Table 2 Comparison of children by website registration status
Variable | Description | Ever registered | Never registered | p-value |
|---|---|---|---|---|
Participants | All children | 13,536 | 49,801 | |
Male | % (n) | 50.36 (6817) | 50.68 (25218) | 0.576 |
Age at start (mean) | years (SD) | 7.30 (2.55) | 7.64 (2.54) | <0.001 |
Age at start (median) | years (IQR) | 7.25 (4.83–9.99) | 7.83 (4.99–10.24) | <0.001 |
Deprivation | % (n) | <0.001 | ||
(IMD rank quintile) | Q1 (most deprived) | 66.94 (9061) | 77.84 (38765) | |
Q2 | 16.04 (2171) | 12.04 (5997) | ||
Q3 | 9.53 (1290) | 5.18 (2580) | ||
Q4 | 4.93 (668) | 2.09 (1039) | ||
Q5 | 1.54 (209) | 0.62 (311) | ||
Not known | 1.01 (137) | 2.23 (1109) | ||
Ethnicity | % (n) | <0.001 | ||
White | 50.43 (6826) | 32.69 (16281) | ||
Mixed black/white | 3.66 (496) | 3.42 (1703) | ||
Black/British black | 7.29 (987) | 12.84 (6396) | ||
Asian/British Asian | 15.92 (2155) | 19.51 (9718) | ||
Other | 5.07 (687) | 5.70 (2838) | ||
Not stated/unknown | 16.98 (2298) | 24.11 (12005) | ||
First recorded BMI | categorical, % (n) | <0.001 | ||
Underweight | 1.30 (176) | 1.47 (734) | ||
Normal weight | 74.99 (10151) | 73.65 (36680) | ||
Overweight | 12.50 (1692) | 12.40 (6173) | ||
Obese | 7.28 (985) | 7.82 (3892) | ||
Severely obese | 3.93 (532) | 4.66 (2322) | ||
Overweight or obese | 23.71 (3209) | 24.87 (12387) | ||
Median first recorded BMI2 | kg/m2 (continuous, IQR) | 16.59 (15.43–18.48) | 16.71 (15.48–18.87) | 0.966 |
Mean annual change in UK90 BMI centile1 | centiles per annum (SD) | −0.47 (±12.14) | 0.51 (±12.21) | <0.001 |
Median annual change in UK90 BMI centile1 | centiles per annum (IQR) | − 0.14 (−6.01–4.44) | 0.07 (−4.88–5.33) | <0.001 |
Median time span of recorded BMI values1 | days (IQR) | 396 (365–427) | 397 (366–427) | <0.001 |
Total number of BMI measurements recorded 2013–2017 | 26,982 | 81,113 | <0.001 | |
Mean number of BMI measurements recorded per child 2013–2017 | 1.99 | 1.63 | <0.001 |