From Efficacy to Effectiveness: Insecticide-treated Bednets in Africa

Overview

Journal Bull World Health Organ

Specialty Public Health

Date 1996 Jan 1

PMID 8789931

Citations 40

Authors

C Lengeler

R W Snow

Affiliations

Soon will be listed here.

Abstract

Insecticide-treated bednets and curtains (ITBC) have proven in recent large-scale trials to have a high efficacy in reducing morbidity and mortality from malaria in African children. However, it is unlikely that the efficacy measured in trials can be entirely sustained under programme conditions. This has important implications for the cost-effectiveness of the intervention. Furthermore, there is a need to assess the long-term impact of ITBC. This article traces the history of ITBC and the different phases of their assessment, especially the determination of efficacy in randomized controlled trials (phase III assessment). It then outlines the reasons for continued assessment of their effectiveness under programme conditions (phase IV assessment). The methodologies for measuring effectiveness are discussed, and a critical review of the issues reveals that it is impractical to measure effectiveness directly. A simple effectiveness model, allowing for differentiation between individual and community effectiveness, provides a useful conceptual framework. First, individual effectiveness is measured through a case-control study. This estimate is then combined with a coverage indicator to estimate community effectiveness. This approach could provide programme managers with a powerful tool to monitor the impact of health interventions at the community level.

Citing Articles

Effective Coverage in Health Systems: Evolution of a Concept.

Karim A, de Savigny D Diseases. 2023; 11(1).

PMID: 36975584 PMC: 10047489. DOI: 10.3390/diseases11010035.

Protective efficacy of holed and aging PBO-pyrethroid synergist-treated nets on malaria infection prevalence in north-western Tanzania.

Lukole E, Cook J, Mosha J, Messenger L, Rowland M, Kleinschmidt I PLOS Glob Public Health. 2023; 2(10):e0000453.

PMID: 36962517 PMC: 10022078. DOI: 10.1371/journal.pgph.0000453.

The fabric of life: what if mosquito nets were durable and widely available but insecticide-free?.

Okumu F Malar J. 2020; 19(1):260.

PMID: 32690016 PMC: 7370456. DOI: 10.1186/s12936-020-03321-6.

Case reduction and cost-effectiveness of the RTS,S/AS01 malaria vaccine alongside bed nets in Lilongwe, Malawi.

Bell G, Loop M, Topazian H, Hudgens M, Mvalo T, Juliano J Vaccine. 2020; 38(25):4079-4087.

PMID: 32362527 PMC: 7282487. DOI: 10.1016/j.vaccine.2020.04.031.

Protecting migratory farmers in rural Tanzania using eave ribbons treated with the spatial mosquito repellent, transfluthrin.

Swai J, Mmbando A, Ngowo H, Odufuwa O, Finda M, Mponzi W Malar J. 2019; 18(1):414.

PMID: 31823783 PMC: 6905030. DOI: 10.1186/s12936-019-3048-8.

References

Velema J, Alihonou E, Gandaho T, Hounye F . Childhood mortality among users and non-users of primary health care in a rural west African community. Int J Epidemiol. 1991; 20(2):474-9. DOI: 10.1093/ije/20.2.474. View

DAlessandro U, Olaleye B, McGuire W, Langerock P, Bennett S, Aikins M . Mortality and morbidity from malaria in Gambian children after introduction of an impregnated bednet programme. Lancet. 1995; 345(8948):479-83. DOI: 10.1016/s0140-6736(95)90582-0. View

Baltazar J . The potential of the case-control method for rapid epidemiological assessment. World Health Stat Q. 1991; 44(3):140-4. View

Smith P . Evaluating interventions against tropical diseases. Int J Epidemiol. 1987; 16(2):159-66. DOI: 10.1093/ije/16.2.159. View

David P, Bisharat L, Kawar S . Using routine surveys to measure mortality: a tool for programme managers. Soc Sci Med. 1991; 33(3):309-19. DOI: 10.1016/0277-9536(91)90365-j. View

Sexton J, Ruebush 2nd T, Breman J, Roberts J, Odera J, Were J . Permethrin-impregnated curtains and bed-nets prevent malaria in western Kenya. Am J Trop Med Hyg. 1990; 43(1):11-8. DOI: 10.4269/ajtmh.1990.43.11. View

Sackett D . Bias in analytic research. J Chronic Dis. 1979; 32(1-2):51-63. DOI: 10.1016/0021-9681(79)90012-2. View

Jaenson T, Gomes M, Barreto dos Santos R, Petrarca V, Fortini D, Evora J . Control of endophagic Anopheles mosquitoes and human malaria in Guinea Bissau, West Africa by permethrin-treated bed nets. Trans R Soc Trop Med Hyg. 1994; 88(6):620-4. DOI: 10.1016/0035-9203(94)90197-x. View

Alonso P, Lindsay S, Armstrong J, Conteh M, HILL A, David P . The effect of insecticide-treated bed nets on mortality of Gambian children. Lancet. 1991; 337(8756):1499-502. DOI: 10.1016/0140-6736(91)93194-e. View

10.

Rodrigues L, Kirkwood B . Case-control designs in the study of common diseases: updates on the demise of the rare disease assumption and the choice of sampling scheme for controls. Int J Epidemiol. 1990; 19(1):205-13. DOI: 10.1093/ije/19.1.205. View

11.

Snow R, Lindsay S, Hayes R, Greenwood B . Permethrin-treated bed nets (mosquito nets) prevent malaria in Gambian children. Trans R Soc Trop Med Hyg. 1988; 82(6):838-42. DOI: 10.1016/0035-9203(88)90011-9. View

12.

Thomson M, DAlessandro U, Bennett S, Connor S, Langerock P, Jawara M . Malaria prevalence is inversely related to vector density in The Gambia, West Africa. Trans R Soc Trop Med Hyg. 1994; 88(6):638-43. DOI: 10.1016/0035-9203(94)90204-6. View

13.

Tanner M . Evaluation and monitoring of schistosomiasis control. Trop Med Parasitol. 1989; 40(2):207-13. View

14.

Snow R, Armstrong J, Forster D, Winstanley M, Marsh V, Newton C . Childhood deaths in Africa: uses and limitations of verbal autopsies. Lancet. 1992; 340(8815):351-5. DOI: 10.1016/0140-6736(92)91414-4. View

15.

Snow R, Schellenberg J, Peshu N, Forster D, Newton C, Winstanley P . Periodicity and space-time clustering of severe childhood malaria on the coast of Kenya. Trans R Soc Trop Med Hyg. 1993; 87(4):386-90. DOI: 10.1016/0035-9203(93)90007-d. View

16.

Picard J, Aikins M, Alonso P, Armstrong Schellenberg J, Greenwood B, Mills A . A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 8. Cost-effectiveness of bed net impregnation alone or combined with chemoprophylaxis in preventing mortality and.... Trans R Soc Trop Med Hyg. 1993; 87 Suppl 2:53-7. DOI: 10.1016/0035-9203(93)90176-q. View

17.

Greenwood B, Marsh K, Snow R . Why do some African children develop severe malaria?. Parasitol Today. 1991; 7(10):277-81. DOI: 10.1016/0169-4758(91)90096-7. View

18.

Premji Z, Lubega P, Hamisi Y, Mchopa E, Minjas J, Checkley W . Changes in malaria associated morbidity in children using insecticide treated mosquito nets in the Bagamoyo district of coastal Tanzania. Trop Med Parasitol. 1995; 46(3):147-53. View

19.

TODD J, De Francisco A, ODempsey T, Greenwood B . The limitations of verbal autopsy in a malaria-endemic region. Ann Trop Paediatr. 1994; 14(1):31-6. DOI: 10.1080/02724936.1994.11747689. View

20.

Tugwell P, Bennett K, Sackett D, Haynes R . The measurement iterative loop: a framework for the critical appraisal of need, benefits and costs of health interventions. J Chronic Dis. 1985; 38(4):339-51. DOI: 10.1016/0021-9681(85)90080-3. View