title: Lumbar nerve root injections: a prospective cohort outcomes study comparing age- and gender-matched patients who returned an outcomes-based postal questionnaire with patients who did not return the postal questionnaire.
abstract: OBJECTIVE
  The purpose of this study is to investigate if relying on postal questionnaires returned by patients provides an accurate representation of reported outcomes from patients receiving imaging-guided lumbar nerve root injections (NRIs).
  
  
  METHODS
  Patients who received imaging-guided transforaminal lumbar NRIs were given short questionnaires inquiring about pain level [numerical rating scale (NRS)] and overall improvement [Patient's Global Impression of Change (PGIC)]. Those who did not return the questionnaires (non-responders) were telephoned and asked about pain level and overall change in condition. Age and gender matching of responders and non-responders resulted in 97 patients in each group. The proportion of patients reporting clinically relevant "improvement" or "worsening" in each group was calculated and the Chi-square test was used to detect differences. NRS and PGIC scores for responders and non-responders were compared using Student's t test and the Mann-Whitney U test, respectively.
  
  
  RESULTS
  A higher proportion of non-responders reported clinically relevant improvement (53.6 %) compared to responders (42.6 %) and responders reported significantly higher levels of worsening of condition (p = 0.01). Both responders and non-responders had significant (p ≤ 0.05) improvement on the 20-30-min and 1-month NRS scores compared to their pre-injection baseline scores. Non-responders had significantly higher baseline NRS scores but no significant difference at the 20-30-min and 1-month NRS scores compared to responders.
  
  
  CONCLUSIONS
  Patients returning postal questionnaires reported less favorable outcomes compared to those who did not return their questionnaires.
authors.affiliation: Department of Radiology, Orthopaedic University Hospital of Balgrist, Forchstrasse 340, 8008 Zurich, Switzerland. marco.lechmann@gmx.ch
authors.forename: Marco
authors.initials: M
authors.lastname: Lechmann
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Peterson
authors.forename: Christian W A
authors.initials: CW
authors.lastname: Pfirrmann
authors.forename: Jürg
authors.initials: J
authors.lastname: Hodler
mesh_terms: D017677:Age Distribution; D000779:Anesthetics, Local / Q000008:administration & dosage; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000706:statistics & numerical data*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D010147:Pain Measurement / Q000706:statistics & numerical data*; D010349:Patient Compliance / Q000706:statistics & numerical data; D017060:Patient Satisfaction / Q000706:statistics & numerical data*; D015995:Prevalence; D011446:Prospective Studies; D015641:Radiography, Interventional / Q000379:methods; D012307:Risk Factors; D017678:Sex Distribution; D013126:Spinal Nerve Roots / Q000187:drug effects; D011795:Surveys and Questionnaires / Q000706:statistics & numerical data*; D013557:Switzerland / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local