Exploring the influence and identifying key predictors of sleep difficulties on health status in long-term breast cancer survivors: a cross-sectional study.

PURPOSE

This study analyzed the relationship between different levels of sleep difficulties and physical, mental, and emotional variables in long-term breast cancer survivors (LTBCSs), and identified predictors of sleep-related complaints.

METHODS

Eighty LTBCSs participated in this cross-sectional study. Sleep difficulties were assessed via item 11 of the EORTC QLQ-C30, classifying participants into two groups: low (n = 44; ≤ 26.29) and high sleep difficulties (n = 36; ≥ 26.30). Additional measures included the EORTC QLQ-BR23, Piper Fatigue Scale, Visual Analog Scale, Brief Pain Inventory, International Fitness Scale, Minnesota Leisure Time Physical Activity questionnaire, and the Scale for Mood Assessment. Statistical analyses comprised ANOVA, Mann-Whitney U, Chi-square, correlation, and multiple regression; effect sizes were calculated using Cohen's d.

RESULTS

Fifty-five percent of LTBCSs reported higher sleep difficulties. This group showed greater physical, mental, and emotional impairments, including cancer-related fatigue (CRF), pain, lower self-perceived fitness, reduced physical activity (PA), worse mood, and diminished health-related quality of life (HRQoL) (all p < 0.05). Regression identified "role functioning" (β = -0.37; p < 0.01), "nausea and vomiting" (β = 0.37; p < 0.01), and "PA level" (β = -0.17; p = 0.02) as significant predictors of higher levels of sleep difficulties (adjusted r = 0.58).

CONCLUSION

Five or more years post-diagnosis, 55% of LTBCSs experienced higher sleep difficulties, associated with poorer HRQoL, self-perceived physical fitness, mood, and increased CRF and pain. Key predictors explained 58.4% of variance in sleep difficulties.