Smartphone use features | Non-PSU: \( \overline{\mathrm{X}} \) ±SD; n (%) | PSU: \( \overline{\mathrm{X}} \) ±SD; n(%) | Multiple comparisons | Test value: Z; X2 | p |
---|---|---|---|---|---|
Age for first mobile phone | 16.00 ± 2.286 | 16.16 ± 2.092 | - | 0.743 | 0.458 |
Number of mobile phones | Â | Â | - | 3.896 | 0.048 |
 1 | 655 (78.3) | 163 (72.1) |  |  |  |
 2 or more | 181 (21.7) | 63 (27.9) |  |  |  |
Daily use time, hours | Â | Â | Â | 23.582 | <0.001 |
  ≤ 2 (1) | 226 (27) | 41 (19.9) | 1–2 | 0.213 | 0.644 |
 2–4 (2) | 319 (38.2) | 64 (27.7) | 1–3 | 17.512 | <0.001 |
  ≥ 4 (3) | 291 (34.8) | 121 (52.4) | 2–3 | 17.813 | <0.001 |
Operating system | Â | Â | Â | 2.074 | 0.355 |
 IOS (Apple) | 171 (21) | 45 (20.1) |  |  |  |
 Android (Google) | 645 (79) | 179 (79.9) |  |  |  |
 Other | 20 | 2 | - | - | - |
Frequency of mobile phone change | Â | Â | Â | 19.291 | <0.001 |
 Not changed yet | 87 | 21 | - | - | - |
  ≤ 1 year (1) | 117 (15.6) | 56 (27.3) | 1–2 | 8.779 | 0.003 |
 1–2 years (2) | 411 (54.9) | 111 (54.2) | 1–3 | 19.083 | <0.001 |
  ≥ 2 years (3) | 221 (29.5) | 38 (18.5) | 2–3 | 4.837 | 0.027 |
Monthly smartphone bill | Â | Â | Â | 13.137 | 0.001 |
  ≤ 50 RMB (1) | 424 (50.7) | 89 (39.4) | 1–2 | 5.907 | 0.015 |
 50–100 RMB (2) | 363 (43.4) | 112 (49.5) | 1–3 | 11.162 | 0.001 |
  ≥ 100 RMB (3) | 49 (5.9) | 25 (11.1) | 2–3 | 3.560 | 0.059 |
Total | 836 | 226 | Â | Â | Â |