Carroll 2005.

Methods	Study design: cluster‐randomised controlled trial Randomisation method: to obtain a balanced sample, each participating provider was paired to the greatest extent possible with another provider by practice location, type of provider, sex, and age. 1 member of each pair was randomly assigned to the ALPHA group (intervention group) or control group by a biostatistician using computer‐generated random numbers Power calculation: reported Study dates: from 1998 to 2002
Participants	Setting: 4 communities in Ontario, including urban, suburban, and rural practices with women from diverse socioeconomic and ethnic backgrounds Country: Canada Inclusion criteria (providers): any HCP (e.g. physicians, obstetricians, midwives) who practised antenatal and intrapartum care, or antenatal plus transfer at 28 weeks, saw at least 10 antenatal women a year, and were not using any antenatal psychosocial screening tool other than the standard Ontario Antenatal Record Inclusion criteria (individuals): female; 12 to 30 weeks' gestation; able to read and write English; able to provide informed consent Exclusion criteria: high obstetric risk as defined by Ontario Antenatal Record Numbers recruited (providers): 60; intervention group 30, control group 30 Number of dropouts (providers): 12; intervention group 9, control group 3 Numbers (%) of eligible individuals recruited: 253/273 (92.7%) Numbers recruited (individuals): 253; intervention group 112, control group 141 Number of dropouts (individuals): 26; intervention group 14, control group 12 Numbers analysed (% of recruited): 227; intervention group 98 (88%), control group 129 (91%) Age: intervention group mean 29.1 (range 17 to 47 years), control group mean 29.4 (range 17 to 44 years) Ethnicity: born in Canada; intervention group 85.7%, control group 84.5% Socioeconomic status < USD 25,000; intervention group 10.3%, control group 4.7% USD 25,000 to 49,999; intervention and control group 22.7% USD 50,000 to 74,999; intervention group 29.9%, control group 32.8% USD 75,000 to 99,999; intervention group 19.6%, control group 24.2% > USD 100,000; intervention group 17.5%, control group 15.6% Education background: high school or less intervention group 19.4%, control group 26.6%; some college or university intervention group 25.5%, control group 20.3%; degree intervention group 55.1%, control group 53.1% Pregnancy problems: no concerns intervention group 55.1%, control group 50%; minor concerns intervention group 39.8%, control group 46.9%; major concerns intervention group 5.1%, control group 3.1%
Interventions	Intervention group Providers administered the ALPHA tool face‐to‐face, which screened for 15 risk factors, including IPV Control group Usual antenatal care
Outcomes	Providers were followed up 1 month postpartum to determine whether antenatal risks were considered 'present' for participants on the basis of providers having 'some' or 'high' concern about the risk factor. This included family violence, which had been assessed in the ALPHA tool using 5 items, one of which directly assessed concern with current or past woman abuse At 4 months' postpartum, the study nurse contacted all women in the trial to again complete a number of psychosocial instruments. Women with providers in the ALPHA group were asked to give feedback about the ALPHA form
Notes	Data on psychosocial outcomes at 4 months' postpartum were not reported. Data on sample characteristics only reported for the people who completed Funding: Ontario Ministry of Health and Long Term Care and the Ontario Women's Health Council
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	To obtain a balanced sample, each participating provider was paired to the greatest extent possible with another provider by practice location, type of provider, sex, and age. 1 member of each pair was randomly assigned to the ALPHA group (intervention group) or control group by a biostatistician using computer‐generated random numbers
Allocation concealment (selection bias)	Unclear risk	There is a lack of information about the level of allocation knowledge of those who enrolled the provider. Presumably providers recruited women after their randomisation had occurred. If providers knew their status, this could have influenced how and which women were recruited based on their own allocation status
Blinding of participants and personnel (performance bias) All outcomes	High risk	Provider participants were aware of the purpose of the study and their status as intervention or control group, which may have influenced their performance. Providers were also responsible for first telling women about the study. Interested women received an explanatory brochure and consent form from their provider and a telephone call from the study nurse to further explain the study and secure consent. We are not told in the report what level of awareness women had about the purpose of the trial. Knowing that the trial included a focus on IPV could have influenced how they responded to their treatment or non‐treatment. However, IPV was just 1 of 15 psychosocial issues and therefore may have not been singled out. Individual women in the intervention group may have been aware that they were in a treatment group based on the introduction of the ALPHA tool into the consultation, which may have influenced their responses to the ALPHA tool. There is no mention about the blinding of other study personnel
Blinding of outcome assessment (detection bias) All outcomes	High risk	Healthcare professional participants provided the primary outcome data in that they reported back on their level of concern with their participating patients. Both intervention and control group providers may have overestimated their level of concern as they would have been prompted by the questions asked in the data collection form. We are told a nurse undertook a follow‐up of women but are not given information on level of awareness of women's allocations. The women themselves would not have been blinded in outcome reporting
Incomplete outcome data (attrition bias) All outcomes	High risk	9/30 (30%) intervention group providers compared to 3/30 (10%) control group providers withdrew from the study. Intervention group: withdrawn because of illness, maternity leave or ineligibility because of language barrier (n = 5); no reason given for withdrawal (n = 4); control group: withdrawn because of illness (n = 1); no reason given for withdrawal (n = 2). 6 family physicians withdrew from the intervention group compared to 1 in the control group. There were no data reported on participants of the 12 providers that withdrew. This high level of attrition in the intervention group provider could indicate deliberate withdrawal associated with the outcome (creating high risk of bias). Among providers who remained in the study, and in terms of the primary outcome, attrition of individual women was low ‐ providers did not complete/return data collection forms on 7.5% of participants. No data were reported on the numbers of women who were assessed at the 4‐month postpartum point to allow us to evaluate bias at the participant reporting level. Only 14/21 intervention group providers gave feedback on experience of using the ALPHA tool. Analysis included sensitivity analysis to accommodate loss of provider participants. Results were not robust enough to withstand the loss of providers
Selective reporting (reporting bias)	High risk	Importantly, there is an absence of information on the postpartum psychosocial outcomes of women. Data on characteristics of the sample are only reported on those who were included in the final analysis. The reporting of results highlighted the one significant finding (family violence, including child abuse) as the great majority of others were non‐significant
Other bias	Unclear risk	Protection against contamination: women in the control group may have seen intervention group providers during subsequent consultations, which may have contaminated women's psychosocial outcome data. There is a lack of information about how the situation of the control group using the ALPHA tool was avoided Reliability of outcome measures: while the primary outcome (akin to identification/detection) was adequately measured as 'some' or 'high' concern about a particular psychosocial issue, the time lapse between the delivery of the intervention and the data collection may have introduced bias through recall bias. Intervention group might have had more notes on which to base recall than that the control group providers