Trouble sleeping inside: a cross-sectional study of the prevalence and associated risk factors of insomnia in adult prison populations in England.

OBJECTIVE: To investigate the prevalence of insomnia and identify associated demographic, clinical and forensic risk factors in adult prisoners in England.

METHODS: A cross-sectional study of 237 prisoners aged 18-72 years, across two male prisons and one female prison in North England. We used the Sleep Condition Indicator to measure probable DSM-V insomnia disorder (ID) and the Pittsburgh Sleep Quality Index to examine sleep quality. Multiple demographic, sleep, clinical and forensic self-reported measures were recorded to identify any associations with insomnia.

RESULTS: Overall, the prevalence of possible DSM-V ID was 61.6% (95% CI, 55.5%-67.8%). Subjective poor sleep quality was reported by 88.2% (95% CI, 84.1%-92.3%). Seven in ten (70.6%) female prisoners had possible DSM-V ID (95% CI, 64.8%-76.4%). Multivariable logistic regression analysis, adjusting for gender and age, indicated odds of having possible ID in prison were increased for the following factors: history of physical ill-health (OR = 3.62, 95% CI, 1.31-9.98); suicidality (OR = 2.79, 95% CI, 1.01.7.66), previously asked for help for insomnia (OR = 2.58, 95% CI, 1.21-5.47), depression (OR = 2.06, 95% CI 1.31-3.24), greater endorsement of dysfunctional beliefs about sleep (OR = 1.50, 95% CI, 1.21-1.87), poor sleep hygiene (OR = 1.11, 95% CI, 1.04-1.19), and problematic prison environment (eg, noise, light or temperature) (OR = 1.07, 95% CI, 1.02-1.12).

CONCLUSIONS: For the first time we have established the prevalence and associated factors of insomnia in a large sample of adult English prisoners. ID and poor sleep quality are common, especially in female prisoners. These findings emphasize/amplify the need for dedicated treatment pathways to improve screening, assessment and treatment of insomnia in prison.