Vaccine Dropout Rate and Associated Factors Among Childeren Age 12-23 Month in Shewa Robit Town, North Shewa Zone, Amahra Region, Ethiopia, A community Based Cross-sectional Study Design

Background: Immunization against disease is one of the most important public health interventions with cost effective means of preventing childhood morbidity, mortality, and disability. However, children in Africa was not fully immunized with in the recommended vaccines thus, many children are still susceptible to the expanded program on immunization target disease. The objective of this study was to assess the magnitude of vaccine dropout rate and associated factors among children age 12-23 month in Shewa Robit town in 2019. Methods: Community based cross sectional study was conducted from April 5 to April 10, 2019 with a total of 432 mothers/caregivers who have children 12-23 month of age were include in the study. Template was prepared and the data was entered, categorized, coded, and summarized using Epi data version 3.1 and analysis by using SSPSS version 21 for further analysis. Bivariate and multivariate logistic regression analysis was done to see the association of each categories of variable with the outcome variable. Significance was checked at 95% CI with p-value <0.05. Result: From the total 432 children 392(90.7%) were fully vaccinated and the BCG- Measle dropout rate were 9.3%. Occupation of mothers/caregiver’s being student (AOR: 0.075(0.006,0.971)), distance of time to reach health facility <15 minute (OR:15.617(2.06, 118.4) and ANC follow-up of mothers/caregivers(AOR:4.87(1.39,16.98)) were significantly associated to vaccine dropout rate. Conclusion: The overall immunization dropout rate in Shewa Robit town was 9.3% in 2019. Time to reach health facility, ANC follow-up of mothers and occupation of mother were statistically significant predictors of vaccine dropout rate of children.


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Vaccination is the administration of a vaccine, that is, a biological substance intended to stimulate a recipient's immune system to produce antibodies or undergo other changes that provide future protection against specific infectious diseases. Immunization is the stimulation of changes in the immune system through which that protection occurs [1] Immunization is considered as one of the most powerful and cost-effective health interventions. It also believed to prevent debilitating illness and disability and saves millions of lives every year [2,3].
Routine immunization programs protect most of the world's children from a number of infectious diseases that previously claimed millions of lives each year [4].

The Expanded Program on Immunization (EPI) was established by the World Health
Organization in 1974 to control vaccine preventable diseases. In Ethiopian, EPI program was launched in 1980 [5]. It was launched with the aim of reducing mortality and morbidity of children and mothers from vaccine preventable diseases. The target group when the program started was children under two years of age until it changed to under one year in 1986 to be in line with the global immunization target [6].
With the introduction of new approaches known as Reaching Every Districts (RED) and Sustainable Outreach Services for immunization in 2003, improvement has been documented. However, system-wide barriers related to geographic coverage remain as gaps, requiring bridging approaches such as the Enhanced Outreach Strategy even as the country moves towards a more equitable geographical coverage with construction and staffing of additional peripheral health facilities [7].
The World Health Assembly in May 2012 endorsed the Global Vaccine Action Plan (GVAP) as a roadmap to prevent millions of deaths through vaccine preventable disease. Under this plan countries hope to achieve vaccination coverage of at least 90% nationally and at least 80% in each district by 2020 [7]. In Ethiopia, number of deaths of children under five years of age is due to vaccine-preventable diseases. Under five age mortality stands at 123 per 1,000 with a plan to reduce to 54 per 1,000 up to the year 2015 to meet Millennium Development Goal-4 (MDG-4) [8]. Ethiopia strictly follows WHO recommendations for developing countries immunization schedule for the ten EPI vaccines for children and tetanus immunization for women of reproductive age [6]. As per the updated Ethiopian immunization policy of 2007, children under the age of one and women of 15-49 years are the targets for the EPI vaccines. Immunization services in Ethiopia are provided free of charge in most of the health facilities as well as in the outreach services for communities residing beyond 5 km from the health facilities [5]. Dropout rate is used to measure program continuity and follow up of immunization.
Dropout rate between the first and third dose of DPT -HepB -Hib is the best indicator for vaccine is not given in the campaigns [11].Approximately 29% of death in children under five age is vaccine preventable [12]. and respectively with vaccine preventable disease [13].
In 2011 alone 1.5million children die from disease prevented by currently recommended vaccine. It has been also recognized that vaccine preventable diseases are responsible for 16% of under-five mortality in Ethiopia [14].WHO recommends that both pentavalent-1 to pentavalent -3 and pentavalent-1 to-measles dropout rate should remain below 10% in order to decrease vaccine dropout rate and to reduce under five morbidity and mortality In NewYork North district [15]. Both the pentavalent 1-to-pentavalent 3 and the pentavalent 1-to-measles dropout rates have remained persistently above 10% over the last ten years. These children who fail to complete the immunization schedule in time was vulnerable to infection with vaccine-preventable diseases as result child morbidity and mortality was increase [15].
During the March 2012 measles outbreak, a total of 278 suspected measles cases had been reported. Out of these, 27 cases been confirmed to be measles at the Kenya Medical Research Institute reference laboratory while most of the others were epidemiologically linked to these confirmed cases. A total of 12 measles-related deaths had been documented since the onset of the outbreak [16].
Similarly, due to the persistent immunization dropout problem, the children in the district were also at a high risk of getting infected with polio since the re-emergence of polio in Kenya in February 2009 [17].
In Ethiopia, vaccine preventable diseases contribute substantially to under-five mortality as well as morbidity. Diarrhea(18%), pneumonia (18%), measles (1%), and meningitis are the leading causes of child mortality in the country [6]. Child immunization is the key to achieving the millennium development goals (MDGs) specially to reduce child morbidity 6 and mortality. The proportion of children immunized against measles is one of the indicators of millennium development goals [20]. However, in Ethiopia, the incidence of measles has increased from 3.19 per 100,000 in 2009 and 7.35 per 100,000 in 2010 with a total of confirmed 1,964 and 3,121 measles cases respectively, in 2012 measles incidence was 146 per 100,000 populations with a total of 125 confirmed measles outbreaks, in 2013, measles incidence was 7.2 cases per 100,000 populations with a total of 243 measles outbreaks and confirmed case was 192 [7,21].
The aim of this study was assessing magnitude of vaccine dropout rate and associated factors in Shewa Robit town. The findings of this study were showed immunization dropout rate in the study area, and the study was contributing to address issues related to vaccine dropout rate. The result get from this study is used to know the vaccination status of children and used for identifying associated factors that leads to dropout rate. This study was conducted to identify the current gaps, supplement the past studies and this study can be used as a reference for health care providers, health care workers, program managers and future researchers in this or other related fields.

Study area and study period
The study was conducted in Shewa Robit town, North Shewa zone, Amhara region, Ethiopia

Study design
A community based cross sectional study design was conducted.

Source population
The source population were all mothers/care givers living in Shewa Robit town and who have at least one 12-23 months of child.

Study population
Study population were sampled mothers who have at least one 12-23 months of child and resident in Shewa Robit town at least for six month prior to the day of the study at selected kebele of Shewa robit.

Sample size determination and sampling procedure
The sample size was calculated by single population proportion formula, the following assumptions was taken. Assumptions: A 95% confidence interval, margin of error (5%), considering design effect 1.5 and the proportion of vaccine dropout rate for all source was (21.7%) in Southern nation ,nationalities and peoples region of Ethiopia in 2015 [25].
Sample size were 392 individuals and add 10% of non-response rate. Then the study were conducted on 432 mothers/caregivers who have children 12-23 months of age.

Sampling procedures
multi-stage sampling method was used, three kebeles from 9 kebeles were selected using simple random sampling methods (lottery method). The sampling was considered probability proportion to population size in each kebeles. Systematic sampling technique was employed for household selection.

Data collection tools and procedures
The data was collected through face to face interview using structured questionnaires and 8 through a review of the vaccination cards and mothers/caregiver's history, questionnaires were adopted from different reviewed literature [25,36,37].Four graduating nursing students were involved in data collection. During data collection when the house was find locked next time the house was revisited three times then if locked the next house was interviewed. Systematic sampling technique was employed for household selection. The first household was selected randomly from the first household list 1 st to 3 rd list by using lottery method then the next household was selected every 3rd households by using the household record used by health extension worker as reference until total sample needed in the kebele was achieved. Within each selected household only one mother with index child age between 12-23 months was selected. Whenever there was more than one mother with 12-23 months of age children in a household only one was selected using lottery method and in case of the twins, one child was selected by lottery method. Mothers or caregivers were asked to show immunization cards, and for those mothers/caregivers who had no vaccination card, different questions were asked to know the vaccination status of the child for each specific vaccine and Vaccination histories of children.

Inclusion Criteria
Mothers/caregivers who have at least one 12-23 months child and living in Shewa robit town for at least six months prior to the day of the study period.

Exclusion criteria
Mothers/ caregivers who are in serious illness and unable to communicate during data collection time.

Dependent Variable
Vaccine dropout rate of children aged between 12-23 months.

Data Processing and Analysis
Data were checked for completeness and inconsistencies, then data processing, master sheet or template was prepared and the data was entered, categorized, coded, and summarized using Epi-data version 3.1 and transformed to SPSS version 21 for further analysis.

Data Quality Control
The questionnaire was prepared in English and translated from English to Amharic and re-translated back to English to check consistence. One day training was given for data collectors on methods of data collection. Questionnaire was checked on daily basis for completeness during data collection and data were cleaned and coded before data entry. Data analysis was started by sorting and performing quality control checkup on field. Data was checked in the field to ensure that all the information was properly collected and recorded. Before and during data processing the information was checked for completeness. Before the actual data collection, the tool was pretested on 5% of the sample size at kebele 01 of Shewa robit town to check the reliability and no modification was done on the tools. The pre-tested data was not including in the main data.

Ethical Consideration
The letter was obtained from research ethical committee and the formal permission letters was written from Debere Birhan University, collage of medicine and health science, department of nursing to Shewa Robit town health office. After obtaining the permission from concerned bodies the informed verbal consent was obtained from each respondent and the purpose of the study is clearly explained to him/ her about the objective, the contents of the study, as well as their right to refuse and discontinue the data collection.
Anonymity and confidentiality of the information was assured and privacy of each respondents wasmaintained throughout data collection and data wasuse for the research purpose only.

Socio-Demographic Characteristics of study population
A total of 432 mothers / caregivers who have children aged between 12-23 months were interviewed and the response rate was100%. More than half of the respondents 256(62.7%) were between the age of 18 -28 years and the mean age of study participants was28. 21  Approximately 162 (37.5%) respondents wereearning less than 300-birr per month.
( Table:1). were heard about campaigns, 121(29%) were heard age of vaccination. Regarding to the time when begin vaccination 316(73.1%) were respondedjust after birth,114(26.4%) after six weeks of birth, the rest 2 respondentswere didn't know the age to begin vaccination.

Vaccination coverage
Regarding Vaccination coverage 392 (90.7%)children were fully vaccinated for recommended vaccine of the country. All 432 children were immunized for BCG vaccine and 392 (90.7%) children were immunized for measles vaccine.
Most respondents 333(77.1%) have immunization card and99(22.1%) had no immunization card. From those who have vaccination card 24 children had drop out their vaccine and 16childrendidn't have immunization card. Vaccination coverage by card 71.5% and coverage by mother history 19. 2%.

Mother's/caregiver's reason for vaccination dropout
Regarding to the reason for vaccination drop out 16(40%) were due to forget appointment, 12(30%) were due to mothers were busy for other activity,7(17.5%) were due to mother was sick, 3(7.5%) were due to fear of side effect, the rest 2 participants were due to child was sick during the time of vaccination date.

Access to immunization service
The study showed that 400(92.6%) were live near to the health facility, the rest 32(7.4%) were lived far from the health facility. Based on means of transport used during
According to this study majority of the respondents 356(81.4%) were deliver their last child in health facility and the reaming 76(17.6%) were deliver at home.

Results of multiple logistic regression analysis
On multivariate logistic regression ANC follow-up of mothers, time to reach health facility and occupation of mothers/caregivers variables were predictors of vaccine dropout rate .Regarding to occupation of mothers/caregivers students had less likely dropout rate than government employee(AOR: 0.075(95% C.I (0.006,0.971), Regarding to time to reach health facility with in less than 15 minute were 15.62 times more dropout rate than mothers/caregivers who reach health facility within 30-60 minute(AOR: 15.62

Discussion
The study was conducted to assess vaccine dropout rate and associated factors among children age between 12-23 month. From the total children include the study 40(9.3%) children didn't complete the recommended vaccine, whereas study done in Yirgalem town, Sideman Zone from 478 participants95(20%) of children was dropout rate their vaccine.
This difference was may be due to socio demographic characteristics of respondents [25].
According to this study the dropout rate of penta-1 to penta-3 was 3.2% and BCG to measles dropout rate was 9.3% whereas other study conducted Ambo , Easter Ethiopia penta-1 to penta-3 dropout rate was 55.2% and BCG to measles dropout rate was 38.1% this difference was may be due to study time and sample size [26]. Similar study conducted in Debere markos show that the Dropout rate of BCG to measles was 6.5% ,the dropout rate of Penta-1 to Penta -3 was 2.7% and PCV 1 to PCV 3 dropout rate was 4.5% this is almost similar to this study [29]. This study reveals that out of the total 432 children between 12-23 months' age group, Majority of respondent's index child 185(42.8%) were between 16-19 months. On this study from the total 432 children 392(90.7%) children were fully immunized. from the total interviewed mother 333(77.1%) could show immunization card whereas study conducted in yirgalem town, south Ethiopia 243(52.5%) could show immunization card. This is may be related toawarenessabout immunization was increase in our study [25].
mother who didn't attend ANC follow-up during pregnancy were more dropout rate for child vaccination than mother who were attend ANC follow-up (AOR: 4.87(1.39, 16.98)) and a study conducted inYirgalem town, Sidama Zone showed that Mothers who didn't attend ANC are more likely to incomplete vaccination than those who attend ANC (AOR: 5.10 (CI. 3.8, 52) [25].
According to this study mothers/care gives who were took less than 15 minute to reachhealth facility had15.617 times more likely dropout rate than took with 30-60 minute (AOR: 15.617(2.06, 118.4).

Conclusion
The overall immunization dropout rate in Shewa robit town was 9.3%. Distance of time to reach health facility, ANC follow-up of mothers/caregivers and occupation of mothers/caregivers were statistically significant predictors of vaccine dropout rate of children in Shewa robit town. The main reasons described for dropout rate by respondents were forgetting the appointment date and mother was busy by other activity. Also as a reason for not vaccinating their child, most respondents replied that mother and child was sick at the time of vaccination date and fear of side effect which led to partially vaccinated. Based on the result of the study, the following recommendations are suggested to Shewa robit town health office, and mothers/caregivers. Ethical approval was obtained from review committee of Debre Berhan University. Oral concent was obtained from each study participants. All the information obtained from the study participants were kept confidential throughout the study,the name of the participant did not write rather replaced by code. Participants can withdraw from the study at any time.