Table 1.
Variables | Categories | Caries prevalence | dmft | |||
---|---|---|---|---|---|---|
No. of surveyed (No. of cases with dental caries) | Caries prevalence (%) | P-value (statistics1) | Mean ± SD | P-value (statistics2) | ||
Age (years old) | 3 | 531 (156) | 29.38 | < 0.001** (−15.992a) | 1.09 ± 2.45 | < 0.001** (304.022b) |
4 | 3626 (1141) | 38.91 | 1.68 ± 3.08 | |||
5 | 3798 (1908) | 50.24 | 2.45 ± 3.57 | |||
6 | 3198 (1769) | 55.31 | 2.71 ± 3.69 | |||
Gender | Boys | 5972 (2818) | 47.19 | 0.702 (0.146) | 2.23 ± 3.43 | 0.574 (0.562c) |
Girls | 5181 (2426) | 46.82 | 2.19 ± 3.45 | |||
Household registration | Shanghai | 10,700 (4959) | 46.35 | < 0.001** (47.890) | 2.14 ± 3.38 | < 0.001** (−8.806d) |
Non-Shanghai | 453 (285) | 62.91 | 3.76 ± 4.43 | |||
Total | – | 11,153 (5244) | 47.02 | – | 2.21 ± 3.44 | – |
**P < 0.01. SD = standard deviation
1a: Cochran-Armitage test for trend (the statistics is Z-value); the others were Pearson Chi-square test (the statistics is χ2-value)
2b: Kruskal-Wallis test (the statistics is χ2-value); c: t test (the statistics is t-value); d: Mann-Whitney test (the statistics is Z-value)