Minimal clinically important change on the Headache Impact Test-6 questionnaire in patients with chronic tension-type headache.

OBJECTIVE

To determine the minimal clinically important change (MCIC) in Headache Impact Test-6 (HIT-6) score in patients with chronic tension-type headache (CTTH).

METHODS

The HIT-6 was administered at baseline and at 8 weeks follow-up in a cohort of 186 participants with CTTH who received manual therapy or usual care by their general practitioner. An anchor-based method was used to determine the MCIC, with the external criterion (anchor) being based on general perceived improvement ('much improved or very much improved' on a 7-point Likert scale) in combination with 50% reduction in headache days. Using receiver operating characteristic (ROC) curve analysis we defined an optimal cut-off score discriminating between improved and not improved participants.

RESULTS

The optimal cut-off point for the MCIC for the HIT-6 was -8 points, on a total scale range of 42 points.

CONCLUSION

A clinically relevant improvement in patients with CTTH is reflected by a decrease of at least 8 points on the HIT-6.