Table 6 Comparison of baseline characteristics between follow-ups and those lost to follow-up
Lost to follow-up Valid n (%) | Follow-ups Valid n (%) | Cohen’s effect size | ||
|---|---|---|---|---|
Gender | 0.10a | |||
Male | 207 (53.6%) | 122 (43.3%) | ||
Female | 179 (46.4%) | 160 (56.7%) | ||
Parental employment status | 0.03a | |||
Both employed | 233 (62.5%) | 180 (65.0%) | ||
At least one unemployed | 140 (37.5%) | 97 (35.0%) | ||
Family income | 0.06a | |||
Less than HK$ 10,000 | 94 (25.3%) | 72 (26.5%) | ||
HK$10,001-HK$30,000 | 175 (47.0%) | 139 (51.1%) | ||
More than HK$ 30,000 | 103 (27.7%) | 61 (22.4%) | ||
Frequency of tooth brushing | 0.06a | |||
Less than twice a day | 119 (30.8%) | 71 (25.2%) | ||
At least twice a day | 267 (69.2%) | 211 (74.8%) | ||
Use of fluoride toothpaste | 0.08a | |||
Yes | 116 (30.1%) | 107 (37.9%) | ||
No or not sure | 270 (69.9%) | 175 (62.1%) | ||
Frequency of taking snack | 0.02a | |||
Less than once a day | 83 (21.5%) | 62 (22.0%) | ||
Once a day | 195 (50.5%) | 145 (51.4%) | ||
At least twice a day | 108 (28.0%) | 75 (26.6%) | ||
CPI | 0.06 a | |||
≤ 50% index teeth with CPI = 0 | 188 (61.2%) | 119 (38.8%) | ||
> 50% index teeth with CPI = 0 | 198 (54.8%) | 163 (45.2%) | ||
BMI | Valid n | 386 | 282 | 0.09b |
Mean (SD) | 19.99 (3.99) | 19.66 (3.35) | ||
WC | Valid n | 386 | 282 | 0.12b |
Mean (SD) | 70.91 (9.90) | 69.82 (8.62) | ||
WHR | Valid n | 386 | 282 | 0.12b |
Mean (SD) | 0.82 (0.06) | 0.81 (0.05) | ||
WHtR | Valid n | 386 | 282 | 0.13b |
Mean (SD) | 0.45 (0.06) | 0.45 (0.05) | ||
TRSKF | Valid n | 208 | 179 | 0.04b |
Mean (SD) | 10.54 (3.95) | 10.69 (4.20) | ||
DMFT | Valid n | 386 | 282 | 0.12b |
Mean (SD) | 0.58 (1.04) | 0.46 (0.94) | ||