A 2007 study provides a possible resolution to the different results found across studies investigating breastfeeding's effect on intelligence.

The intensity of monitoring will vary across studies and among sites.

These networks are found to be quite consistent across studies, despite differences in the data acquisition and analysis techniques.

The evidence on productivity growth in the industrial sector varies across studies, however.

Age younger than 1 year may increase risk, but this is not consistent across studies.

However, it noted considerable heterogeneity in the impact on recall rate across studies.

Other factors concerned with study design will influence the degree to which prevalence rates may be compared across studies.

Simple comparisons of prevalence estimates across studies is, therefore, problematic.

Inconsistency of results across studies can be quantified and analyzed.

Overall, slight health benefits have been found fairly consistently across studies.