BackgroundIn October 2015, discharge data coding in the USA shifted to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), necessitating new indicator definitions for drug overdose morbidity. Amid the drug overdose crisis, characterising discharge records that have ICD-10-CM drug overdose codes can inform the development of standardised drug overdose morbidity indicator definitions for epidemiological surveillance.MethodsEight states submitted aggregated data involving hospital and emergency department (ED) discharge records with ICD-10-CM codes starting with T36–T50, for visits occurring from October 2015 to December 2016. Frequencies were calculated for (1) the position within the diagnosis billing fields where the drug overdose code occurred; (2) primary diagnosis code grouped by ICD-10-CM chapter; (3) encounter types; and (4) intents, underdosing and adverse effects.ResultsAmong all records with a drug overdose code, the primary diagnosis field captured 70.6% of hospitalisations (median=69.5%, range=66.2%–76.8%) and 79.9% of ED visits (median=80.7%; range=69.8%–88.0%) on average across participating states. The most frequent primary diagnosis chapters included injury and mental disorder chapters. Among visits with codes for drug overdose initial encounters, subsequent encounters and sequelae, on average 94.6% of hospitalisation records (median=98.3%; range=68.8%–98.8%) and 95.5% of ED records (median=99.5%; range=79.2%–99.8%), represented initial encounters. Among records with drug overdose of any intent, adverse effect and underdosing codes, adverse effects comprised an average of 74.9% of hospitalisation records (median=76.3%; range=57.6%–81.1%) and 50.8% of ED records (median=48.9%; range=42.3%–66.8%), while unintentional intent comprised an average of 11.1% of hospitalisation records (median=11.0%; range=8.3%–14.5%) and 28.2% of ED records (median=25.6%; range=20.8%–40.7%).ConclusionResults highlight considerations for adapting and standardising drug overdose indicator definitions in ICD-10-CM.

The histoplasmosis surveillance system was evaluated using the 2001Centers for Disease Control and Prevention Updated Guidelines for Evaluating Public Health Surveillance Systems. From 2004 to 2014, a total of 1,608 confirmed or probable cases were reported into MDSS, with a slight increasing trend in case numbers over time. Michigan’s histoplasmosis surveillance system is relatively simple, but the misclassification of cases is troublesome. Development of tools for LHDs to aid in classification of cases may improve the PPV and decrease case investigation time. Increasing the number of hospitals that report directly to MDSS would indicate more acceptability, and increase sensitivity.

In Michigan, legionellosis cases are reportable through the Michigan Disease Surveillance System (MDSS), a web-based database. The objectives of this study were to evaluate Michigan's legionellosis surveillance system and determine whether diagnostic methods influenced case distribution. Michigan's legionellosis surveillance system was evaluated using the 2001 MMWR surveillance system evaluation guidelines focusing on data quality, timeliness, and sensitivity. Additional analyses were performed on the diagnostic test data. The system showed moderate sensitivity, and reporting times over the 24-hour state requirements. Data completeness improved 20% over time. Decreasing culture diagnoses make linking cases to environmental sources in an outbreak investigation challenging.