To the Editor:
We would like to congratulate Kaiho et al. for their study published in the April 2017 issue. The study results showed that moderate-to-severe pain is significantly associated with a future risk of functional disability in patients with joint pain and/or fractures. The authors administered a cogent questionnaire to a significant sample size of the elderly population and then compared their findings to data from the Long-term Care Insurance database.1
In this study, it is interesting to note that pain severity was positively associated with disability due to joint pain and/or fractures, yet there was a negative association with disability due to dementia and no significant association with stroke. The authors administered a questionnaire to assess pain in all study participants; however, pain in conditions such as dementia and stroke often is underestimated and undertreated owing to the limited ability of patients with these disease states to self-report.2 Healthcare providers may need specialized skills, tools, and training to assess the severity of pain in patients with moderate-to-severe dementia.2,3 The authors did not mention how pain was assessed in this subset of patients. Self-reporting should be used whenever it is appropriate, but behavior assessment tools are recommended in patients with advanced dementia.4,5
In elderly patients with dementia, various measures (tools) have been developed for caregivers to assess the severity of pain. Among those, the Pain Assessment Checklist for Seniors with Limited Ability to Communicate (PACSLAC) and the Pain Assessment in Advanced Dementia Scale (PAINAD) are found to have the strongest psychometric evidence.5 Furthermore, PACSLAC-J is a modified scale developed mainly for the Japanese population with communication impairments.6
Taking the above factors into consideration, we believe that an assessment with the appropriate tools may show that the severity of pain increases the risk of disability in elderly patients with dementia. Overall, this is an excellent study with compelling results. However, the incidental disability due to pain may be more than what the study suggests. This is particularly true in patients with dementia. Future studies may need to focus on assessment of pain with appropriate tools in elderly patients with dementia to better understand the association between pain and disability in these patients.
The authors declare no competing interests.