The course of cancer-related insomnia: don't expect it to disappear after cancer treatment.

OBJECTIVE

The study aimed to examine the 12-month course of cancer-related insomnia (CRI) and to identify possible predictors for the prevalence and persistence of CRI.

METHODS

This longitudinal multicenter study included N = 405 patients with cancer (56% females, mean age: 58.6 years). CRI was measured by the Insomnia Severity Index (ISI). Socio-demographic and clinical data, as well as psychological parameters (Distress Thermometer, PHQ-9, GAD-7, and EORTC-Fatigue), were assessed at baseline (T1) and 12 months later (T2).

RESULTS

In our sample, a high prevalence of relevant insomnia symptoms (49.4%, ISI > 7) was found, while a clinical insomnia diagnosis was verified in 12.8% (ISI > 14). When insomnia was present at T1, this problem was persistent after one year in 64%. At T2, however, significantly more women suffered from insomnia symptoms (53.3% women vs. 39.3% men; p = 0.003). Insomnia was associated with many clinical and psychological parameters, especially with fatigue (r = 0.5). Multiple regression analysis revealed that, in women, only insomnia at T1 was a significant predictor for insomnia at T2 (R = 0.40; F(5) = 12.5; p < 0.001), whereas in men insomnia, depressive symptoms and the use of psychotropic drugs at T1 predicted the extent of insomnia at T2 (R = 0.28; F(7) = 9.5; p < 0.001). In all participants, levels of distress, depression, and anxiety decreased from T1 to T2 (p's < 0.016).

CONCLUSION

Insomnia is a common disorder in cancer patients. Although medical and psychological parameters improved during the 12-month course of cancer treatment, our results show that insomnia is highly persistent, especially in women. This indicates that adequate support for those affected is needed.

CLINICAL TRIAL REGISTRATION NUMBER

DRKS00004860.