Query purpose:
To assist state, local, tribal, territorial, and federal public health practitioners in trend monitoring for long COVID (also commonly described as Post-COVID Complications (PCC) or long-haul COVID) related visits in the emergency department (ED) setting using syndromic surveillance data.
How it was developed:
Subject matter experts from seven jurisdictions (WA; VA; Harris County, TX; Pierce-Tacoma County, WA; NE; KS; KY) created and validated the definition using ED visit data from January – December 2023.
- Literature review on long COVID to identify common symptoms and complaints and alternative syndrome names.
- Search for diagnosis codes (International Classification of Diseases, 10th Revision (ICD10-CM) and Systematized Nomenclature of Medicine (SNOMED)) relevant to long COVID.
- Query relevant diagnosis codes under Discharge Diagnosis Parsed and relevant free text terms under Chief Complaint History in ESSENCE and run text analysis to identify: 1. Any missing, relevant diagnosis codes and/or free text terms to include, 2. Any irrelevant diagnosis codes and free text terms to exclude.
- Update definition to include free text and diagnosis code inclusion and exclusion terms.
- Validate definition using validation steps outlined below.
How it works:
The Discharge Diagnosis Parsed Free Text field (also applied to Chief Complaint History, Triage Notes Orig, and Admit Reason Combo) is used to query discharge diagnosis codes and free text with exclusions (as necessary), to develop the syndrome definition. This broad definition requires EITHER discharge diagnosis OR free-text indication of suspected long COVID.
- Inclusions based on long COVID related discharge diagnosis codes:
- The visit is included if it contains:
- A discharge diagnosis code of Post-COVID conditions (U099 or 1119304009) or Post-Viral Fatigue Syndrome (G933)
- Visits with G933 are only included if they also have free text mention of “covid”
- A discharge diagnosis code of Post-COVID conditions (U099 or 1119304009) or Post-Viral Fatigue Syndrome (G933)
- The visit is included if it contains:
- Inclusions based on free text terms:
- The visit is included if it contains:
- “long term covid”, “post acute covid”, “post acute sequela” and “covid”, “long haul covid”, “long covid”, “post covid”, “after covid”, “pots” and “covid”, “viral fatigue syndrome” and “covid”
- Visits picked up via free text inclusion terms must not include:
- Concurrent free text terms:
- “positive for covid on [MTWFS0-9]”, “covid positive on [MTWFS0-9]”, “covid positive mond”, “covid positive tue”, “covid positive wed”, “covid positive th”, “covid positive fri”, “covid positive sat”, “covid positive sun”, “covid positive today”, “covid positive yesterday”, “covid positive [0-9][0-9]/”, “covid positive [0-9]/”, “positive for covid mond”, “positive for covid tue”, “positive for covid wed”, “positive for covid th”, “positive for covid fri”, “positive for covid sat”, “positive for covid sun”, “covid today”, “covid yesterday”, “covid this”, “positive for covid [0-9][0-9]/”, “positive for covid [0-9]/”, “resolved post_covid”, “post covid result”, “covid” and “shot” or “vacc” or “vax” or “vaccine” or “booster” or “immunization” or “injection” or “exposure” or “reaction”, “requested covid test”, “covid [123] w”, “covid [123]w”, “covid x[123][wd]”, “covid x [123][wd]”, “covid x[123] [wd]”, “covid x [123] [wd]”, “covid positive [123] [wd]”, “covid positive [123][wd]”, “covid positive x[123][wd]”, “covid positive x [123][wd]”, “covid positive x[123] [wd]”, “covid positive x [123] [wd]”, “covid [12].5 w”, “covid [12].5w”, “covid x[12].5w”, “covid x [12].5w”, “covid x[12].5 w”, “covid x [12].5 w”, “covid positive [12].5 w”, “covid positive [12].5w”, “covid positive x[12].5w”, “covid positive x [12].5w”, “covid positive x[12].5 w”, “covid positive x [12].5 w”, “covid three [wd]”, “covid two [wd]”, “covid one [wd]”, “covid a [wd]”, “covid positive three [wd]”, “covid positive two [wd]”, “covid positive one [wd]”, “covid positive a [wd]”, “days post_covid”, “[23] weeks post_covid”, “[23] wks post_covid”, “wk post_covid”, “week post_covid”, “twoish weeks post_covid”, “two weeks post_covid”, “two wks post_covid”, “three weeks post_covid”, “three wks post_covid”, “recently covid”, “recent covid”, “hx pots”, “covid [123] ago”, “covid three ago”, “covid two ago”, “covid one ago”, “covid positive [123] ago”, “covid positive three ago”, “covid positive two ago”, “covid positive one ago”, “covid [1-9] day”, “covid [12][0-9] day”, “covid x[1-9] day”, “covid x[12][0-9] day”, “covid x [1-9] day”, “covid x [12][0-9] day”, “covid positive [1-9] day”, “covid positive [12][0-9] day”, “was positive last w”, “covid last [TWFS]”, “covid last mond”, “covid positive last [TWFS]”, “covid positive last mond”, “[23] wks after covid”, “[23] weeks after covid”, “wk after covid”, “week after covid”, “two weeks after covid”, “two wks after covid”, “three weeks after covid”, “three wks after covid”, “after covid check_up”, “medical clearance”
- Concurrent free text terms:
- The visit is included if it contains:
For consideration:
By design, this definition picks up all visits presenting with the U09.9 (Post-COVID conditions) ICD-10 code. We found that sometimes providers may improperly use this code for patients currently infected with COVID-19 or those recently infected (less than 3-4 weeks ago). As a result, this query picks up some false positives with current or recent COVID-19 infection, as determined via review of free-text fields. These visits will need to be excluded via manual review. The definition also picks up some visits that are not at all related to COVID-19 (ex: injury, alcohol withdrawal, stroke, etc.). Sometimes, hospitals enter diagnosis codes from a patient’s full medical history. As a result, visits with the U09.9 code may reflect a prior history of post-COVID conditions rather than the current reason for visit being for post-COVID conditions. Use the long COVID narrow definition, which requires both a long COVID related discharge diagnosis code AND free-text term, to better exclude these non-COVID related visits.
Discharge Diagnosis Parsed Free Text also apply to Chief Complaint History, Triage Notes Orig, Admit Reason Combo:
(,^;U099^,or,^;1119304009;^,or,(,^covid^,and,^;G933^,),or,^long_term covid^,or,^post_acute covid^,or,(,^post_acute sequela^,and,^covid^,),or,^long_haul covid^,or,^long_covid^,or,^post_covid^,or,^after covid^,or,(,(,!pots!,or,^[;., ]pots[ ;.,]^,),and,^covid^,),or,(,^viral fatigue syndrome^,and,^covid^,),),ANDNOT,(,^positive for covid on [MTWFS0-9]^,or,^covid positive on [MTWFS0-9]^,or,^covid positive mond^,or,^covid positive tue^,or,^covid positive wed^,or,^covid positive th^,or,^covid positive fri^,or,^covid positive sat^,or,^covid positive sun^,or,^covid positive today^,or,^covid positive yesterday^,or,^covid positive [0-9][0-9]/^,or,^covid positive [0-9]/^,or,^positive for covid mond^,or,^positive for covid tue^,or,^positive for covid wed^,or,^positive for covid th^,or,^positive for covid fri^,or,^positive for covid sat^,or,^positive for covid sun^,or,^covid today^,or,^covid yesterday^,or,^covid this^,or,^covid [0-9][0-9]/^,or,^covid [0-9]/^,or,^resolved post_covid^,or,^post covid result^,or,(,^covid^,and,(,^shot^,or,^vacc^,or,^vax^,or,^booster^,or,^immunization^,or,^injection^,or,^exposure^,or,^reaction^,),),or,^requested covid test^,or,^covid [123] w^,or,^covid [123]w^,or,^covid x[123][wd]^,or,^covid x [123][wd]^,or,^covid x[123] [wd]^,or,^covid x [123] [wd]^,or,^covid positive [123] [wd]^,or,^covid positive [123][wd]^,or,^covid positive x[123][wd]^,or,^covid positive x [123][wd]^,or,^covid positive x[123] [wd]^,or,^covid positive x [123] [wd]^,or,^covid [12].5 w^,or,^covid [12].5w^,or,^covid x[12].5w^,or,^covid x [12].5w^,or,^covid x[12].5 w^,or,^covid x [12].5 w^,or,^covid positive [12].5 w^,or,^covid positive [12].5w^,or,^covid positive x[12].5w^,or,^covid positive x [12].5w^,or,^covid positive x[12].5 w^,or,^covid positive x [12].5 w^,or,^covid three [wd]^,or,^covid two [wd]^,or,^covid one [wd]^,or,^covid a [wd]^,or,^covid positive three [wd]^,or,^covid positive two [wd]^,or,^covid positive one [wd]^,or,^covid positive a [wd]^,or,^days post_covid^,or,^[23] weeks post_covid^,or,^[23] wks post_covid^,or,^wk post_covid^,or,^week post_covid^,or,^twoish weeks post_covid^,or,^two weeks post_covid^,or,^two wks post_covid^,or,^three weeks post_covid^,or,^three wks post_covid^,or,^recently covid^,or,^recent covid^,or,^hx pots^,or,^covid [123] ago^,or,^covid three ago^,or,^covid two ago^,or,^covid one ago^,or,^covid positive [123] ago^,or,^covid positive three ago^,or,^covid positive two ago^,or,^covid positive one ago^,or,^covid [1-9] day^,or,^covid [12][0-9] day^,or,^covid x[1-9] day^,or,^covid x[12][0-9] day^,or,^covid x [1-9] day^,or,^covid x [12][0-9] day^,or,^covid positive [1-9] day^,or,^covid positive [12][0-9] day^,or,^was positive last w^,or,^covid last [TWFS]^,or,^covid last mond^,or,^covid positive last [TWFS]^,or,^covid positive last mond^,or,^[23] wks after covid^,or,^[23] weeks after covid^,or,^wk after covid^,or,^week after covid^,or,^two weeks after covid^,or,^two wks after covid^,or,^three weeks after covid^,or,^three wks after covid^,or,^after covid check_up^,or,^medical clearance^,)