Table II.

Lifetime risk of symptomatic^* hip osteoarthritis in the Johnston County Osteoarthritis Project cohort

	Proportion† (95% confidence interval)
Stratified
Sex
Men	18.5 (12.5–24.5)
Women	28.6 (23.6–33.6)
Race
Black	23.9 (20.2–27.6)
White	26.0 (21.2–30.7)
Education‡
Less than high school	24.3 (18.8 –29.7)
Completed high school	27.6 (23.5 – 31.8)
More than high school	23.2 (20.9 – 29.7)
Body mass index at age 18 years**
Underweight or normal (<25)	24.6 (20.3 – 28.9)
Overweight or obese (≥25)	20.6 (7.5– 33.6)
Body mass index‡,**
Underweight or normal (<25)	25.5 (18.2 –32.7)
Overweight (25 to <30)	23.5 (17.8–29.2)
Obese (≥30)	31.1 (23.1–39.2)
History of hip injury‡,††
No	22.1 (18.3–25.8)
Yes	50.0 (14.4–85.6)
Overall‡‡	25.3 (21.3 – 29.3)

^*Symptomatic was defined as either “pain, aching, or stiffness in at least one hip joint” or “pain in groin” in the radiographically affected hip.

^†Weighted to Johnston County population distribution in the1990 United States Census.

^‡Education, body mass index (BMI), and history of hip injury were time dependent (i.e., participants’ measurements at baseline and follow up were analyzed).

^**BMI at age 18 was calculated from self-reported height and weight. Baseline BMI was calculated from height and weight measurements at baseline clinical examination.

^††History of hip injury in the symptomatic and radiographically affected joint

^‡‡Stratified lifetime risk estimates may not sum to overall lifetime risk estimate because of missing data for stratification variables (Table 1).