Wave 12 included an advance letter experiment whereby one-third of the sample was provided with information on their nearest pharmacy to enable blood pressure measurement. One-third included an altruistic/pro-social appeal text to the letter to encourage participants to get their blood pressure measured. The remaining sample did not receive any of these treatments – the control group.
Allocations to treatment were at household level so everyone in the household was treated the same.
All sample members received a conditional £5 if blood pressure was measured.
Group 1 – Information treatment
This group was given specific information about a pharmacy local to them that provides free blood pressure checking.
For sample members outside London, we had information about a nearby pharmacy that provides free blood pressure checks for around 95% of sample members. For those living in London, this fell to around 75%. Thus, the allocation to experimental group was stratified by region (London/outside London) to ensure that the sample was balanced between the three groups within each area. Within the information treatment group there were some sample members for whom we did not have the required information (around 5% of those outside London, 25% of those within London). These sample members were re-allocated after the initial allocation to the control group.
Group 2 – pro-social message
This group was sent an advance letter which included a sentence or two about the social benefits of getting one’s blood pressure measured.
The variable controlling this experiment is l_ff_bpinfo on record l_hhsamp_ip:
1 Information Treatment
2 Pro-social appeal Treatment
3 Control
Variables used for this experiment are on record l_indresp_ip:
