Study design and setting
In Ecuador, two influenza vaccination campaigns were carried out for all priority groups, including pregnant women (December to February 2015-2016 and May 2016). We carried a cross-sectional survey on the knowledge, attitudes, and practices regarding the influenza vaccination during pregnancy from September 2016 to January 2017 in three public hospitals in Quito, the capital of Ecuador. Quito sits at an altitude of 2,850 meters above sea level and has 2,239,191 inhabitants being the second most populous city in Ecuador[27].
Study population and sampling
The three public hospitals chosen (Luz Elena Arismendi, Isidro Ayora and Pablo Arturo Suárez) had the highest number of births in 2015 and each hospital is located in a specific area of the city (south, center and north, respectively). In these hospitals, women in immediate postpartum period between 18 and 50 years old were recruited. We interviewed a sample of 854 women (Luz Elena Arismendi, n = 168; Isidro Ayora, n = 536 and Pablo Arturo Suárez, n = 150 women) with probability of selection proportional to the number of live births reported for each health care facility in 2015. This sample size provided 80% power to detect a 10% difference in survey responses to questions about knowledge, attitudes and practices between vaccinated and unvaccinated women (assuming 50% of surveyed women are vaccinated, a 10% non-response rate and alpha = 0.05). Women who did not reside within the Metropolitan District of Quito were excluded from the study.
Data collection and recruitment
Participant enrollment into the study was carried out by convenience sampling in the postpartum wards of the three hospitals until sample size was reached. Signed informed consent was obtained from each eligible woman interested in enrolling prior to administration of survey. Illiterate mothers were consented by their thumb print after verbal consent. A KAP modified survey from the study “Policies, knowledge, attitudes and practices of the use of seasonal influenza vaccine, oseltamivir and palivizumab in Guatemala, 2016” (Centers for Disease Control and Prevention, Atlanta, GA, USA and University del Valle de Guatemala- Cooperative Agreement; unpublished data) was applied by two experienced survey interviewers without medical background who were trained by the authors of the present study. The survey included questions on demographics, educational level, employment, antenatal care, high-risk conditions, knowledge (influenza, influenza vaccine and severity of influenza), attitudes (perception of vaccine safety and effectiveness) and practices (uptake of influenza vaccine) about influenza vaccine, influenza vaccine during pregnancy, reasons for not receiving vaccination, health provider recommendation and offer of the vaccine. To validate the questionnaire, a team of experts (Influenza Division, CDC, Atlanta, USA) reviewed the items to ensure clarity and adequacy of comprehension prior to administration. Field validation was then carried out and the survey instrument was adjusted accordingly. Self-reported data about influenza vaccination was corroborated through vaccination cards and medical records.
Statistical analysis
For the analysis of the data, the vaccination report of the mother was used. Age was categorized in four groups: 18-24, 25-30, 31-35, ≥36. Patients were classified as high obstetric risk if they reported having diagnosis of bronchitis, asthma, chronic obstructive pulmonary disease, cystic fibrosis, diabetes, HIV, cardiovascular disease, chronic kidney disease or stroke. We calculated the percentage of women that were vaccinated against influenza by provider recommendation and offer of influenza vaccination. Among unvaccinated persons, we categorized main reasons reported for not being vaccinated into 4 main groups: access issues, not wanting or needing the vaccine, concern with safety, lack of offer / recommendation of the vaccine. We also assessed the categorized main reported reasons for not being vaccinated by demographic characteristics, education, number of children, antenatal care, and high-risk conditions. Finally, we analyzed the relationship of receipt of influenza vaccination with predictors for vaccination (age, educational level, marital status, employment, antenatal care, number of children, high-risk conditions, gestational age at birth, recommendation or offer of vaccination by health care provider, and knowledge and attitudes about vaccination) by bivariate and multivariate analysis (log-binomial regression). We present unadjusted and adjusted prevalence ratios (PRs) with 95% confidence intervals. Data were analyzed using STATA® software (version 14.0).