Table 3.

Factors predicting (indication for) total hip replacement (THR)

Prognostic factor	Studies	Associations	Best-evidence synthesis
Patient variables
No association
Body mass index			Strong evidence for no association
	2 low risk of bias cohorts [16, 37] 5 cohorts [20, 39, 50, 51, 67]	No, no No, no, no, negative, positive
Female			Moderate evidence for no association
	3 low risk of bias cohorts [16, 34, 37] 5 cohorts [20, 39, 50–52]	No, positive, no No, no, no, no, no
Lower educational level			Moderate evidence for no association
	1 low risk of bias cohort [16] 1 cohort [39]	No No
Western or White ethnicity			Moderate evidence for no association
	1 low risk of bias cohort [16] 1 cohort [39]	No No
Alcohol consumption			Limited evidence for no association
	1 low risk of bias cohort [16]	No
Conflicting evidence
Higher age at baseline			Conflicting evidence
	3 low risk of bias cohorts [16, 34, 37] 5 cohorts [20, 39, 50, 51, 67]	No, positive,no No, positive$, no, no, positive
Disease characteristics
Faster or more progression
Lower global assessment (self-reported) at baseline			Moderate evidence for faster or more progression
	1 low risk of bias cohort [37] 2 cohorts [39, 50]	Positive Positive, positive
Previous use of NSAIDs			Limited evidence for more progression
	1 low risk of bias cohort [37]	Positive
No association
Longer duration of symptoms at baseline			Moderate evidence for no association
	1 low risk of bias cohort [37] 1 cohort [19]	No No
Having another disease (comorbidity)			Moderate evidence for no association
	1 low risk of bias cohort [16] 1 cohort [39]	No No
Morning stiffness			Moderate evidence for no association
	1 low risk of bias cohort [16] 1 cohort [51]	No No
Use of pain medication at baseline			Moderate evidence for no association
	1 low risk of bias cohort [16] 1 cohort [19]	No No
Presence of Heberden’s or Bouchard’s nodes			Moderate evidence for no association
	1 low risk of bias cohort [16] 2 cohorts [50, 51]	No No, no
Previous intra-articular injection in the hip			Limited evidence for no association
	1 low risk of bias cohort [37]	No
Conflicting evidence
More limitations in physical function at baseline			Conflicting evidence
	3 low risk of bias cohorts [16, 34, 37] 2 cohorts [19, 39]	Positive, positive, no No, no
More pain at baseline			Conflicting evidence
	3 low risk of bias cohorts [16, 34, 37] 4 cohorts [19, 39, 50, 51]	Conflicted$$, positive, positive Positive, no, positive, no
Painful hip flexion (active or passive)			Conflicting evidence
	1 low risk of bias cohort [16] 1 cohort [51]	Positive No
Painful hip internal rotation (active or passive)			Conflicting evidence
	1 low risk of bias cohort [16] 1 cohort [51]	Positive No
Night pain at baseline			Conflicting evidence
	2 cohorts [50, 51]	Positive, no
Limited range of motion of flexion of the hip			Conflicting evidence
	1 low risk of bias cohort [16] 2 cohorts [19, 51]	Positive Positive, no
Limited range of motion of internal hip rotation			Conflicting evidence
	1 low risk of bias cohort [16] 2 cohorts [19, 51]	Positive Positive, no
Limited range of motion of external hip rotation			Conflicting evidence
	2 cohorts [19, 51]	Positive, no
Chemical or imaging markers
Faster or more progression
Higher K-L grade at baseline			Strong evidence for more or faster progression
	2 low risk of bias cohorts [34, 37] 1 cohorts [51]	Positive, positive Positive
Superior or superolateral migration of the femoral head			Strong evidence for more or faster progression
	2 low risk of bias cohorts [34, 47] 1 cohort [38]	Positive, positive Positive
Subchondral sclerosis			Strong evidence for more progression
	2 low risk of bias cohorts [16, 47]	Positive, positive
Statistical shape modeling			Moderate evidence that certain modes of SSM can predict progression
	3 cohorts [11, 12, 12]	Positive, positive, positive
Joint space narrowing at baseline			Moderate evidence for more or faster progression
	1 low risk of bias cohort [16] 1 cohort [67]	Positive Positive
No association
Cam-type deformity (alpha angle > 60°)			Limited evidence for no association
	1 low risk of bias cohort [16]	No
Conflicting evidence
Erythrocyte sedimentation rate			Conflicting evidence
	1 low risk of bias cohort [16] 1 cohort [51]	Positive No
Atrophic bone response (no osteophytes present)			Conflicting evidence
	1 low risk of bias cohort [16] 2 cohorts [50, 51]	Positive Positive, no
Decrease in joint space width at baseline			Conflicting evidence
	1 low risk of bias cohort [34] 1 cohort [51]	Positive No
Wiberg’s center edge angle (CEA)			Conflicting evidence
	1 low risk of bias cohort [16] 1 cohort [20]	Negative No

^$Exception: age ≥ 82 years showed a negative association with progression, compared to age ≤ 62 years

^$$Pain at baseline measured with NRS past week showed a statistically significant positive association with THR; pain at baseline measured with WOMAC pain showed no statistically significant association with THR