Table 3. Associated factors for anemia in Brazilian young children who visited primary health care.

Variables	n	Crude		Multiple adjustment
		PR (95% CI)	P-valuea	PR (95% CI)	P-valueb
Distal level of determination
Maternal education (years)
< 7	103	1.62 (1.00–2.62)	0.051	1.45 (0.88–2.39)	0.148
≥ 7 - < 11	187	1.29 (0.83–2.00)	0.256	1.19 (0.76–1.86)	0.435
≥ 11	218	Ref.	-	Ref.	-
Drinking water treatment
Inadequate	217	1.37 (0.91–2.07)	0.126	1.23 (0.81–1.87)	0.329
Adequate	303	Ref.	-	Ref.	-
Children younger than 5 years in the house
1 child	379	Ref.	-	Ref.	-
> 1 child	141	1.55 (1.07–2.24)	0.021	1.47 (1.01–2.14)	0.044
Intermediate level of determination
Birth weight (g)
< 2500	29	1.27 (0.65–2.46)	0.485	1.45 (0.74–2.85)	0.281
≥ 2500 - < 3500	332	Ref.	-	Ref.	-
≥ 3500	151	0.69 (0.44–1.08)	0.103	0.71 (0.45–1.11)	0.132
Introduction of fruits or/and vegetablesc
Early	217	1.14 (0.74–1.75)	0.561	1.03 (0.67–1.61)	0.877
Adequate	211	Ref.	-	Ref.	-
Late	90	2.08 (1.29–3.33)	0.002	1.92 (1.19–3.10)	0.007
Proximal level of determination
Stuntingd
No	483	Ref.	-	Ref.	-
Yes	25	2.49 (1.38–4.50)	0.003	2.44 (1.32–4.50)	0.005
Hospitalization at least once
No	396	Ref.	-	Ref.	-
Yes	124	1.39 (0.93–2.07)	0.103	1.55 (1.03–2.33)	0.036
Presence of inflammatione
No	399	Ref.	-	Ref.	-
Yes	68	1.97 (1.27–3.05)	0.003	1.57 (0.97–2.54)	0.065
Iron deficiencyf
No	315	Ref.	-	Ref.	-
Yes	188	1.38 (0.91–2.08)	0.129	1.35 (0.88–2.07)	0.163
Marginal vitamin A statusg
No	322	Ref.	-	Ref.	-
Yes	172	1.53 (1.05–2.25)	0.028	1.31 (0.86–1.99)	0.208
Folate (nmol/L)
1 tercil (6.3–32.2)	152	2.54 (1.49–4.33)	0.001	2.24 (1.30–3.85)	0.003
2 tercil (32.4–50.1)	152	1.69 (0.96–2.99)	0.070	1.58 (0.89–2.82)	0.119
3 tercil (> 50.1)	156	Ref.	-	Ref.	-

PR, prevalence ratio; CI, confidence interval.

^a P values were estimated by multilevel mixed-effects Poisson regression models adjusted for child’s sex and age.

^b P values were estimated by multilevel mixed-effects Poisson regression models adjusted for child’s sex and age, and the variables from each level of determination associated with the outcome at P < 0.10 or if their inclusion in the model changed the PR by 10% or more in each level.

^c Defined as early (< 6 months); adequate (≥ 6 months—< 8 months); late (≥ 8 months).

^d Defined as HAZ < -2 Z-score.

^e Defined as CRP > 5 mg/L and AGP > 1 g/L.

^f Defined as plasma ferritin < 12 μg/L and/or sTfR > 8.3 mg/L.

^g Defined as serum retinol < 1.05 μmol/L.

Missing observations were included in the analysis by creating missing-values categories.