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. Author manuscript; available in PMC: 2024 Dec 16.
Published in final edited form as: J Pediatric Infect Dis Soc. 2023 Dec 16;12(12):646–651. doi: 10.1093/jpids/piad100

Table 2.

Demographic and Clinical Factors Associated With In-hospital Mortality Among Infants Aged <1 Year, South Africa, July 2016–October 2018

Variable Categories Total, No.
N = 1321
No. of deaths
N = 27
Mortality ratio, %
(95% CI)
P-valueg Odds ratioh
(95% Cl)
P-value Adjusted ORi (95% CI) P-value
HIV status HUU 721 12 1.7 (0.9–2.9) <.001 Reference Reference
HEU 526 8 1.5 (0.7–2.3) 0.99 (0.40–2.44) 0.974 0.80 (0.31–2.09) .652
HI 47 6 12.8 (4.7–27.8) 7.39 (2.58–21.19) <0.001 4.79 (1.49–15.37) .008
Unknown 27 1 3.7 (0.1–19.0) 2.06 (0.25–16.83) 0.499 1.94 (0.21–17.91) .557
Site Mpumalanga 214 6 2.8 (1.0–6.1) <.001 N/A
KwaZulu-Natal 682 4 0.6 (0.2–1.5) N/A
North West 425 17 4.0 (2.3–6.41 N/A
Year 2016 177 5 2.8 (0.9–6.6) .667 Reference
2017 574 10 1.7 (0.8–3.2) 0.68 (0.22–2.07) 0.493
2018 570 12 2.1 (1.1–3.7) 0.81 (0.27–2.10) 0.702
Sex Male 762 13 1.7 (0.9–2.9) .311 Reference
Female 559 14 2.5 (1.3–3.9) 1.47 (0.68–3.18) 0.324
Race Black African 1301 27 2.1 (1.4–3.0) .515 Reference
Non-black African 20 0 0.00
Age group (months) <1 108 3 2.8 (0.6–8.1) .138 1.09 (0.28–4.29) 0.897 0.49 (0.09–2.76) .416
1 to <3 363 4 1.1 (0.3–2.8) 0.24 (0.07–0.80) 0.020 0.15 (0.04–0.63) .010
3 to <6 335 8 2.4 (1.0–4.7) 0.60 (0.23–1.60) 0.307 0.51 (0.18–1.44) .200
6 to <9 277 3 1.1 (0.2–3.2) 0.26 (0.07–0.97) 0.045 0.20 (0.05–0.82) .025
9 to <12 238 9 3.8 (1.7–7.2) Reference Reference
Underlying conditiona No 1282 25 1.95 (1.3–2.9) .167 Reference
Yes 39 2 5.1 (0.6–18.5) 5.48 (1.12–26.79) 0.036
Malnutritionb No 975 9 0.92 (0.4–1.8) <.001 Reference Reference
Yes 345 18 5.2 (3.1–8.3) 5.19 (2.29–11.79) <0.001 4.80 (2.00–11.51) <.001
Unknown 1 0 0.0
Feeding type Exclusive breastfeeding 705 13 1.8 (1.0–3.2) .946 Reference Reference
Mixed feeding 240 5 2.1 (0.7–4.9) 1.04 (0.36–2.95) 0.948 1.02 (0.32–3.24) .975
Formula feeding 333 8 2.4 (1.0–4.7) 1.39 (0.57–3.40) 0.475 1.27 (0.48–3.35) .634
Unknown 43 1 2.3 (0.1–12.3) 1.30 (0.16–10.34) 0.802 0.57 (0.05–5.96) .635
Prematurityc No 1081 23 2.1 (1.4–3.2) .648 Reference
Yes 240 4 1.7 (0.5–4.3) 0.76 (0.26–2.25) 0.618
Birthweightd Normal 970 21 2.2 (1.3–3.3) .457 Reference
Low 280 6 2.1 (0.8–4.7) 1.01 (0.40–2.54) 0.986
Unknown 71 0 0.0
Vaccinatione Full coverage 962 16 1.7 (1.0–2.7) .253 0.49 (0.21–1.13) 0.095 0.20 (0.06–0.66) 008
No full coverage 307 9 2.9 (1.3–5.6) Reference Reference
Unknown 52 2 3.9 (0.5–13.2) 1.35 (0.28–6.54) 0.713 0.62 (0.10–4.02) .617
Admission diagnosisf Non-respiratory 630 15 2.4 (1.3–3.9) .663 Reference
Respiratory 682 12 1.76 (0.9–3.1) 0.64 (0.30–1.40) 0.264
Unknown 9 0 0.0
Mothers/caregivers education level None/Primary 616 18 2.9 (1.7–4.6) .103 Reference Reference
Secondary/Tertiary 692 9 1.3 (0.6–2.5) 0.61 (0.26–1.41) 0.244 0.77 (0.31–1.89) .570
Unknown 13 0 0.0
a

Underlying condition includes any of the following: asthma, chronic lung, heart, liver or renal disease, stroke, sinusitis, organ transplant, anemia, immunosuppressive therapy, splenectomy, diabetes, burns immunoglobulin deficiency, autoimmune disease, nephrotic syndrome, cancer, spinal cord injury, seizure disorder, cerebral palsy, congenital heart disease, other congenital disorder, obesity, or chronic gastrointestinal problems.

b

Malnutrition defined as a weight-for-age <−2 standard deviations from the WHO mean Z-score.

c

Prematurity defined as gestational age at birth of <37 weeks.

d

Low infant birthweight defined as <2500 g.

e

Vaccination defined as full vaccine coverage for age, using the Haemophilus influenzae type b vaccine given as part of the routine infant immunization schedule at 6,10, 14 weeks as a proxy.

f

Admission diagnosis: respiratory diagnosis includes apnea, neonatal sepsis, bronchiolitis, pneumonia, tuberculosis, and bronchitis and non-respiratory diagnosis includes encephalitis, viral illness, diarrhea, febrile seizures, meningitis, sepsis (non-neonatal), and other diagnosis.

g

Chi-squared test P-value.

h

Univariate mixed effects regression model, accounting for clustering by site.

i

Multivariable mixed effects regression model, accounting for clustering by site.