Interview versus questionnaire symptom reporting in people with the postconcussion syndrome.

OBJECTIVE

To compare spontaneous, interview-based, postconcussion symptom reporting to endorsement of symptoms on a standardized questionnaire.

PARTICIPANTS

Sixty-one patients referred to a concussion clinic following mild traumatic brain injury.

PROCEDURE

Patients recalled their current symptoms and problems via open-ended interview and then completed a structured postconcussion checklist.

MAIN OUTCOME MEASURES

Open-ended interview and the British Columbia Postconcussion Symptom Inventory (BC-PSI).

RESULTS

On average, patients endorsed 3.3 symptoms (SD = 1.9) during open-ended interview and 9.1 symptoms (SD = 3.2) on the BC-PSI (P < .001). Approximately 44% endorsed 4 or more symptoms during interview compared with 92% on the BC-PSI. The percentage of patients endorsing items on the BC-PSI compared with interview was significantly greater on all 13 items. It was common for patients to endorse symptoms as moderate-severe on the BC-PSI, despite not spontaneously reporting those symptoms during the interview.

CONCLUSIONS

Clinicians need to be cautious when interpreting questionnaires and be aware of the possibility of nonspecific symptom endorsement, symptom overendorsement, symptom expectations influencing symptom endorsement, and the nocebo effect.