Hip-specific and generic patient-reported outcome measure scores after primary hip replacement are associated with early revision surgery: a national registry study

Journal of Patient-Reported Outcomes

Table 2 Comparison of patient-reported outcome scores after primary total hip replacement

Outcome	Revised at 6–24 months (n = 88)	Not revised at 6–24 months (n = 21,148)	p-value	Effect size or relative improvement*
6-month post-operative score, mean (SD)
Hip pain VAS	3.6 (3.0)	1.5 (2.2)	< 0.01	0.95
Low back pain VAS	3.6 (3.1)	2.8 (2.9)	0.02	0.28
Oxford Hip Score	31.3 (12.6)	41.7 (7.1)	< 0.01	-1.46
HOOS-12 Pain	63.5 (26.5)	87.2 (16.7)	< 0.01	-1.42
HOOS-12 Function	69.4 (24.8)	88.5 (14.2)	< 0.01	-1.35
HOOS-12 Quality of life	53.9 (30.4)	80.6 (19.1)	< 0.01	-1.40
HOOS-12 Summary	62.3 (26.4)	85.4 (15.3)	< 0.01	-1.51
EQ-5D-5L utility score	0.50 (0.40)	0.80 (0.20)	< 0.01	-1.50
EQ VAS	71.4 (18.6)	80.5 (16.0)	< 0.01	-0.57
Baseline to 6-months, mean change (SD)
Hip pain VAS	-3.5 (3.5)	-5.3 (2.8)	< 0.01	66%
Low back pain VAS	-1.3 (3.5)	-1.4 (3.2)	0.87	93%
Oxford Hip Score	12.3 (13.9)	21.3 (10.1)	< 0.01	58%
HOOS-12 Pain	31.1 (26.5)	47.8 (22.7)	< 0.01	65%
HOOS-12 Function	30.7 (27.1)	41.6 (21.7)	< 0.01	74%
HOOS-12 Quality of life	29.0 (26.1)	49.0 (24.2)	< 0.01	59%
HOOS-12 Summary	30.2 (24.3)	46.1 (20.8)	< 0.01	66%
EQ-5D-5L utility score	0.30 (0.40)	0.40 (0.40)	< 0.01	75%
EQ VAS	7.7 (21.3)	14.7 (21.4)	< 0.01	52%

EQ-5D-5L: Euroqol 5-dimension quality of life index; EQ VAS: Euroqol Health Today Visual Analogue Scale; HOOS-12: 12-item Hip disability and Osteoarthritis Outcome Score; SD: standard deviation; VAS: visual analogue scale
Higher 6-month score indicates greater pain (for hip pain VAS and low back pain VAS), better hip-related outcomes (Oxford Hip Score and HOOS-12 scores), higher quality of life (for EQ-5D-5L utility score) and better health (for EQ VAS)
Positive change scores indicate improvement for the Oxford Hip Score, HOOS-12, EQ-5D-5L and EQ VAS; negative change scores indicate improvement for the hip pain VAS and low back pain VAS
*Effect sizes are presented for the 6-month post-operative scores as an indication of the magnitude of between-group difference; relative improvement is presented for the baseline to 6-month change scores (reported as mean improvement for the revised group, relative to the mean improvement for the non-revised group)