Yeephu 2013.

Study characteristics
Methods	Design: parallel Duration: 13 weeks Assessment: baseline and post‐intervention Country: Thailand
Participants	Pain condition: fibromyalgia Population: Thai adults with fibromyalgia Minimum pain intensity: ≥ 40 on 0‐100 scale Inclusion criteria Adult outpatients, aged ≥ 18 years, descended from Thai parents, met fibromyalgia criteria as defined by the ACR criteria Pain intensity of ≥ 40 on 0‐100 scale Exclusion criteria Physical health comorbidities Severe or unstable physical or psychiatric conditions were excluded Total participants randomised: 40 Age in years (mean, SD): 44.66 (10.77) Gender: 40/40 were female Pain duration in years (mean, SD): 3.44 (2.71)
Interventions	Placebo n = 13 Inert Identical appearance to mirtazapine Mirtazapine 15 mg n = 13 NaSSA Fixed dose, forced titration Mirtazapine 30 mg n = 14 NaSSA Fixed dose, forced titration
Outcomes	Moderate pain relief PGIC AEs SAEs Withdrawal
Missing data methods	ITT with LOCF, BOCF
Funding source	Non‐pharmaceutical: This study was supported by a scholarship from the Commission on Higher Education Staff Development Project for the Joint PhD Program in Biopharmaceutical Sciences, Thailand.
Conflicts of interest	Study authors reported no conflicts of interest.
Notes	Same study as Suttiruksa 2016 ‐ however different outcomes were reported in the two papers.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The patients were allocated using a block size of 3 in a ratio of 1:1:1 with parallel assignment to 1 of 3 groups using a pharmacy‐controlled randomisation process.
Allocation concealment (selection bias)	Low risk	Participants were allocated with sequentially numbered identical containers.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, identical study drugs
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes from blinded participants
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	State that they use LOCF and BOCF measures, but don't present the numbers of participants in each of these analyses. Low attrition rates across all arms. Attrition Total: 8/40 (20.0%) Placebo: 3/13 (23.1%) Mirtazapine 15 mg: 2/13 (15.4%) Mirtazapine 30 mg: 3/14 (21.4%)
Selective reporting (reporting bias)	Low risk	All outcomes in protocol reported either in this article or Suttiruksa 2016
Other bias	Low risk	No other sources of bias were identified