Attendance versus compliance with tuberculosis treatment in an occupational setting--a pilot study.

AIM

To determine the prevalence of non-compliance with tuberculosis treatment at Freegold Mines.

OBJECTIVES

1. To establish the rates of attendance and collection of anti-tuberculosis drugs. 2. To determine prevalence of non-compliance by means of urine tests.

DESIGN

A cross-sectional study conducted over 2 weeks at mine medical stations.

METHOD

Urine samples were collected from tuberculosis patients 3 hours after drug ingestion. Non-compliance was established by testing these samples for rifampicin and/or isoniazid (INH) metabolites. Non-compliance was defined as a negative urine test result for these drugs in participants whose treatment regimens included one or both. Daily attendance and collection of drugs statistics are recorded in the medical station tuberculosis register. The patient rate of adherence was calculated as the observed number of days on which medication had been collected over the expected treatment days in a given period.

RESULTS

Urine test results showed an overall prevalence of non-compliance of 14.6 +/- 3.3%. The study showed that non-compliance with tuberculosis treatment was underestimated by the surveillance data. The rate of non-adherence with treatment established from the formal surveillance procedure was 0.2%. The poor response rate of patients was found to be a major problem and fewer than 40% per day returned to bring urine specimens. The mean prevalences of non-compliance established by rifampicin and INH tests were 19.5 +/- 5.3% and 9.8 +/- 3.9%, respectively, and these were significantly different (Chi 2 = 7.44; P < 0.05). The proportion of false-positive results for INH and rifampicin urine tests were 21% (11/53) and 35% (17/48), respectively, showing that some patients were taking the wrong treatment.

CONCLUSIONS

It is clear that attendance at the clinics does not accurately reflect compliance. Both programme compliance (dispensing of the correct treatment) and patient compliance need to be improved. This has important implications for the new national tuberculosis control policy adopted by the South African government that stresses the importance of directly observed therapy, short-course (DOTS) and a patient-centred approach.