ISRCTN - ISRCTN95083356: Barriers to vaccination decision in north-eastern Nigeria.

Plain English Summary

Background and study aims
Despite the huge benefits of preventing diseases at low cost, the persistent low vaccine take-up remains hard to explain. The relevance of psychological factors as barriers to vaccination has been commonly documented in Africa, without rigorous evidence. This study conducts a field experiment explicitly designed to evaluate psychic and monetary costs as potential barriers to tetanus vaccine take-up among women of childbearing age in 80 villages in Adamawa state, in rural Nigeria.

Who can participate?
Women aged 15 to 35 and had not received a tetanus vaccine less than six months prior to the baseline survey.

What does the study involve?
We have three interventions; 1) condition under which a respondent can receive the cash incentives (clinic visit s. clinic visit + vaccination), 2) amount of cash incentives (low, middle, and high), and 3) priming intervention (control flipcharts vs. " scared-straight" intervention)

What are the possible benefits and risks of participating?
The possible benefits include the tetanus-toxoid vaccination and cash incentives. Through receiving the tetanus-toxoid vaccination, they can be protected against tetanus. If the respondents are pregnant, vaccination can also protect their new-born baby from neonatal tetanus.
There are side effects of the tetanus-toxoid vaccination such as swelling of the body part of the injection, fever, and headache. However, these side effects are expected to be at minimal.

Where is the study run from?
This is a single-site study. We cover 10 health clinics which covers 80 villages in Jada local government areas in Adamawa state, Nigeria. The lead center is Adamawa Primary Healthcare Development Agency based in Yola, the capital city of Adamawa state.

When is the study starting and how long is it expected to run for?
March 2013 to August 2013

Who is funding the study?
This project was supported with research grants from the Institute for Research on Women & Gender, the Rackham Graduate School, the Department of Afroamerican and African Studies, the Department of Economics, and the Center for the Education of Women at the University of Michigan; the Japan Society for the Promotion of Science; and Yamada Scholarship Foundation.

Who is the main contact?
Ryoko Sato, rsato@hsph.harvard.edu

This study evaluates the relative importance of psychic costs of vaccination compared to monetary costs through a field experiment that randomizes several factors affecting tetanus vaccine take-up among women in rural Nigeria. We conducted our study in 80 villages in Adamawa state, which is in the northeastern region of Nigeria.

To capture monetary costs as potential barriers to vaccination, we randomized the amount of cash incentives provided to women whose condition was simply to attend a clinic. To capture psychic costs of vaccination as potential barriers, we gave a group of women their cash incentives with the additional condition of receiving a vaccine at the clinic. Because the only difference between these two conditions is whether or not a woman was is required to receive a vaccine for cash rewards upon arrival at the clinic, the difference in clinic attendance between these two groups captures the psychic costs of vaccination. Furthermore, if those women whose condition for cash provision was clinic attendance refused to take the vaccine after showing up at the clinic, this is directly attributed to the psychic costs of vaccination.
Finally, to examine the effect of priming on vaccination, we randomized a disease message: either a “scared-straight” message, which emphasizes the severity of tetanus, or a control message, which provides the same information on tetanus without emphasis on the severity of the disease.

Trial website

Contact information

Type

Scientific

Primary contact

Dr Ryoko Sato

ORCID ID

http://orcid.org/0000-0001-7040-317X

Contact details

161 S. Huntington Ave
APT 218
Boston
02130
United States of America
2022905064
rsato@hsph.harvard.edu

Additional identifiers

EudraCT number

Nil known

ClinicalTrials.gov number

Nil known

Protocol/serial number

HUM00063832

Study information

Scientific title

Psychic vs. Economic Barriers to Vaccine Take-up: a Field Experiment in Nigeria in
Northeastern Nigeria

Acronym

Study hypothesis

It is expected that psychological factors are major barriers to vaccination, and that cash incentive and emphasizing the severity of the disease increase vaccine take-up

Ethics approval

Approved 09/11/2012, University of Michigan Health Sciences and Behavioral Sciences Institutional Review Board (2800 Plymouth Road, Bldg. 520, Rm. 1169, Ann Arbor, MI 48109-2800; +1 (734) 936-0933; irbhsbs@umich.edu), ref: HUM00063832

Study design

Interventional single-centre study randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Home

Trial type

Prevention

Patient information sheet

None available

Condition

We studied the uptake of tetanus-toxoid vaccine.

Intervention

To capture monetary costs as potential barriers to vaccination, we randomly chose the amount of cash incentives provided to women whose condition was simply to attend a clinic. To capture psychic costs of vaccination as potential barriers, we gave another group of women their cash incentives with the additional requirement of receiving a vaccine at the clinic. As the only difference between these two conditions is whether or not a woman was is required to receive a vaccine for cash rewards upon arrival at the clinic, the difference in clinic attendance between these two groups captures the psychic costs of vaccination. Furthermore, if those women whose condition for cash provision was clinic attendance refused to take the vaccine after showing up at the clinic, this is directly attributed to the psychic costs of vaccination.
Finally, to examine the effect of priming on vaccination, we randomized a disease message: either a “scared-straight” message, which emphasizes the severity of tetanus, or a control message, which provides the same information on tetanus without emphasis on the severity of the disease.

There were 9 groups in the study:
group 1) clinic visit condition + control flipcharts + 5 naira
group 2) clinic visit condition + control flipcharts + 300 naira
group 3) clinic visit condition + control flipcharts + 800 naira
group 4) vaccination condition + control flipcharts + 5 naira
group 5) vaccination condition + control flipcharts + 300 naira
group 6) vaccination condition + control flipcharts + 800 naira
group 7) vaccination condition + scared-straight flipcharts + 5 naira
group 8) vaccination condition + scared-straight flipcharts + 300 naira
group 9) vaccination condition + scared-straight flipcharts + 800 naira

Participants were randomised into groups upon enrollment. Baseline survey forms contained randomisation information in the middle page: interviewers randomly picked one of the baseline survey forms (without looking at the middle page) and initiated the baseline interview.

Intervention type

Behavioural

Phase

Drug names

Primary outcome measure

The primary outcome is the take-up of the tetanus-toxoid vaccination measured by observation at health clinics.

Secondary outcome measures

The risk perception is measured by interview at baseline and at follow-up survey (right after the intervention).

Overall trial start date

01/01/2012

Overall trial end date

31/07/2013

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

Female, between the ages of 15 and 35

Participant type

Healthy volunteer

Age group

Adult

Gender

Female

Target number of participants

2500

Participant exclusion criteria

Received the tetanus-toxoid vaccine within 6 months prior to the study

Recruitment start date

01/03/2013

Recruitment end date

31/03/2013

Locations

Countries of recruitment

Nigeria

Trial participating centre

Adamawa State Primary Health Care Development Agency
Wuro Jabbe
Jimeta
NA
Nigeria

Sponsor information

Funder name

Center for the Education of Women, University of Michigan

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Yamada Scholarship Foundation

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Department of Economics, University of Michigan

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

We intend to publish the results of the trial in public health journals, upon completion of the data analysis.

IPD sharing statement:
The datasets generated during and/or analysed during the current study are not expected to be made available due to the sensitive and identifiable nature of the data.