Randomization To account for differences in living arrangement and ensure that elderly living in the same household are assigned to the same intervention or control group, stratified permuted block randomization will be used in this study. Participants will be grouped according to either of the three strata: (1) single elderly in a household, (2) two elderly from same household participating in the trial (a pair) and (3) only one out of two elderly from same household participating in the trial. Blocks of 10, with the assignment of 5 to experimental group and 5 to control group, will be used for each strata. Using a computerized randomization software, a statistician will generate the randomization list and prepare 3 different sets of sealed envelopes. According to their strata, the participant or the pair of participants will choose from the respective set of envelopes themselves to determine the group assignment.