Improving dementia diagnosis rates in England has been a key strategic aim of the UK Government but the variation and low diagnosis rates are poorly understood. The aim of this study was to explore the variation in actual versus expected diagnosis of dementia across England, and how these variations were associated with general practice characteristics.

A cross-sectional, ecological study design using secondary data sources and median regression modelling was used. Data from the year 2011 for 7711 of the GP practices in England (92.7%). Associations of dementia diagnosis rates (%) per practice, calculated using National Health Service England’s ‘Dementia Prevalence Calculator’ and various practice characteristics were explored using a regression model.

The median dementia diagnosis rate was 41.6% and the interquartile range was 31.2–53.9%. Multivariable regression analysis demonstrated positive associations between dementia diagnosis rates and deprivation of the population, overall Quality and Outcomes Framework performance, type of primary care contract and size of practice list. Negative associations were found between dementia diagnosis rates and average experience of GPs in the practice and the proportion of the practice caseload over 65 years old.

Dementia diagnosis rates vary greatly across GP practices in England. This study has found independent associations between dementia diagnosis rates and a number of patient and practice characteristics. Consideration of these factors locally may provide targets for case-finding interventions and so facilitate timely diagnosis.