Is the presence of mild to moderate cognitive impairment associated with self-report of non-cancer pain? A cross-sectional analysis of a large population-based study.
BACKGROUND
Research, guidelines, and experts in the field suggest that persons with cognitive impairment report pain less often and at a lower intensity than those without cognitive impairment. However, this presupposition is derived from research with important limitations, namely, inadequate power and lack of multivariate adjustment.


OBJECTIVE
We conducted a cross-sectional analysis of the Canadian Study of Health and Aging to evaluate the relationship between cognitive status and pain self-report.


METHODS
Cognitive status was assessed using the Modified Mini-Mental State Examination. Pain was assessed using a 5-point verbal descriptor scale. For analysis, responses were dichotomized into "no pain" vs. "any pain" and "pain at a moderate or higher intensity" vs. "pain not at a moderate or higher intensity." Additional predictors included demographics, physical function, depression, and comorbidity.


RESULTS
Of 5,703 eligible participants, 306 (5.4%) did not meet inclusion criteria, leaving a total of 5,397, of whom 876 (16.2%) were cognitively impaired. In the unadjusted analysis, significantly more cognitively intact (n=2,541; 56.2%) than cognitively impaired (n=456; 52.1%; P=0.03) participants reported noncancer pain. There was no significant difference in the proportion of cognitively intact (n=1,623; 35.9%) and impaired (n=329; 37.6%; P=0.36) participants who reported pain to be at moderate or higher intensity. In multivariate analyses, cognitively impaired participants did not have lower odds of reporting any noncancer pain (odds ratio [OR]=0.83 [0.68-1.01]; P=0.07) or pain at a moderate or higher intensity (OR=0.95 [0.78-1.16]; P=0.62).


CONCLUSIONS
Non-cancer pain was equally prevalent in people with and without cognitive impairment, which contrasts with the currently held opinion that cognitively impaired persons report noncancer pain less often and at a lower intensity.
Shega
Joseph W
JW
Section of Geriatrics and Palliative Medicine, University of Chicago, Chicago, Illinois, USA. jshega@gmail.com
Paice
Judith A
JA
Rockwood
Kenneth
K
Dale
William
W
D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D015984:Causality; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology; D010146:Pain / Q000175:diagnosis* / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D013223:Statistics as Topic