Insomnia and Self-Reported Infections in Cancer Patients: An 18-Month Longitudinal Study

Objective: This study, conducted in cancer patients, aimed to evaluate longitudinally whether the presence of insomnia is associated with the occurrence of self-reported infections. Method: Patients scheduled to receive a curative surgery for a first diagnosis of nonmetastatic cancer were solicited on the day of their preoperative visit. In total, 962 cancer patients completed the Insomnia Interview Schedule and a clinical interview to assess infectious symptoms at 6 time points: at the perioperative phase (baseline), as well as 2, 6, 10, 14, and 18 months later. At each assessment, patients were categorized into the following 3 groups: insomnia syndrome (SYN), insomnia symptoms (SX), and good sleepers (GS). Results: The analyses revealed that SYN patients at 1 time point were at a significantly higher risk of reporting at least 1 infectious episode at the subsequent assessment (OR = 1.31, p = .04), whereas SX patients were at a marginally significant higher risk of reporting such episodes (OR = 1.19, p = .08), as compared with GS. Conclusions: Although these results need replication and the causality needs to be established, they suggest that insomnia may potentiate the risk of experiencing infections during the cancer care trajectory.