Pain in the elderly: validity of facial expression components of observational measures

Assessing pain in elderly persons, who have diminished capacity to communicate verbally, requires use of observational scales that focus upon nonverbal behavior. Facial expression has been recognized as providing the most specific and sensitive nonverbal cues for pain. This study examined the validity of facial expression components of 6 widely used pain assessment scales developed for elders with dementia. Descriptions of the facial expression of pain vary widely on these scales.

The detailed, anatomically based, objectively coded, and validated Facial Action Coding System was used as a criterion index to provide a definitive description of the facial expression of pain. Thirty elderly inpatients with clinically significant pain in the back or hip, the majority of whom had cognitive impairments, provided videotaped reactions to physical activities. Participants' facial expressions were videotaped during 4 randomly ordered physical activities and coded by a qualified Facial Action Coding System coder. Three 6-second clips indicative of mild, moderate, and severe pain intensities were selected for study for each participant. The 90 clips were coded by 5 raters using the facial expression components of the following observational scales: Doloplus-2, Mahoney, Abbey, pain assessment checklist for seniors with limited ability to communicate, noncommunicative patient's Pain Assessment Instrument, and Pain Assessment in Advanced Dementia.

Overall, scales that provided specific descriptions using the empirically displayed facial actions associated with pain yielded greater sensitivity, interjudge reliability, and validity as indices of pain.

Facial expression items on observational scales for assessing pain in the elderly benefit from adherence to empirically derived descriptions. Those using the scales should receive specific direction concerning cues to be assessed. Observational scales that provide descriptors that correspond to how people actually display facial expressions of pain perform better at differentiating intensities of pain.