The assessment of pain using self-report pain scales in persons with aphasia can be challenging due to communication and cognitive problems. The current study found that self-reporting pain was not possible in one third of the 71 persons with aphasia. This study investigated the validity and reliability of the pain observation instrument PAIC15 in persons with aphasia and is therefore of clinical value for professionals to optimize pain assessment in persons with aphasia.
The prevalence of individual items of the PAIC15 observed in persons with aphasia was low for most items. Higher prevalence was observed in the facial expressions domain. This is in accordance with findings of a PAIC15 study in a long-term care setting in patients with dementia (van Dalen-Kok et al., 2019). The items of the domains body movements and vocalizations showed the lowest prevalence. This result was expected, because of the minimal movement of the musculoskeletal system during rest. Regarding results during transfer, the overall prevalence of the individual items of PAIC15 was higher compared to the results during rest, which was expected.
The results of the current study indicate fair criterion validity because of largely fair positive correlations between PAIC15 and the self-report pain scales that could be completed by persons with aphasia. This study utilized consensus scores of PAIC15 after discussing the scores recorded by observer A and B following independent observations during rest and transfer on measurement 1. These consensus scores were needed to assess the correlations between the PAIC15 and self-report pain scales. If we compare the consensus scores to the scores of the independent observations, a few of the consensus scores were higher. However, discussion of the combined independent observations by observers A and B still yielded a higher score. An implication of this study is that using two observers improves the PAIC15 scores, because two observers see more than one observer during rest and transfer.
Another important finding, in terms of construct validity and assessed with hypothesis one: significantly more pain was observed with the PAIC15 during transfer compared to during rest. However, hypothesis two (more pain observed when treated with pain medication) was rejected. Contrary to other studies, we did not find more pain in persons with aphasia when pain medication was used compared to when not treated with pain medication (Rajkumar et al., 2017; van Dam et al., 2019). Many studies have stressed that pain after stroke was under-recognized and persons received inadequate pain management, and this may have obscured this potential relation (Harrison & Field, 2015; Widar et al., 2002). Hypothesis three was also rejected because more pain was not observed in patients with joint disease. Joint disease is one of the most frequent general causes of pain, but not for stroke patients specifically. Patients experience significant pain after stroke, especially headache, shoulder pain, pain from increased muscle stiffness, and central post-stroke pain that are not related to joint disease (Liampas et al., 2020; Trouvin & Perrot, 2018). Therefore, this hypothesis may not work well in this population and further research on causes of pain in stroke patients is warranted.
Regarding reliability, we found acceptable internal consistency of PAIC15 in persons with aphasia. We found that intra- and interobserver agreement for the items of the PAIC15 domains body movements and vocalizations are both good (≥ 70%). Results on the domain facial expressions show good intraobserver agreement for almost all items and good interobserver for all items during rest. This is contrary to the findings during transfer with a high percentage only on both intra- and interobserver agreement for the items ‘narrowing eyes’ and ‘raising upper lip’. These results resemble those of Van Dalen-Kok et al. (2019) who also found that fewer items in the domain facial expressions had good intraobserver- and interobserver agreement during both rest and transfer. Lower intra- and interobserver agreement for the facial expression items suggest that these items are more difficult to observe in a clinical setting. Research of Oosterman et al. (2016) reported that recognizing and observing facial expressions for pain assessment in dementia requires specific training and education (Oosterman et al., 2016). Assessing pain based on the observation of facial expressions in persons with dementia can be compared to persons with aphasia, because of their impaired cognition and communications problems. Percentages of 70 or higher for both intra- and interobserver agreement indicate good reliability of PAIC15 with dichotomized scores. This implies that assessing the presence of a pain-related item using PAIC15 is more reliable than assessing the degree/intensity of the pain-related items of PAIC15 with the 4-point scale in persons with aphasia.
Our study is the first to explore alternative methods for the long-standing and distressing situation of poor assessment and management of pain in persons with aphasia. Other strengths include the use of clinical situations and providing elaborate training for the research assistants. Also, no other pain research in persons with aphasia has used several self-report pain scales and a combined self-report scale. A limitation is that we did not check the competency of the different raters after training. However, we used a standardized training. Another limitation might be that the time between the observations of measurements 1 and 2 varied from 1 to 7 days, and the use of self-report pain scales was not checked again after 7 days. Within rehabilitation, spontaneous recovery can certainly occur within 7 days or the situation changes, e.g., re-admission to hospital or discharge home. These changes could affect the intraobserver agreement more strongly if the interval is 7 instead of 2 days.
In conclusion, results show fair criterion validity, and significantly more pain was observed during transfer compared to rest using PAIC15 regarding construct validity. Regarding reliability, we found an acceptable internal consistency of PAIC15 and good intra- and interobserver agreement for most PAIC15 items, particularly for the domains body movements and vocalizations in persons with aphasia. This study shows that PAIC15 can be used to assess pain in persons with aphasia. Further research in the daily practice setting should clarify whether combining PAIC15 with self-report and other clinical leads will deliver results that can be confidently used in practice.