The selection of study sites involved convenience sampling. For practical purposes, it was
important to choose sites where the research team had contacts that could act as
intermediaries in the recruitment of participants. First, in each region, one province was
selected: Chiang Mai in the North, Khon Kaen in the Northeast, Songkhla in the South and
Nakhon Pathom in the Central region. Each province was divided into urban and rural areas,
and each area consisted of five groups, four of which were comprised of working-age
participants from the formal and informal sectors. Both were included in the study because
those who work in the formal sector have a mandatory retirement age which is closely related
to the definition of old age, while those who work in the informal sector do not. The final
group was comprised of participants aged 60 or older regardless of working status. Thus, each
region consisted of ten groups (five groups in both urban and rural areas), and Bangkok
consisted of five groups since all of Bangkok is considered urban. Thus, there were 45 FGDs in
this study with five to eight people in each group. Each group consisted of participants in the
same occupation, except for the group of older participants. Males and females were included
together in the groups since the retirement age in Thailand is the same for both sexes (Table 1).
All data were collected by the key investigators. The discussions followed the questions listed
in Table 2.