Analytical Methods
Data were analysed using the same general approach as described for the primary outcome [Mean daily blood glucose data were collected from intermittent blood gas measurements adjusted for the variable frequency and timing, as previously described [Plasma mineral and electrolyte data comprised the morning sample taken as part of a daily biochemical monitoring protocol for infants receiving PN. Missing daily data were replaced with either an average value (between the preceding and subsequent measurements) or a repeat sample (if the original was inadequate for analysis). Outlier measurements were excluded only if there were blood gas trend data (potassium and calcium only) to confirm a measurement was unlikely to be valid. The resulting missing value was then replaced as described.