| Risk factors – level of evidence |
|
|
|
|
|
|
|
|
|
|
|
|
| n | If the criteria
for identifying a risk factor are to be met, |
||||||||||
| longitudinal
studies must be used |
|||||||||||
| – | However
longitudinal studies are expensive to |
||||||||||
| conduct and may
take many years to complete |
|||||||||||
| – | Consequently
variables thought to be risk factors |
||||||||||
| frequently are
uncovered through associations seen |
|||||||||||
| in prevalence
(cross-sectional) studies |
|||||||||||
| ohcd603 |
| 20 |