Table 1.
Characteristics of randomised controlled trials included in this study
| Trial (first publication) | |||||||
|---|---|---|---|---|---|---|---|
| NEP15 | NETSGA16 | LCPUFAP17 | LCPUFAT18 | IRONT11 | PALMT46 | NUCLEOT47 | |
| Study design | |||||||
| Population | Preterm infants: bw <1750 g, <37 weeks ga | SGA term infants: bw <10th centile, ≥37 weeks ga | Preterm infants: bw ≤1850 g, ≤37 weeks ga | Term infants: ≥37 weeks ga | Term infants: bw >2500 g, ≥37 weeks ga, age: 9 months | Term infants: ≥37 weeks ga, bw >5th centile | Term infants: ≥37 weeks ga |
| Formula modification | Nutrient enriched (mainly protein and calorie) term formula (after discharge) | Nutrient enriched (mainly protein and calorie) term formula | Preterm formula supplemented with 0.17% DHA + 0.31% AA | Term formula supplemented with 0.32% DHA + 0.30% AA | Term formula with 12 mg/L iron | Term formula supplemented with 50% sn-2 palmitate | Term formula supplemented with 31 mg/L nucleotides |
| Standard formula | Term formula (after discharge) | Standard term formula | Standard preterm formula (without DHA + AA) | Standard term formula (without DHA + AA) | Standard term formula with 0.9 mg/L iron | Standard term formula with 12% sn-2 palmitate | Standard term formula with <5 mg/L nucleotides |
| Randomisation period | 7 October 1993-19 November to 1996 | 21 September 1993-11 January 1996 | 11 August 1993-11 May 1996 | 2 November 1993-30 June 1995 | 26 October 1993-21 May 1995 | 15 May 1995-26 November 1996 | 11 February 2000-29 October 2001 |
| Place of recruitment | NT, L, C, I | NT, L, C | NT, L | NT, L | NT, L, NW | C | NT, L |
| Start and duration of intervention | Week before planned hospital discharge*, 9 months | Birth, 9 months | Birth, 3 weeks | Birth, 6 months | 9, 18 months | Birth, 12 weeks | Birth, 20 weeks |
| No of contacts per participant (mean (SD)) | 5.0 (1.5) | 4.8 (1.9) | 1.7 (0.8) | 4.1 (1.8) | 5.5 (1.0) | 3.1 (0.8) | 2.7 (0.9) |
| Risk of bias | |||||||
| Random sequence generation | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Allocation concealment | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Blinding | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Formula supplier | Farley (now Heinz) | Farley (now Heinz) | Milupa (now Danone) | Nestlé | Wyeth (now part of Nestlé) | Nutricia (Danone) | Heinz |
| Role of formula supplier in initial trial | Supply of formula, financial assistance | Supply of formula, financial assistance | Supply of formula, financial assistance | Supply of formula, financial assistance | Supply of formula, financial assistance | Supply of formula, financial assistance | Supply of formula, financial assistance |
SD=standard deviation; bw=birth weight; ga=gestational age; DHA=docosahexaenoic acid; AA=arachidonic acid; NT=Nottingham; L=Leicester; C=Cambridge; I=Ipswich; NW=Norwich.
Trials: NEP=nutrient enriched post-discharge formula for babies born preterm; NETSGA=nutrient enriched term formula for babies born at term and small for gestational age; LCPUFAP=preterm formula supplemented with long chain polyunsaturated fatty acids (0.17% DHA + 0.31% AA) for babies born preterm; LCPUFAT=term formula supplemented with long chain polyunsaturated fatty acids (0.32% DHA + 0.30% AA) for babies born at term; IRONT=term follow-on formula with high iron content (12 mg/L iron) for babies born at term; PALMT=term formula with sn-2 palmitate for babies born at term; NUCLEOT=term formula with added nucleotides for babies born at term.
In the NEP trial, week before planned hospital discharge corresponds to the expected date of delivery if the infant had not been born prematurely (term equivalent age).