The Pain Assessment in Impaired Cognition scale (PAIC15): A multidisciplinary and international approach to develop and test a meta-tool for pain assessment in impaired cognition, especially dementia

Background: Over the last decades, a considerable number of observational scales have been developed to assess pain in persons with dementia. The time seems ripe now to build on the knowledge and expertize implemented in these scales to form an improved, “best‐of” meta‐tool. The EU‐COST initiative “Pain in impaired cognition, | KUNZ et al. 193 1 | INTRODUCTION The need for better pain assessment in cognitively impaired individuals who are not able to verbally communicate their pain, including people with dementia, has been widely acknowledged (Achterberg et al., 2013; Hadjistavropoulos et al., 2014). Standard pain assessment methods that rely heavily on self‐report lead to a dramatic under‐detection and under‐treatment of pain in these patient groups (Gibson & Lautenbacher, 2017; Hadjistavropoulos et al., 2014). To improve this situation, a considerable number of diverse observational scales has been developed, which aim to assess pain by observing behavioural responses, mainly including facial expressions, body movements and vocalizations (see Herr, Zwakhalen, & Swafford, 2017; Zwakhalen, Hamers, Abu‐ Saad, & Berger, 2006; Zwakhalen, Herr, & Swafford, 2017 for reviews). Most of these tools have undergone initial psychometric testing; however, many were not developed using evidence‐based methods and they lack comprehensive psychometric data from larger samples of patients. Few define the specific situation in which assessment should take place (e.g. rest vs. activity of daily living), most were not developed for ease of use in clinical settings. Moreover, given the considerable number of scales, it is difficult to gather comparable data. As a result, no widely accepted and internationally agreed‐upon tool for detecting pain in individuals with cognitive impairment exists and national guidelines vary in recommendations. To change this, we initiated a collaboration and combined clinical, research and methodological expertize from different European countries and disciplines, with the aim to develop an internationally agreed‐upon tool to assess pain in individuals with cognitive impairment, especially dementia (Corbett et al., 2014). After reviewing and discussing the many existing scales, we came to the conclusion that all relevant pain‐related observational items had been identified. However, existing scales include pain‐ irrelevant items or items of poor psychometric quality. Therefore, the main task was to reduce and refine the number of items. Thus, rather than starting from scratch, we Funding information The initiative was funded by the EU‐COST (action TD 1005). especially dementia” aimed to do this by selecting items out of existing observational scales and critically re‐assessing their suitability to detect pain in dementia. This paper reports on the final phase of this collaborative task. Methods: Items from existing observational pain scales were tested for “frequency of occurrence (item difficulty),” “reliability” and “validity.” This psychometric testing was carried out in eight countries, in different healthcare settings, and included clinical as well as experimental pain conditions. Results: Across all studies, 587 persons with dementia, 27 individuals with intellectual disability, 12 Huntington's disease patients and 59 cognitively healthy controls were observed during rest and movement situations or while receiving experimental pressure pain, respectively. The psychometric outcomes for each item across the different studies were evaluated within an international and multidisciplinary team of experts and led a final selection of 15 items (5x facial expressions, 5x body movements, 5x vocalizations). Conclusions: The final list of 15 observational items have demonstrated psychometric quality and clinical usefulness both in their former scales and in the present international evaluation; accordingly, they qualified twice to form a new internationally agreed‐on meta‐tool for Pain Assessment in Impaired Cognition, the PAIC‐15 scale. Significance: Using a meta‐tool approach by building on previous observational pain assessment scales and putting the items of these scales through rigorous empirical testing (using experimental as well as clinical pain studies in several European countries), we were able to identify the best items for pain assessment in individuals with impaired cognition. These selected items form the novel PAIC15 scale (pain assessment in impaired cognition, 15 items).