Table 1 Summary of demographic and study data in a longitudinal study of Danish children/adolescents at three time points (T1, T2 and T3).
From: Prevalence and tracking of back pain from childhood to adolescence
Description of studies | |||
|---|---|---|---|
Time point | T1 | T2 | T3 |
Number of participants: males/females | 227/252 | 250/234 | 192/251 |
Age mean [range] | 9.7 [8.7,15.5] | 13.1 [12.1 - 14.4] | 15.7 [14.7 - 17.1] |
Years since last interview [range] | Â | 3.4 [3.0 - 4.0] | 2.7 [2.2 - 3.1] |
Period of data collection | August 1997 -June 1998 | March 2001 -October 2001 | November 2003 -May 2004 |