Prevalence of Paget's disease of bone in Spain.

INTRODUCTION: Epidemiological studies in Europe have revealed that the prevalence of Paget's disease of bone (PDB) has marked geographic variations. At present, the prevalence of PDB in Spain is unknown, limited to data from isolated towns or centers. We conducted a radiological national-based survey, to estimate the age and sex prevalence of PDB and its geographic variation within the country. In addition, we tested the patients' awareness of their disease. METHODS: Stratified samples throughout Spain of abdominal radiographs, of subjects aged >or=55 years, from stored consecutive digitalized films in selected hospitals were obtained, over the period of 2006-2007. Radiographs including all lumbar vertebrae, pelvis, sacrum and femoral heads were examined for the diagnosis of PDB, according to standardized criteria. Age, sex and information regarding patient's awareness of the illness were obtained from the hospital files. RESULTS: A total of 4528 radiographs from 13 centers were evaluated. The crude prevalence of PDB was 1% (95%CI: 0.7-1.3) in individuals older than 55, and the estimated prevalence ranged from 1.1% (95%CI: 0.8-1.4) to 1.6% (95%CI: 1.1-2.1) when a reported pelvic involvement in 60-90% of PDB patients was considered. The prevalence was slightly higher in men than in women, and significantly higher in individuals older than 75. A significant geographic variation in prevalence was observed within the country (p=0.004). 73% of PDB patients were unaware of their illness at the time of the radiological survey. CONCLUSIONS: Prevalence of PDB in Spain is at least 1% in individuals older than 55, with remarkable geographical variations and age related differences. Most patients were unaware of their disease.