The annual incidence of TB cases among Singapore
residents fell steadily from 306 per 100,000 population in 1960
to 56/100,000 in 1987 but has since remained at between 50 and 55/100,000.
One of the possible reasons for this non-decline may be persistence
of transmission of TB in the community due to delayed diagnosis,
treatment and ineffective case holding.
Compared to non-defaulting patients as controls,
defaulters were mostly non-Chinese, and those live on their own
or with friends. There was no significant association of defaulting
with age, sex, marital or employment status, disease characteristics,
or treatment-related factors. Seventy per cent defaulted during
the continuation phase of treatment.
The study was a retrospective patient record based
case control study conducted in the TB Control Unit (TBCU), Singapore.
This being the main treatment centre, which treats about 50% of
the cases was the venue of the study. The objectives were to: (i)
identify any demographic, social, disease or treatment-related characteristics
which may be predictive of patients defaulting from treatment; (ii)
assess the effectiveness of home visits as a means of defaulter
recall; and (iii) ascertain outcome in these patients. TB treatment
defaulters were defined as the patients who missed their scheduled
appointments and required a home visit to recall for treatment.
Equal number of controls were randomly selected from non-defaulting
patients who started treatment on the same dates as the defaulters.
Majority of the patients were supplied drugs for self-administration
at home and there were about 10% of the patients who were on DOTS
during the study period.
Of the 44 treatment defaulters, 6 (13.6%) were
contacted directly, 20 (45.5%) through a person at home during the
visit and for 18 (40.9%) a recall letter was slipped through the
door due to no contact with patient or any other person at home.
Following home visits, 20 (45.5%) returned within 7 days. The treatment
outcome was not very encouraging as only 19 (43.2%) completed treatment,
21 (47.7%) were not traceable, 1 was dead and 3 were hospitalized.
However, of the 21 patients who were lost to follow-up, all except
one had culture negative results. The study identifies the future
prediction of default as those who were non-Chinese, living alone,
male and had a previous history of treatment.