Table 3.

Association of plasma vitamin A in children with morbidity

Quartiles of plasma vitamin Aa	Morbidity rate (episodes/child-year)	Relative riskb (univariate)	Relative riskc (multivariate)	95% CIc	P-value for trendc
All children
Respiratory infectiond
1	0.57	1.00	1.00
2	0.61	0.88	0.94	0.67–1.31
3	0.58	0.62	0.70	0.48–1.01
4	0.55	0.71	0.78	0.52–1.17	0.18
Diarrheae
1	1.38	1.00	1.00
2	1.53	1.06	1.10	1.00–1.21
3	1.50	1.05	1.09	0.99–1.21
4	1.45	1.06	1.11	0.99–1.23	0.15
HIV infected
Respiratory Infection
1	0.95	1.00	1.00
2	1.21	0.73	0.85	0.45–1.61
3	0.98	0.52	0.55	0.27–1.14	0.14
4	0.86	0.59	0.56	0.25–1.26
Diarrhea
1	1.80	1.00	1.00
2	2.06	1.08	1.13	0.95–1.35
3	1.94	1.01	1.09	0.90–1.33	0.60
4	1.87	1.01	1.07	0.89–1.30
HIV un-infected
Respiratory Infection
1	0.42	1.00	1.00
2	0.46	1.13	1.11	0.74–1.68
3	0.49	0.82	0.81	0.50–1.30	0.57
4	0.46	0.91	0.91	0.55–1.48
Diarrhea
1	1.22	1.00	1.00
2	1.39	1.07	1.08	0.96–1.21
3	1.41	1.09	1.08	0.95–1.22	0.26
4	1.33	1.10	1.10	0.96–1.26

Quartile divisions for plasma vitamin A (µmol/l) were ≤0.36, 0.37–0.45, 0.46–0.57, ≥0.58 (at 6 weeks) and ≤0.37, 0.38–0.49, 0.50–0.62, ≥0.63 (at 6 months).

^aFrom generalized estimating equations using a binomial distribution and a log link function.

^bFrom separate multivariate models and adjusted for maternal trial regimen, maternal education, maternal baseline CD4 count and the following child factors: age, HIV status (as time-varying), low birth weight, baseline CD4 count, plasma vitamin B-12 and albumin.

^cP-value for trend based on median concentration in each quartile.

^dDefined as presence of cough along with rapid respiratory rate.

^eDefined as three or more watery stools in a 24 h period.