Pain and delirium in people with dementia in the acute general hospital setting

BACKGROUND: Pain and delirium are common in people with dementia admitted to hospitals. These are often under-diagnosed and under-treated. Pain is implicated as a cause of delirium but this association has not been investigated in this setting. OBJECTIVE: To investigate the relationship between pain and delirium in people with dementia, on admission and throughout a hospital admission. DESIGN: Exploratory secondary analysis of observational prospective longitudinal cohort data. SETTING: Two acute hospitals in the UK. METHODOLOGY: Two-hundred and thirty participants aged ≥70 years were assessed for dementia severity, delirium ((Confusion Assessment Method (CAM), pain (Pain Assessment in Advanced Dementia (PAINAD)) scale and prescription of analgesics. Logistic and linear regressions explored the relationship between pain and delirium using cross-sectional data. RESULTS: Pain at rest developed in 49%, and pain during activity for 26% of participants during their inpatient stay. Incident delirium developed in 15%, of participants, and 42% remained delirious for at least two assessments. Of the 35% of participants who were delirious and unable to self-report pain, 33% of these participants experienced pain at rest, and 56 experienced pain during activity. The odds of being delirious were 3.26 times higher in participants experiencing pain at rest (95% Confidence Interval 1.03–10.25, P = 0.044). CONCLUSION: An association between pain at rest and delirium was found, suggesting pain may be a risk factor for delirium. Since pain and delirium were found to persist and develop during an inpatient stay, regular pain and delirium assessments are required to manage pain and delirium effectively.