title: Parkinson's and Alzheimer's diseases in Costa Rica: a feasibility study toward a national screening program.
abstract: BACKGROUND
  The integration of mental and neurologic services in healthcare is a global priority. The universal Social Security of Costa Rica aspires to develop national screening of neurodegenerative disorders among the elderly, as part of the non-communicable disease agenda.
  
  
  OBJECTIVE
  This study assessed the feasibility of routine screening for Parkinson's disease (PD) and Alzheimer's disease (AD) within the public healthcare system of Costa Rica.
  
  
  METHODS
  The population (aged ≥65) in the catchment areas of two primary healthcare clinics was targeted for motor and cognitive screening during routine annual health check-ups. The screening followed a tiered three-step approach, with increasing specificity. Step 1 involved a two-symptom questionnaire (tremor-at-rest; balance) and a spiral drawing test for motor assessment, as well as a three-word recall and animal category fluency test for cognitive assessment. Step 2 (for those failing Step 1) was a 10-item version of the Unified Parkinson Disease Rating Scale and the Mini-Mental State Examination. Step 3 (for those failing Step 2) was a comprehensive neurologic exam with definitive diagnosis of PD, AD, mild cognitive impairment (MCI), other disorders, or subjects who were healthy. Screening parameters and disease prevalence were calculated.
  
  
  RESULTS
  Of the 401 screened subjects (80% of target population), 370 (92%), 163 (45%), and 81 (56%) failed in Step 1, Step 2, and Step 3, respectively. Thirty-three, 20, and 35 patients were diagnosed with PD, AD, and MCI, respectively (7 were PD with MCI/AD); 90% were new cases. Step 1 sensitivities of motor and cognitive assessments regarding Step 2 were both 93%, and Step 2 sensitivities regarding definitive diagnosis 100 and 96%, respectively. Specificities for Step 1 motor and cognitive tests were low (23% and 29%, respectively) and for Step 2 tests acceptable (76%, 94%). Based on international data, PD prevalence was 3.7 times higher than expected; AD prevalence was as expected.
  
  
  CONCLUSIONS
  Proposed protocol adjustments will increase test specificity and reduce administration time. A routine screening program is feasible within the public healthcare system of Costa Rica.
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica; Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden; inekewesseling@gmail.com.
authors.forename: Catharina
authors.initials: C
authors.lastname: Wesseling
authors.affiliation: Hospital San Juan de Dios, Social Security of Costa Rica (CCSS), San José, Costa Rica.
authors.forename: Norbel
authors.initials: N
authors.lastname: Román
authors.affiliation: Clínica de Santo Domingo de Heredia, Social Security of Costa Rica (CCSS), Santo Domingo de Heredia, Costa Rica.
authors.forename: Indiana
authors.initials: I
authors.lastname: Quirós
authors.affiliation: Clínica de Santo Domingo de Heredia, Social Security of Costa Rica (CCSS), Santo Domingo de Heredia, Costa Rica.
authors.forename: Laura
authors.initials: L
authors.lastname: Páez
authors.affiliation: Development of Health Services, Social Security of Costa Rica (CCSS), San José, Costa Rica.
authors.forename: Vilma
authors.initials: V
authors.lastname: García
authors.affiliation: Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica; School of Public Health, University of California at Berkeley, Berkeley, CA, USA.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Mora
authors.affiliation: Department of Neurology, Emory University, Atlanta, GA, USA.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Juncos
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Kyle N
authors.initials: KN
authors.lastname: Steenland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D003364:Costa Rica / Q000453:epidemiology; D019033:Delivery of Health Care, Integrated / Q000458:organization & administration*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000458:organization & administration*; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D011634:Public Health / Q000379:methods*; D011795:Surveys and Questionnaires
keywords: Alzheimer's; Costa Rica; Parkinson's; aging; public health system; screening