Validation of the Intermittent and Constant Osteoarthritis Pain Questionnaire in Patients with Hand Osteoarthritis: Results from the Nor-Hand Study.

ICOAP-hand is a reliable pain index that correlates with other available pain questionnaires. However, our results indicate that constant and intermittent pain do not represent separate constructs in hand OA, questioning the usefulness of the 2 subscales. [ClinicalTrials.gov: NCT03083548].