Prevalence and severity of insomnia in chronic low back pain patients.

The purpose of this study was to assess prevalence and severity of insomnia in participants diagnosed with chronic low back pain (CLBP) and to identify factors associated with this insomnia. One hundred CLBP consenting participants were recruited. Sociodemographic, CLBP features and sleep characteristics were collected. Patients answered validated measures of insomnia severity and fatigue. Statistical analysis examined the relationship between insomnia, sociodemographic characteristics of patients and CLBP parameters. Seventy-eight percent of patients suffered from insomnia. Insomnia due to back pain was reported in 64 % of cases. Insomnia was early, middle and late in, respectively, 39, 60 and 41 % of patients. Insomnia was sub-threshold, moderate and severe in, respectively, 34, 42 and 2 % of patients. ISI Global score was at 18.07 ± 7.3. ISI correlated significantly with pain intensity (r = 0.587; p < 0.0001), fatigue level (r = 0.495; p < 0.0001) and body mass index (r = -0.209; p = 0.03). Multiple linear regression models have revealed that pain intensity (β = 1.984; 95 % CI (1.517-2.451); p < 0.0001) and fatigue (β = 0.284; 95 % CI (0.192-0.377); p < 0.0001) were the strongest determinants for predicting insomnia in CLBP patients. Our study suggests that the prevalence of insomnia is important in CLBP patients, occurring especially at the middle of sleep. Insomnia was essentially sub-threshold or moderate. Back pain and fatigue experienced by patients were the strongest factors associated with this insomnia.