title: Test-retest agreement and reliability of quantitative sensory testing 1 year after breast cancer surgery.
abstract: OBJECTIVE
  Quantitative sensory testing (QST) is used to assess sensory dysfunction and nerve damage by examining psychophysical responses to controlled, graded stimuli such as mechanical and thermal detection and pain thresholds. In the breast cancer population, 4 studies have used QST to examine persistent pain after breast cancer treatment, suggesting neuropathic pain being a prominent pain mechanism. However, the agreement and reliability of QST has not been described in the postsurgical breast cancer population, hindering exact interpretation of QST studies in this population. The aim of the present study was to assess test-retest properties of QST after breast cancer surgery.
  
  
  METHODS
  A total of 32 patients recruited from a larger ongoing prospective trial were examined with QST 12 months after breast cancer surgery and reexamined a week later. A standardized QST protocol was used, including sensory mapping for mechanical, warmth and cold areas of sensory dysfunction, mechanical thresholds using monofilaments and pin-prick, thermal thresholds including warmth and cold detection thresholds and heat pain threshold, with bilateral examination. Agreement and reliability were assessed by Bland-Altman plots, descriptive statistics, coefficients of variance, and intraclass correlation.
  
  
  RESULTS
  Bland-Altman plots showed high variation on the surgical side. Intraclass coefficients ranged from 0.356 to 0.847 (moderate to substantial reliability). Between-patient variation was generally higher (0.9 to 14.5 SD) than within-patient variation (0.23 to 3.55 SD). There were no significant differences between pain and pain-free patients. The individual test-retest variability was higher on the operated side compared with the nonoperated side.
  
  
  CONCLUSIONS
  The QST protocol reliability allows for group-to-group comparison of sensory function, but less so for individual follow-up after breast cancer surgery.
authors.affiliation: *Section for Surgical Pathophysiology †Department of breast surgery, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Kenneth Geving
authors.initials: KG
authors.lastname: Andersen
authors.forename: Henrik
authors.initials: H
authors.lastname: Kehlet
authors.forename: Eske Kvanner
authors.initials: EK
authors.lastname: Aasvang
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008408:Mastectomy / Q000009:adverse effects*; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis* / Q000503:physiopathology*; D010812:Physical Stimulation; D015203:Reproducibility of Results; D012677:Sensation / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D013223:Statistics as Topic