Anyone who is suffering from severe hip or knee osteoarthritis knows how debilitating the condition can be. It causes pain, loss of function and, in some cases, significantly reduced quality of life which can lead to depression.

Research study on the benefits of hip replacement

A study published in The Bone and Joint Journal from the Royal Infirmary of Edinburgh set out to examine just how many patients awaiting total hip replacement surgery (total hip arthroplasty) or total knee replacement surgery (total knee arthroplasty) were experiencing a state categorised as “Worse Than Death” (WTD) according to the EuroQol five-dimension (EQ-5D) measure. It also looked at co-morbidities associated with this state and considered how patients scored as WTD fared one year after surgery.

What is EQ-5D?

Developed in 1987 by the European Quality of Life Group, the EQ-5D is a globally-used health measure that can be applied to a wide range of health conditions. It measures a patient’s health across five separate areas – mobility, self-care, usual activities, pain/discomfort and anxiety/depression – and uses this to quantify their health-related quality of life. The coding system is used to evaluate the clinical and economic benefits of certain healthcare interventions. This is needed because pressure on the healthcare system means that it’s increasingly important for interventions to be economically viable.

The “Worse Than Death” state

EQ-5D calculates the number of quality-adjusted life years that a healthcare intervention delivers. Each of the five areas outlined above are scored according to three different levels of severity – mild, moderate and severe. These scores are then converted into a single score which ranges from -0.594 to 1. A score of 1 represents full health and 0 represents death. Negative scores relate to a state deemed “worse than death” (WTD). Of the 243 possible health states, 84 are categorised as WTD.

Why was this study carried out?

Total hip replacement and total knee replacement are used for the most severe states of degenerative joint diseases like osteoarthritis. Both procedures are generally considered clinically effective and cost-effective. The cost per number of quality-adjusted life years is £1372 for total hip replacements and £2101 for total knee replacements.

Yet, despite this, there is pressure to reduce and even ration their use. As a consequence, patients may be left in deteriorating health and suffering increasing levels of pain. The study by the Royal Infirmary of Edinburgh, therefore, set out to determine how many patients in the later stage of degenerative joint disease were in a “worse than death” health state as they awaited total hip or knee replacement surgery.

Which patients were studied?

The study looked at a total of 2073 patients awaiting total hip replacement. The average age was 67 years and 60% (1253) of patients were female. It also considered 2168 patients awaiting total knee replacement surgery. The average age in this case was 69 years and 57% (1244) were female.

Research findings

Before surgery, 19% of patients awaiting total hip replacement surgery and 21% of patients awaiting total knee replacement surgery were deemed to be in a state “worse than death”. In patients awaiting hip surgery, there was a tendency for comorbidities like deprivation and Chronic Obstructive Pulmonary Disease to be present. Patients awaiting knee replacements were found commonly to have peripheral arterial disease and inflammatory arthropathy.

After surgery, EQ-5D scores improved significantly – WTD scores were just 2% following total hip replacement and 3% following total knee replacement. However, those patients who had deteriorated to a WTD state prior to surgery were significantly less likely to achieve good Oxford Hip Scores or Oxford Knee Scores (which measure joint-specific function) one year after surgery. Their satisfaction rates were also lower.


The study shows that total hip replacement and total knee replacement reliably reverse WTD status for most patients, as well as reducing pain and improving function. Studies of impact one-year on suggest that there are no benefits to delaying surgery, in fact allowing a patient to deteriorate may actually have a detrimental impact on surgical outcomes.

If you are suffering from osteoarthritis, talk to an experienced orthopaedic surgeon, who can help you make the decision about the best time to undergo joint replacement surgery.

Joseph Queally is an experienced hip surgeon who can diagnose and recommend the right time for hip replacement surgery.

Whereas in the past, patients having a hip replacement might need to spend three weeks in hospital, now some patients can go home the same day or the following day.

This means you can get back to full function more quickly and limit the risks of an extended hospital stay.


[1] Worse than death and waiting for a joint arthroplasty C.E.H. Scott, D.J. MacDonald, C.R. Howie