HIERARCHICAL ANALYSIS OF THE FACTORS ASSOCIATED WITH ANEMIA IN INFANTS

Cross-sectional study with a representative sample of 366 children aged 6 to 23 months. A questionnaire was applied to the caregiver, and the children’s anthropometric measurements and hemoglobin levels were collected. The associations were identified by Poisson regression with robust variances based on a hierarchical analysis model.

Results:

The prevalence of anemia was 26.8%, and the associated factors were: family income equal to or lower than one minimum wage (PR: 1.50; 95%CI 1.03-2.18), number of household members higher than five (PR: 1.50; 95%CI 1.07-2.11), use of unfiltered water (PR: 1.68; 95%CI 1.11-2.56), number of offspring higher than three (PR: 1.64; 95%CI 1.01-2.68), consumption of meat and/or viscera less than once/week (PR: 1.78; 95%CI 1.24-2.58) and age 6-11 months (PR: 1.75; 95%CI 1.20-2.55).

Conclusions:

Anemia in the infants assessed is a moderate public health problem, which is associated with socioeconomic, demographic, and dietary factors; thus, measures are necessary for its prevention.

Keywords:
Anemia; Infant; Social class; Iron, dietary; Risk factors

	n (%)	Prevalence of anemia (%)	PR (crude)	95%CI	p-value^a
Family income (minimum wage)
>1	61 (17.4)	23.9	1	1.19-2.47	0.004*
≤1	289 (82.6)	41.0	1.72	1.19-2.47	0.004*
Paternal schooling (years of study)
≥8	175 (53)	22.3	1	1.03-2.11	0.032*
<8	155 (47)	32.9	1.48	1.03-2.11	0.032*
Maternal schooling (years of study)
≥8	227 (62.7)	22.5	1	1.08-2.13	0.016*
<8	135 (37.3)	34.1	1.52	1.08-2.13	0.016*
Parental work
Yes	325 (91.3)	25.5	1	1.04-2.59	0.032*
No	31 (8.7)	41.9	1.64	1.04-2.59	0.032*
Maternal work
No	256 (70.5)	28.1	1	0.56-1.23	0.358
Yes	107 (29.5)	23.4	0.83	0.56-1.23	0.358
Number of residents in the household
≤5	273 (74.6)	23.4	1	1.11-2.20	0.011*
>5	93 (25.4)	36.6	1.56	1.11-2.20	0.011*
Sewerage system
Yes	209 (57.1)	24.4	1	0.87-1.72	0.236
No	157 (42.9)	29.9	1.23	0.87-1.72	0.236
Sanitary installation
Yes	362 (98.9)	26.7	1	0.25-6.25	0.788
No	4 (1.1)	33.3	1.25	0.25-6.25	0.788
Garbage collection
Yes	362 (98.9)	26.8	1	0.17-5.15	0.937
No	4 (1.1)	25.0	0.93	0.17-5.15	0.937
Filtered water
Yes	336 (91.8)	25.0	1	1.22-2.86	0.004*
No	30 (8.2)	46.7	1.87	1.22-2.86	0.004*

	n (%)	Prevalence of anemia (%)	PR (crude)	95%CI	p-value^a
Maternal age (years)
≥20	314 (86.5)	26.4	1	0.73-1.84	0.532
<20	49 (13.5)	30.6	1.16	0.73-1.84	0.532
Number of children
≤3	320 (87.4)	23.1	1	1.60-3.18	<0.001*
>3	46 (12.6)	52.2	2.26	1.60-3.18	<0.001*
Number of children aged <5 years
<2	284 (77.6)	23.6	1	1.13-2.27	0.008*
≥2	82 (22.4)	37.8	1.60	1.13-2.27	0.008*
Type of delivery
Normal	146 (40)	24.0	1	0.84-1.71	0.316
Cesarean	219 (60)	28.8	1.20	0.84-1.71	0.316
Breastfeeding
Yes	337 (92.3)	27.6	1	0.29-1.46	0.295
No	28 (7.7)	17.9	0.65	0.29-1.46	0.295
Exclusive breastfeeding
Yes	307 (84.8)	28.0	1	0.41-1.25	0.237
No	55 (15.2)	20.0	0.71	0.41-1.25	0.237
Time of exclusive breastfeeding
6 months	154 (50.5)	22.14	1	1.17-2.08	0.279
<6 months />6 months	151 (49.5)	31.40	1.42	1.17-2.08	0.279
Consumption of meat and/or viscera
≥once a week	306 (84.5)	23.2	1	1.41-2.83	<0.001*
<once a week	56 (15.5)	46.4	2.00	1.41-2.83	<0.001*
Bean consumption
Daily	214 (60.6)	21.5	1	1.14-2.27	0.007*
Non daily	139 (39.4)	34.5	1.61	1.14-2.27	0.007*
Consumption of dark green leafy vegetables
Daily	48 (13.3)	20.8	1	0.74-2.38	0.336
Non daily	314 (86.7)	27.7	1.33	0.74-2.38	0.336
Use of iron supplement
Yes	148 (41.1)	18.2	1	1.22-2.68	0.003*
No	212 (58.9)	33.0	1.81	1.22-2.68	0.003*

	n (%)	Prevalence of anemia (%)	PR (crude)	95%CI	p-value^a
Gender
Female	183 (50.0)	27.9	1	0.66-1.29	0.637
Male	183 (50.0)	25.7	0.92	0.66-1.29	0.637
Age (months)
12 to 23	199 (54.4)	18.6	1	1.38-2.80	<0.001*
6 to 11	167 (45.6)	36.5	1.96	1.38-2.80	<0.001*
Skin color
White	188 (51.2)	25.0	1	0.79-1.58	0.518
Non white	175 (48.2)	28.0	1.12	0.79-1.58	0.518
Gestational age at birth (weeks)
≥37	338 (92.9)	26.9	1	0.42-1.77	0.677
<37	26 (7.1)	23.1	0.86	0.42-1.77	0.677
Weight at birth (g)
≥2500	326 (89.8)	26.4	1	0.66-1.91	0.657
<2500	37 (10.2)	29.7	1.13	0.66-1.91	0.657
Previous hospitalization
No	249 (68.2)	26.9	1	0.69-1.43	0.971
Yes	116 (31.8)	26.7	0.99	0.69-1.43	0.971
Weight/age index (score Z)
≥-2	344 (95.6)	27.0	1	0.39-2.20	0.860
<-2	16 (4.4)	25.0	0.92	0.39-2.20	0.860
Height/age index (score Z)
≥-2	311 (86.4)	27.0	1	0.60-1.62	0.944
<-2	49 (13.6)	26.5	0.98	0.60-1.62	0.944
Weight/height ratio (score Z)
≥-2	340 (94.4)	27.1	1	0.42-2.02	0.842
<-2	20 (5.6)	25.0	0.92	0.42-2.02	0.842

	Model 1		Model 2		Model 3
	PR	95%CI	PR	95%CI	PR	95%CI
Block 1
Family income (minimum age)
>1	1	1.03-2.18*	1	0.93-2.07	1	1.01-2.20*
≤1	1.50	1.03-2.18*	1.39	0.93-2.07	1.49	1.01-2.20*
Number of residentes in the household
≤5	1	1.07-2.11*	1	0.70-1.68	1	0.70-1.60
>5	1.50	1.07-2.11*	1.08	0.70-1.68	1.06	0.70-1.60
Filtered water
Yes	1	1.11-2.56*	1	0.90-2.23	1	0.91-2.30
No	1.68	1.11-2.56*	1.41	0.90-2.23	1.45	0.91-2.30
Block 2
Number of children
≤3			1	1.01-2.68*	1	1.02-2.57*
>3			1.64	1.01-2.68*	1.62	1.02-2.57*
Consumption of meat and/or viscera
≥once a week			1	1.24-2.58**	1	0.97-2.07
< once a week			1.78	1.24-2.58**	1.42	0.97-2.07
Block 3
Age (months)
12 to 23					1	1.20-2.55**
6 to 11					1.75	1.20-2.55**
Akaike Criterion	432.07		422.77		418.67

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[1] *Corresponding author. E-mail: drochaufba@gmail.com (D.S. Rocha).