Table 1.

Description of study populations in the Parkinson’s Epidemiology and Genetics Association Studies in the U.S (PEGASUS)

Study	Parkinsonism Epidemiology at Kaiser (PEAK) Studies I & II18	Parkinson's disease Environment & Genes (PEG) Study23	Columbia University (Washington Heights/ Inwood) Studies I20 & II21	Agricultural Health Study of Farming and Movement Evaluation (FAME) 19	Honolulu Asia Aging Study (HAAS) 22
	Case-control study	Case-control study	Case-control studies (2)	Nested case-control study	Nested case-control study
Study Population	Kaiser Permanente Medical Care Program of Northern California (3 million members)	Residents of Fresno, Kern, & Tulare, who resided in CA in last 5 yrs before recruitment	Residents of Washington- Heights-Inwood Section of northern Manhattan	Cohort of licensed pesticide applicators and their spouses in Iowa and N. Carolina	Men of Japanese and Okinawan ancestry born between 1900 –1919, resided on Oahu, Hawaii in 1965
Case Identification	Cases ascertained by treating neurologist or computerized inpatient, outpatient and pharmacy databases	Recruitment through rural health care providers and neurologists. Cases ascertained by treating neurologist or physician	Community-based PD patients and PD cases seen at referral/senior centers, all living in same geographical area in northern Manhattan	Multistage screening method that includes in- person evaluation and diagnosis by expert consensus	Ongoing search of hospital records, review of death certificates, and medical records of local neurologists
Number of PD cases, controls with DNA	n = 584 PD cases n = 639 controls	n = 279 PD cases n = 254 controls	From 2 studies total: n = 296 PD cases n = 299 controls	n = 100 PD cases n = 367 controls	n = 72 PD cases n = 185 controls
Method of Case Definition	Medical record review by movement disorder specialist, case definition according to CAPIT/Hughes criteria 24,25	Examined by movement disorder specialists, case definition according to CAPIT/Hughes criteria 24,25	Neurology clinic record review, neurologic exam and diagnosis confirmed by study neurologist*	Diagnosed by movement disorder specialist based on neurologic exam, structured videotape, and medical records review; according to CAPIT/Hughes criteria, 24,25	Neurologist case confirmation, according to CAPIT/Hughes criteria, 24,25
Time period of case/control ascertainment	1994–1995 and 2000–2003	Jan 1st, 1998 thru Aug 31st, 2004	1988–1996	2000–2005	1965–1991
Control Selection	Controls randomly selected from Kaiser membership rolls, matched to cases by gender and year of birth	Age-sex matched population controls from Medicare and random sample from residential tax assessors’ parcels (residents of CA for the past 5 yrs)	Healthy community volunteers living in same geographical area in northern Manhattan	Selected from all non affected pesticide applicators in the AHS cohort	Selected from all non affected men in study cohort

^*Diagnostic criteria (a) bradykinesia, (b) one of the following: rigidity, rest tremor or postural instability, (c) at least 3 of the following (unilateral onset, persistent asymmetry of signs or symptoms, good response to levodopa, progressive course, levodopa-induced chorea) and (d) no evidence of drug-induced parkinsonism.