Severity score for worst head injury is determined with questions from the Brain Injury Screening Questionnaire (BISQ) and based partially on American Congress of Rehabilitation Medicine (ACRM) criteria.

Participants are asked to report the number of times they have experienced a blow to the head in 7 situations then asked to record the longest duration of loss of consciousness (LOC) and if they were dazed and confused in each situation. The longest period of LOC is the maximum duration of LOC reported across all situations. This variable ranges from 1 to 7, with higher values indicating greater severity.

Participants are asked the following questions:

Have you ever experienced a blow to the head in the following situations? Have you ever lost consciousness [in the following situations]? (If yes, what was the longest duration?) Have you ever been dazed or confused [in the following situations]?

1. Vehicle accident? (ex: MVA, pedestrian accident, motorcycle/ATV crash)
2. Hit by an object? (ex: equipment, falling object)
3. Falling? (ex: down stairs, during a fainting spell, from a high place)
4. Sports/leisure? (ex: sports, biking, skiing, on the playground)
5. Physical abuse/assault? (ex: mugged)
6. Military service? (ex: training, blast injury)
7. Other? Please specify.

Note: This variable is not calculated if no blows to head are reported.

Reference: Dams-O'Connor K, Cantor JB, Brown M, Dijkers MP, Spielman LA, Gordon WA. Screening for Traumatic Brain Injury: Findings and Public Health Implications. Journal of Head Trauma Rehabilitation. 2014; 29(6): 479-489. PubMed PMID: 25370440. PMCID: PMC4985006.