Risk factors for defaulting from anti-tuberculosis treatment under directly observed treatment in Hong Kong.
OBJECTIVE
To identify risk factors for defaulting from anti-tuberculosis treatment.


METHODS
Directly observed treatment in Hong Kong Government chest clinics.


METHODS
Defaulters were recruited from a cohort of tuberculosis patients registered from 1 January to 31 March 1999. Three controls per case, matched for age and sex, were selected randomly from the cohort. Patient factors, initial tuberculosis characteristics and treatment-related variables were collected by review of medical records.


RESULTS
On matching 102 defaulters and 306 controls, a logistic risk model of default that considered patient factors, initial disease characteristics and treatment-related factors identified seven risk factors: current smoking (OR 3.00, 95% CI 1.41-6.39), past TB with default (OR 6.23, 95% CI 1.95-19.91), poor initial adherence (OR 117.21, 95% CI 13.52-1015.92), fair initial adherence (OR 11.02, 95% CI 2.15-56.43), unknown initial adherence (OR 6.59, 95% CI 3.47-12.49), treatment side effects (OR 13.30, 95% CI 3.23-54.79), and subsequent hospitalisation (OR 0.27, 95% CI 0.11-0.67). Its predictive power was 85%. Another model that considered only factors on registration for treatment gave a lower predictive power of 70%.


CONCLUSIONS
Treatment default could be predicted fairly accurately by considering patient and treatment-related factors.
Chang
K C
KC
TB and Chest Service, Department of Health, Hong Kong. ymtcc@dh.gov.hk
Leung
C C
CC
Tam
C M
CM
D000995:Antitubercular Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D023801:Directly Observed Therapy; D005260:Female; D006723:Hong Kong; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016312:Treatment Refusal; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*
D000995:Antitubercular Agents