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U.S. Department of Health and Human Services


TB Notes 1, 2005

No. 1, 2005

Highlights from State and Local Programs

Immediate Cost Impact of Extended Treatment for Patients at High Risk for Relapse of TB in North Carolina

Short-course (6 month) treatment regimens, where indicated, are preferred and are highly effective for cure of TB. However, within the population of patients for whom a short-course regimen is indicated, there are those patients who have risk factors for treatment failure or relapse. The latest TB treatment guidelines include a recommendation to prolong the treatment for patients at high risk of treatment failure or relapse. These recommendations were based in part on US Public Health Service Study 22 of the TB Trials Consortium. Study 22 suggested that patients who had cavitation on initial chest radiograph, plus positive sputum culture after 8 weeks of treatment, were at higher risk for treatment failure and relapse. Pursuant to that observation, the current recommendation is to extend treatment from 6 to 9 months for patients who have these two risk factors. We evaluated past TB cases in North Carolina to determine how many would have met the new criteria for extended therapy and their length of treatment, and estimated the immediate cost of extending treatment for these patients.

Methods: The cohort included reported cases of TB from 1993 to 2002, inclusive. Patients who had positive sputum cultures and who had a documented culture conversion were included (n=2173). We limited our cost considerations to the cost of medication for the added length of the regimen and the time factor for a public health worker to perform biweekly directly observed therapy (DOT) using isoniazid (INH) at $2.80/month and rifampin (RIF) at $14.58/month. For personnel costs, we determined that $30,000 was an approximate average annual salary for those providing DOT in North Carolina, resulting in a computed hourly rate of $15.63. We estimated 3 hours per patient to perform DOT (1 hour to travel each direction to visit the patient and 1 hour to give DOT and complete records). Based on those two factors, we estimated the cost at $392.50 for 1 month of treatment for one additional TB patient to receive the extended regimen. We assumed that TB patients with risk factors for treatment failure and relapse were evenly distributed for each year.

Results: Of the 2,173 patients who had documented culture conversion, 469 met the high-risk definition (21.6%) of having a cavitary lung lesion on chest radiograph plus delayed sputum conversion; only 119 (25.4%) received 9 months or more of treatment. Of the remaining 350 patients, 104 received 6 months of therapy (22.2%) and 246 (52.5%) received between 6 and 9 months of therapy. Thus, 6 hrs/wk of DOT for 12 additional weeks per patient, plus the cost of additional INH and RIF, amounts to $1,177.50/patient. Assuming 35 patients per year would need 3 months’ additional treatment to comply with the new TB treatment guidelines, North Carolina TB Program costs are expected to increase approximately $41,212.50/year.

Discussion: The cost to treat patients who have active TB is generally borne by the public health system. In North Carolina, the cost of medication for TB patients is funded by general revenue funds allocated by the state legislature. Hence, the rise in costs for treating this subset of TB patients presents a significant challenge to the North Carolina TB Program when viewed along with budget cuts in three major categories of state funding. Funding for TB medication has been reduced three times within the past 4 years. General revenue funds for TB aid to counties have been reduced, and funding for TB medical services for the counties has also been reduced. Like many other states, North Carolina is a “home rule” state (home rule is a delegation of specific types of power from the state to its subunits of government, including counties, municipalities, towns or townships, or villages). Therefore, responsibility for TB control rests with the county or regional health district. The North Carolina TB Program works with these jurisdictions, providing limited funding and program guidance, to achieve state and national TB program objectives. The cost of extending treatment for those having risk factors for relapse is an issue with which public health officials have to contend, but it is balanced by the costs incurred when a patient relapses, resulting in an additional 6 full months of therapy. TB Controllers will need to provide the educational leadership to help their state public health officials understand the longer-term benefits that we hope will accrue with this approach.

As to the limitations of this study, for those patients receiving 6 to 9 months of therapy, we do not have a way of knowing exactly how many doses they received.

Conclusion: Proactive intensification of TB treatment for high-risk individuals will result in additional program costs. A more formalized cost-benefit analysis is planned to consider the costs of re-treatment, including contact investigations and possible secondary cases, to better delineate the public health benefit of the new treatment recommendations.

—Submitted by Carol D. Hamilton, MD, Jimmy Keller, MA
Ashley Ewing, BS, Dee Foster, RN, Elizabeth Zeringue, RN,
Myra Allen, RN, and Julie Luffman, RN
North Carolina TB Program


Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
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