Low-Cost Community-Based Personal Alarm Intervention for Preventing Sexual Victimization in Indian Urban Slums: A Cluster Randomized Controlled Trial

Sexual violence is a major threat to women living in the urban slums of India, where structural limitations often render traditional interventions ineffective. This study evaluated the effectiveness of a low-cost community-based alarm intervention in preventing sexual victimization in informal urban settlements. A single-blind cluster randomized controlled trial was conducted across 20 blocks of slums in Delhi. Five hundred adult women were randomized by block into the intervention (nine blocks; <i>n</i> = 239) and control (11 blocks; <i>n</i> = 261) groups. The intervention included the distribution of personal safety alarms and community-based training workshops. Data on sexual victimization and interpersonal trust were collected before and after the 6-month intervention. Of the 500 participants, 485 (intervention group, <i>n</i> = 226; control group, <i>n</i> = 259) completed both assessments. The rates of lifetime sexual victimization were high at baseline: stalking (<i>n</i> = 413, 84.9%), verbal harassment (<i>n</i> = 338, 69.7%), and non-consensual physical contact (<i>n</i> = 304, 62.7%). Significant group-by-time interaction effects were observed for reductions in underwear theft (odds ratio [<i>OR</i>] = 0.207, 95% CI [0.062, 0.694]) and non-consensual physical contact (<i>OR</i> = 0.199 [0.059, 0.670]). Other types of victimization declined over time in both groups. A significant main effect of time on interpersonal trust was also observed (<i>F</i>[1, 966] = 40.47, partial η² = .040, <i>p</i> < .001). This context-sensitive intervention effectively reduced opportunistic sexual violence and improved interpersonal trust among participants. The community self-defense method offers a pragmatic and scalable harm reduction approach for high-risk settings in the absence of a formal protection infrastructure.<b>Trial registration:</b> Trial registry name, URL, and registration number: UMIN-CTR (https://www.umin.ac.jp/ctr/index-j.htm), ID# JPRN-UMIN000050136.