The ultimate goal of OEND programs is to reduce the number of opioid overdose deaths. Many observational studies use routinely collected mortality data to compare the per capita opioid overdose death rate before and after the implementation of a community-based OEND program. 

In a study of the Massachusetts Department of Public Health OEND program from 2008-2009, researchers evaluated counties with high enrollment in OEND programs and found that these counties had nearly half the rate of overdose death compared to counties with no OEND programs. In a simulation analysis using data from multiple observational studies, 6% of overdose deaths among heroin users were prevented by distributing naloxone to laypersons. 

OEND programs can help reverse opioid overdoses in progress. This could be reported as an absolute number or a proportion. When reported as an absolute number, studies typically rely on self-reporting from individual recipients of dispensed naloxone kits or n routinely collected public health data, such as the number of emergency department visits for nonfatal opioid overdose. When this outcome is reported as a proportion, studies typically divide this absolute number by the per capita population of a county or other defined catchment area. 

In a study of the Massachusetts Department of Public Health OEND program from 2008-2009, researchers trained 2912 potential bystanders who reported 327 opioid overdose reversals. A 2010 assessment of 644 community-base OEND programs in the United States found that 152,283 persons had received OEND training to date, with 26,463 reported overdose reversals. 

OEND programs have been shown to improve important process outcomes among training recipients, such as opioid overdose knowledge and attitudes surrounding the use of naloxone. This can be measured using validated surveys such as the Opioid Overdose Knowledge Scale and Opioid Overdose Attitudes Scale. 

Multiple studies have demonstrated improvements in opioid overdose risk factors, recognition of the signs and symptoms of opioid overdose, and ability to administer naloxone following OEND training. Participants in OEND programs have also demonstrated lower levels of stigma towards opioid use and higher levels of confidence and willingness to use naloxone when encountering a person experiencing an opioid overdose.