EPIDEMIOLOGY 379
disease by age and sex, but by ethnic group as well. These
differences in Table 2 illustrate the importance of controlling
for various confounders such as sex, age, and race in epidemio-
logical studies.
When examining the incidence rate of Parkinson’s dis-
ease (Table 3), this study reports 83 new cases during the
3-year period. For the incident cases, the mean age was 76.3
years, with a standard deviation of 9.5 and a time period of
symptoms (duration of 1.4 years). There was reported no dif-
ference in the mean age (75.2 years) for men and womenfor the onset of symptoms. From Table 3, the annual inci-
dence of Parkinson’s disease in New York City is 13 per
100,000. Unlike that reported for prevalence, there were no
incidences of Parkinson’s diseases below the age of 45 years
during this study period. However, as noted for prevalence,
the incidence rate of disease increases with age. There is
also a difference in the rates for men and women and among
ethnic groups evaluated.
The data in Tables 2 and 3 can be used to evaluate
the numbers of cases and the occurrence of disease in aTABLE 3
Annual incidence of idiopathic Parkinson’s disease over a 3-year period in a community diseases registry, New York City, 1988–1989Ethnic group And sex Age group (years) Total45–64 65–74 75–84 85 Crude Age-adjusted
Black men
No. 1 7 6 1 15 — —
Population 4,265 1,216 530 150 25,556 — —
Prevalence rate — 23.4 575.7 666.7 58.7 92.0
(29.0–88.4)‡92.0
(54.7–129.0)
White men
No. 1 7 8 3 19 — —
Population 6,020 2,296 1,305 443 30,349 — —
Prevalence rate 16.6 304.9 613.0 667.0 62.6 54.7
(34.5–90.7)—
(28.4–81.0)
White women
No. 14 12 34 12 73 — —
Population 7,036 2,446 1,710 636 38,275 — —
Prevalence rate 199.0 490.6 1,074.7 1,886.8 167.3 86.0
(147.0–243.0)—
(131.0–114.0)
Hispanic men
No. 1 7 6 1 15 — —
Population 4,265 1,216 530 150 25,556 — —
Prevalence rate 23.4 575.7 666.7 58.7 92.0 92.0
(29.0–88.4)—
(54.7–129.0)
Hispanic women
No. 1 7 6 1 15 — —
Population 4,265 1,216 530 150 25,556 — —
Prevalence rate 23.4 575.7 666.7 58.7 92.0 92.0
(29.0–88.4)—
(54.7–129.0)
Total
No. 1 7 6 1 15 — —
Population 4,265 1,216 530 150 25,556 — —
Prevalence rate 23.4 575.7 666.7 58.7 92.0 92.0
(29.0–88.4)—
(54.7–129.0)
Source: From Mayeux et al. (1995), The frequency of idiopathic Parkinson’s disease by age, ethnic group and sex in northern Manhattan, 1988–1993,
American Journal of Epidemiology, 142:820–27; with permission from Oxford Press.C005_011_r03.indd 379C005_011_r03.indd 379 11/18/2005 10:25:42 AM11/18/2005 10:25:42 AM