EVALUATIVE COMPARISON OF PATIENT BASED VERSUS PHYSICIAN BASED OUTCOME IN POSTERIOR LUMBAR FUSION – AN ANALYSIS BASED ON THE ‘SPINE TANGO’ REGISTRY

Abstract

Introduction: Posterior lumbar fusion, in many variations, is one of the frequently performed procedures in spinal surgery. High percentages of good and excellent results are indicated by physicians. On the other hand isolated patient-based outcomes are reported. However, little is known about correlation of these two assessment types. We aimed at their comparison.

Methods: The analysis included 567 patients from the international registry ‘Spine Tango’. 453 patients with degenerative disease and posterior lumbar fusion had preop and postop VAS separately indicating back- and leg-pain, surgery and follow up data. Mean age was 57y; female/male ratio was 52% to 48%. Remaining 114 patients with the same diagnoses and treatment had additional preop and postop Oswestry disability indices (ODI). Mean age was 61y; female/male ratio was 55% to 45%.

Physician administered McNab criteria “excellent, good, fair and poor” were compared to ODI, VAS back- and leg pain and to the patients answer describing the outcome of the operation with the following options: helped a lot, helped, helped only little, didn’t help and made things worse. Then the concept of minimum clinically important difference (MCID) was applied

Results: In the “excellent” group ODI-improvement was detected for all patients, the proposed MCID was reached in 90% for ODI. According to this model 85.2% of patients reached MCID for VAS leg pain and 54.1% for VAS back pain. All patient said that the treatment helped or helped a lot

In the “good” group 86% (MCID: 51.7%) of patients improved regarding ODI, 81% (MCID: 65,7%) regarding back and 93% (MCID: 89.4%) regarding leg pain. 99% of patients said that the treatment helped a lot, helped or helped only little.

65% (MCID: 40%) of patients in the “fair” group had improved ODIs. Even in this group 88% of patients perceived the treatment as helping a lot, helping or helping only little.

Moreover in the “poor” group had 60% (MCID: 40%) of patients improved ODIs, 55% (MCID: 40%) alleviated back and 36% (MCID: 30%) reduced leg pain. But only 30% of patient stated that the treatment helped or helped only little.

Spearman correlation coefficients for ODI, VAS back, VAS leg and patient’s verbal statement on overall outcome were 0.42, 0.18, 0.27 and 0.53.

Discussion: ‘Spine Tango’ registry, to date containing more than 13.000 documented surgeries and three times more outcome datasets, provides excellent opportunities for comparison of outcomes. The analysis of patient and physician-based outcomes showed good correlation with the highest correlation coefficient for patient’s verbal statement. With this study we can state that there is strong evidence that physicians evaluation of outcome is very good corresponding with the patients’ perception of success or failure of the analyzed procedure.