This study aimed to assess whether sleep quality (SQ) at baseline is related to improvement in pain and disability at three months. 422 subacute and chronic patients with neck pain (NP) were recruited in 32 physiotherapy, primary care and specialized centers. NP, referred pain, disability, catastrophizing, depression and SQ were assessed by use of validated questionnaires, upon recruitment and 3 months later. Correlations between baseline scores were calculated through the Spearman’s coefficient. Improvements in NP, disability and SQ were defined as a reduction≥30% of baseline score. Six estimative logistic regression models were developed to assess the association between baseline SQ and improvement of NP, baseline SQ and improvement of disability, baseline NP and improvement of SQ, baseline disability and improvement of SQ, the evolutions of NP and SQ, and the evolutions of disability and SQ. The majority of patients were subacute and mildly impaired. Regression models showed that: better SQ at baseline is associated with improvement of NP (OR [95%CI]=0.91 [0.83:0.99]), but not disability (1.04 [0.95;1.13]); the improvement of SQ is associated with more severe NP at baseline (1.26 [1.07;1.49)], but not with baseline disability (0.99 [0.97;1.02]); and that improvement in SQ is associated with improvements in NP (3.48 [1.68; 7.20]), and disability (5.02 [2.39;10,11]).
The study found that neck pain is less likely to improve in patients with poorer sleep quality, regardless of age, sex, catastrophizing, depression or treatments prescribed for NP. Future studies ought to confirm these results in patients with a greater severity of impairment.