Table 4.

Stratification analysis of osteoarthritis risk in patients with HS.

	Cases occurring new-onset osteoarthritis
Subgroups	HS cohort (no. of event/HS patient amount in each subgroup)	Control cohort (no. of event/non-HS patient amount in each subgroup)	HR (95% CI) a
Gender
Male	707/12,376	597/12,376	1.20 (1.07, 1.33)
Female	2,084/36,498	1,588/36,498	1.31 (1.23, 1.40)
Age at index date
18–64 years old	745/12,728	625/12,728	1.19 (1.07, 1.33)
≥ 65 years old	722/3,950	555/3,950	1.38 (1.24, 1.54)

^aPropensity score matching was performed on age at index, sex, race, body mass index, status of comorbidities (including diabetes mellitus, hypertension, hyperlipidemia, fracture, and osteoporosis), status of comedication use (glucocorticoids), status of smoking, alcoholism and substance use, medical utilization status, lab data (CRP), and socioeconomic status (problems related to housing and economic circumstances, and persons with potential health hazards related to socioeconomic and psychosocial circumstances).

^bIn order to protect the privacy of participants, the TriNetX system was not able to present the exact number of participant if the number was less than 10. Hence, for these stratification groups, we were not able to calculate the hazard ratio.

Bold values indicates that those values were of statistical significance.