Epidemiology of alcohol dependence in UK primary care: Results from a large observational study using the Clinical Practice Research Datalink

This study aims to investigate the incidence and annual presentation rates of alcohol dependence in general practice in the UK, and examine age-, gender-, socioeconomic-, and region -specific variation. We conducted a retrospective 'open' cohort study using the Clinical Practice Research Datalink (CPRD), an anonymised primary care database. Prior to data extraction, a case definition for alcohol dependence in CPRD was established using 47 Read codes, which included primary alcohol dependence and consequences of alcohol dependence. Directly standardised rates for incidence and annual presentation were calculated for each year between 1990 and 2013. Rates were compared by gender, age, UK home nation, and practice -level Index of Multiple Deprivation. The directly standardised annual incidence rates were 8.3 and 3.7 per 10,000 male and female patients, respectively. The estimated annual rates of presentation per 10,000 were 17.1 for males and 7.6 for females. Female to male rate ratios were: 0.40 (95% CI: 0.39-0.41) for incident cases; and 0.37 (95% CI: 0.36-0.39) for annual presentation. Rates were highest in those aged 35-54 for both measures and across genders, and lowest in those aged over 75 years. With England as the reference nation, Northern Ireland and Scotland had significantly higher rates for both measures. Patients from the most deprived areas had the highest incidence and annual presentation rates. There is unequal distribution of patients with severe alcohol dependence across population subgroups in general practice. Given the health and economic burden associated with dependent drinking, these data will be useful in informing future public health initiatives.