# Table 4 Associations between linkage accuracy (using the bespoke algorithm) and characteristics of the cohort

True matches
N = 123
n (%)
Missed-matches
N = 68
n (%)
OR (95% CI) p-value False-matches
N = 8
n (%)
OR (95% CI) p-value
Age of the mother in years
< 20 25 (20.3) 19 (27.9) 1 p = 0.047 -   p = 0.095
20–35 67 (54.5) 30 (44.1) 1.7 (0.8–3.5) 8 (100)
> 35 22 (17.9) 7 (10.3) 2.3 (0.8–6.7) -
Missing 9 (7.3) 12 (17.5)   -
Maternal literacy
Illiterate 7 (5.7) 5 (7.3) 1 p = 0.113 - 1 p = 0.617
1–3 years 8 (6.5) 4 (5.9) 1.4 (0.3–7.5) 1 (12.5) 0.9 (0.4–1.9)a
4–7 years 32 (26.0) 14 (20.6) 1.6 (0.4–6.0) 2 (25.0)
> 8 years 34 (27.6) 20 (29.4) 1.2 (0.3–4.3) 4 (50.0)
> 11 years 19 (15.4) 3 (4.4) 4.5 (0.8–24.1) -
Missing 23 (18.7) 22 (32.3)   1 (12.5)
Previous fetal death or abortion
No 36 (29.3) 17 (25.0) 1 p = 0.574 2 (25.0) 1 p = 0.966
Yes 59 (48.0) 31 (45.6) 0.9 (0.4–1.8) 4 (50.0) 1.2 (0.2–7)a
Missing 28 (22.7) 20 (29.4)   2 (25.0)
Gestational age
< 22 weeks 9 (7.3) 2 (2.9) 1 p = 0.248 -   p = 0.492
22–27 weeks 29 (23.6) 18 (26.5) 0.3 (0.1–1.8) 3 (37.5) 1
28–31 weeks 21 (17.8) 11 (16.2) 0.4 (0.1–2.3) 3 (37.5) 0.7 (0.4–1.3)a
32–36 weeks 26 (21.1) 19 (27.9) 0.3 (0.1–1.5) 2 (25.0)
37–41 weeks 28 (22.8) 9 (13.2) 0.7 (0.1–3.8) -
≥ 42 weeks 2 (1.6) -   -
Missing 8 (6.5) 9 (13.2)   -
Birth or death weight
≥ 2500 23 (18.7) 16 (23.5) 1 p = 0.798 -   p = 0.165
1500–2500 26 (21.2) 16 (23.5) 1.1 (0.4–2.7) -
< 1500 64 (52.0) 31 (45.6) 1.4 (0.6–3.0) 7 (87.5)
Missing 10 (8.1) 7 (7.3)   1 (12.5)
1. aDue to the small number of observations, we used only two categories, the first category without missing value as the reference one