A Systematic Review of Economic Evaluations of Chemoprophylaxis for Tuberculosis

Table 1

Summary of selected studies.

(a)

	Study objective	Study population and setting
Rose et al. [11]	To compare TB prevention with isoniazid (INH) chemoprophylaxis to no intervention, for low risk as well as high-risk tuberculin reactors	Men aged 20, recently infected with tubercle bacillus and thus at high risk; men aged 55, older tuberculin reactors having low risk of activation US
Salpeter et al. [12]	To evaluate the effectiveness and cost effectiveness of monitored INH prophylaxis for low-risk tuberculin reactors older than 35 years of age	35, 50 and 70-year-old low risk tuberculin reactors who have normal chest radiograph and are not at increased risk of tuberculin activation US
Jasmer et al. [13]	To determine cost effectiveness of rifampin-pyrazinamide (RZ) for 2 months compared with INH for 6 months for treatment of latent tuberculosis in adults without HIV infection	Adult aged 17 years or older with a tuberculin skin test result, in whom active TB is excluded and in whom treatment of latent TB infection would ordinarily be recommended; exclusion criteria are pregnancy, HIV infection, and history of gout US
Diel et al. [14]	To perform a cost-effectiveness analysis in young-and middle-aged adults with latent tuberculosis infection	20- and 40-year old close contacts of active TB cases with positive Mantoux test and in whom active TB is excluded Germany
Holland et al. [15]	To evaluate cost and cost effectiveness of different regimens for treatment of LTBI	Hypothetical cohort of individuals with LTBI contacts of infectious case, all adults with average age of 39 years US
Tan et al. [16]	To evaluate cost effectiveness of LTBI therapy for different TB contact population defined by important risk factors and to propose optimal policy based on different recommendations for each subgroup of contact	TB contacts with tuberculin test size ≥5 mm, defined by age group (<10 y/o or above), ethnicity (Canadian born/foreign born), BCG vaccination status British Columbia, Canada
Fitzgerald and Gafni [17]	To evaluate role of INH prophylaxis in low-risk patients with positive Mantoux test result and identify most efficient use of health care resources	20-, 50-, and 70-years-old low-risk patients with positive Mantoux test Canada
Ziakas and Mylonakis [18]	To compare efficacy, toxicity, and cost of the 4-month Rifampin treatment (4RIF) with the standard 9-month INH strategy (9INH) from pooled meta-analysis of published clinical studies	Patient-related data from eight Canadian centres, two US centres, one Saudi Arabian centre, and one Brazilian centre

(b)

	Measure of outcomes	Cost effectiveness	Implications
Rose et al. [11]	Life years gained, quality-adjusted life years (QALYs); Incremental cost effectiveness ratio (ICER)	For high-risk reactors over 35, isoniazid dominates no intervention; cost savings and greater benefits (increased life expectancy).; For low-risk reactors over 35, ICER of isoniazid over no intervention of $12,625 per year of life gained and $35,011 per death averted	Study can contribute to a change in existing policy and practice; consideration of INH therapy for all infected persons irrespective of age group and risk of tuberculin reactors
Salpeter et al. [12]	Number needed to treat,; life years gained, and probability of survival at 1-year; Cost saving	Isoniazid dominates no intervention for 35, 50 and 70 year olds; cost savings and increased life expectancy	Study can contribute to a change in existing policy and practice; consideration of all age groups for preventive therapy leading to potential public health benefits
Jasmer et al. [13]	Number of TB cases averted, number of TB-related deaths ICER	Isoniazid dominates no intervention; cost savings and increased life expectancy, more deaths prevented Isoniazid costs less than rifampin-pyrazinamide; both treatments have the same gain in life expectancy; ICER of rifampin over no intervention of $2,494 per case prevented	Justify existing policy of INH prophylaxis
Diel et al. [14]	Number needed to treat, number of TB-related deaths avoided; Cost saving	Isoniazid dominates no intervention for 20 and 40 year olds; cost savings, more cases, and TB-related deaths prevented	Acceleration of expansion of INH prevention
Holland et al. [15]	Life years gained,; QALYs; ICER	Rifampin dominates (self-administered and, directly observed) isoniazid; cost savings and more QALYs gained, more cases of active TB-prevented; ICER of isoniazid-rifapentine over rifampinof $48,999 per QALY gained	Study can contribute to a change in existing policy and practice; highlights important knowledge gaps
Tan et al. [16]	Number of active TB cases prevented, QALYs; Net monetary benefit	Test and treat (with isoniazid) more cost effective (in terms of net monetary benefit, the difference between benefits, valued at $50,000 per QALY, and costs) than no screening and treat all, for most subgroups	Justifies existing policy; support current practice of provision of treatment on the basis of TST size; exclusion of low-risk groups from screening and providing treatment to high-risk contacts without screening could improve the performance of the program
Fitzgerald and Gafni [17]	Number of TB cases prevented, life years gained; Direct as well as indirect costs in different age groups	Average cost per case prevented in low-risk patients by isoniazid of $8,586 (20-year old), $28,260 (50 year old), and $40,102 (70-year old)	Justifies existing policy of INH prophylaxis; considers of all age groups; highlights importance of including indirect as well as direct costs
Ziakas and Mylonakis [18]	Hepatotoxicity, compliance; Cost saving	Rifampin dominates isoniazid; cost savings and lower risk of noncompletion, lower rate of hepatotoxicity	Justifies existing policy; 9INH therapy is considered as standard of care