Appendix B: selected studies of the cost-effectiveness of preventive interventions in developing countries.
THE TABLE BELOW SUMMARIZES STUDIES OF THE cost-effectiveness of interventions to prevent HIV HIV (Human Immunodeficiency Virus), either of two closely related retroviruses that invade T-helper lymphocytes and are responsible for AIDS. There are two types of HIV: HIV-1 and HIV-2. HIV-1 is responsible for the vast majority of AIDS in the United States. in developing countries and several other studies that have measured only the costs of program outputs, without measuring their effects. (1)
Readers are advised to use this table cautiously. The cost-effectiveness of a particular intervention is not a constant; the costs, effects, and ranking of different interventions are very likely to differ across countries because of the degree to which the intervention is targeted to those with high rates of partner change, the prevalence of HIV in high- and low-risk groups, the length of time that an intervention has been in the field, the labor-intensity of the intervention, and the local cost of labor and other inputs (background paper, Mills and Watts 1996). Thus, the results of the different studies in the table are not directly comparable with each other. Ideally, we would like to have measures of cost-effectiveness across multiple interventions for a single country (see box 3.9 of the text).
The cost per HIV infection averted a·vert
tr.v. a·vert·ed, a·vert·ing, a·verts
1. To turn away: avert one's eyes.
2. is available for only four interventions--one targeted to people with very high rates of partner change (sex workers) in Nairobi and three others addressed to those with lower rates of partner change. As discussed in chapter 3, government has a strong interest in supporting interventions that prevent the most secondary infections per dollar spent. However, except for one study, secondary infections were not included in the benefits.
* The annual operating costs operating costs npl → gastos mpl operacionales of the Nairobi, Kenya, sex worker program came to roughly $70,000, or $140 per sex worker per year (Moses and others 1991). At the beginning of the program, 80 percent of the participants were infected in·fect
tr.v. in·fect·ed, in·fect·ing, in·fects
1. To contaminate with a pathogenic microorganism or agent.
2. To communicate a pathogen or disease to.
3. To invade and produce infection in. with HIV and they had a mean of four clients per day. The annual cost per case of HIV averted came to $8, under the assumption of 80 percent condom 1. condom - The protective plastic bag that accompanies 3.5-inch microfloppy diskettes. Rarely, also used of (paper) disk envelopes. Unlike the write protect tab, the condom (when left on) not only impedes the practice of SEX but has also been shown to have a high failure use, or $12, under the assumption of 50 percent condom use. The number of cases of HIV prevented among the clients of sex workers and among sex workers themselves were included in the calculations, but infections prevented among the partners of clients were not included. Had they been, the intervention might have been even more cost-effective. Reportedly, the largest share of the programs costs was for STD (Subscriber Trunk Dialing) Long distance dialing outside of the U.S. that does not require operator intervention. STD prefix codes are required and billing is based on call units, which are a fixed amount of money in the currency of that country. treatment, although most of the benefits arose because of increases in condom use (Mills and others 1993). However, the availability of STD treatment may have been a major factor in obtaining the cooperation of participants.
* The Mwanza, Tanzania, STD intervention is the only one in the table for which the cost per DALY DALY Disability Adjusted Life-Years saved has been calculated--$10-11 (Richard Hayes, personal communication). The cost-effectiveness of this intervention is understated because the authors did not include prevention of any secondary infections in their analysis. The intervention might also have been more cost-effective had it been implemented in an urban area, where the number of secondary infections prevented might have been greater for each primary case. Of the total cost of $10.08 per treated case of STD, $2.11 was for drugs (Richard Hayes, personal communication). The incremental annual cost of this intervention, which served a catchment catch·ment
1. A catching or collecting of water, especially rainwater.
a. A structure, such as a basin or reservoir, used for collecting or draining water.
b. population of about 150,000 people, was $59,000, or $0.39 per capita [Latin, By the heads or polls.] A term used in the Descent and Distribution of the estate of one who dies without a will. It means to share and share alike according to the number of individuals. . By comparison, the recurrent recurrent /re·cur·rent/ (re-kur´ent) [L. recurrens returning]
1. running back, or toward the source.
2. returning after remissions.
1. health budget of Tanzania in 1993 amounted to $2.27 per capita.
* The cost-effectiveness of safe blood programs is strongly dependent on the level of HIV prevalence in the population and on the extent of risky behavior among transfusion recipients. The Ugandan study included only averted primary infections, that is, infections due directly to transfusions (European Commission 1995a, b). It assumed a prevalence rate of 16 percent among blood donors and of 40 percent and 9 percent, respectively, among adult and child transfusion recipients. The calculations concerning the number of primary infections averted are in box 4.2 of this report. The cost per HIV infection averted was obtained by dividing the total additional costs of HIV screening in 1993 ($319,894) by the total number of infections averted (1,863).
* The effectiveness of short-course zidovudine zidovudine /zi·do·vu·dine/ (zi-do´vu-den) a synthetic nucleoside (thymidine) analogue that inhibits replication of some retroviruses, including the human immunodeficiency virus; used in the treatment of HIV infection and AIDS. (AZT AZT or zidovudine (zīdō`vydēn'), drug used to treat patients infected with the human immunodeficiency virus (HIV), which causes AIDS; also called ) therapy to prevent mother-to-child transmission is not known as of this writing; clinical efficacy trials are under way in a number of countries. The cost-effectiveness numbers in the table are, therefore, hypothetical Hypothetical is an adjective, meaning of or pertaining to a hypothesis. See:
The cost per case of HIV averted or per DALY has not been calculated for the other studies in the table; only the costs are available. A needle exchange and bleach bleach
Solid or liquid chemical compound used to whiten or remove the natural colour of fibres, yarns, paper, and textile fabrics. Sunlight was the chief bleaching agent up to the discovery of chlorine in 1774 by Karl Wilhelm Scheele (b. 1742—d. program serving injecting drug users in Katmandu, Nepal, cost $3.21 per contact after only one year of observation and was organized with community-based outreach Outreach is an effort by an organization or group to connect its ideas or practices to the efforts of other organizations, groups, specific audiences or the general public. . A second program in Lubljana, Slovenia (not shown), was based in a fixed facility and had been operating only 5 months when costed at $12.59 per contact (Mills and others 1993). The cost per condom distributed varied from $0.10 to $0.70 for three highly targeted programs that had peer education and condoms for sex workers. Costs were much lower for ten condom social marketing programs--from $0.02 to $0.30 per condom distributed, including the value of donated do·nate
v. do·nat·ed, do·nat·ing, do·nates
To present as a gift to a fund or cause; contribute.
To make a contribution to a fund or cause. condoms.
(1.) For examples of studies of cost-effectiveness and cost-benefit analysis of HIV/AIDS interventions in industrial countries, see Holtgrave, Quails, and Graham (1996) and National Research Council (1991). Key principles of the economic analysis of health projects are reviewed in Hammer (1997).
Table B.1 Annual Costs per Infection Averted, per Condom, and per Contact for Interventions To Prevent HIV Location, implementing Intervention agency and year of launch Intervention targeted to people with high risk behavior Information, condoms, Nairobi Kenya, research project (1985-91) STD treatment for female sex workers Peer education and Prostitute peer education project, condoms, female sex workers Yaounde, Cameroon; Ministry of Health (1989) Education and condoms, Pegacao programme, Riod de Janeiro, male sex workers aged 11-23 Brazil; Social Health Guidance Unit (NOSS, 1989) Peer education and condoms, Bulawayo peer education project, females sex workers and Bulawayo, Zimbabwe; Bulawayo City Health clients, others (d) Department, University of Zimbabwe, AIDSTECH (1989) Needle exchange, bleach, Kathmandy, Nepal; Lifesaving and education, condoms, Lifegiving Society (1992) health care to IDUs Population-level interventions Treatment of symptomatic Research project, six rural communities STDs of Mwanza Region, Tanzania, early 1990s Maputo city and province Mozambique Johannesburg, South Africa Condom social marketing Ten programs (Bolivia, Congo DR, (e) Cote d'Ivoire, Dominican Republic, Ecuador, Ghana, Indonesia, Mexico, Morocco, Zimbabwe) Safe blood supply Uganda Short-course AZT therapy Hypothetical intervention in Sub-Saharan to prevent mother-to-child Africa, assuming perinatal transmission transmission is reduced from 25% to 16.5%. Cost per HIV Cost per infection condom Intervention averted distributed Intervention targeted to people with high risk behavior Information, condoms, $8.00-$12.00 (a) STD treatment for female sex workers Peer education and $0.34 (b) condoms, female sex workers Education and condoms, $0.70 (b) male sex workers aged 11-23 Peer education and condoms, $0.10 (b,c) females sex workers and clients, others (d) Needle exchange, bleach, education, condoms, health care to IDUs Population-level interventions Treatment of symptomatic $234 STDs Condom social marketing $0.02-$0.30 (b) Safe blood supply $172 Short-course AZT therapy $3,748 to prevent mother-to-child transmission Cost per Intervention contact Intervention targeted to people with high risk behavior Information, condoms, STD treatment for female sex workers Peer education and condoms, female sex workers Education and condoms, $3.73 male sex workers aged 11-23 Peer education and condoms, $0.47 females sex workers and clients, others (d) Needle exchange, bleach, $3.21 education, condoms, health care to IDUs Population-level interventions Treatment of symptomatic $10.08 STDs $9.46 $10.16 Condom social marketing Safe blood supply $30 (per unit of blood) (f) Short-course AZT therapy to prevent mother-to-child transmission (a.) Lower figure assumes 80% condom use, higher figure assumes 50% condom use. (b.) Includes the value of donated condoms. (c.) Cost excluding technical assistance from AIDSTECH is $0.07 per condom distributed. (d.) Also included people in bars, workers, STD patients. (e.) Formerly Zaire. (f.) $27-29 per unit collected, $33-35 per unit used in 1993. Mills and others (1993) find a cost of $51 per unit produced for the same program but possibly for an earlier year. Source: Nairobi study, Moses and others (1991); Cameroon, Brazil, Zimbabwe sex worker peer counseling and condom programs, condom social marketing programs, and STD treatment in Mozambique and South Africa, Mills and others (1993); Mwanza STD treatment, Richard Hayes, personal communication, and Gilson and others (1996); Ugandan safe blood, European Commission (1995a,b); AZT therapy in Sub-Saharan Africa, Mansergh and others (1996).