Prevalence of Parkinson's disease in lower Aragon, Spain.

OBJECTIVE

We attempted to measure the prevalence of Parkinson's disease (PD) and to improve PD diagnosis in Lower Aragon (LA), a rural area located in northeast Spain with an elderly population numbering 60,724.

METHODS

Hospital records and a questionnaire targeted at general practitioners and retirement home personnel were used for case finding. Neurologic diagnoses were ascertained by a neurologist using a clinicoepidemiologic protocol and established diagnostic criteria after examining 84% of patients diagnosed with PD. Using stratified analysis, a comparison was run against reported PD prevalence from worldwide door-to-door surveys.

RESULTS

On the prevalence date, 134 individuals were found to be affected with PD. The prevalence per 100,000 population was 220.6 (crude) and 121.9 when age-adjusted using the European Standard Population. Prevalence increased with age, declining at 90 years and over. Questionnaires returned by general practitioners disclosed 20% of the prevalent PD cases. The prevalence of PD in pooled European populations was 2.56 times (95% confidence interval [CI]: 2.02-3.24) greater than that found in our study.

CONCLUSION

PD prevalence in Lower Aragon ranks at levels similar to those reported for white populations (European and non-European). One out of two individuals with PD was estimated to be undiagnosed before and three out of eight after the study.