The purpose of this study is to investigate the knowledge about randomised clinical trials and the attitude towards clinical research among Danish outpatients. The INFO Trial was designed as a randomised, parallel group, observer-blinded trial comparing three types of written information (a leaflet, a brochure, and a booklet) to each other and to a no intervention group.

To improve the patient education process in clinical research, three information materials describing general aspects of design and conduct of randomised clinical trials were developed. The materials varied in length, reading ability level, and reader appeal. Their influence on knowledge about and attitude toward randomised clinical trials was assessed in a randomised, parallel group, evaluator-blinded trial among 415 outpatients recruited from four departments at a university hospital in Copenhagen. The patients were randomised to the following groups: control (no intervention), leaflet, brochure, or booklet in a 1:1:1:1 ratio. Knowledge (KN) was assessed by a 17-item multiple-choice questionnaire and attitude (AT) was assessed by a 32-item Likert questionnaire at entry and 2 weeks after the intervention. The interventions and the questionnaires were pilot tested and power calculations were performed.

Assessment of scales for knowledge and attitudes was performed using Rasch analysis and Cronbach 's alpha. Associations between demographic variables, knowledge score and attitude score were examined using analysis of variance.

Inclusion Criteria:

• Outpatient
• Ability to read and understand Danish and written informed consent.

Exclusion Criteria:

• Patients under 18 years of age and patients enrolled in another clinical trial on the same day.

No plan for data sharing