Insomnia prevalence in an oncology patient population: an Irish tertiary referral centre experience

Abstract

Background: NCCN survivorship guidelines recommend dedicated sleep assessment reflecting its association with increased symptom distress scores and mortality Reported insomnia prevalence in the general Irish population is 15%; reported prevalence internationally amongst new or recently diagnosed cancer patients varies from 23-50%. Insomnia prevalence has not been quantified in an Irish oncology cohort. Methods: With ethical approval an 8 page questionnaire was prospectively administered to ambulatory cancer patients aged ≥ 18 attending a tertiary referral centre. Pre-specified criteria for insomnia syndrome (IS) combined those of International Classification of Sleep Disorders and DSM-IV. The Hospital Anxiety and Depression scale (HADS-D/A) was used to screen for depression and anxiety as confounding variables. Logistical regression model was used for analysis. Results: Response rate was 87% (294/337). Median respondent age was 55-64.80% were female. Breast (37%) colorectal (13%) and lung (12.2%) were the most common cancer subtypes. 62% reported sleep disturbance after diagnosis.33% met IS criteria. 60% reported moderate/severe insomnia related distress, 23% a significant impact on physical function. 45% who did not meet criteria had ≥1 of 4 critical features. On univariate analysis female sex, age <65, cancer subtype, alcohol consumption, HADS-D/A ≥ 11 were associated with statistically significant higher odds ratios (OR) of IS. Multivariate analysis identified breast cancer (OR 3.17; p = 0.01), age < 65 (OR 1.8; p = 0.03) and alcohol consumption (OR 1.9; p = 0.01) as independent predictors of IS. Interestingly, 45% were unaware that alcohol consumption could impact on sleep. 62% felt cancer management should incorporate sleep assessment; 34% recalled such assessment. Written information (29%) was favoured over pharmacological management (18.7%). Conclusions: Insomnia prevalence in this Irish cohort is comparable to that previously reported and sleep assessment is justified. Alcohol is a modifiable risk factor independently predicting IS. HADS-D/A ≥11 increased OR of IS demonstrating additional utility of this scale. A patient education leaflet on sleep management is in progress to incorporate and reinforce our findings.