The results o f the logistic regression analyses in the study o f the relationships between clinical dental status and the binary OIDP are summarized in Table 5.32. Because the univariate analysis related to the relationships between sociodemographic factors, and self-perceived general health and the OIDP scores not binary OIDP, therefore, the results o f the logistic regression analysis in relationships between sociodemographic
factors and self-perceived general health and binary OIDP are also presented here.
5.5.4.1. Sociodemographic factors and binary OIDP
In the unadjusted logistic regression model there were no significant associations between binary OIDP and age, sex, occupation and self-assessed social class (Table 5.32). People with low self-assessed social class were more likely to report oral impacts on their daily life when compared to people with high self-assessed social class (OR = 1.24, 95% Cl = 0.99 - 1.57). However, the difference was marginally not significant (p
= 0.07) (Table 5.32).
5.5.4.2. Self-perceived general health and binary OIDP
There was a significant relationship between self-perceived general health and oral impacts (p < 0.001). People who perceived their general health status as “fair or less”
had 2.17 (95% Cl = 1.65 - 2.86) times higher odds o f experiencing an oral impact than people who perceived their general health as “good or better” (p < 0.001) (Table 5.32).
5.5.4.3. Number of teeth and binary OIDP
Both number o f natural teeth and number o f natural plus replaced teeth were significantly related to prevalence o f OIDP before and after adjusting for confounders (p
< 0.001). There was a trend for the odds o f reporting oral impacts to increase as the number o f natural teeth and number o f natural plus replaced teeth decreased. When compared with people who had 26-28 natural teeth, people with 1-20 natural teeth were 2.34 (95% Cl = 1.62 - 3.24) times and those with 21-25 natural teeth were 1.50 (95%
Cl = 1.13 - 1.99) times more likely to report oral impacts after adjusting for age, sex, occupation, self-assessed social class and self-perceived general health (Table 5.32).
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The trend was similar for the respective relationship with the number o f natural plus replaced teeth. People with 1-20 natural plus replaced teeth were 2.89 (95% Cl = 1.70 — 4.90) times, and those with 21-25 natural plus replaced teeth 1.61 (95% Cl = 1.17 - 2.21) times more likely to report oral impacts compared with those with 26-28 natural plus replaced teeth after adjusting for age, sex, occupation, self-assessed social class and self-perceived general health (Table 5.32).
Similar results were obtained from the data analysed separately for people with only natural teeth and people with replaced teeth (Table 8.22-23 in Appendix 8).
5.5.4.4. Number of occluding pairs o f teeth and binary OIDP
The relationship between the number o f occluding pairs o f teeth and oral impacts was very similar to that found for the number o f teeth. Overall, there were significant relationships between the different variables referring to the numbers o f occluding pairs o f teeth (OPs, POPs, AOPs, OPRs. POPRs, and AOPRs) and oral impacts (p < 0.001).
The significant relationships were maintained after adjusting for potential confounders (p < 0.001 for both models) (Table 5.32). However, some o f the differences between some groups o f those ordinal variables were not statistically significant. There was a trend for the odds o f reporting oral impacts to increase as the numbers o f occluding pairs o f teeth decreased (Table 5.32). People with 010 OPs were 2.06 (95% Cl =1.51 -2.82) times were more likely to report oral impacts compared with those with 16-18 OPs after adjusting for potential confounders. People with 1115 OPs were 1.29 (0.97 -1.72) times were more likely to report oral impacts when compared with those with 16-18 OPs after controlling for potential confounders. This result was not statistically significant. People with 0-4 POPs were 2.14 (95% Cl =1.55 - 2.97) times, those with 5-9 POPs were 1.26 (95% Cl = 0.95 - 1.66) times more likely to report oral impacts
when compared with those with 10-12 POPs after adjusting for potential confounders.
The former was statistically significant (p < 0.001) but the latter was not (p = 0.11).
People with 0-3 AOPs had 2.00 (95% Cl =1.42 - 2.81) times; those with 4-5 AOPs had 1.48 (95% Cl =1.07 - 2.04) times higher odds o f experiencing oral impacts when compared with those with 6 AOPs after adjusting for potential confounders (Table 5.32).
A similar pattern existed in relationships between the numbers o f occluding pairs o f natural plus replaced teeth and binary OIDP (Table 8.24 in Appendix 8).
Similar results from the data analysed separately for people with only natural teeth and people with replaced teeth (Table 8.22-23 in Appendix 8).
5.5.4.5. Number of unfilled spaces and binary OIDP
Significant relationships existed between the number o f unfilled spaces and binary OIDP in both unadjusted and adjusted models (p < 0.001, Table 5.32). People with more unfilled spaces, unfilled posterior spaces and unfilled anterior spaces were more likely to have oral impacts. For example, people with more than 2 unfilled anterior spaces were 2.87 (95% Cl =1.54 - 5.35) times and those with 1-2 unfilled spaces 1.65 (95% Cl
= 1.09 - 2.49) times were more likely to experience oral impacts when compared to those respondents that did not have unfilled spaces in the adjusted model (Table 5.32).
5.5.4.6. Self-perceived dry mouth and binary OIDP
A significant relationship existed between self-perceived dry mouth and binary OIDP in both unadjusted and adjusted models (p < 0.001) (Table 5.32). People reporting dry mouth were more likely to have experienced oral impacts on their daily life when compared with people without dry mouth. After adjusting for the effects o f age, sex,
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occupation and self-perceived general health, people with self-perceived dry mouth were 1.72 (1.34 - 2.21) times more likely to experience oral impacts than those without.
The results for the relationships between different measures o f clinical dental status and the prevalence o f OIDP eating impact in the adjusted models were very close to the results for the respective relationships between clinical dental status and the binary OIDP (Table 5.33 and Table 8.25-8.27 in Appendix 8)
5.5.5. Summary
The prevalence o f OIDP was relatively high (60%) in a sample o f older Chinese population in this study. The most common OIDP impact referred to eating impact.
Toothache was the main condition causing oral impacts, while food catching was the main cause o f the eating impact. There were significant relationships between clinical dental status (number o f teeth, number o f occluding pairs and number o f unfilled spaces) and OIDP scores and the prevalence o f OIDP eating impact in the unadjusted models.
These significant relationships were maintained after adjustment for confounding factors.
Significant relationships also existed between self-perceived dry mouth and OIDP scores, binary OIDP and OIDP eating impact. People with self-perceived dry mouth were more likely to have higher OIDP scores and higher odds o f experiencing eating impact.
5.6. The relationships between eating difficulty and OIDP scores and