There is robust research evidence that insomnia is highly prevalent in the general population, with a significant adverse impact on physical and mental health and quality of life. There is also strong evidence of the cost-effectiveness of cognitive-behavioural therapy for insomnia (CBT-I), the first-line treatment for insomnia recommended by the UK's National Institute for Health and Care Excellence. However, data from primary care records has not been used in the UK to establish real-world impact, including local prevalence, treatment rates and inequalities. This study's aim was to establish these in North London.

Pseudonymised data were extracted from primary care records across three North London boroughs for 765,035 patients (aged 15+ years). Insomnia prevalence was determined by identifying patients with a code for insomnia in previous five years, sleeping tablet prescription in previous three months, or code for insomnia treatment. Data were aggregated upon extraction and analysed using descriptive statistics.

Insomnia prevalence was 4.3%. Prevalence increased steadily with age, being highest in those aged 85–90 years (10.8%). There was significant variation by ethnic group and deprivation quintile, with highest prevalence in the most deprived quintile (5.2%) and those of Bangladeshi ethnicity (7.3%). Variation in insomnia prevalence, diagnosis and treatment occurred between GP practices. Prevalence was significantly higher in patients with comorbidities, including those with chronic obstructive pulmonary disease (17.5%), diabetes mellitus (11.8%), severe mental illness (16.6%), and depression (14.1%). 0.3% of people with an insomnia code had been referred for CBT-I.

Insomnia was found to be as common as other illnesses that receive high levels of focus and resourcing in the UK. Prevalence estimates were likely underestimates since patients were only counted as having insomnia if this could be identified from coded data or prescription information. Significant variation in prevalence and treatment rates by factors such as ethnicity and deprivation quintile may represent health inequalities. Additionally, insomnia was particularly common among patients with certain comorbid illnesses and of advancing age, meaning that those groups should be actively screened for insomnia. Concerningly, referral rates for CBT-I were extremely low. It is vital that clinicians receive training in diagnosing insomnia and local treatment pathways, and that culturally appropriate services are commissioned to address this unmet need and ensure equitable access. Although this study included data from only one locality, it is consistent with international research findings. Therefore, prevalence and unmet need is likely to be high in many other areas and should be investigated locally.