Table 2. Linear regression analysis of factors affecting PISA.
| Factors | Simple linear analysis | Multivariate linear analysis | ||||
|---|---|---|---|---|---|---|
| Coefficient (95% CI) | P value | Coefficient (95% CI) | P value | |||
| Gender (female) | −0.18 (−0.69, 0.32) | 0.47 | - | - | ||
| Age (yr) | 0.01 (−0.01, 0.03) | 0.42 | - | - | ||
| BMI (kg/m2) | 0.06 (0.00, 0.13) | 0.05 | 0.02 (−0.03, 0.23) | 0.55 | ||
| Smoking | ||||||
| No smoker | 1.00 | N/A | - | - | ||
| Ever smoker | 0.07 (−0.46, 0.59) | 0.79 | - | - | ||
| Current smoker | 0.47 (−0.04, 0.98) | 0.07 | - | - | ||
| Current smoking quantity | 0.04 (0.01, 0.08) | 0.03 | 0.03 (0.00, 0.06) | 0.03 | ||
| Periodontal disease | ||||||
| Mild | 1.00 | N/A | 1.00 | N/A | ||
| Moderate | 0.78 (0.39, 1.17) | <0.01 | 0.49 (0.15, 0.83) | <0.01 | ||
| Severe | 1.20 (0.70, 1.70) | <0.01 | 0.52 (0.01, 1.03) | 0.05 | ||
| Brushing (times per day) | −0.39 (−0.70, 0.08) | 0.01 | −0.11 (−0.35, 0.14) | 0.39 | ||
| BOP (%) | 0.13 (0.11, 0.15) | <0.01 | - | - | ||
| PI (%) | 0.04 (0.03, 0.06) | <0.01 | 0.03 (0.01, 0.04) | <0.01 | ||
| P. gingivalis DNA detection | 0.86 (0.50, 1.21) | <0.01 | 0.31 (−0.10, 0.71) | 0.13 | ||
| Serum P. gingivalis antibody level | 0.27 (0.09, 0.46) | <0.01 | 0.05 (−0.12, 0.23) | 0.55 | ||
PISA: periodontal inflamed surface area, CI: confidence interval, BMI: body mass index, BOP: bleeding on probing, PI: plaque index, N/A: not applicable, P. gingivalis: Porphyromonas gingivalis.