The number of knee replacement operations carried out has dropped in regions of England with restrictions on surgery for overweight patients, with people in more deprived areas worst affected, researchers have found.
Patients needing surgery but unable to lose weight are being denied surgery that could ease pain and increase mobility, the team from the University of Bristol said.
Health campaigners expressed alarm, claiming the policy was a “blunt tool” being used to replace conversations between doctors and patients and risked exacerbating health inequalities.
Over the past decade, rules have been brought in by some clinical commissioning groups (CCGs) across England to restrict access to hip and knee replacement surgery for patients who are overweight or obese.
There are significant regional differences, with stricter CCGs telling patients they must attain a certain body mass index (BMI) before surgery can take place or mandating a waiting time. Others do not impose restrictions.
The study, funded by the National Institute for Health and Care Research, suggests that regions that introduced policy changes for access to knee replacement surgery based on a patient’s weight or BMI have seen a decline in surgery.
Researchers analysed the rates of knee replacement surgery of 481,555 patients between January 2009 and December 2019 – before the Covid pandemic hit – using data from the National Joint Registry and compared regions with and without a BMI/weight policy.
The study found that more than two-thirds of CCGs in England had a BMI policy for knee replacement surgery, with 61% of these policies denying access to surgery or mandating extra waiting time. It said surgery was down by 14% overall on what would have been expected had no policies restricting access been introduced.
By looking at patients’ postcodes, the researchers could see that people from more deprived areas appeared more likely to be denied surgery.
The lead author, Joanna McLaughlin, of the Bristol Medical School, said: “Our study raises the concern that these policies are linked with worsening health inequalities with fewer NHS operations for the least affluent groups.
“We could see the rates of surgery dropped for those worst off but increased for those who are best off, which correlates with more private surgery going on in those areas.”
She said it was not helpful to pick out the figures for particular CCGs as local factors could skew the data. But it is clear that different approaches are being taken in neighbouring areas. South Lincolnshire, for example, has more liberal rules while requirements are stricter next door in north Norfolk.
The report says that with one in 10 people likely to need a knee replacement, many thousands of patients are being affected.
Jacob Lant, head of policy, partnership and research at Healthwatch England, said: “Blunt use of BMI in this way is not helpful and it should be treated as a guideline rather than a hard and fast rule. What really needs to happen is a conversation between doctors and patients about the patient’s specific circumstances.
“Weight loss can be incredibly challenging, particularly for those whose mobility is already affected by problems with their joints.”
The study – entitled What effect have NHS commissioners’ policies for body mass index had on access to knee replacement surgery in England? – has been published in the journal PLOS ONE.
Prof John Skinner, a council member of the Royal College of Surgeons of England and consultant orthopaedic surgeon, said: “Hip and knee replacement surgery for osteoarthritis leads to a dramatic improvement in quality of life. Surgical decision making should be made on an individual basis for each patient.
“Restrictive referral policies, such as BMI thresholds, penalise patients who become more immobile and then they are likely to suffer further health problems. Nice guidelines clearly state that restricting access to joint replacement based on BMI, smoking or other characteristics should not happen.
“This research paper confirms that restricting access to surgery on the grounds of BMI has a significant effect on access to care and worsens inequalities.
“It is reasonable to encourage weight loss where appropriate and most hospitals operate a system of encouraging weight loss in patients with a BMI of 40. However, this research shows that if commissioners restrict access for patients with a high BMI, then variability and much greater inequality occurs for patients.”
A Department of Health and Social Care spokesperson said: “We are helping local authorities improve public health by increasing their grant to just over £3.4bn this year, and we are investing a further £39bn in overall health and care over the next three years.”
An NHS spokesperson said: “Patients and clinicians work together prior to surgery to optimise the chance of getting the best outcome and in some cases losing weight prior to surgery reduces risk to patients and improves the chances of success for the procedure.”