Secondary outcomes
To evaluate whether the surveyed persons were aware of the effort to influence their choice each surveyed person was asked which of two statements he/she agreed with the most: ‘The pamphlet provides me information in order to help me make my own choice’ or ‘The pamphlet provides me information in order to direct me towards the choice that the pamphlet favours’. If the surveyed person felt that the pamphlet tried to direct their choice, (s)he was asked if there were anywhere specific in the pamphlet that made them feel so. It was then noted if the selected paragraph contained an influence or not. More general responses were also recorded, i.e. ‘the first page is trying to scare me’ or ‘there is no mention of harms’. It was then decided by the coding interviewer whether the response indicated awareness or non-awareness to the influence.The effect of awareness of the influences on intention to participate was assessed by comparing odds ratios (ORs) of intention to participate between three groups: one group who felt the pamphlet tried to help the receiver make their own choice, one group who felt the pamphlet tried to direct their choice and subsequently correctly located an influence and the last group who felt the pamphlet was trying to direct their choice but failed to correctly locate an influence.