Comparison of subjectively and objectively assessed sleep problems in breast cancer patients starting neoadjuvant chemotherapy

PURPOSE: To characterize sleep problems and to compare subjective and objective assessments in breast cancer patients starting neoadjuvant chemotherapy. METHODS: Sleep characteristics of 54 breast cancer patients starting neoadjuvant chemotherapy were analyzed. Subjective sleep characteristics were assessed with the Pittsburgh Sleep Quality Index (PSQI) and objective sleep measurements with an accelerometer (ActiGraph wGT3X-BT) worn on the wrist for 7 consecutive days. RESULTS: According to the common PSQI cut-off of 8, 10 (18.87%) of the patients were poor sleepers. ActiGraph measures did not mirror this classification as values for poor, and good sleepers did not differ significantly. Overall, Bland-Altman plots illustrated higher ActiGraph values for sleep efficiency and effective sleep time and lower values for sleep latency, compared with PSQI. For total sleep time, less disagreement between both measures was observed. Actigraphy was limited in precise identification of sleep begin and sleep latency but provided supplementary information about number and minutes of awakenings during the night. CONCLUSION: Subjective and objective measurement methods differed substantially in various parameters, with limitations in both methods. A combination of both methods might be most promising. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02999074 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00520-020-05580-0) contains supplementary material, which is available to authorized users.