Example of pre-existing data used to derive target variables (FFQ)
The table below shows an example of pre-existing data used to derive target variables (FFQ).
Table adapted from the Measurement Toolkit [145]
| Fish items in the original cohort | Harmonised items | ||||
|---|---|---|---|---|---|
| Fish types | Assumption of g/portion | Frequency and quantity | Target variable (g/d) | Harmonisation – categorisation of fish | Harmonisation – frequency and quantity |
| White fish (hake, whiting, bream, grouper, sole) | 150 g | Frequency: never/almost never; 1-3 times/month; once a week; 2-4 times/week; 5-6 times/week; once per day; 2-3 times/day; 4-6 times/day; more than 6 times/day | Lean fish | White fish/day + Cod/day | Lean fish: multiply portion/day*150 g |
| Cod | 150 g | ||||
| Blue fish (sardines, tuna, bonito, mackerel, salmon) | 150 g | Fatty fish | Blue fish/day | Fatty fish: multiply portion/day*150 g | |
| Salted or smoked fish | 50 g | Salted/smoked/dried | Salted or smoked fish/day | Salted/smoked/dried fish: multiply portion/day*50 g | |
| Clam, oyster, mussels | 60 g | Seafood other than fish | Total seafood per day | Source data already in g/d | |
| Prawn, king prawn, crayfish | 100 g | ||||
| Octopus, squid, cuttlefish | 150 g | ||||
| Total fish and seafood per day (derived) | g/d | Total fish | Total fish and seafood per day | Source data already in g/d | |
| Total seafood per day (derived) | g/d | ||||
Next page: example of pre-existing data used to derive target variables (diet history)