Table 1

Power analysis

Outcome Measure

PMA

Reference Population μ (σ)

Detectable Difference |μFN-μSC|

Effect Size d

Total N Required


Infant

EEG [73]

Term

6.044 (.434)

0.2

.46

150

NNNS [88]*

Term

4.32 (1.73)

1.0

.58

96

HRV [22]

Term

1.77 (1.10)

0.5

.45

154

Bayley-III [69]

18 months

96.4 (14)

6.0

.41

174

Mother

Cortisol [89]

4 months

Median = 2.4

0.45

.40

186

(IQR: 1.6-4.1)

CES-D [53]

4 months

10.24(9.67)[90]

5.0

.52

120

19.8 (11.1)[91]

.45

158


A power analysis was conducted to determine the sample size needed to ensure statistical power of (1-β) = .80.

*Non-optimal reflexes. Illustrative of the 13 NNNS subscales. Citation for the reference population is the same as that for all Outcome Measures except CES-D. Abbreviations: Bayley-III, Bayley Scales of Infant Development, III; CES-D, Center for Epidemiological Studies Depression Scale; HRV, heart rate variability; NNNS, NICU Network Neurobehavioral Scale; PMA, post-menstrual age of the infant.

Welch et al. BMC Pediatrics 2012 12:14   doi:10.1186/1471-2431-12-14

Open Data