24 July 2023
Red flags for imaging in musculoskeletal conditions
New research suggests many referrals ‘are at odds with recommended practice’.
One in three patients with musculoskeletal complaints are referred for imaging by GPs, new Australian research reveals.
In most instances, diagnostic imaging of non-specific musculoskeletal complaints offers little value due to the commonality of age-related degenerative changes in asymptomatic individuals.
Consequently, many clinical care standards and practice guidelines encourage imaging only when certain conditions are met, such as when serious pathology is suspected.
But the findings of a new Australian study, published in Arthritis Care & Research, suggest 37% of patients with an atraumatic musculoskeletal complaint had imaging requested by their GP.
“The estimated proportion of people attending primary care with low back pain who have serious pathology ranges from 1 to 6%,” author Professor Danielle Mazza, chair of general practice at Monash University, and colleagues wrote.
“Based [on these figures], it is likely our findings are at odds with recommended practice.”
Professor Mazza and colleagues used data from 130,000 patients treated by 4500 GPs across about 300 practices in Victoria to examine GP-initiated imaging requests for patients with low back, neck, shoulder and/or knee complaints.
One in three patients had at least one imaging request during the five-year study period. More than 75,000 imaging requests were made in total. Half of the patients with a shoulder complaint received an imaging request, along with 43% of those with a knee complaint, 34% with a neck complaint and 26% with a low back complaint.
Patients living in socioeconomically disadvantaged areas were 18% more likely to receive a request for an x-ray, 17% more likely to receive a CT request and 23% more likely to receive an ultrasound request. However, these patients were 46% less likely to receive an MRI request.
Changes in specific imaging modalities requested for specific complaints was noted over the course of the study.
There was a 1.3% annual increase in the proportion of MRI requests for low back pain and a corresponding 1.3% annual decrease in CT requests.
Similarly, there was a 3% annual increase in neck MRI requests and a 3% reduction in neck x-ray requests. There were no changes over time in imaging modalities requested for shoulder or knee complaints.
Professor Chris Maher, physiotherapist and internationally renowned back pain researcher from The University of Sydney, offered an explanation for the stagnant statistics.
“It is interesting that the RACGP Choosing Wisely recommendations do not include musculoskeletal diagnostic imaging, which may suggest that the general practice profession does not see this as an important issue to focus attention on,” Professor Maher told The Medical Republic.
Professor Mazza offered a different explanation, saying GPs were getting the message that x-rays for back- and neck-related issues were not useful.
“GPs are often stuck between a rock and a hard place [when a patient presents with a musculoskeletal complaint].” she said.
“On the one hand, some patients push for imaging because they think that will lead to faster recovery, or they want reassurance with a diagnosis [because they] find it hard to accept they’re in pain.
“On the other hand, the modalities we know that can help, such as physiotherapy, are not easy to come by in the public system and expensive in the private system. It’s one of the most difficult areas to manage.”
The median timing of most imaging requests was on the same day as the GP made their diagnosis, with only one in three requests made in the two weeks before a diagnosis was delivered.
This was a particularly interesting finding, according to Dr Adrian Traeger, a Sydney-based physiotherapist and lead of an NHMRC-funded trial on behavioural nudging interventions to reduce unnecessary imaging for low back pain in emergency departments.
“It’s almost like there’s confirmation happening with the imaging test, where many [people] might argue that a clinical diagnosis would be sufficient for a lot of these conditions. That indicates a lot of these tests could be unnecessary,” Dr Traeger told TMR.
However, Dr Traeger noted database studies such as these often don’t have the necessary clinical information to determine whether individual tests were appropriate or not.