RESUMEN
BACKGROUND: Disturbed sleep is strongly correlated with chronic pain. The aim of this study was to examine the association between sleep disturbance and incident joint pain focusing on neuropathic-like pain symptoms. METHODS: A total of 423 individuals who had undergone total joint replacement (TJR) for osteoarthritis were assessed at the mean time of 3.6 years post-surgery and again at 5.9 years post-TJR, using the Medical Outcomes Survey sleep subscale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and painDETECT questionnaire instruments. Cox hazard ratios (HRs) and 95% confidence intervals (CIs) were computed adjusting for age, body mass index, sex, and use of hypnotic and analgesic medication. RESULTS: The presence of neuropathic pain symptoms predicted incidence of disturbed sleep after adjustment for covariates and pain severity (adjusted HR [aHR] 2.01, 95% CI: 1.00-4.10; p<0.05). There was no association between joint pain and incidence of disturbed sleep when individuals with neuropathic pain symptoms at the baseline visit were excluded (aHR 1.11, 95% CI: 0.47-2.67). Disturbed sleep at baseline predicted incident neuropathic joint pain symptoms (aHR 2.75, 95% CI: 1.21-6.26; p<0.016) but had no effect on incidence of joint pain when all types of pain were considered together (aHR 0.63, 95% CI: 0.30-1.39). CONCLUSION: These data suggest a causal bidirectional link between sleep disturbance and joint pain with neuropathic features but not with other types of joint pain.
RESUMEN
OBJECTIVE: To survey the use of analgesic medication 4.8 years after total joint replacement (TJR) surgery and assess the determinants of medication usage. PATIENTS AND METHODS: Of 852 patients who had undergone TJR for osteoarthritis were recruited from secondary care. Participants (mean age, 73.7 years) responded to a questionnaire on medication use, physical function and pain (WOMAC, VAS and body pain), pain catastrophizing and illness behaviour (somatization). RESULTS: Only 37% of study participants were not on any pain relief medication, 25.1% were taking opioids, 6.9% were taking prescription NSAIDs and 25.9% were taking only non-prescription analgesics. Use of NSAIDs correlated with presence of back pain, body pain and high illness behaviour. The strongest associations with use of opioids were severe joint pain, high pain catastrophizing, body and back pain. After adjustment for covariates plus presence of pain, catastrophizing remained significantly associated with higher risk of opioid use (OR = 1.66, 95% CI: 1.13-2.43, p < 0.009) and of other prescription medication that can be used to treat pain (anti-depressants, anti-epileptics and hypnotics) (OR = 2.52, 95% CI: 1.61-3.95, p < 0.0005). CONCLUSIONS: Use of opioid medication 4 years post-TJR is very high in our study population. In addition to joint, back and body pain, a major contributor to opioid use is pain catastrophizing. Our data suggest that current opioid and other analgesic prescribing patterns may benefit from considering the catastrophizing characteristics of patients.
