Aims: To characterize the prevalence of diabetes in a large health district in 2004 and compare it with a previous estimate made in 1996.
Methods: The study population comprised the resident population of Cardiff and the Vale of Glamorgan. Routine record linkage was used to identify patients from various sources of hospital and mortality data. Patients with diabetes were identified according to biochemistry test results, coding on routine data or attendance at a diabetes-related clinic. Diabetes-related complications were ascribed according to coding on routine data.
Results: It was possible to identify 17 088 people with diabetes alive on 1 January 2005. Of these patients, 9064 (53.0%) were male and 8024 (47.0%) were female. Mean age (+/- sd) was 59.6 +/- 18.9 years for males and 61.2 +/- 20.4 years for females. The crude prevalence of diabetes in 2005 was 3.9% (3.4% adjusted) compared with 2.5% in 1996 (2.3% adjusted). With the exception of females aged > or = 75 years, the prevalence of diabetes increased in all age- and sex-specific subgroups. Within the 2005 cohort, over two-thirds has no recorded complications compared with approximately one half of the 1996 cohort. The prevalence of individual complications decreased, with the exception of renal complications.
Conclusions: The prevalence of identified diabetes appears to have increased substantially over a relatively short period of 9 years to 2004. The increase in prevalence was 46%, with an increase in numbers of patients with diabetes of 53%. A number of factors are likely to have contributed to this, including an increase in case ascertainment.