Investigations into the association between soil-transmitted helminth infections, haemoglobin and child development indices in Manufahi District, Timor-Leste

Table 7 Odds ratios for anaemia, by Necator americanus and Ascaris spp. infection intensity, Manufahi District, Timor-Leste. Logistic regression was used for investigating factors associated with anaemia. The outcome variable is binomial anaemic/non-anaemic and associations therefore presented as odds ratios

	Children; aged 1 < 18 years (N = 1018)					Adults; aged ≥ 18 years (N = 1020)
	Univariable		Multivariable			Univariable		Multivariable
Parameter	OR	95% CI	AOR	95% CI	P	OR	95% CI	AOR	95% CI	P
Ascaris heavy-intensity	0.93	0.49–1.8	0.91	0.46–1.8	0.8820	1.7	0.84–3.3	1.8	0.86–3.6	0.1165
Ascaris moderate-intensity	0.73	0.39–1.4	0.85	0.44–1.6		1.7**	1.04–2.9	1.6	0.93–2.7
N. americanus heavy-intensity	0.52***	0.33–0.83	0.69	0.41–1.1	0.1606	0.92	0.62–1.4	0.86	0.56–1.3	0.7280
N. americanus moderate-intensity	0.42^a	0.18–1.0	0.50^a	0.21–1.2		0.99	0.52–1.9	1.0	0.52–1.9
Ancylostoma infection	1.5^a	0.58–3.9	1.5^a	0.58–4.1	0.3940	0.93^a	0.42–2.1	0.68^a	0.27–1.7	0.4130
G. duodenalis infection	0.92	0.56–1.5				0.42^a	0.16–1.1
Male sex	1.1	0.70–1.6	0.97	0.64–1.5	0.8940	0.93	0.66–1.3	0.98	0.68–1.4	0.9180
Age group 6 to 11 years	0.35***	0.22–0.54	0.39	0.24–0.61	< 0.0001
Age group 12 to 17 years	0.20***	0.11–0.38	0.19	0.09–0.38	< 0.0001
Age group 65+ years						1.2	0.74–1.9	1.2	0.76–2.0	0.3920
Socioeconomic quintile 4	1.0	0.49–2.0	0.93	0.46–1.9	0.0098	0.58	0.31–1.1	0.58	0.31–1.1	0.3718
Socioeconomic quintile 3	0.52	0.23–1.2	0.49	0.22–1.1		0.85	0.48–1.5	0.83	0.46–1.5
Socioeconomic quintile 2	1.2	0.60–2.4	1.1	0.55–2.2		1.1	0.65–2.0	1.1	0.62–1.9
Socioeconomic quintile 1 (poorest)	2.1**	1.0–4.1	2.1	1.0–4.3		0.97	0.54–1.7	0.91	0.50–1.7

Notes: Ascaris (categorical infection intensity), N. americanus (categorical infection intensity), Ancylostoma infection prevalence (binary), age group, sex and socioeconomic quintile were included in all multivariable regression models as exposure outcomes and covariates. Reference categories: no Ascaris infection, no N. americanus infection, no Ancylostoma infection, no Giardia infection, age group 1–5 years (for child model), age group 18–64 years (for adult model), male sex, socioeconomic quintile 5 (wealthiest)
Abbreviations: OR odds ratio, AOR adjusted odds ratio, CI confidence interval; P, Wald test P-value
**P < 0.05, ***P < 0.01 in univariable analysis
^aLess than 10 observations in a subgroup; result should be interpreted cautiously
Ascaris and N. americanus intensity infections were defined according to following cut-points: Ascaris: heavy-intensity C_q ≤ 15.4, moderate-intensity C_q > 15.4 < 31, no infection C_q ≥ 31; N. americanus: heavy-intensity C_q ≤ 24.6, moderate-intensity C_q > 24.6 < 35, no infection C_q ≥ 35

ISSN: 1756-3305