Koziol‐McLain 2010.

Methods	Study design: randomised controlled trial Randomisation method: randomly assigned individually 1:1 to intervention or control group Power calculation: sample size was calculated to detect a 50% treatment effect for 1 or more physically abusive events occurring in the follow‐up period Study dates: from 16 April 2007 to not reported
Participants	Setting: North Island New Zealand hospital ED Inclusion criteria: women aged 16 years and over, presenting to the ED for care during selected shifts were eligible Exclusion criteria: acute presentations precluding informed consent, functional or organic impairment based on clinician assessment, emergency health needs, non‐English speaking or entered study during previous visit Number (%) of eligible recruited: 399/983 (40.6%) Numbers randomised: 399; intervention group 199, control group 200 Number of dropouts at exit interview: intervention group 32, control group 23 Numbers analysed (% of randomised): 344; intervention group 167 (84%), control group 177 (88.5%) Age: median 40 years, range 16 to 94 years, interquartile range 27 to 59 years Relationship status: current relationship 67.4%, relationship within past year 8.3%, no relationship in past year 22.3%, never had a partner 2% Ethnicity: Maori 37.6%, New Zealand European 60.4%, other 2% Socioeconomic status (annual individual income): NZD 0 to 10,000 15.2%, NZD 10,001 to 20,000 32.1%, NZD 20,001 to 35,001 26.1%, > NZD 35,000 20.3%, do not know 5.8% Employed: yes 49.1%, no 31.6%, retired 19.3% Education: < high school 23.3%, high school 22.8%, other completed qualification 45.6%, college degree 8.3% Depression (CES‐D): mean 14.0 Mental health (SF‐12): mean 64.8 (SD 24.6) General health (SF‐12): mean 61.9 (SD 30.9) Acute injury: 79 (19.9%); intervention group 34 (17.3%), control group 45 (22.9%) One or more children in household: 73.4% Level of violence (treatment group only): 18% screen result positive, 51% lifetime result positive
Interventions	Intervention group Standardised 3‐item IPV screen incorporating the Partner Violence Screen and the Abuse Assessment Screen, statements about the unacceptability of violence, risk assessment, and referral by a health professional (e.g. nurse, midwife, social worker) research assistants Control group Usual emergency care
Outcomes	Primary outcome Violence exposure by a current or past partner in the last 3 months on the Composite Abuse Scale (CAS) Secondary outcomes Safety behaviours (9‐item Safety Behaviors Checklist) Resource use ‐ informal (9‐item) and formal (7‐item) resource use (Community Resources Checklist) Other outcomes Medical ED charts of all presumed eligible participants were abstracted to collect data including documentation of IPV; however, these data were not reported as a comparison Timing of measurement/follow‐up: 3 months after index ED visit women had a face‐to‐face structured follow‐up interview
Notes	Analysis: by ITT Funding: Health Research Council of New Zealand
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The biostatistician i) computer‐generated a series of randomly selected shifts across 7 days of the week and times of the day during which recruitment was to be undertaken and ii) provided a computer‐generated randomised sequence for group assignment within those periods
Allocation concealment (selection bias)	Low risk	The concealment of allocation followed strict protocols. The randomisation schedule was not available to anyone other than the biostatistician. The biostatistician oversaw the preparation of sealed, opaque, tamper‐proof, sequentially numbered envelopes containing the randomised treatment allocation. Research log sheets were used for the real‐time documentation of recruitment and the use of envelopes to provide a clear audit trail that was closely monitored by the site project leader
Blinding of participants and personnel (performance bias) All outcomes	High risk	It was not feasible to blind participants in the intervention group from the purpose of the intervention. Also, personnel may have become aware of the participant's allocation (e.g. through medical record), which may have influenced their treatment of that participant. The study did employ strict protocols in order to attempt to reduce the risk of differential behaviour by participants and personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"All follow‐up staff were blinded to group assignment" at 3 months in collecting the primary and secondary outcome data. Medical records were abstracted by a nurse blinded to group assignment to determine if it was documented that there was an IPV screen or diagnosis
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	32/199 (16.1%) LTFU in the intervention group; 23/200 (11.5%) LTFU in the control group. There is a lack of information about whether or not reasons for withdrawal/loss to follow‐up differed between the groups. However, the researchers indicate "logistic regression of missing data because of attrition demonstrated no significant associations with variables associated with the primary outcome measure, supporting their being missing completely at random"
Selective reporting (reporting bias)	High risk	There is no reference to a trial protocol. However, the trial was registered (ACTRN12607000210471) and some pre‐selected outcomes (e.g. SF‐12) were not reported here
Other bias	Low risk	No evidence of contamination, measures are valid and reliable but some baseline differences reported. "There were some potentially important group differences: compared with women in the usual care group, women in the treatment group were somewhat older (42 versus 38.5); more likely to be New Zealand European (63% versus 58%) and more likely to have been admitted to hospital (43% versus 36%)." They were also less likely to be poorly educated (with less than secondary school) (17.1% versus 29.5%) but study analysis tested and adjusted for baseline differences. "Age and ethnicity were individually associated with violence in the follow‐up period and included in the final model as design effects caused by differences at baseline... the final best subset model included measures of socioeconomic status... Hosmer and Lemeshow test statistic was NS"