2. Materials and methods
2.1 Target sites and survey population
The provinces of Kampong Cham (KC) and Pursat (PS) were purposively
selected for this study. These provinces contribute significantly to
cattle production and contain primary access routes for the cattle trade
into Vietnam. PS is located in the west of the country, bordering four
provinces, the Tonle Sap (Sap River, a tributary of the Mekong River)
and Thailand, whereas KC is located in the central lowlands of the
Mekong River, bordering six provinces, the Mekong River and Vietnam.
Target smallholder farmer households for the study were households
participating in the ‘Domestic and International market development for
high-value-cattle and beef in South-East Cambodia’ project (ACIAR
project AH/2012/046), a collaborative research effort facilitated by the
University of New England and the Cambodian General Department of Animal
Health and Production (DAHP), with funding by the Australian Centre for
International Agricultural Research (ACIAR). The communes and villages
targeted for the survey were identified and selected through discussions
and consultations between the researcher, representatives of the
Provincial Office of Animal Health and Production (POAHP), and the
ACIAR-funded project team located in DAHP and POAHP offices. These
communes and villages were considered more likely to have an outbreak of
FMD than other areas, and village selection was based on the main
criteria of “at least 50% of households kept cattle”. Subsequently,
five villages were selected in each of the two provinces. A total of 300
smallholder farmers with at least three cattle per household were
identified for the survey, comprising 150 in each province.
2.2 Survey questionnaire design and interview technique
A semi-structured questionnaire consisting of open, closed and
semi-closed questions was developed to collect both quantitative and
qualitative information from the smallholder farmers. The questionnaire
was developed in English and translated into Khmer, ensuring all
questions were easy to understand and answer. The questionnaires
collected information on the background of farmers, household assets,
household incomes, cattle management, cattle trading, knowledge and
experiences of diseases and vaccination practice, and the financial
impact of FMD and perception on the importance of vaccination. In
addition to the specific questions, information on opportunities and
obstacles in the previous FMD vaccination programs was elicited, and
suggestions for improvements to future vaccination programs obtained.
Before the survey, the independent survey team received a full day of
training to ensure they understood the aims and objectives of the study
and were confident in their roles. To ensure best practice, a pilot
study was carried out to test the survey questions, delivery technique
and the length of time required for the interview. After initial field
testing, the survey questionnaires were reviewed and revised according
to feedback by the team. To ensure confidentiality and encourage honest
responses from the farmers, government officials were excluded from
participation in the interviews. At the end of the session, completed
questionnaires were checked to ensure that no information was missing.
2.3 Data collection and analysis
The survey data were collected, translated from Khmer into English and
transcribed into a database. The statistical analysis was performed
using SPSS version 21.0 (SPSS Inc., IL, USA). Outlier values were
compared with the questionnaires and corrected where necessary. Standard
descriptive analysis of the data was performed to summarize household
and livestock information, cattle trading, household assets and incomes,
knowledge, experiences of FMD and vaccination practice, plus their
perceptions on the importance of vaccination. Statistical analyses were
undertaken by the application of both univariable and binary logistic
regression methods. The influence of smallholder farmer attitudes and
knowledge on FMD outbreak and vaccination practices were classified into
three groups: age, education, and the number of household members;
livestock husbandry and management; and vaccination knowledge. Variables
from each group were subsequently tested against the binary independent
variable of whether farmers had undertaken vaccination (i.e., Yes or No
to FMD vaccination) using the Pearson’s chi-square test for independence
and a P values <0.05 as evidence of significance. Odds ratios
(OR) and their 95% confidence interval were also calculated to measure
the magnitude of the association between factors and yes/no of the
dependent variable. Variables that were significant at P ≤0.25 in the
univariate analyses were selected for inclusion in a logistic regression
model (Hosmer & Lemeshow, 2000). The
model was performed using backwards conditional testing, and odds ratios
were calculated. In the final model, variables with P values
>0.05 and which had value 1 in the 95% confidence interval
of OR were excluded. The model was evaluated by calculating the Hosmer
and Lemeshow statistical methodology
(Hosmer & Lemeshow, 2000).