title: Clinical miscount of involved joints denotes the need for ultrasound complementation in usual practice for patients with rheumatoid arthritis.
abstract: OBJECTIVE
  Ultrasound (US) examination can visualise and clarify involved joints anatomically in patients with rheumatoid arthritis (RA), and it enables physicians to verify the accuracy of clinical assessments of involved joints. Here, we studied the practical 'miscount'- calculated by subtracting US-determined involved joint count from clinically determined involved joint count - and analysed possible contributing factors for increased miscount.
  
  
  METHODS
  The study population consisted of 137 patients with RA. Physical joint examination was performed by 3 assessors with different levels of experience in rheumatology, followed by US joint examination. Clinical and US examinations were performed on 28 joints (proximal interphalangeal, metacarpophalangeal, wrist, elbow, shoulder, and knee on both sides). Miscount was calculated for all patients, and multivariate analysis was conducted on possible contributing factors for miscount, including age, sex, body mass index, disease duration, Steinbrocker stage, erythrocyte sedimentation rate (ESR), C-reactive protein level, patient global assessment (GA), evaluator GA, matrix metalloproteinase-3 level, and power Doppler (PD) score.
  
  
  RESULTS
  A high variability in concordance rate among the joint sites was observed among the 3 assessors. The average miscount was 1.07 (SD, 5.19; range, 18 to -11). ESR and patient GA were determined as significant contributing factors for false-positive miscount, whereas PD score and age were significant factors for false-negative miscount.
  
  
  CONCLUSIONS
  In addition to the condition of the involved joint distribution and the assessor's clinical examination skills, the patients' background can also lead to increased miscount. Assessors should be blinded to patients' background information, and US complementation should be included in usual clinical joint examinations.
authors.affiliation: Department of Internal Medicine and Rheumatology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Murayama
authors.forename: Michihiro
authors.initials: M
authors.lastname: Ogasawara
authors.forename: Takuya
authors.initials: T
authors.lastname: Nemoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamada
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ando
authors.forename: Kentaro
authors.initials: K
authors.lastname: Minowa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kon
authors.forename: Kurisu
authors.initials: K
authors.lastname: Tada
authors.forename: Masakazu
authors.initials: M
authors.lastname: Matsushita
authors.forename: Ken
authors.initials: K
authors.lastname: Yamaji
authors.forename: Naoto
authors.initials: N
authors.lastname: Tamura
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Takasaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000473:pathology; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010808:Physical Examination / Q000592:standards*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography / Q000592:standards*; D055815:Young Adult