Does Your Hospital Z-Code?

Quality Quarterly Article

The ICD-10 codes between Z55 and Z65 are the social determinants of health (SDOH) discharge codes. Social determinants of health include factors like:  

  • Socioeconomic status 
  • Education 
  • Neighborhood and physical environment 
  • Employment 
  • Social support networks  
  • Access to health care  

Addressing social determinants of health is important for improving health and reducing longstanding disparities in health and health care. 

There is a large difference between the usage of the homelessness code Z59.0 and all the other SDOH codes combined among emergency department (ED) discharges. For that reason, we have split up the analysis for Z59.0 versus all the others. 

Use of the Homeless SDOH code (Z59.0): 

  • Z59.0 (homelessness) was overwhelmingly the most used SDOH code with 137,600 cases (1.1% of all ED discharges) in 2018. 
  • 318 of the 322 (98.8%) hospital EDs coded for homeless (Z59.0) at least once in 2018. 

Use of the Other SDOH codes (excluding Z59.0): 

  • 315 of the 322 (97.8%) EDs used at least one SDOH codes during 2018 (up from 310 in 2017) 
  • Only three EDs never used a SDOH code, during both 2017 and 2018. 
  • 28,304 ED discharges in 2018 (0.22% of 12,660,433) had at least one SDOH code (up from 0.14% in 2017). 
  • 10,298 more ED discharges had at least one SDOH code in 2018 than in 2017 (28,304 vs. 18,006, a 157% increase). 
  • 3,772 ED discharges in 2018 (0.03%) had more than one SDOH code. 
    • This represents 13.4% of all 2018 SDOH discharges, versus 8.92% in 2017. 
  • Code Z60.2, Problems Related to Living Alone, was the penultimate SDOH code used in 2018, coded on 5,111 ED discharges (0.04%). 
  • Only one SDOH code was used zero times in 2018: Z63.71, Stress on Family Due to Return of Family Member from Military Deployment. 
    • Four codes were used zero times in 2017, including Z63.71. 

Emerging research suggests that SDOH codes could be valuable for predicting patients with high readmission risk, as well as other undesirable outcomes. Because of this, HQI encourages hospitals to use SDOH codes as appropriate to improve the quality of data available for this research. 

For more information, email bsherman@hqinstitute.org