Table 2 GRADE evidence profile (EP) for the 15 studies included in the systematic review
Quality assessment of evidence | ||||||
|---|---|---|---|---|---|---|
Study | Limitation | Inconsistency | Indirectness | Imprecision | Risk of bias | Quality grading |
1) Nga et al. 2011 [48] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ⊕⊕ High |
2) Nga et al. 2009 [47] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ⊕ ⊕ High |
3) Nchito et al. 2009 [45] | Serious limitation (sample size used for analysis was smaller than that required for statistical significance; mean number of supplementation tablets taken was only 50% of tablets provided) | Serious inconsistency (administration of albendazole at baseline was not stated under study design but was mentioned under results) | No serious indirectness | No serious imprecision | Serious risk of bias (47% of children were lost to follow-up; method of recruitment and inclusion/exclusion criteria were not mentioned) | ⊕ ⊕ ◯ ◯ Low |
4) Long et al. 2007 [39] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ⊕ ⊕ High |
5) Long et al. 2006 [38] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ⊕ ⊕ High |
6) Olsen et al. 2003 [44] | Serious limitation (compliance rates for the multi-micronutrient tablet and placebo were low at 46%) | Serious inconsistency (the allocation of anthelminthic treatment and placebo was not clear) | No serious indirectness | No serious imprecision | Serious risk of bias (number of stool samples collected for each child varied) | ⊕ ⊕ ◯ ◯ Low |
7) Olsen et al. 2000 [43] | No serious limitation | Serious inconsistency (reporting of results was not consistent for all helminth species) | No serious indirectness | No serious imprecision | Serious risk of bias (method of recruitment and blinding procedures not mentioned; number of stool samples collected varied at each follow-up) | ⊕ ⊕ ◯ ◯ Low |
8) Grazioso et al. 1993 [36] | No serious limitation | Serious inconsistency (data reported under abstract is different from that found in the results section) | No serious indirectness | Serious imprecision (stratification of results according to soil-transmitted helminth species was not performed) | Very serious risk of bias (number of intervention days not clear; reporting of primary outcome measures were not complete) | ⊕ ◯ ◯ ◯ Very low |
9) Halpenny et al. 2013 [41] | Serious limitation (compliance rate for albendazole at both treatment cycles was low at 48%) | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ◯ ◯ Low |
10) Hesham Al-Mekhlafi et al. 2008 [46] | No serious limitation | Serious inconsistency (reporting of sample size was not consistent throughout the study) | No serious indirectness | Serious imprecision (stratification of results according to soil-transmitted helminth species was not performed) | None detected | ⊕ ◯ ◯ ◯ Very low |
11) Payne et al. 2007 [40] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | Serious risk of bias (vitamin A supplemented children came from families with significantly higher income and latrine access than the non-supplemented children; 34% children were lost to follow-up) | ⊕ ⊕ ◯ ◯ Low |
12) Saldiva et al. 2002 [37] | No serious limitation | Serious inconsistency (stratification of undernourished and eutrophic children not clear) | No serious indirectness | Serious imprecision (stratification of results according to soil-transmitted helminth species was not performed) | None detected | ⊕ ◯ ◯ ◯ Very low |
13) Hagel et al. 1999 [50] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | Serious risk of bias (poverty level as a confounding factor was not taken into account during data analysis) | ⊕ ◯ ◯ ◯ Very low |
14) Kightlinger et al. 1996 [42] | No serious limitation | Serious inconsistency (number of children included for analysis varied for different outcome measures) | No serious indirectness | No serious imprecision | Serious risk of bias (about 41% children were lost to follow-up) | ⊕ ◯ ◯ ◯ Very low |
15) Hagel et al. 1995 [49] | No serious limitation | No serious inconsistency | No serious indirectness | No serious imprecision | None detected | ⊕ ⊕ ◯ ◯ Low |