Smallest worthwhile effect of surgery for sciatica

 
Surgeons performing surgery

Smallest worthwhile effect of surgery for sciatica

 
Surgeons performing surgery

A multidisciplinary team from the University of Sydney conducted a benefit–harm trade-off study to determine how much additional benefit people with sciatica would need to receive from discectomy to consider it worthwhile compared to non-surgical management. The corresponding author, Dr Giovanni Ferreira, agreed to answer some questions about the trial.

What inspired you to use the benefit–harm trade-off method to estimate the smallest worthwhile effect (SWE) for discectomy versus non-surgical treatments for sciatica? How does this method provide a more patient-centred perspective than traditional approaches?

The benefit–harm trade-off method allows patients to weigh the perceived benefits of surgery against its potential risks and
inconveniences and compare it to non-surgical treatments.

Therefore, this method directly incorporates patient preferences into the decision-making process, unlike traditional approaches that rely solely on statistical significance or clinical expertise, such as the minimum clinically important difference.

What was the SWE estimated by the study?

The study estimated the SWE to be an additional 15 per cent reduction in leg pain with discectomy, beyond any reduction in leg pain achieved by non-surgical treatments.

The study found that dissatisfaction with non-surgical treatments and low pain self-efficacy were associated with a lower SWE for surgery. Is that what you expected or is that a counterintuitive finding? Why do you think you got that result?

We expected these findings. It is reasonable to assume that people who had not had a satisfactory result with non-surgical treatments would have considered surgery worthwhile even if it provided fewer benefits.

Similarly, we thought that people with lower self-efficacy (ie, less confidence in themselves to function despite pain) would be more likely to prefer surgery to non-surgical treatments.

Your results suggest that chronic sciatica patients are more likely to consider surgery. Why do you think you got that result?

Patients with chronic sciatica might have tried several non-surgical treatments before, probably with little to no response, making them more likely to lean towards surgery if offered.

Those with chronic pain might be more interested in finding a ‘definitive solution’ to their problem, making surgery a more attractive option for them.

One of the strengths of this study is that it provides concrete data on the pain reduction patients expect from surgery. How can this information help physiotherapists engage in shared decision-making with patients with sciatica?

Physiotherapists can use these findings to facilitate discussions about treatment expectations, helping patients weigh the benefits and risks of surgery versus continued non-surgical care.

Understanding that the average person expects discectomy to reduce their leg pain by an additional 15 per cent, on top of the benefit they would get from non-surgical treatments, might help patients put their expectations into context.

What do you think the findings of this study mean for future research on sciatica treatments, particularly regarding the long-term effectiveness of discectomy and non-surgical interventions?

Future research should explore the long-term SWE of discectomy, as its benefits diminish over time.

Studies should compare long-term outcomes of surgical and non-surgical treatments, particularly in chronic versus acute sciatica.

Expanding SWE estimates to include broader patient populations and outcomes beyond pain reduction, such as function, quality of life and neurological outcomes (eg, strength deficits), is essential.

Additionally, integrating SWE data into decision aids could enhance shared decision-making.

This body of work can be used to refine treatment guidelines and ensure that patients receive interventions that align with their long-term expectations.

>>Dr Giovanni Ferreira is a senior research fellow and National Health and Medical Research Council fellow at the University of Sydney. His research investigates the effectiveness of pharmacological and nonpharmacological interventions and new models of care to improve outcomes for people with musculoskeletal pain. 

 

Course of interest:

 

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