Table 1.

Baseline characteristics of study group hip OA patients*

Variables	Hip OA patients (n = 391)
Demographics
Age at incidence date, years	66.8 (14.0)
Female, %	71.1
Clinical factors
Exposure during FB, years	4.8 (2.8)
Hip-related contact during FB, person-years, %
< 1	89.8
1-2	6.4
2 >	3.8
Number of comorbidities during FB, %
< 2	58.1
2-4	29.2
> 4	12.8

* Values are the mean (SD) unless otherwise indicated.

OA: osteoarthritis; FB: follow-back.