced, reasons fully reported
Selective reporting (reporting bias)	Unclear risk	No information
Other bias	Low risk	No financial support provided by drug companies