Trial protocol

Patient recruitment to the study took place between November 2007 and October 2009 in the coronary care units and cardiology wards of the participating sites. A flow diagram of patient recruitment and follow-up is presented in Figure 4. Gatekeepers provided the interventionists with a list of potentially interested patients. These patients were subsequently approached and their eligibility and interest in hearing more information about the study was verified. This usually occurred within 2 to 4 days of the patient’s admission. Verbal and written information was provided and all questions were answered. If

106

the patient was willing to proceed with the study, informed consent was obtained and the participant was provided with a copy of the consent form. The CONSORT checklist (Schulz et al. 2010) for this study can be located in Appendix 7.

Randomisation

A computerised random number generator was used to randomly allocate 250 participants to the control group and 250 to the intervention group in each research site. Using block randomisation, each random sequence was further sub-divided into blocks of 20. Within each block of 20, there were 10 participants assigned to the intervention group and 10 to the control group. While the numbers were generated sequentially, the allocations of intervention and control assignments were totally random.

Concealment of group allocation

Sequentially-numbered, opaque, sealed envelopes were used as the means of group concealment. The study number was visible through a window in the envelope, but the allocation to the intervention or control group was concealed. Thus, there was no way of knowing the group allocation associated with the random number. Pre-prepared envelopes were filed in numerical order from 1- 500, ready for allocation. As patients were recruited to the study, they were automatically given the next number in the sequence. This process further precluded the potential for selection bias as the group to which the patient was randomised was never revealed to the interventionist or the participant until informed consent was obtained and baseline data collected.

107

108 Blinding

Due to the educational nature of the intervention, it was not possible for the interventionist or participant to be blinded to the randomised group. Furthermore, the interventionist was responsible for reinforcing the intervention at one and six months. Therefore, knowledge of randomised group was necessary for intervention delivery.

Blinding was executed in the collection of 3 and 12 month outcome data as postal questionnaires were identified by study number only and contained no identifiable reference to group allocation. In addition, these questionnaires measured objective data. Clinical staff were not made aware of participant group allocation, which avoided any temptation by them to provide additional information to the control group, beyond that of usual care. These measures maximised the use of blinding in this study.

4.8.2 Baseline data collection

Baseline data collection preceded the revelation of group allocation. Data were collected through face-to-face interviews, using pen and paper. When participants were comfortable and happy to begin, each question was read aloud and time was given for them to follow what was being read on the identical copy they had been provided with. Participants were instructed to choose the responses that most closely reflected their opinion. Their selected responses were then recorded on the questionnaire on which their study number was written. If the participant demonstrated any ambiguity in their understanding of a question, the question was re-read for clarification. On completion of the interview, demographic and clinical information were checked against their medical notes and inconsistencies were reconciled with the participant.

Participants who were randomised to the control group were thanked for their participation and reminded of the next steps in the data collection process, which was the completion of the 3 and 12 month questionnaires. A refrigerator magnet with the study logo and name was provided to remind them of the study. The interview was closed with a final expression of gratitude.

109 4.8.3 Follow-up

Knowledge, attitudes and beliefs were measured at 3 and 12 months after recruitment. The baseline questionnaire was again administered at these time- points, but it was labelled according to the relevant time-point (3 month or 12 month) (Appendix 6). Questionnaires were posted to participants in both groups. Those who had not returned their questionnaire within two weeks of distribution were telephoned to check if they had received it. During the call, their interest in remaining in the study was ascertained and on-going consent confirmed. Participants often requested that the questionnaire be resent to them, if they had mislaid or forgotten to complete it. Occasionally participants requested that the questionnaire be completed over the telephone. These requests were upheld. On receipt of completed questionnaires, participants were telephoned to thank them for their on-going assistance and to advise them of the next step in the data collection process.

4.8.4 Methods of minimising attrition bias

Strategies were employed to minimise attrition bias in this study. These involved efforts to minimise the extent of missing data through maximising the number of returned completed questionnaires. Attempts to limit attrition bias were made through the inclusion of a stamped addressed envelope and a return address on the back of each envelope. This helped to ensure that undelivered questionnaires could be returned to the interventionist. In addition, a personalised message was written on each standardised letter that was sent to participants at 3 and 12 months. Personalised notes included for example, good wishes sent to a new grandchild or a get-well message to a participant’s ill spouse. This helped to increase the likelihood that participants would return their completed questionnaires through the maintenance of a good rapport. The follow-up courtesy telephone call provided an opportunity to rectify any missing data that were noted on returned questionnaires. These approaches helped to minimise the extent of missing data. Strategies were consistent across randomised groups.

110 Per protocol analysis

A decision was made a priori to employ a per protocol analysis (PPA) to address missing data. Therefore, only participants who completed questionnaires at all three time-points and who had no missing data were included in the analyses. Specific details of participants who were lost to follow- up and the rationale for same are provided in the CONSORT flow diagram in Chapter 5.