One implication of the increased immunisation rates

in the villages with camps with incentives (and in the

surrounding villages) is that they were busier than

those without incentives. Inspection of the logbook

showed that for any given camp, each day an average

of 4.5 immunisations were given without incentives

and 13.4 with incentives.

Interpretation, unanswered questions, and future research

Our results also suggest reasons that immunisation has

not been more widely embraced in developing coun-

tries. Previous work has emphasised the need to

strengthen health systems to achieve the millennium

development goals.

27

Our results suggest that to

achieve this strengthening, improving the supply

alone might not be enough: even a fully reliable supply

system has a relatively modest effect on uptake of

immunisation. In intervention A, even when access

was good and a social worker constantly reminded

parents of the benefits of immunisation, more than

80% did not get their children fully immunised. Never-

theless, more than 75% obtained the first injection

without the incentive and stopped attending the

camps only after two or three injections. This shows

that the parents do not have strong objections or fears

about immunisation, but that they are not persuaded

enough about its benefits to overcome the natural ten-

dency to delay a slightly costly activity (immunisation

is free, but it takes some time and effort to go to the

centre and get the child immunised, and the child

might have a fever afterwards). This fits the findings

of sociological research in India, where nurses describe

parents forgetting to bring their children to the immu-

nisation day, and where they are particularly careful to

manage even benign side effects of immunisation to

avoid discouraging parents from coming back.

5

It

also explains the tendency for children not to complete

the whole course of immunisation. Providing the len-

tils helps to overcome this procrastination because the

lentils make the occasion a small “ plus ” rather than a

small “ minus. ” Thus, in the case of preventive care,

small barriers might turn out to have large implica-

tions. Finding effective ways to overcome small bar-

riers might hold the key to large improvements in

immunisation rates and uptake of other preventive

health behaviours. In the case of immunisation, small

incentives coupled with regular delivery of services

seem to have the potential to play this role.

While we primarily examined the effect of small

incentives and supply improvement when they are cor-

rectly implemented, we need to know whether and

how such an incentive programme could be general-

ised. Under the National Rural Health Mission, the

government of India now has a health worker in each

village who is responsible for encouraging uptake of

preventive care. Furthermore, several Indian states,

including those with comparatively low immunisation

rates (Orissa, Bihar, Rajasthan), are already imple-

menting a “ camp ” approach, where the regular auxili-

ary nurse midwife immunises children in villages on a

rotating schedule. We are hoping to conduct an impact

evaluation of the addition of small incentives to parents

in this structure, in collaboration with the state govern-

ment in India, to evaluate the potential of these types of

intervention to be adopted as large scale policies and

the challenges that would need to be overcome.

We tha nk Je nnifer Tobin for her help in editing this manus cript for

publication. She was funded by the Abdul Lati f Jameel Poverty Action lab.

Contributors: AVB, ED, and RG participa ted in the study design. ED a nd DK

completed the data analysis. All authors participated in data collection,

data interpret ation, a nd drafting of the manuscript. E D is guarantor.

Funding: T his study was funded by the Mac Arthur Fo undation. All

researchers declare that the research was entirely independent f rom the

funders. The funders had no involvement in t he design and conduct of the

study; collection, management, analysis, and interpretation of the data;

and preparation , review, or approval of the manuscript. The intervention

was funde d by the Evangelischer E ntwicklungdi enst (Germany), I nter

Church Cooperation for Development Cooperation (Netherlands), and

Plan International, through Seva Mandir comprehensiv e plan. None of the

funding organ isations participated in the design of the study (although

the MacAr thur Foun dation reviewed the design before making the

funding de cision), the data collection or analysis, or the decision to su bmit

the paper for publica tion.

Competi ng interests: All authors have completed the Unified Competing

Interest form at www.icmje.org/coi_disclosure.pdf (available on request

from the corresponding author) and declare that they have no competing

interests relevant to this work.

Ethical approval: This study was approved by the health ministry of the

government of Rajasthan, the office on the use of human su bjects at

Massachusetts Ins titute of Technology, and the ethics committee of

Vidhya Bhawan, the univer sity which hosted the project in Udaipur.

Informed consent was first obt ained orally at the community level fro m

the research villages through village meeti ngs to which all adult members

of the village were invited. Individua l level informed consent was then

obtained orally from every family participating in the study.

Data shari ng: Statistical code an d full dataset available from the

corresponding author at eduflo@mit.edu. Consen t was not obtained, but

the presented data are a nonymised a nd risk of identification is ext remely

low.

1 WHO and UNICEF. Global immunization vision and strategy. World

Health Organization, 2005. www.who.int /vaccines-documents/

DocsPDF05/GIVS_Final_EN.pdf.

2 Bloom D, Canning D, Weston M. The value of vaccination. World

Economics 2005;6:15-39.

3 WHO and UNICEF. Global immunization data. World Health

Organization, 2008. www.who.int/immunization/newsroom/

Global_Immunization_Data.pdf.

4 Lim SS, Stein DB, Charrow A, Murray CJ. Tr acking progress towards

universal childhood immunisation and the impact of global

initiatives: a systematic analysis of t hree-dose diphtheria, tetanus,

and pertussis immunisation coverage. Lancet 2008;372:2031-46.

5 Coutinho L, Bisht S, Raje G. Numerical narratives and documentary

practices: vaccines, targets and reports of immunisation programme.

Econ Polit Wkly 2000;35:656-6 6.

6 National Family Health Survey, 2005-2006 (NHFS-3). www.nfhsindia.

org/pdf/RJ.pdf.

WHAT IS ALREADY KNOWN ON THIS TOPIC

Fina nc ial incen tive s, such as in condit iona l cash transfer progra mmes , can be effect iv e in

prom ot ing the use of certai n preventi ve heal thcar e servic es

In settin gs with reliab le immuni sati on serv ices and a high pre-ex is ting immu nisa tio n rate

suc h pr ogra mm es have little impac t on immu nisa tion

WHAT THIS STUDY ADDS

In a settin g with a low immuni sati on rate (under 6%), impr ovin g the re liab il ity of serv ic es

mode stly improved uptake of im muni sa tion

Sma ll non-fi nanc ia l in cent ives , combin ed with improv ed reli abil ity, had large positi ve

impa cts on th e uptake of im muni sati on and were more cos t effecti ve

RESEARCH

page 8 of 9 BMJ | ONLINE FIRST | bmj.com