Table 2.
Points awarded by the Newcastle-Ottawa Scale to the four studies on hypoxic ischemic encephalopathy (HIE) and heart rate variability (HRV)
| Selection | Comparability | Outcome | Quality scorei | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Representativeness of exposed cohorta | Selection of non-exposed cohortb | Ascertainment of exposurec | Presences of outcome of interestd | Comparability of cohortse | Assessment of outcomef | Long enough follow-upg | Adequacy of follow uph | ||
| Aliefendioglu et al. 2012, Turkey [19] | A (✹) | A (✹) | A (✹) | A (✹) | A, B (✹✹) | A (✹) | A (✹) | A (✹) | Good quality |
| Vergales et al. 2013, USA [20] | A (✹) | A (✹) | A (✹) | A (✹) | B (✹) | B (✹) | A (✹) | C | Good quality |
| Goulding et al. 2015, Ireland [21] | A (✹) | A (✹) | A (✹) | A (✹) | B (✹) | B (✹) | A (✹) | A (✹) | Good quality |
| Goulding et al. 2017, Ireland [22] | A (✹) | A (✹) | A (✹) | A (✹) | B (✹) | B (✹) | A (✹) | A (✹) | Good quality |
a A, truly representative; B, somewhat representative; C, selected group; D, no description of the derivation of the cohort
b A, drawn from the community as the exposed cohort; B, drawn from a different source; C, no description of the derivation of the non-exposed cohort
c A, secure record (e.g., surgical records); B, structured interview; C, written self-report; D, no description
d Demonstration that outcome of interest was not present at the start of the study: A, yes; B, no.
e Comparability of cohorts based of the design or analysis: A, study controls for the most important factor (malformation); B, study controls for any additional factor (infections, metabolic diseases, gender, birth weight, gestational age, postnatal age, therapeutic hypothermia, and medication)
f A, independent blind assessment; B, record linkage; C, self-report; D, no description
g Was follow-up long enough for outcomes to occur? A, yes; B, no.
h A, complete follow-up - all subjects were accounted for; B, subjects lost to follow-up were unlikely to introduce bias - small numbers were lost (< 5%) or description was provided of those lost; C, follow-up rate < 95%, and there was no description of those lost; D, no statement
I ‘Good quality’ was given 3–4 points (✹) in selection and 1–2 points in comparability and 2–3 points in outcome; ‘fair quality’ was given 2 points in selection and 1–2 points in comparability and 2–3 points in outcome; and ‘poor quality’ was given 0–1 points in selection or 0 points in comparability or 0–1 points in outcome