Daily treatment may be superior to the standard three-times-weekly treatment for preventing early relapse in tuberculosis patients.
In a nested case-control study of 12,183 patients with pulmonary tuberculosis who completed treatment in 1 year, the overall 30-month relapse rate was 0.9%. The rate in those treated three times weekly was increased, compared with the rate in those treated daily (odds ratio 3.92), reported Kwok C. Chang, M.D., of Grantham Hospital, Hong Kong, and colleagues.
The investigators also found that prolonging intensive-phase treatment and overall treatment by at least 50% reduced the relapse rate (odds ratio 0.24). They found significant associations between relapse and each of the following: extensive disease on chest radiograph, presence of conditions associated with active tuberculosis (such as diabetes), and coexisting tuberculosis lymphadenitis (Am. J. Respir. Crit. Care Med. 2004;170:1124-30).
Standard dosing might be cost effective in those without cavitation on initial radiograph, but further research to determine the best treatment strategy in other settings is warranted, they said.