TABLE 2.
Association of social isolation with the number of remaining teeth and rate of tooth loss over the 7-year follow-up (n = 4268)
| Model 1 | Model 2 | Model 3 | Model 4 | Model 5 | Model 6 | |
|---|---|---|---|---|---|---|
| Parameter | β-coefficients (95% Cl) | |||||
| Social isolation (ref. No) | ||||||
| Yes | −.05 (−0.11, −0.00)* | −.06 (−0.11, −0.00)* | −.06 (−0.11, −0.01)* | −.06 (−0.11, 0.00)* | −.06 (−0.12, −0.01)* | −.06 (−0.13, −0.00)* |
| Time (in years) | −.06 (−0.06, −0.05)*** | −.06 (−0.06, −0.05)*** | −.05 (−0.06, −0.05)*** | −.05 (−0.06, −0.04)*** | −.05 (−0.05, −0.04)*** | |
| Smoking (ref. Never) | ||||||
| Former | −.01 (−0.06, 0.05) | −.03 (−0.12, 0.05) | −.03 (−0.12, 0.05) | −.03 (−0.11, 0.05) | ||
| Current | −.01 (−0.07, 0.05) | −.03 (−0.13, 0.07) | −.03 (−0.13, 0.07) | −.03 (−0.13, 0.07) | ||
| Drinking (ref. Never) | ||||||
| Former | −.02 (−0.07, 0.03) | −.00 (−0.09, 0.08) | −.00 (−0.09, 0.08) | −.01 (−0.09, 0.07) | ||
| Current | −.01 (−0.06, 0.04) | −.03 (−0.05, 0.11) | −.03 (−0.05, 0.11) | −.03 (−0.05, 0.11) | ||
| Toothbrushing frequency (ref. Never) | ||||||
| Less than once a day | .12 (0.06, 0.18)*** | .08 (0.02, 0.14)*** | .08 (0.02, 0.14)*** | .08 (0.02, 0.14)*** | ||
| Once a day | .16 (0.10,0.21)*** | .11 (0.02, 0.21)*** | .11 (0.02, 0.21)*** | .11 (0.02, 0.20)*** | ||
| More than once a day | .17 (0.10, 0.24)*** | .12 (0.01, 0.24)*** | .12 (0.01, 0.24)*** | .12 (0.01, 0.23)*** | ||
| Impaired activities of daily living (ref. No) | ||||||
| Yes | −.18 (−0.26, −0.09)** | −.18 (−0.26, −0.09)** | −.18 (−0.26, −0.09)** | |||
| Cognitive impairment (ref. No) | ||||||
| Yes | −.09 (−0.16, −0.02)*** | −.09 (−0.16, −0.02)*** | −.09 (−0.16, −0.02)*** | |||
| With one or more chronic conditions (ref. Without) | ||||||
| Yes | .01 (−0.06, 0.08) | .01 (−0.06, 0.08) | .01 (−0.06, 0.08) | |||
| Loneliness (ref. No) | ||||||
| Yes | .03 (−0.02, 0.09) | .03 (−0.02, 0.09) | ||||
| Social isolation ×Time | −.02 (−0.02, −0.01)** | |||||
| Covariates | ||||||
| Age | −.03 (−0.03, −0.03)*** | −.03 (−0.04, −0.03)*** | −.03 (−0.03, −0.03)*** | −.03 (−0.03, −0.02)*** | −.03 (−0.03, −0.02)*** | −.03 (−0.03, −0.02)*** |
| Women (ref. Men) | −.07 (−0.12, −0.03)** | −.07 (−0.12, −0.02)** | −.09 (−0.14, −0.03)** | −.06 (−0.12, −0.00)* | −.06 (−0.12, −0.00)* | −.06 (−0.12, −0.01)* |
| Current residence (ref. Urban areas) | ||||||
| Rural areas | −.02 (−0.09, 0.05) | −.01 (−0.08, 0.06) | .01 (−0.06, 0.08) | .01 (−0.06, 0.09) | .01 (−0.06, 0.09) | .01 (−0.06, 0.09) |
| Education level (ref. 0 year of schooling) | ||||||
| 1–6 years | .10 (0.04,0.15)*** | .10 (0.05, 0.15)*** | .08 (0.02, 0.13)** | .07 (0.02, 0.13)** | .08 (0.02, 0.13)** | .08 (0.02, .13)** |
| ≥6 years | .21 (0.14, 0.27)*** | .21 (0.14, 0.27)*** | .18 (0.12, 0.24)*** | .18 (0.11, 0.24)*** | .18 (0.11, 0.25)*** | .18 (0.11, 0.25)*** |
| Financial sufficiency (ref. Not enough) | ||||||
| Enough | −.03 (−0.09, 0.02) | −.03 (−0.08, 0.03) | −.02 (−0.08, 0.03) | −.01 (−0.07, 0.05) | −.02 (−0.07, 0.04) | −.02 (−0.07, 0.04) |
| Log-pseudolikelihood | −33623 | −33469 | −32823 | −31782 | −30918 | −30123 |
Note: CI, confidence interval; ref, reference group; β-coefficients are standardized regression coefficient derived from mixed-effects Poisson models.
Model 1 included only the effect of social isolation.
Model 2 introduce a random effect for time (in years) to estimate individual variability in slope estimates.
Models 3–5 added the effects of lifestyle and oral hygiene behaviour, physical and cognitive health, and loneliness.
Model 6 added a time by social isolation interaction to determine whether the rate of tooth loss varied by social isolation.
All models include sociodemographic characteristics as covariates (age, sex, area of current residence, education and financial sufficiency)
p < .05
p < .01
p < .001.