Evaluation of using ICD‐10 code data for respiratory syncytial virus surveillance

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infection (ALRI) in young children. ICD‐10‐based syndromic surveillance can transmit data rapidly in a standardized way. OBJECTIVES: We investigated the use of RSV‐specific ICD‐10 codes for RSV surveillance. METHODS: We performed a retrospective descriptive data analysis based on existing ICD‐10‐based surveillance systems for ALRI in primary and secondary care and a linked virological surveillance in Germany. We described RSV epidemiology and compared the epidemiological findings based on ICD‐10 and virological data. We calculated sensitivity and specificity of RSV‐specific ICD‐10 codes and in combination with ICD‐10 codes for acute respiratory infections (ARI) for the identification of laboratory‐confirmed RSV infections. RESULTS: Based on the ICD‐10 and virological data, epidemiology of RSV was described, and common findings were found. The RSV‐specific ICD‐10 codes had poor sensitivity 6% (95%‐CI: 3%‐12%) and high specificity 99.8% (95%‐CI: 99.6%‐99.9%). In children <5 years and in RSV seasons, the sensitivities of RSV‐specific ICD‐10 codes combined with general ALRI ICD‐10 codes J18.‐, J20.‐ and with J12.‐, J18.‐, J20.‐, J21.‐, J22 were moderate (44%, 95%‐CI: 30%‐59%). The specificities of both combinations remained high (91%, 95%‐CI: 86%‐94%; 90%, 95%‐CI: 85%‐94%). CONCLUSIONS: The use of RSV‐specific ICD‐10 codes may be a useful indicator to describe RSV epidemiology. However, RSV‐specific ICD‐10 codes underestimate the number of actual RSV infections. This can be overcome by combining RSV‐specific and general ALRI ICD‐10 codes. Further investigations are required to validate this approach in other settings.