Syndromic surveillance as an early indicator of the effectiveness of overdose prevention legislation in Utah, 2012-2015

Drug overdose deaths in Utah have increased by 315% since 2000.  In Spring 2014, legislation became effective with the potential to impact Utah’s drug overdoses rates.  The objective of this analysis was to evaluate the impact of the Good Samaritan and Naloxone Administration laws on emergency department (ED) visits for overdose in Utah using a revised “poisoning by medicines” syndrome definition.  Line-level syndromic surveillance data for ED visits from June 2012-June 2015 were exported from BioSense 2.0.  Visits binned to the “poisoning by medicines” syndrome were identified and manually reviewed and gender of patient and intention of overdose were characterized and tabulated.  Monthly counts of overdoses were determined 24 months pre-legislation and 12 months post-legislation.  The Loess procedure for smoothed non-parametric fit was utilized to examine trends in overdose.  A segmented regression analysis of interrupted time series data was utilized to determine the impact of legislation on overdose ED visits overall and stratified by gender and intent.   Regression coefficients were compared using Student’s t-tests.  The majority of the 11,767 overdose visits identified were female (56%) and of undermined intent (88%). There was a significant reduction in ED visits for overdose following the legislation (p<0.05).  This decrease was similar for men and women and accidental and intentional overdoses.  This preliminary analysis suggests that ED visits for overdoses are decreasing.  While awaiting other evaluations, including analysis of mortality data, to reinforce these conclusions, syndromic surveillance provides an early indicator of the positive impact of this legislation on drug overdoses in Utah.