The effect of written informed consent on detection of violence in the home

Studies of programmatic interventions for victims of violence in the home m ay require the use of informed consent. The use of informed consent may res ult in ascertainment bias, with victims of violence being less likely to pa rticipate. Objective: To investigate the effect of written informed consent on the detection of violence in the home during emergency department (ED) screening. Methods: The authors performed a nonrandomized, controlled trial of 3,466 patients at an urban university ED. On odd days, patients (n = 1, 857) were read a brief scripted statement and screened using standardized q uestions. On even days, patients (n = 1,609) received standard written info rmed consent prior to the same screening questions (writ-IC). The main outc ome was the number of cases of violence in the home detected using each scr eening protocol. Results: Fewer writ-IC patients participated in screening (82% vs 92%; p < 0.001). Despite a higher refusal rate in the writ-IC. grou p, there was no difference in the number of victims detected by each screen ing method: choked/kicked/bit/punched? (writ-IC, 7.3 vs routine screen, 6.5 %; p = 0.3); slapped/grabbed/shoved? (7.3 vs 6.7%; p = 0.4); threatened/act ually used knife/gun to scare/hurt you? (8.3 vs 9.4%; p = 0.3); thrown obje ct to harm you? (5.2 vs 4.6%; p = 0.4); forced sex? (5.8 vs 4.7%; p = 0.15) ; or afraid current/former intimate partner would hurt you physically? (13. 9 vs 11.9%; p = 0.9). Conclusions: A written informed consent process in sc reening for violence in the home is associated with a higher refusal rate t han routine screening, but use of written informed consent does not result in a lower rate of detection for multiple forms of violence. The authors di d not find any support for the hypothesis that the use of written informed consent would decrease detection of violence in the home.