title: Interpreting the results of the Semmes-Weinstein monofilament test: accounting for false-positive answers in the international consensus on the diabetic foot protocol by a new model.
abstract: OBJECTIVE
  The Semmes-Weinstein monofilament is the most widely used test to diagnose the loss of protective sensation. The commonly used protocol of the International Consensus on the Diabetic Foot includes a 'sham' application that allows for false-positive answers. We sought to study the heretofore unexamined significance of false-positive answers.
  
  
  METHODS
  Forty-five patients with diabetes and a history of pedal ulceration (Group I) and 81 patients with diabetes but no history of ulceration (Group II) were studied. The three original sites of the International Consensus on the Diabetic Foot at the hallux, 1st metatarsal and 5th metatarsal areas were used. At each location, the test was performed three times: 2 actual and 1 "sham" applications. Scores were graded from 0 to 3 based upon correct responses. Determination of loss of protective sensation was performed with and without calculating a false-positive answer as a minus 1 score.
  
  
  RESULTS
  False-positive responses were found in a significant percentage of patients with and without history of ulceration. Introducing false-positive results as minus 1 into the test outcome significantly increased the number of patients diagnosed with loss of protective sensation in both groups.
  
  
  CONCLUSIONS
  False-positive answers can significantly affect Semmes-Weinstein monofilament test results and the diagnosis of LOPS. A model that accounts for false-positive answers is offered.
authors.affiliation: Diabetic Foot Clinic, Assaf Harofeh Medical Center Affiliated to Tel Aviv University, Zerifin, Israel.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Slater
authors.forename: Shlomit
authors.initials: S
authors.lastname: Koren
authors.forename: Yoram
authors.initials: Y
authors.lastname: Ramot
authors.forename: Andreas
authors.initials: A
authors.lastname: Buchs
authors.forename: Micha J
authors.initials: MJ
authors.lastname: Rapoport
mesh_terms: D002985:Clinical Protocols / Q000592:standards*; D015897:Comorbidity; D032921:Consensus; D017719:Diabetic Foot / Q000175:diagnosis* / Q000453:epidemiology; D042241:Early Diagnosis; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D038622:Internationality; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D010808:Physical Examination / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055698:Touch Perception
keywords: Semmes-Weinstein monofilament; false-positive; loss of protective sensation