Table 2.

Correlations of questionnaire items with PD assessments

Patient questionnaire item	Number of missing values	Spearman’s corr. with dentist’s assessment	Spearman’s corr. with assessment of radiographs
Number of teeth	22	− 0.49	− 0.40
Receding jaw bone	25	0.41	0.43
Receding gums	14	0.37	0.33
Presence of gum pockets	16	0.36	0.31
Loose teeth	9	0.36	0.36
Tooth extractions because of inflammation and deep gum pockets	13	0.27	0.22
More dentist visits because of inflammation than because of caries	12	0.26	0.17
More tooth/gum problems than other persons of the same age and sex	22	0.19	0.10
Inflammation of the gums/bleeding	8	0.12	0.08
Magnitude of suffering from dental problems	6	0.11	0.07
Cold- or heat sensitivity	6	0.09	0.08
Use of antibiotics	6	0.08	0.13

Correlations of questionnaire items with dentists’ assessment of PD and with an independent assessment of PD via radiographs. Items in italics were found to be the most suitable to detect PD via factor analysis and are included in the final score