The association of painful and non-painful morbidities with frailty: a cross sectional analysis of a cohort of community dwelling older people in England

INTRODUCTION

The association between chronic pain and frailty might indicate that pain is an independent driver of frailty but might alternatively be explained by inclusion within frailty identification tools of morbidities that commonly lead to chronic pain. This research examines the extent to which the association of pain with frailty might be attributed to morbidities.

METHODS

A cross-sectional analysis of older people in a UK cohort with or at risk of musculoskeletal problems or frailty (Investigating Musculoskeletal Health and Wellbeing study), used multivariable logistic regression and Z-tests to assess the degrees of associations of pain (McGill Pain Rating Index), and painful and non-painful morbidity counts with frailty (modified FRAIL questionnaire).

RESULTS

Data were from 2,185 participants, 56% female, median age 73 (range 60 to 96) years. 430 (20%) participants were classified as frail. In a fully adjusted standardised model, pain (aOR 2.07 (95%CI 1.83 to 2.33) and 'any' morbidity aOR (1.74 (95%CI 1.54 to 1.97) were both significantly associated with frailty. When morbidity was subclassified as painful or non-painful, painful (aOR 1.48 (95%CI 1.30 to 1.68) and non-painful (aOR1.39 (95%CI 1.24 to 1.56)) morbidities each were associated with frailty, as also was pain (aOR 2.07 (95%CI 1.83 to 2.34, p < 0.001).

CONCLUSIONS

Pain is associated with frailty, over and above any effect of painful and non-painful morbidities. This forms the justification for future research which focuses on pain management in the identification, prevention, and treatment of frailty.

1321 THE ASSOCIATION OF PAINFUL AND NON-PAINFUL COMORBIDITIES WITH FRAILTY

Introduction

Chronic pain is associated with frailty. We hypothesised that painful comorbidities would be more strongly associated with frailty than non-painful comorbidities.

Method

Data were from Investigating Musculoskeletal Health and Wellbeing, a UK-based cohort of people with or at risk of musculoskeletal problems or frailty. Average pain over the previous month was assessed using an 11-point numerical rating scale (NRS). The original FRAIL questionnaire comprises five self-report items: Fatigue, Resistance, Ambulation, Illnesses and Loss of weight. In this study risk of frailty was operationalised using a modified FRAIL questionnaire, omitting the “illnesses” item which related to comorbidities. Comorbidities were classified as either ‘painful’ or ‘non-painful’ based on the International Association for the Study of Pain chronic pain classification criteria. Ordinal logistic regression models explored associations of comorbidity counts with frailty.

Results

Cross-sectional data were from 2473 participants, 57% female, median age 72 (range 40 to 96) years. 518 (21%) participants were classified as frail. Mean (SD) pain score was 5.5 (2.5). Median (IQR) painful comorbidities was 2 (1 to 3) and non-painful 1 (0 to 2). Highest comorbidity frequency: arthritis (66%) and hypertension (38%). Pain was associated with frailty (OR 1.58 (1.52 to 1.64)). Painful comorbidities (aOR 1.64 (1.54 to 1.75) and non-painful comorbidities (aOR 1.31 (1.21 to 1.41)) were both associated with frailty when included in the same multivariable model adjusted for age, sex and BMI.

Conclusions

Painful comorbidities were most strongly associated with frailty, although non-painful comorbidities also contributed. Pain and frailty are interconnected, and this might in part be due to comorbidities or their treatments. These findings provide justification for further research to identify the mechanisms through which pain is involved in frailty and to include pain management in interventions to ameliorate frailty.

AB1432 THE ASSOCIATION OF PAINFUL AND NON-PAINFUL COMORBIDITIES WITH CENTRAL MECHANISMS OF KNEE PAIN

Background

Central mechanisms of knee pain occur in the central nervous system and may intensify and prolong pain. Central pain mechanisms might be facilitated by ongoing nociceptive input. A link between multimorbidity and central mechanisms of knee pain is proposed; ongoing sensory inputs due to comorbidities may trigger changes in pain processing by the CNS. This might be particularly expected with painful comorbidities.

Objectives

To investigate potential relationships of painful and non-painful multimorbidity with central mechanisms of knee pain.

Methods

Cross-sectional analysis of self-report data from participants of the Investigating Musculoskeletal Health and Wellbeing cohort, who reported knee as their most bothersome site of joint pain over the previous month, with pain rated ≥1/10, and who had completed FRAIL and CAP-Knee (1) questionnaires. Two indirect measures suggesting central mechanisms involvement in knee pain were used as dependent variables; pain intensity (0-10 numerical rating scale) and CAP-Knee score (0-16 scale). Comorbidities were assigned either “painful comorbidity” or “non-painful comorbidity” status based on IASP classification of chronic pain criteria (2). Multivariable linear regression models, adjusted for age and sex, were employed to explore associations of comorbidity counts with pain intensity and CAP-Knee score.

Results

736 participants satisfied inclusion criteria. 55% were female, mean age 71 (range 40 to 95). Painful comorbidity count and non-painful comorbidity count each had positive associations with pain intensity (β=0.42, 95% CI=0.29 to 0.54, p<0.001; and β=0.31, 95%CI=0.16 to 0.45, p<0.001, respectively). Painful and non-painful comorbidity counts each also were associated with CAP-Knee score (β=0.80, 95% CI=0.59 to 1.01, p<0.001; and β=0.52, 95% CI=0.27 to 0.77, p<0.001, respectively). Painful and non-painful comorbidity counts each remained significantly associated both with pain intensity and with CAP-Knee scores when both types of comorbidity count were included in the same multivariable model.

Conclusion

Both painful and non-painful comorbidities were positively associated with central mechanisms of knee pain, providing further insight into the interconnectedness of pain processing systems and the rest of the body. The explanation behind these relationships may depend on more than just ongoing nociceptive input. Future work should address possible contributions from genetic, pathophysiological, psychological, and pharmacological factors associated with comorbid diagnosis.

References

[1]Akin-Akinyosoye K, Frowd N, Marshall L, Stocks J, Fernandes GS, Valdes A, et al. Traits associated with central pain augmentation in the Knee Pain In the Community (KPIC) cohort. Pain [Internet]. 2018 Jun PMC5959005]; 159(6):[1035-44 pp.]. Available from: https://dx.doi.org/10.1097%2Fj.pain.0000000000001183.

[2]IASP-Task-Force-on-Taxonomy. Classification of Chronic Pain (Second Edition) [E-Book]. Seattle: IASP Task Force on Taxonomy. IASP Press; 1994 [Part I: Topics and Codes]. Available from: https://www.iasp-pain.org/publications/free-ebooks/classification-of-chronic-pain-second-edition-revised/ [date accessed: October 22, 2021].

Disclosure of Interests

Harrison R. Lewis: None declared, Wendy J. Chaplin: None declared, Daniel F. McWilliams Grant/research support from: Receives grants and research support from Pfizer and Eli Lilly., Bonnie S. Millar: None declared, Seyed Shahtaheri: None declared, John F.R. Gladman: None declared, David Walsh Grant/research support from: Grants and research support were received from Pfizer and Eli Lilly.