External validity of randomized clinical trial studying preventing depressive symptoms following acute coronary...

The objective of the current study was to quantitatively explore aspects of external validity, both researcher's choices (eligibility) and patient's choices (consent), of a recently conducted clinical trial.

A cohesive comparison between the MEDACIS trial (NCT02451293) database and a national quality and research database was conducted. Comparisons between both participants and nonconsenting patients (patient consent) and participants and noneligible patients (researcher selection) were performed. Comparisons of outcomes were depressive and anxiety symptoms, demographics, and somatic or psychiatric comorbidity.

Noneligible patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to suffer from unstable angina pectoris. Furthermore, noneligible patients were less likely to be married, had a lower educational level, used more medication, and had a higher frequency of comorbidity. Nonconsenting patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to be females compared to participants.

Significant differences were present between noneligible patients and participants; however, more troublingly significant differences were shown between nonconsenting patients and participants. The presence of depressive symptoms and anxiety has a significant impact on patients' willingness to give informed consent in clinical trials in cardiology with a focus on psychological outcomes.