Vitamin D3 supplementation as an adjunct in the management of childhood infectious diarrhea: a systematic review

BMC Infectious Diseases

Table 2 The methodological quality of the nine selected studies using the Newcastle-Ottawa Scale and Cochrane Collaboration tool

Study (Study design)	Selection (max. of 5 stars)	Comparability (max. of 2 stars)	Exposure/outcome (max. of 3 stars)	Total (ten stars)^†	RSG *	AC *	BPP *	BOA *	IOD *	SR *	OB *
Thornton et al. [23] (Longitudinal/prospective study)	2 stars	-	1 star	3 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Mileva et al. [15] (Cohort study)	4 stars	1 star	3 stars	8 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Talachian et al. [22], (Cross-sectional study)	4 stars	1 star	2 stars	7 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Bucak et al. [25] (Cross-sectional study)	4 stars	2 stars	2 stars	8 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Ahmed et al. [26] (Cohort study)	3 stars	1 star	2 stars	7 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Palframan et al. [24], (Longitudinal study)	2 stars	-	1 star	3 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Mahyar et al. [16] (Cross-sectional study)	3 stars	2 stars	2 stars	7 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Hassam et al. [21] (Case-control study)	3 stars	2 stars	2 stars	7 stars	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Aluisio et al. [17], (Randomized control trial)	N/A	N/A	N/A	N/A	(+)	(+)	(+)	(?)	(+)	(+)	(?)

^†Total rating of ≥ 7 stars and < 7 stars suggests high methodological quality and low methodological quality, respectively
N/A, not applicable max., maximum * Parameters of the Cochrane Collaboration tool for randomized control trials
RSG, Random Sequence Generation AC, Allocation Concealment BPP, Blinding of Participants and Personnel BOA, Blinding of Outcome Assessment IOD, Incomplete Outcome Data SR, Selective Reporting OB, Other Bias
Key to the risk of bias assessment: low risk of bias (+), high risk of bias (-), or unclear risk of bias (?)

ISSN: 1471-2334