Table 2 Principal diagnosis and principal procedures for sport-related hospitalisations for concussion, US Nationwide Inpatient Sample, 2000–2004
Dx1ICD9/ICD9MConcussions by principal diagnosis,* nPrincipal procedures, n (%)Principal procedures with imaging,† n (%)
Total‡755143 (18.9)93 (12.3)
850.0Concussion with no loss of consciousness30857 (18.5)38 (12.3)
850.1Concussion with brief loss of consciousness (<1 hr)29454 (18.4)32 (10.9)
850.2Concussion with moderate loss of consciousness (1–24 hrs)DS§DS§DS§
850.5Concussion with loss of consciousness of unspecified duration9521 (22.1)17 (17.9)
850.9Concussion, unspecified52DS§DS§
  • *Concussion was defined based on primary diagnosis of seven ICD-9-CM codes (see Methods). †Imaging included CT and MRI. ‡There was no concussion case with primary diagnosis codes of 850.3 or 850.4 in the data. §Discharge information suppressed because cell count was ⩽10 (The Nationwide Inpatient Sample data user agreement precludes us from publishing cell counts ⩽10).