Sleep reactivity predicts insomnia in patients diagnosed with breast cancer

Study Objectives: To examine the role of sleep reactivity as a predictor of insomnia in patients diagnosed with breast cancer. Methods: A total of 173 women with breast cancer participated and were followed up over a period of 9 months. At baseline, participants were assigned to a high (n = 114) or low (n = 59) sleep reactivity group, based on their responses to the Ford Insomnia Response to Stress Test (FIRST). We assessed whether these FIRST groupings (high/low sleep reactivity) predicted changes in insomnia over time using the Insomnia Severity Index. We also tested if these FIRST groupings predicted insomnia disorder (using Insomnia Severity Index cutoffs) at 3 different time points (T3, T6, and T9). Results: Individuals with high sleep reactivity were more likely to experience a worsening of insomnia. Using logistic regression, we also found that FIRST grouping predicted insomnia disorder. Results remained significant after controlling for estimated premorbid sleep, age, and whether someone had chemotherapy. Conclusions: Our study shows that sleep reactivity may be a robust predictor of insomnia within breast cancer populations. Sleep reactivity should be considered in routine clinical assessments as a reliable way to identify patients at risk of developing insomnia. This would facilitate early sleep intervention for those patients who are considered high risk.