We thank you for your comments. In our randomised trial we assessed the effect of early access to MRI compared with referral to an orthopaedic specialist on GPs' diagnoses and treatment plans for patients with knee problems. Therefore, the paper presents what were the treatment plans that GPs used and not that of the orthopaedic specialist. Similarly, the diagnoses recorded were that of the GPs and we must therefore assume that these diagnoses were as definitive as what the GPs thought at the time. It was not the objective of the paper to examine the effect of MRI or not on orthopaedic management, but as part of the broader project we collected data on the proportion of arthroscopies performed in each trial arm. There is evidence that a significantly higher proportion of patients in the MRI group had an arthroscopy. Furthermore, we found that the proportion of patients who had a diagnostic arthroscopy was significantly higher in the orthopaedic referral group. GP access to MRI, therefore, did significantly affect orthopaedic specialist treatment plans in terms of the use of arthroscopies, which is presented in more detail in a further paper.
The evidence from our trial does show that GPs were more confident in their diagnoses and treatment plans when MRI was accessible to them. The effect of MRI findings on GPs' decisions, however, was compared with the effect of the orthopaedic specialist letter after initial consultation with the patient. Therefore, GPs were not recording their diagnoses or management plans based on surgical findings from arthroscopy. In the paper, we provide reasons why GPs might be more confident in the report of a radiologist:
differences in the content of an MRI report compared with an orthopaedic referral letter;
early access to MRI provides greater continuity in care as a result of the patient receiving an intervention earlier in the care pathway; and
evidence for other body areas, such as the lumbar spine, where GPs request radiographs to reassure themselves and their patients.
Ultimately, despite the significant increase in confidence, GPs did not diagnose or treat patients differently on the basis of an MRI report compared with an orthopaedic specialist letter. Interestingly, as described above, it appears that the availability of the MRI examinations had more of an effect on orthopaedic specialists' practice.
- © British Journal of General Practice, 2008.
