Lambert 2001.

Study characteristics
Methods	Randomised trial, USA
Participants	609 clients treated in a university counselilng centre. Mean age of participants was 22.23 years and were mainly female (70%)
Interventions	Participants were randomly assigned to the experimental (feedback) or control (no feedback) groups. Feedback was provided to participants weekly by a therapist and was based on participant scores on the Outcome Questionnaire.   Intervention features Multiple simple feedback (one PROM at multiple times) PROM(s) used as intervention: Outcome Questionnaire (OQ) Constructs measured: Symptoms, Functioning Instrument categories/domains: Domain/Disease specific (mental health)   Administration features Where PROMs administered: Unclear How administered: Self‐administered Format of PROMs questionnaire(s): Paper   Feedback features Format of PROMs feedback: Paper How often information fed back: Weekly Who information fed back to: Clinicians Information fed back: Scores, Previous scores, Interpretation guidance, Management recommendations
Outcomes	Main outcome: psychological dysfunction (Outcome Questionnaire)
Notes	The study was supported by Brigham Young University; German‐American Academic Council Foundation. The study period was not reported. Conflicts of interest were not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation procedure not reported.
Allocation concealment (selection bias)	Unclear risk	Both control and experimental groups of therapists were given same information. Clients were unaware
Blinding of participants and personnel (performance bias) All outcomes	High risk	Due to nature of intervention not possible to blind patients and personnel.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Due to nature of the intervention blinding of outcomes not possible: PROM used for feedback also used to assess outcome, patients were aware they received the intervention.
Baseline outcome measurements similar	Low risk	All pretreatment OQ scores were similar at baseline
Baseline characteristics similar	Low risk	No sig differences were found between groups
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention of how incomplete data was handled
Was study protected against contamination	High risk	Physicians saw participants from all groups so cross‐contamination possible.
Selective reporting (reporting bias)	Unclear risk	None apparent.