4.2 Behavioral Observation
Behavioral observations assess pain through the visual inspection of patients’ responses or actions. These techniques are especially useful for those who may have difficulty self-reporting their pain, such as children124, the critically ill125, sedated patients126, and individuals with cognitive impairment127. Other pain-related behavioral findings identified in the literature include changes in facial expressions, affect, agitation, irritability, and the use of self-soothing or distraction techniques128. For those with OUD, shifts in behavior related to pain may include social withdrawal, which has been identified as a potential consequence of chronic pain that may contribute to worsening OUD symptoms129. However, the literature specifically examining the role of these techniques in assessing pain among persons with OUD is insipient.