Intended for healthcare professionals


Household ownership and use of insecticide treated nets among target groups after implementation of a national voucher programme in the United Republic of Tanzania: plausibility study using three annual cross sectional household surveys

BMJ 2009; 339 doi: (Published 02 July 2009) Cite this as: BMJ 2009;339:b2434
  1. Kara Hanson, reader 1,
  2. Tanya Marchant, lecturer1,
  3. Rose Nathan, senior scientist2,
  4. Hadji Mponda, scientist2,
  5. Caroline Jones, senior lecturer1,
  6. Jane Bruce, research fellow1,
  7. Hassan Mshinda, former director2, director general 3,
  8. Joanna Armstrong Schellenberg, reader1
  1. 1London School of Hygiene and Tropical Medicine, London WC1E 7HT
  2. 2Ifakara Health Institute, Mikocheni, Dar es Salaam, Tanzania
  3. 3Tanzania Commission for Science and Technology, Dar es Salaam, Tanzania
  1. Correspondence to: K Hanson kara.hanson{at}
  • Accepted 6 March 2009


Objectives To evaluate the impact of the Tanzania National Voucher Scheme on the coverage and equitable distribution of insecticide treated nets, used to prevent malaria, to pregnant women and their infants.

Design Plausibility study using three nationally representative cross sectional household and health facility surveys, timed to take place early, mid-way, and at the end of the roll out of the national programme.

Setting The Tanzania National Voucher Scheme was implemented in antenatal services, and phased in on a district by district basis from October 2004 covering all of mainland Tanzania in May 2006.

Participants 6115, 6260, and 6198 households (in 2005, 2006, and 2007, respectively) in a representative sample of 21 districts (out of a total of 113).

Interventions A voucher worth $2.45 (£1.47, €1.74) to be used as part payment for the purchase of a net from a local shop was given to every pregnant woman attending antenatal services.

Main outcome measures Insecticide treated net coverage was measured as household ownership of at least one net and use of a net the night before the survey. Socioeconomic distribution of nets was examined using an asset based index.

Results Steady increases in net coverage indicators were observed over the three year study period. Between 2005 and 2007, household ownership of at least one net (untreated or insecticide treated) increased from 44% (2686/6115) to 65% (4006/6198; P<0.001), and ownership of at least one insecticide treated net doubled from 18% (1062/5961) to 36% (2229/6198) in the same period (P<0.001). Among infants under 1 year of age, use of any net increased from 33% (388/1180) to 56% (707/1272; P<0.001) and use of an insecticide treated net increased from 16% (188/1180) to 34% (436/1272; P<0.001). After adjusting for potential confounders, household ownership was positively associated with time since programme launch, although this association did not reach statistical significance (P=0.09). Each extra year of programme operation was associated with a 9 percentage point increase in household insecticide treated net ownership (95% confidence interval −1.6 to 20). In 2005, only 7% (78/1115) of nets in households with a child under 1 year of age had been purchased with a voucher; this value increased to 50% (608/1211) in 2007 (P<0.001). In 2007, infants under 1 year in the least poor quintile were more than three times more likely to have used an insecticide treated net than infants in the poorest quintile (54% v 16%; P<0.001).

Conclusions The Tanzania National Voucher Scheme was associated with impressive increases in the coverage of insecticide treated nets over a two year period. Gaps in coverage remain, however, especially in the poorest groups. A voucher system that facilitates routine delivery of insecticide treated nets is a feasible option to “keep up” coverage.


  • We are grateful to the National Malaria Control Programme, the Tanzania National Voucher Scheme implementing partners, the Mennonite Economic Development Associates, CARE, World Vision, and Population Services International for their cooperation in the implementation of the study. We thank Karen Kramer and Christian Lengeler for their important contributions to the overall design of the monitoring and evaluation process, and Christian Lengeler for his helpful comments on the manuscript. Thanks are especially due to Alex Mwita, Renata Mandike, and Nick Brown for their continued support of the monitoring and evaluation process.

  • Contributors: KH and RN are principal investigators. KH, TM, RN, HMp, CJ, HMs, and JAS designed the study. HMp and TM oversaw data collection. Analysis was undertaken by JB, TM, and KH. All authors contributed to the interpretation of the data and the drafting of the paper, and all have approved the final version. KH is the guarantor for the study.

  • Funding: Funds for the 2005 and 2006 surveys were provided by the Ministry of Health through its Global Fund Round 1 grant and the Gates Malaria Partnership. The UK Department for International Development and the Royal Netherlands Embassy provided funds through their grants to Population Services International. The 2007 surveys were funded by the United States President’s Malaria Initiative. Although the study was conceived in collaboration with the National Malaria Control Programme, the programme managers had no role in the collection, analysis or interpretation of the data, in the writing of the report, or in the decision to submit the paper for publication.

  • Competing interests: None declared.

  • Ethical approval: The study received ethical clearance from the Medical Research Coordinating Committee of the Tanzanian National Institute of Medical Research and the ethics committees of the Ifakara Health Institute and the London School of Hygiene and Tropical Medicine.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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