Wang 2011.

Methods	Allocation: parallel, randomised Blind: not stated Setting: hospital (inpatient), single centre Country: China Length of study: 12 weeks
Participants	Diagnosis: treatment‐resistant schizophrenia (CCMD‐3) Total N at randomisation = 74 Sex: male 37, female 37 Age (years): mean 26.5, SD 10.2 Length of illness (years): mean 15.7, SD 12.8 History: failure after more than 3 types of antipsychotics (at least 2 types of antipsychotics with different chemical structure; each drug with full dose used more than 6 weeks, no significant improvement or response) over the last 5 years; PANSS score > 60. Exclusion criteria: patients with severe physical illness or mental retardation; alcohol or drug abuser.
Interventions	ECT group (n = 37): MECT + clozapine Content: keep the same dose of clozapine as previous (mean dose: 325 ± 45 mg/d). The ECT device was Thymatron. Frequency: once daily for the first 3 days, then 2 to 3 times a week for ECT; not stated for clozapine Course of treatment (MECT): 12 sessions Treatment duration: 12 weeks Control group (n = 37): Clozapine alone Content: the usage and dosage schedule of clozapine was same as above. Frequency: not stated Treatment duration: 12 weeks
Outcomes	Response to treatment: clinically significant response to treatment* Mental state: assessed by PANSS Adverse events Unable to use: Memory assessed by WMS (data for control group not reported)
Notes	*Clinically significant response assessed by the reducing score rate of PANSS: 1) cure: reducing rate ≥ 75%; 2) significant improvement: reducing rate between 50% and 74%; 3) improvement: reducing rate between 25% and 49%; 4) no clinical response: reducing rate < 25%. The clinically significant response to treatment was defined as cure + significant improvement. Contact information: wangzhuawuhu@126.com; Fourth People's Hospital, Wuhu, Anhui, China No reply.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...were randomly assigned to receive..." (p.252) Comments: The author described a random component in the sequence generation process, but no details were provided on randomisation method.
Allocation concealment (selection bias)	Unclear risk	Comments: The author did not describe the allocation concealment. Insufficient information to permit judgement of 'low risk' or 'high risk'.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comments: The participants and personnel could not be blinded as 1 group did not use ECT, and no sham‐ECT was used.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comments: The author did not describe the blinding of outcome assessment. Insufficient information to permit judgement of 'low risk' or 'high risk'.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comments: No missing outcome data.
Selective reporting (reporting bias)	Unclear risk	Comments: The protocol is not available; all outcomes stated in methods reported in results. However, data for memory in the control group were not reported.
Other bias	Low risk	None obvious.