title: Reliability of direct and indirect clinical attachment level measurements.
abstract: OBJECTIVE
  To investigate the influence of subject-, tooth- and site-level characteristics on intra-examiner reproducibility of direct and indirect clinical attachment level (CALDIR and CALIND ) recordings, and to quantify the impact of less-than-perfect reliability on our ability to assess periodontitis progression.
  
  
  METHODS
  Within a 1-week interval, a single examiner performed duplicate probing depth (PD), CALDIR and gingival recession (GR) recordings in six sites of all teeth present in 148 periodontitis patients. CALIND was calculated on the basis of the PD and GR.
  
  
  RESULTS
  Agreement was observed in 65%, 62%, 69% and 84% of the duplicate CALDIR , CALIND , PD and GR recordings, respectively, and >95% of the differences were within ±1 mm. This study identified multiple predictors for CAL measurement errors ≥1 mm, including tooth and site location, presence of supra- and subgingival calculus, bleeding on probing and suppuration. Measurement errors were more likely in patients diagnosed with "extensive" rather than "less extensive" periodontitis. In over half of the patients, measurement error frequencies were too high to allow for detection of possible CAL changes ≥2 mm with a false-positive rate ≤5%. Detection of CAL changes with low false-positives was more likely using recordings obtained by the direct method.
  
  
  CONCLUSIONS
  From a measurement error point of view, CALDIR recordings are preferable over CALIND .
authors.affiliation: Department of Dentistry, Section of Periodontology, Health, Aarhus University, 8000 Aarhus C, Denmark. p.corraini@odontologi.au.dk
authors.forename: Priscila
authors.initials: P
authors.lastname: Corraini
authors.forename: Vibeke
authors.initials: V
authors.lastname: Baelum
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Lopez
mesh_terms: D000328:Adult; D003724:Dental Arch / Q000473:pathology; D003728:Dental Calculus / Q000473:pathology; D003773:Dental Plaque / Q000473:pathology; D018450:Disease Progression; D005189:False Positive Reactions; D005260:Female; D005884:Gingival Hemorrhage / Q000473:pathology; D005889:Gingival Recession / Q000473:pathology; D005891:Gingivitis / Q000473:pathology; D006801:Humans; D008297:Male; D015588:Observer Variation; D017622:Periodontal Attachment Loss / Q000473:pathology*; D010514:Periodontal Pocket / Q000473:pathology; D010517:Periodontics / Q000295:instrumentation; D010518:Periodontitis / Q000473:pathology; D015203:Reproducibility of Results; D012907:Smoking; D014070:Tooth / Q000473:pathology
keywords: clinical attachment level; indirect measurement; measurement error; periodontitis; probing depth; recession