Table 1.
1 | Size of the study population of relevance | Range 0–1 |
2 | Power calculation: whether performed or not | Range 0–1 |
3 | Confounding: degree of adjustment for obvious confounders | Range 0, none; 1, age/gender; 2, age/gender and socio-economic indicators |
4 | Ethnicity definition: whether explicit, accurate and hypothesis based | Range 0, none; 1, a definition; 2, self assigned; 3 rated on basis of self identification and parental origins |
5 | Deliberate self harm: whether attempts had been made to ensure the episode was an actual self harm | Range 0, none; 1 self report; 2, some attempt at measurement; 3, well defined and measured |
The maximum possible score was 10. This schema was piloted to ensure that it discriminated adequately between the papers included. How well a study measured deliberate self harm and how accurately it measured ethnicity were weighted more highly than other criteria because they were considered particularly important for this review