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

Table 10 Relative risk ratios for wasting, Manufahi District, Timor-Leste

	Moderate wasting (n = 145)					Severe wasting (n = 44)
Parameter	RR	95% CI	ARR	95% CI	P	RR	95% CI	ARR	95% CI	P
Ascaris heavy-intensity	0.83	0.42–1.6	0.83	0.40–1.7	0.4465	0.51^a	0.13–2.1	0.37^a	0.07–1.9	0.4942
Ascaris moderate-intensity	0.73	0.38–1.4	0.64	0.32–1.3		1.1^a	0.41–3.1	0.92^a	0.32–2.7
N. americanus heavy-intensity	1.7**	1.1–2.8	1.3	0.76–2.1	0.5964	2.1**	0.91–4.7	1.2	0.51–3.0	0.8431
N. americanus moderate-intensity	0.87^a	0.35–2.1	0.91^a	0.36–2.3		1.5^a	0.40–5.6	1.4^a	0.35–5.4
Giardia infection	0.79	0.47–1.3				0.46^a	0.17–1.2
Anaemia prevalence	0.63	0.32–1.2	0.83	0.41–1.7	0.6140	0.66^a	0.22–2.0	1.2^a	0.37–3.8	0.7770
Male sex	1.3	0.84–1.9	1.2	0.79–1.9	0.3580	1.3	0.68–2.7	1.3	0.61–2.6	0.5340
Age group 6 to 11 years	3.0***	1.7–5.2	2.9	1.6–5.1	< 0.0001	3.5**	1.3–9.3	3.2	1.2–8.9	0.0220
Age group 12 to 17 years	4.9***	2.6–9.2	4.3	2.2–8.4	< 0.0001	7.8***	2.6–22.7	7.1	2.3–21.8	0.0010
Socioeconomic quintile 4	0.80	0.40–1.6	0.82	0.39–1.7	0.9181	0.89^a	0.27–3.0	0.92^a	0.27–3.2	0.8840
Socioeconomic quintile 3	0.72	0.35–1.5	0.77	0.35–1.7		1.3^a	0.36–4.4	1.3^a	0.35–4.6
Socioeconomic quintile 2	0.69	0.34–1.4	0.79	0.37–1.7		0.60^a	0.16–2.3	0.70^a	0.18–2.7
Socioeconomic quintile 1 (poorest)	0.66	0.31–1.4	0.68	0.30–1.5		0.59^a	0.15–2.3	0.66^a	0.16–2.7

Notes: Ascaris (categorical infection intensity), N. americanus (categorical infection intensity), Ancylostoma infection prevalence (binary), anaemia prevalence (binary), age group, sex and socioeconomic quintile were included in all multivariable regression models as exposure outcomes and covariates. Insufficient Ancylostoma spp. observations to investigate in this regression model. No interactions were significant in this model. Reference categories: No Ascaris infection, no N. americanus infection, no Ancylostoma infection, no Giardia infection, no anaemia, female sex, age group 1–5 years, socioeconomic quintile 5 (wealthiest)
Abbreviations: RR relative risk adjusted for age², ARR adjusted relative risk, CI confidence interval; P, Wald test P-value
**P < 0.05, ***P < 0.01 in univariable analysis
^aTen observations or less in subgroup; result should be interpreted cautiously
Normal growth (no wasting) is reference category, i.e. moderate and severe wasting need to be interpreted relative to this reference. Ascaris and N. americanus intensity infections 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