Context: Pain assessment in people with cognitive impairment is challenging.

Objective: The study sought to 1) identify pain subgroups based on staff-assessed pain, agitated and reactive behavior, functional status, and symptoms of depression; and 2) understand if cognitive impairment was associated with transitions between pain subgroups at nursing home admission, 3 months, and 6 months.

Methods: Using national Minimum Data Set 3.0 data (2011-2016), we included 26,816 newly admitted residents with staff-assessed pain at admission, 3 months, and 6 months. Pain subgroups were identified by latent class analysis at each time point. Transitions between pain subgroups were described using latent transition analysis.

Results: Five latent statuses of pain were identified at admission: "Behavioral and Severe Depression" (prevalence stable, severe or worsening cognitive impairment: 11%, mild/moderate or improved cognitive impairment: 10%), "Functional" (21%; 25%), "Physical" (22%; 23%), "Behavioral" (23%, 19%), and "Low" (23%; 24%). Regardless of change in cognitive status, most residents remained in the same pain latent class. Among residents with stable, severe or worsening cognitive impairment, 11% in the "Behavioral" class transitioned to the "Behavioral and Severe Depression" class by 3 months. Fewer residents transitioned between latent classes in the 3- to 6-month period ( > 80% remained in their 3-month class).

Conclusion: For nursing home residents unable to self-report pain, consideration of additional indicators including functioning, depressive symptoms, and agitation may be useful in identifying pain subgroups. Longitudinal changes in the pain subgroups over 6 months post-admission highlight that residents with severe cognitive impairment may be at risk for worsening pain.