External validity of the cold pressor task in pediatric pain research.

The cold pressor task (CPT) is a commonly used experimental method of inducing pain requiring a child to submerse his/her hand or forearm in cold water for as long as can be tolerated, lasting several minutes. Use of the CPT has led to numerous critical advances in our understanding of children's pain. Lab-based methods, such as the CPT, are particularly valuable because they provide greater control over the environment, allowing researchers to investigate important research questions that cannot be adequately addressed in a clinical setting. Although the CPT is thought to produce pain similar to that of a medical procedure such as a needle, the extent to which this lab-based task produces a similar experience to clinical pain has surprisingly never been tested. To address this knowledge gap, the proposed study will examine the extent to which pain experienced by a child during a lab-based CPT corresponds to their pain experiences during a Hepatitis B immunization received during a school-based clinic. It will also determine whether child characteristics known to negatively impact pain experience (e.g., sex, anxiety, medical fears, previous pain experiences, coping style) have a similar impact on pain in both contexts. One hundred children (50% boys) aged 12-14 years will be video-recorded completing the CPT and the immunization. Children will report on the intensity, unpleasantness, and quality of their pain. Behavioural and physiological indicators of pain will also be obtained. Children and parents will complete questionnaires to assess the influence of child characteristics on the child's pain experiences. This study will contribute critically to our understanding of how well knowledge obtained from CPT studies can inform us about children's pain experiences in clinical contexts.