Figure 1.

Longitudinal effect of pain on incidence of disturbed sleep and vice versa in 423 individuals post-TJR.

Notes: (A) The effect of different types of pain categories (severe OA pain, NP, severe pain but excluding NP) on the development of disturbed sleep 2 years later in individuals in the top two tertiles for sleep score at baseline. Severe joint pain is defined as WOMAC score <50; presence of NP symptoms is defined as PDQ score >12. *Model includes age, sex, BMI, severe joint pain and NP. All individuals with disturbed sleep at baseline are excluded from the analysis. (B) Risk of developing different types of pain (NP symptoms or moderate to severe joint pain) among individuals who neither had severe joint pain (WOMAC score >50) nor NP symptoms (PDQ ≤12) at baseline depending on their sleep disturbance status (bottom tertile of the sleep scores). Individuals with severe pain or NP at baseline were excluded from the analysis.

Abbreviations: TJR, total joint replacement; OA, osteoarthritis; NP, neuropathic pain; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; PDQ, painDETECT questionnaire; BMI, body mass index; ns, not significant; HR, hazard ratio.