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.