Country
| Switzerland | Sweden | Finland | Finland | England |
Design
| Cross Sectional | Cross sectional + follow up | Cross sectional | Cross sect. + follow up | Cross sectional |
Study sample
| Schoolchildren in primary and secondary school- one school district | Pupils from 26 urban schools | Pupils from 45 different public schools | Population register. All Finns born on adjacent dates in summer (1985–9, 1993–7) | Pupils from secondary schools; state + private, urban + rural |
Response rate
| 99% | 87% | 82% | 77% | 92% (LBP) |
Valid sample size
| 1666 | 1245/ 471 | 1171 | 62677 | 1376 (LBP) |
Data collection
| Questionnaire | Questionnaire | Questionnaire | Questionnaire | Questionnaire |
Age group
| 7-17(mean 12) | 8, 11, 13, 17 | 7, 10, 14, 16 | 12,14,16,18(12.6, 14.6, 16.6, 18.6) | 11-14 |
Definition of back pain
| LBP, BP (=all spinal pain) | Do you often have back pain? | LBP interfering with school/leisure activities + recurrent LBP past 12 months | Back or neck pain during the past half a year | LBP for one day or longer in the past month |
Gender
| Girls > Boys (+BP ++LBP) | Girls > Boys all age groups. Significant among the 13 and 17-year-old pupils | No general difference. Girls > boys in recurrent LBP reporting | Girls > boys No interaction between sex but increasing trend was seen in girls – boys U shaped curve | Girls > Boys |
Age (prevalence increase)
| >13 | Trend of more long-lasting BP in older age groups. Especially among girls | Recurrent LBP increases > 14, 16 | Prevalence increased with age | Increase with age in girls and boys |