Published in:
Open Access 01-08-2012 | Original Article
Imaging-guided lumbar facet injections: is there a difference in outcomes between low back pain patients who remember to return a postal questionnaire and those who do not?
Published in: Insights into Imaging | Issue 4/2012
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Objectives
To determine whether data obtained from patients returning postal questionnaires accurately reflect how patients receiving imaging-guided lumbar facet injections respond.
Methods
Seventy-eight patients receiving lumbar facet joint injections who returned an outcomes questionnaire (responders) were age and gender matched with 78 patients who did not return the postal questionnaire (non-responders) after facet joint injections. Baseline numerical rating scale (NRS) pain data were collected. NRS and Patients’ Global Impression of Change (PGIC) data were collected 1 month after injection by postal questionnaire or telephone interview.
Differences in NRS scores were calculated using the unpaired t-test. One level injection patients were compared to patients having ≥2 levels injected using the paired and unpaired t-test. The proportion of patients reporting significant improvement in each group was calculated.
Results
NRS scores were significantly improved compared to baseline (p = 0.0001). Thirty-eight percent of responders were significantly improved compared to 50 % of non-responders. Patients having ≥2 levels injected reported significantly higher baseline NRS scores, but by 1 month there was no difference in NRS scores between groups.
Conclusions
Patients returning postal questionnaires report a less favourable outcome. Telephone interview patients having injections at more than one level have better outcomes.
Main messages
• Patients returning postal questionnaires report worse outcomes after facet injection.
• Method of data collection should be considered when reporting treatment outcomes.
• Patients receiving facet injections at more than one level report greater levels of pain reduction.