Prevalence of PD and other types of parkinsonism in three elderly populations of central Spain

The prevalence of Parkinson's disease (PD) and other types of parkinsonism in three elderly populations of central Spain was investigated using a door-to-door, two-phase approach. This design called for the administration of a brief questionnaire to subjects 65 years of age or older taken from the census of one urban municipality of Greater Madrid (Margaritas, Getafe), one rural site (Arévalo County, Avila), and one urban district of Madrid (Lista) in Spain (N = 5,278). Study neurologists extensively investigated those subjects who screened positively. The diagnoses, based on specified criteria, were reviewed to increase reliability across neurologists. We found 118 subjects with parkinsonism: 81 affected by PD (68.6%), 26 drug-induced parkinsonism (22.0%), 6 parkinsonism in dementia (5.1%), 3 vascular parkinsonism (2.5%), and 2 unspecified parkinsonism (1.7%). The prevalence was 2.2% (95% confidence interval [CI], 1.8-2.6) for all types of parkinsonism and 1.5% (95% CI, 1.2-1.8) for PD. The prevalence estimates of parkinsonism and PD increased with age, declining at 85 years and over. Age prevalence ratios were higher for men. Twenty-three subjects (28.4%) of the subjects with PD were detected through the screening and had not been diagnosed previously. Overall prevalence estimates of PD and other types of parkinsonism in central Spain rank at levels similar to those recently reported for other European and non-European elderly populations. Despite improvement in access to health services, an important proportion of PD patients may never seek neurological attention.