Validation of central nervous system‐induced seizures and other neurological variables in the Swedish Neonatal Quality Register

AIM: We sought to validate neurological variables and relevant International Classification of Diseases, Tenth Revision (ICD‐10) codes in the Swedish Neonatal Quality (SNQ) Register. METHODS: Register data were collected for 351 neonates, born between January 2009 and December 2016, who were treated at a neonatal unit in the Stockholm region on 385 occasions. They were eligible if the check‐box for central nervous system (CNS)‐induced seizures was ticked. The Register data, including relevant ICD‐10 codes, were validated by checking the patients' electronic medical charts. RESULTS: Most of the neonates were born at term (76%) and weighed >2500 g (80%). The variable CNS‐induced seizures had a positive predictive value of 46%. The ICD‐10 diagnosis P90.9A had a positive predictive value of 90%. This comprises seizures validated with electroencephalography, amplitude‐integrated electroencephalography or continuous function monitoring. The majority of the associated neurological variables in the Register had positive predictive values above 85%. CONCLUSION: When the check‐box was ticked for central nervous system‐induced seizures, most of the neurological variables in the Register had high validity. However, the CNS‐induced seizures variable per se had a lower positive predictive value. Future SNQ Register‐based studies of such neonatal seizures should also include ICD‐10 P90.9A.