Table 2.

Summary of comparisons made for the association between helminths and allergy‐related diseases outcomes by studies conducted in Africa between 2008 and March 2018

Direction of effect	Number of published studies	Total number of participants in the given studies	Specific examples of comparisons made
Positive	3	4474	A. lumbricoides ↔EIB; A. lumbricoides ↔wheeze; T. trichiura ↔SPT (×2)
Inverse	6	5700	Schistosoma spp ↔SPT (×4); A. lumbricoides ↔SPT; Hookworm ↔ wheeze; Hookworm ↔ eczema; T. trichiura ↔eczema; Maternal hookworm in pregnancy ↔ eczema 0‐5 y
No statistically significant association reported by the whole study	8	7888	A wide range of combinations
Both statistically significant and insignificant results reported by the same study	4	6448	A wide range of combinations
Positive (anthelmintic treatment)	1	2507	Albendazole in pregnancy→eczema in infancy Albendazole in pregnancy→wheeze in infancy Praziquantel in pregnancy →eczema in infancy
No association (anthelmintic treatment)	1	1188	Albendazole in pregnancy→wheeze & SPT at age 9 y Praziquantel in pregnancy→wheeze & SPT at age 9 y Albendazole in early childhood→wheeze & SPT at 9 y

↔ The two variables tested for association in observational studies

→ The two variables tested for association in clinical trials