Comparison of methods used in Thorax series and Californian EPA reviews
| Thorax series | Californian EPA | |
|---|---|---|
| General approach | Systematic search of the literature | Update of previous EPA review |
| Scope | Children only | All ages |
| Respiratory (including SIDS but not CF) | All systems (including SIDS, respiratory and CF) | |
| Inclusions and exclusions | Emphasis on groups of similar studies | Inclusion of all, even isolated studies |
| Disease definition | Specific outcomes distinguished | Broader groups of diseases |
| Community versus hospital | Distinguished where possible | Usually combined |
| Maternal and paternal smoking | Distinguished where possible | Rarely analysed separately |
| Prenatal and postnatal exposure | Rarely possible to distinguish | Rarely possible to distinguish |
| Confounding | Addressed in meta-analysis where possible | Discussed in text |
| Publication bias | Discussed and evaluated where possible | Not discussed |
| Summarisation | Emphasis on meta-analysis, less narrative | More narrative, selective use of meta-analysis3-150 |
| Causal inference | Discussed | Discussed |
| Population attributable risk estimates | Not attempted | Included for USA and California |
| Experimental (chamber) studies | Very limited evidence in children | Limited evidence, mainly in adults |
| Mechanisms | Not discussed | Discussed |
SIDS = sudden infant death syndrome; CF = cystic fibrosis.
↵3-150 Only used for asthma induction, including early wheezing illnesses.