Answer
Nonresponse bias.
The conclusion could be incorrect.
Samples are not very large
Work Step by Step
The study contains nonresponse bias, because no results are available for 2 of the 49 patients that were in the study.
The conclusion could be incorrect; just because there was no significant difference between the two samples, does not mean a 3-day course of antibiotics following pediatric tonsillectomy is as effective as a 7-day course with regard to postoperative analgesic use and resumption of normal diet and level of activity.
The samples are not very large, so increasing the sample sizes could make the result significant instead of insignificant.
