Hip replacements don’t lie
Do public or private providers get better health outcomes?
Adjusted for case mix differences between hospitals
© 2020 BMJ Publishing Group Ltd.
Change in EQ-5D score
NHS Digital 2019 - patient reported outcome measure (PROM) questionnaires
Each circle in this diagram represents a provider of NHS hip replacements. Their vertical position
shows how much patients’ quality of life improved after their operations, on average. This is
measured with the EQ-5D score, which ranges from -0.59 to 1 (perfect health). On average,
across all providers, the scores increased by 0.46, but this varied widely: from 0.33 to 0.57.
Around 30% of NHS patients included in this dataset have their hip operations carried out by
non-NHS providers. The average health gain for these patients is 0.47, which compares with 0.46
for patients treated by NHS hospitals – a small but statistically significant difference. However,
some of the best performing hospitals are public and some of the worst private (and vice versa).
Using 95% confidence limits, NHS Digital estimated that only 26 hospitals report health
outcomes for their hip replacement patients which are statistically better (13) or worse (13) than
the national average health gain. By fading out the 186 hospitals that are statistically no different
from average, we can see that more NHS hospitals than private ones are the best performers.