This quality improvement study used a difference in difference in differences design and included adults aged 65 years and older who were reported to Texas APS in the study region (246 cities in Denton, Johnson, and Tarrant Counties) between December 31, 2014, and February 28, 2018. The mean (SD) age of the 11,178 older adults included in this study was 76 (8) years (range, 65-105 years); there were no reported data on patient sex. A total of 18,080 reports of elder mistreatment were recorded. Medics within the study region reported more cases of elder mistreatment during the implementation of the screening tool (relative risk [RR], 4.14; 95 percent CI, 3.25-5.27). After adjusting for changes in the number of elder mistreatment reports in the comparison groups (i.e., underlying changes in reporting trends), the number of reports to APS increased (RR, 3.03; 95 percent CI, 2.06-4.46). The occurrence of elder mistreatment was validated in 83 percent (95 percent CI, 75 percent - 91 percent) of the reports investigated by APS during the periods when medics did not have access to the screening tool compared with 82 percent (95 percent CI, 77 percent - 87 percent) during the periods when medics had access to the screening tool, indicating that there were no differences in the proportion of reports that resulted in a validated APS investigation. These findings suggest that incorporating the DETECT screening tool into the routine practices of medics is associated with substantial increases in the frequency with which clinicians report potential cases of elder mistreatment to APS.