Pain assessment in advanced dementia. Validity of the German PAINAD-a prospective double-blind randomised...

Pain in combination with dementia is a common condition that makes pain recognition significantly more difficult. This results in undertreatment of pain in those suffering from dementia. The Pain Assessment in Advanced Dementia (PAINAD) scale currently represents one of the best approaches to pain detection in dementia. In a pilot study, strong inter-rater and retest reliability of the German version (PAINAD-G) was proven. However, the available data concerning the validity of this instrument were insufficient. The aim of the study was to validate the PAINAD-G scale by a double-blind randomised placebo-controlled trial in people with advanced dementia expected to be in pain. A second aim was to examine whether other observational tools (BISAD = Observation Instrument for Assessing Pain in the Elderly with Dementia) (German: Beobachtungsintrument für das Schmerzassessment bei alten Menschen mit Demenz, Checklist of Nonverbal Pain Indicators, Algoplus) were also able to demonstrate a significant difference between the study groups. Surprisingly, the study revealed no difference in "pain reduction" between those treated by oxycodone compared with those treated by placebo. Equally, none of the other 3 observational tools were able to demonstrate a significant difference between the study groups. However, correlations among the 4 observational tools were mostly moderate to high. A number of possible reasons for this observation, such as difficulties regarding sensitivity to change/responsiveness, consistence of the fundamental construct, influence of the early onset study, and efficacy of the analgesic in advanced dementia are discussed.