Methods
Study population
The study area is located in the Kaengkhoi district, Saraburi
Province, Thailand, which is approximately 100 km north of
Bangkok. The area includes a small city with some industry; it
is surrounded by rural villages and residents depend on agriculture
for their income. Data from the 2001 census maintained
by government health-care officers show a total population of
80 141 in the catchment area, including 5686 (7%) children
less than 60 months of age.
Health-care system
Health-care utilization in the Kaengkhoi district has been reviewed
in detail (6). In brief, the health-care system has three
tiers with the first point of contact being the community health
centre; this is usually a free-standing structure staffed by one or
more nurses who provide basic health services, stabilize emergency
patients for transport elsewhere and perform uncomplicated
deliveries. There are 20 community health centres in the catchment area. Patients who cannot be adequately cared for at
the community centre are transferred to the district hospital in
Kaengkhoi, which is staffed by internists, paediatricians and
surgeons. Patients who require subspecialty services or therapies
not available in the district hospital are transferred to the
provincial hospital near Kaengkhoi. Some doctors working
at government hospitals earn extra income by seeing patients
at their private clinics in the evenings. A survey conducted in
2000 identified 16 private clinics in the study area. Not all
patients seek care at public or private clinics; some patients treat
themselves with over-the-counter pharmaceuticals or traditional
products. Residents are assigned to government health
centres, which may be the community health centre or the outpatient
department of a hospital. Government policy encourages
patients to see their assigned primary health-care provider by
charging reduced fees for seeing the assigned provider. All community
health centres in the study area, the district hospital and
the provincial hospital participated in the surveillance study.