Vw. Spolsky et Ja. Gornbein, COMPARING MEASURES OF RELIABILITY FOR INDEXES OF GINGIVITIS AND PLAQUE, Journal of periodontology, 67(9), 1996, pp. 853-859
THE PURPOSE OF THIS METHODOLOGICAL STUDY was to compare methods used t
o assess reliability for gingival inflammation and plaque. Duplicate e
xaminations were conducted by one examiner on 17 subjects (506 scoring
sites), using the gingival index (GI), bleeding points index (BPI), a
nd plaque index (PI). The percentage of agreement, the weighted and un
weighted kappa coefficients, and Pearson correlation coefficients were
calculated as statistics of reliability for mesial buccal site scores
and whole mouth mean scores when appropriate. For mesial buccal sites
the respective values of the. GI, BPI, and PI for weighted kappas wer
e: 0.47, 0.49, and 0.75; for the correlation coefficients: 0.47, 0.49,
and 0.76; for unweighted kappas, 0.39, 0.39, and 0.39; and for percen
tage of agreement 66.2%, 76.1%, and 51.2%;. For whole mouth means the
correlation coefficients for the GI, BPI, and PI were 0.87, 0.59, and
0.87, respectively. In conclusion, the most useful statistics in asses
sing the intraexaminer reliability of a solo examiner in descending or
der were the weighted kappa coefficient, Pearson correlation coefficie
nt, the unweighted kappa coefficient, and percentage of agreement.