P094 Incidence of clinically diagnosed Paget’s disease of bone: evidence of a continuing decline

Abstract

Abstract Background/Aims Evidence from the UK suggest that the incidence of Paget's disease of bone declined during the latter half of the last century with a decline also in the incidence of clinically apparent disease. We aimed to characterise the recent incidence of clinically diagnosed Paget’s disease of bone in the UK by age and sex among those aged >18 years and, to determine whether the incidence has changed from 1999-2015. Methods Incident cases of Paget’s disease during 1999-2015 were identified from the first recorded diagnostic code for Paget’s disease in the UK Clinical Practice Research Datalink (CPRD) database. Crude incidence was calculated for each year from 1999 to 2015 and, to account for changes in the distribution of age and sex over time within the CPRD, direct age- and sex-standardised incidence rates were calculated for each year. This was done by multiplying the crude incidence in each age-sex stratum by the age-sex stratum weight of the 1999 population of those at risk of developing Paget’s disease. We looked also at the incidence of disease by quintile of index of multiple deprivation and geographic region. Using Poisson regression, we looked at the influence of deprivation and geography on occurrence of the disease after adjustment for age and sex. Results In total 3,592 incident cases of Paget’s disease were identified between 1999 and 2015. Overall the incidence increased with age and at all ages was greater in men than women. In men, and women, respectively, incidence increased from 0.074 and 0.037 per 10,000 per year at the age of 45-49 years to 6.3 and 3.7 per 10,000 per year at age of 85 years and older. When stratified by year, the age- and sex-standardised incidence fell from 0.75/10,000 person years in 1999 to 0.20/10,000 person years in 2015. Crude incidence (1999-2015) was slightly higher in those living in the most deprived areas (0.53/10,000 person years) compared to those in least deprived areas (0.43/10,000 person years). After adjustment for age and sex, compared to those in the highest quintile of index of multiple deprivation, those in the lowest quintile of index of multiple deprivation had over a 30% increased risk of disease. There was evidence also of geographic variation in the occurrence of disease with the highest incidence in the North West of England. Conclusion The incidence of clinically diagnosed Paget’s disease has continued to decrease since 1999. The reason for the decline remains unknown, though the rapidity of change points to an alteration in one or more environmental determinants. Disclosure M.J. Cook: None. S.R. Pye: None. W.G. Dixon: None. T.W. O'Neill: None.