Pain in older persons with severe dementia. Psychometric properties of the Mobilization-Observation-Behaviour-Intensity-Dementia (MOBID-2) Pain Scale in a clinical setting.

BACKGROUND: To assess pain in older persons with severe dementia is a challenge due to reduced self-report capacity. Recently, the development and psychometric property testing of the Mobilization-Observation-Behaviour-Intensity-Dementia (MOBID) Pain Scale was described using video-recording. The purpose of this article was to present the further development of this instrument. In MOBID-2 Pain Scale, the assessment of inferred pain intensity is based on patient's pain behaviours in connection with standardized, guided movements of different body parts (Part 1). In addition, MOBID-2 includes the observation of pain behaviours related to internal organs, head and skin registered on pain drawings and monitored over time (Part 2).

OBJECTIVE: The aim of this study was to examine psychometric properties of the MOBID-2 Pain Scale, like inter-rater and test-retest reliability, internal consistency, as well as face-, construct- and concurrent validity.

SUBJECTS AND SETTING: Patients with severe dementia (n = 77) were examined by 28 primary caregivers in clinical practice, who concurrently and independently completed the MOBID-2 Pain Scale. Characteristics of the patients' pain were also investigated by their physicians (n = 4).

RESULTS: Prevalence of any pain was 81%, with predominance to the musculoskeletal system, highly associated with the MOBID-2 overall pain score (rho = 0.82). Most frequent and painful were mobilizing legs. Pain in pelvis and/or genital organs was frequently observed. Moderate to excellent agreement was demonstrated for behaviours and pain drawings (kappa = 0.41-0.90 and kappa = 0.46-0.93). Inter-rater and test-retest reliability for pain intensity was very good, ICC (1, 1) ranging 0.80-0.94 and 0.60-0.94. Internal consistency was highly satisfactory; Cronbach's alpha ranging 0.82-0.84. Face-, construct- and concurrent validity was good. Overall pain intensity by MOBID-2 was well correlated with physicians' clinical examination and defined pain variables (rho = 0.41-0.64).

CONCLUSION: On the basis of pain behaviours, standardized movements and pain drawings, MOBID-2 Pain Scale was shown to be sufficiently reliable, valid and time-effective for nurses to assess pain in patients with severe dementia.