Table 3.

 Examples of eligibility criteria that differed between trial protocols and subsequent publications

Protocol including amendments	Publication	Impact on readers’ interpretation
Type or severity of illness:
Hormone plasma level <280 ng/dl (exclusion criterion)	Hormone plasma level <240 ng/dl (exclusion criterion)	Broader study population
Crohn’s disease activity index 220-400. In amendment: 180-400 (inclusion criterion)	Crohn’s disease activity index >220 (inclusion criterion)	Unclear because of ambiguity between amendment to protocol and publication
Personal criteria:
Age range 30-80 years (inclusion criterion)*	Age range 18-80 years (inclusion criterion); age >50 and <20 years (exclusion criterion)	Unclear because of ambiguity between reported inclusion and exclusion criterion
Comorbidity:
Primary refractory disease (exclusion criterion)	Primary refractory disease (inclusion criterion)	Broader study population
Diabetes mellitus (exclusion criterion)	Other endocrine or metabolic diseases (exclusion criterion)	Narrower study population
Other criteria:
Not stated	Common exclusion criteria of clinical studies	Narrower study population

*Stated only on application form, not in protocol.