Misleading description

Few subjects or events

Look out for intervention effects that are based on small studies with few subjects. Fair comparisons with few subjects or effect measures can be misleading.

When there are only few effect measures, differences in outcome frequencies between the intervention comparison groups may easily have occurred by chance and may mistakenly be attributed to differences between the interventions.

It is like tossing coins. Imagine you have two coins that are exactly the same. You would expect to get the same result from tossing each coin in the air 100 times. But if you tossed each coin just 5 times, you might get “heads” 4 times with one coin and 1 time with the other coin, just by chance.

REMEMBER: Be cautious about relying on the results of intervention comparisons with few effect measures (small sample sizes). The results of such comparisons can be misleading.