Table 1.
Accuracy and reproducibility studies of Pea Pod in full-term and preterm infants
| Reference | Country | Comparison methods | Inclusion/ Exclusion | Number (sex) | Number of tests | Age at measurement | Results |
|---|---|---|---|---|---|---|---|
| Animal and Animal Tissues | |||||||
| Accuracy studies | |||||||
| Sainz et al. (2003) [17] |
The US | ADP, chemical analysis (CA), hydrostatic weighing | Bovine tissue with wide ranges of mass (1.39–9.95 kg) and FM% (2.08–34.40%) | 24 bovine tissue phantoms (NA) | NR | NA | %Fat: ADP: 18.55% CA: 18.59% SD %fat ADP: 0.70% CA: 0.73% 95% LoA: −1.22-1. 13 %Fat |
| Frondas-Chauty et al. (2012) [44] | France | ADP, chemical analysis | Live piglets with wide ranges of mass (1.03–8.49 kg) and FM% (3.2–16.4%) | 34 live piglets | NR | 2, 7, and 21 days | %Fat: Pea Pod, 8.01 ± 4.03%; CA, 8.7 ± 4.1% Standard error of the estimate: 1.7% R2: 0.83 |
| Reproducibility studies | |||||||
| Frondas-Chauty et al. (2012) [44] | France | ADP within a day | Live piglets (aa above) | 34 live piglets | Four times | 2, 7, and 21 days | CV: ranging from 2.2 to 44.1% Root mean square CV: 17.9% CV values and median differed by age and %fat assessed using CA, with less variability in piglets with higher %fat |
| Full-Term Infants | |||||||
| Accuracy studies | |||||||
| Ma et al. (2004) [18] | The US & China | ADP, deuterium dilution | Healthy f ull-term infants (mixed ethnicity; white and Chinese) | 53 (28F, 25 M) | 2 days and 2 tests on first day | 5.8 (6.0) (0.4–24.4) wks | %fat Pea Pod: 20.32–6.87%; deuterium: 20.39–6.68 95% LoA: − 6.84-6.71% (not related to body mass) |
| Ellis et al. (2007) [45] |
The US | ADP, 4-CM | Full term healthy infants (mixed ethnic groups; white, African American, Hispanic American) | 49 (24F, 25 M) | Twice | 8.0 (5.4) wks | %Fat Pea Pod: 16.9 (6.5), 4-CM: 16.3 (7.2) (P = 0.62) 95% LoA: − 6.8-8.1% |
| Fields et al. (2012) [49] | The US | Pea Pod, DXA | Full term singleton infants, average for gestational age and with gestational age > =37, staying in hospital less than 3 days after delivery. nfants with congenital malformation were excluded. (ethnicity nor reported) | 84 (47F, 37 M) | NR | 6 mo; 168.4 (3.8) days | %Fat Pea Pod: 26.7 (4.7), DXA: 31.3 (3.6), (P < 0.001) |
| Reproducibility studies | |||||||
| Yao et al. (2003) [16] | The US | ADP within and between-days – data from multiple compartment studies of Butte et al. and Fomon et al | Full term healthy infants with weight ranging between 3.40–7.45 kg and age ranging between 1.40–21.70 weeks (ethnicity not reported) | 17 (8F, 9 M) | 2 days and 2 tests per only one day | 1.40–21.70 weeks (all 3 tests); | %fat: ranging 7.49–32.08% SD %Fat within day: 0.52; between day: 0.60 CV %fat within day: 2.85; between day: 2.95 95% LoA within day: − 2.0-1.2%; between day: − 2.2-1.7% (not a function of behavioural state) |
| Ma et al. (2004) [18] |
The US & China | ADP within and between days | Healthy full-term infants (mixed ethnicity; white and Chinese) | 36 (16F, 20 M) | 2 days and 2 tests on first day | 7.6 (7.2) (0.4–21.7) wks | SD %fat within day: 0.69%; between day: 0.72% CV %fat within day: 4.94; between day: 5.10% 95% LoA within day: − 2.7-3.1%; between day: − 2.9-1.9 (not a function of body f atness) |
| Ellis et al. (2007) [45] |
The US | ADP within day | Full term healthy infants (mixed ethnic groups; white, African American, Hispanic American) | 31 (18F, 13 M) | Twice | 6.0 (3.3) wks | SD %fat within: 0.7% CV %fat within: 7.9% 95% LoA: − 2.3-3.1% |
| Pre-Term Infants | |||||||
| Accuracy studies | |||||||
| Roggero et al. (2012) [50] |
Italy | Pea Pod, deuterium dilution | Preterm singleton infants with gestational age = < 36 weeks were included. Also term infants with gestational age > =37 were included. Infants aged > 1 mo of age, with congenital diseases, chromosomal abnormalities, respiratory distress syndrome, or severe brain, metabolic, cardiac, or gastrointestinal diseases were excluded. |
10 (4F, 6 M) | NR | < 1 month | %fat Pea Pod: 5.67 (1.84), deuterium dilution: 5.99 (2.56), P = 0.53 95% LoA: −3.4-2.76% (not a function of mean values) |
| Forsum et al. (2016) [51] |
Sweden | Pea Pod, deuterium dilution | Infants without sepsis or malformations born between 32 and 37 gestational weeks (ethnicity not reported) | 14 (4F, 10 M) | NR | 3–7 days old | %Fat Pea Pod: 4.2 (3.9), deuterium dilution 3.2 (3.8) (P > 0.05) 95% LoA: − 6.8-4.8% FFM density by Pea Pod did not correlate with those of deuterium dilution (r2 = 0.04, P > 0.05) Hydration factor: 83% |
| Reproducibility studies | |||||||
| Roggero et al. (2012) [50] |
Italy | NA | Preterm singleton infants with gestational age = < 36 weeks were included. Also term infants with gestational age > =37 were included. Infants aged > 1 mo of age, with congenital diseases, chromosomal abnormalities, respiratory distress syndrome, or severe brain, metabolic, cardiac, or gastrointestinal diseases were excluded. |
Precision: 57 (29F, 28 M) Inter-devise reproducibility: 9 full term and 3 preterm (6F, 6 M) |
Twice | < 1 month | %Fat SD: 1.1 95% LoA: − 2.05-2.36% Inter-device reproducibility: %fat test 1: 8.97%, test 2: 8.55% 95% LoA: − 1.87-2.71 |
NA, not applicable; ADP, air displacement plethysmography; CA, chemical analysis; SD, standard deviation; LoA, limits of agreement; wks, weeks; US, united states; CV, coefficient of variation; 4-CM, 4 compartment model; DXA, dual energy X-ray absorptiometry