To examine the reported rates and predictive factors for sleep disturbance in patients with bone metastases.
Patients with symptomatic bone metastases treated with palliative radiotherapy (RT) were eligible. At initial consultation, demographic information, baseline Brief Pain Inventory (BPI) questionnaire, and analgesic consumption were recorded. The BPI functional interference sleep item was categorized into none (0), mild (1-3), moderate (4-6), and severe (7-10). Follow-up BPI was collected in person or via telephone post-RT at week 4, 8, and 12. Subgroup analysis for BPI between responders and nonresponders was performed. Ordinal logistic regression analysis was used to search for the relationship between sleep disturbance and other covariates.
Four hundred patients were enrolled between May 2003 and June 2007. Two hundred thirty-five males (59%) were accrued. The median age was 68 years old (range, 30-91). Within the study population, primary cancer sites included breast (25%), lung (25%), prostate (24%), bladder (4%), pancreas/gastric (3%), and other primaries (18%). In the BPI functional interference items, the mean baseline score for sleep disturbance was 4.8. When categorized in terms of severity, 99 (25%) patients had moderate sleep disturbance and 144 (36%) patients had severe sleep disturbance, respectively. There was an improvement in sleep scores for both responders and nonresponders at week 4 and 8, but scores worsened for nonresponders at week 12.
Age, Karnofsky Performance Scale (KPS), pain score, and lung primary were the significant variables associated with sleep disturbance. The scores for sleep disturbance improved significantly post-RT in responders at week 4 and 12.