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Table 2 Baseline periodontal characteristics defined by the World Health Organization Community Periodontal Index in unmatched and matched cohorts

From: Periodontitis and early mortality among adults treated with hemodialysis: a multinational propensity-matched cohort study

Variables Full cohort After propensity score matching
None or mild periodontitis
(n = 1983)
Moderate to severe periodontitis
(n = 1355)
Standardized differencea None or mild periodontitis
(n = 1355)
Moderate to severe periodontitis
(n = 1355)
Standardized differencea
Periodontal probing depth, mm 0.68 (0.38) 1.53 (0.70) −1.36 0.70 (0.38) 1.53 (0.70) −1.33
Clinical attachment loss, mm 2.03 (1.56) 3.15 (1.55) −0.59 2.12 (1.55) 3.15 (1.55) −0.54
Distance between cementum-enamel junction and free gingival margin, mm 1.35 (1.49) 1.62 (1.49) −0.15 1.42 (1.50) 1.62 (1.49) −0.11
Bleeding on probing, % sites per person 13.1 (22.3) 20.7 (27.4) −0.26 12.7 (21.7) 20.7 (27.4) −0.28
  1. Data are mean (SD). The periodontal pocket depth measurements were made at three sites on the vestibular and lingual aspects of each tooth and the periodontal probing depth (PPD) score was calculated as a mean value divided by the number of sites examined. The Bleeding on Probing (BOP) index evaluated the buccal, lingual, mesial and distal sulci of all teeth based on the tendency to bleed after a standard stimulus. The four surfaces of each tooth were tested to provide a maximum total of 128 sites and the index is the percentage of sites positive for bleeding on probing for each participant. The Clinical Attachment loss score was calculated as the sum of the mean PPD (sum of all values divided by the number of sites examined (6 per tooth)) and the mean (free gingival margin [GM]-cementum-enamel junction [CEJ]) (sum of all values divided by the number of sites examined (2 per tooth)). aStandardized differences of 0.2, 0.5 and 0.8 can be considered to represent small, medium and large differences, respectively [29]. These differences do not denote statistical significance
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