Affiliations: Division of Neurology, Northern Navajo Medical Center, Shiprock, NM, USA | Division of Pharmacy, Northern Navajo Medical Center, Shiprock, NM, USA | Department of Epidemiology and Biostatistics, Texas A&M University, College Station, TX, USA | Navajo Nation Division of Health, Window Rock, AZ, USA | Department of Neurology, Community Environmental Health Program, University of New Mexico Health Sciences Center, Albuquerque, NM, USA | Public Health Program, Department of Family and Community Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
Note:  Correspondence to: Paul H. Gordon, MD, PhD, Northern Navajo Medical Center, Box 160 Highway 491 North, Shiprock, NM 87420, USA. Tel.: +1 505 368 6339; E-mail: [email protected]
Abstract: Background: The prevalence of Parkinson disease (PD) varies by geographic location and ethnicity, but has never been studied among the Navajo. Methods: Period prevalence was calculated using the number of people diagnosed with PD in the Shiprock Service Unit Indian Health Service database during 1995–1999, 2000–2004, and 2005–2009 as the numerator, and the number seen for any reason as the denominator. Age-standardized rates were calculated using the 2000 US population. Results: During 2005–2009, 126 people were seen with PD (crude prevalence = 203.7/100,000 population). The age-adjusted rate was 335.9 (95% C. I. 277.8–394.0) overall, 438.5 (95% C.I. 336.5–540.5) in men and 259.7 (95% C.I. 192.8–326.7; p = 0.004) in women. The adjusted rate increased with age: 788.8 (95% C.I. 652.0–925.7) for age 40 and above to 1964.9 (95% C.I. 1613.7–2316.1) for age 60 and above. Adjusted rates were 246.6 (95% C.I. 187.2–306.0) in 1995–1999 and 284.7 (95% C.I. 227.0–342.4) in 2000–2004. Conclusion: Parkinson disease appears common among the Navajo. Estimates increased with age and time, and were higher in men. In-person interviews are needed to confirm these estimates, and to determine incidence, quality of care, and risk factors for PD among the Navajo.
Keywords: Parkinson disease, prevalence, Navajo, Indians, North American, epidemiology, health status disparities