Purposive sampling of every mother-child pair who fit the inclusion criteria was done, and the mother-child pairs were recruited over four months (15 August to 15 December 2016) as part of another study. Two research assistants deployed a semi-structured interview-based questionnaire. The sociodemographic details of each child brought for vaccination was recorded. The parents occupation was grouped into five categories according to Oyedeji: (I) professionals, owners of large business; (II) secondary school teachers, owners of medium-sized business; (III) artisans, primary school teacher, clerks; (IV) petty traders, laborers; and (V) students, unemployed, housewives.13 Questions were asked about antenatal care (ANC) history, such as the location and number of visits. The delivery details of the infant, including date and place of birth, were also recorded. Previous vaccination for a child and whether it was completed was also noted. Responses on the ownership of a phone by the mother or father, as well as willingness to have the phone number recorded for reminders, were noted and recorded if applicable. The mother’s opinion about whether she would want a reminder for subsequent vaccines was sought and recorded. Responses to reasons for either wanting or not wanting reminders were also recorded. If mother answered in the affirmative, answers on the type of reminder, and the preferred language for communication were sought.

Data was analyzed using SPSS Statistics (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.). Continuous variables were expressed as the mean and standard deviation (SD) and categorical variables as number and percentage. After the generation of frequency tables and simple proportions, the chi-square test was used to identify significant differences for categorical variables. Variables with a p-value less than 0.050 on bivariate analysis were included in the binomial logistic regression model to identify factors that predicted willingness to receive reminders. A p-value of less than 0.050 was considered statistically significant.

Results

The mean age of all mothers recruited was 28.5±4.8 years, and the age range of mothers recruited was between 17 years and 45 years old. Of the 526 children enrolled, 267 (50.7%) were male, and 259 (49.2%) were female. Islam was the religion of 380 (72.2%) mothers, and 146 (27.7%) mothers were Christians. The major occupation of the mothers and fathers were artisans accounting for 318 (60.4%) and 257 (48.8%) of participants, respectively. Ten (1.9%) mothers were single, and 516 (98.0%) mothers were married. Other sociodemographic features are shown in Table 1. The majority of mothers had ANC and delivery at a government-owned facility (n = 421, 80.0% and n = 420, 79.8%, respectively). Most mothers (41.6%) had one child, with a decrease in the proportion recorded with an increasing number of children [Table 1].

Previous immunization experience was recorded for 299 (56.8%) mothers while 227 (43.1%) mothers had no experience taking a child for immunization. Information about the NPI schedule on the number of visits and the infant’s age at each visit was identified correctly by 273 (51.9%) mothers and wrongly by 253 (48.0%) mothers.

Four hundred and eighty-eight (92.7%) mothers had a personal phone. Of the 488 mothers who had a personal phone, 484 willingly provided their phone number while four provided only the phone number of their spouse. All (100%) fathers had a phone, and the mothers willingly provided the phone numbers of the 526 fathers.

A positive response on willingness to receive reminders for immunization visits was given by 363 (69.0%) mothers and a negative response by 163 (30.9%) mothers. Forgetfulness of the date of the next scheduled visit was the main reason mothers opted for reminders. Of the 163 who opted out of receiving reminders, 73 (44.7) reported that they would remember the date of the next scheduled visit given verbally by the healthcare worker while 90 (55.2%) reported they would check the immunization card for the date of the next visit.

Of the 363 mothers who were willing to receive reminders, 189 (52.0%) chose text messages as the preferred reminder type, while 174 (47.9%) mothers preferred phone calls. English was the preferred language for reminders for 194 (53.4%) mothers while the remaining mothers preferred their native language. A total of 206 (56.7%) mothers were willing to pay for the reminders.

On bivariate analysis, the educational level of parents, maternal occupation, number of children in the family, previous immunization experience, knowledge of the immunization schedule, and place of ANC and delivery were factors significantly associated with the acceptance of reminders [Table 2].

The multivariate logistic regression model of these factors had a goodness of fit measure which was statistically significant (chi-square = 68.013, df = 10, p < 0.001) with an R-square of 17.1. Table 3 shows mothers with children less than or equal to four in number had a three-fold increased odds of wanting reminders. Postsecondary education and ANC in a hospital increased the odds of wanting reminders by two- and eight-fold, respectively. The chances of those not willing to receive reminders were increased in mothers with group III occupation compared to those with group IV and V occupational class.

Discussion

The current study found that 93% of the mothers owned a phone, and all had access to a phone in the household. This finding is similar to the proportion of maternal phone ownership of 92.6% and 100% access reported in Benin,12 but lower than that reported in Ibadan14 (98.9%) and Lagos (98%).15
All mothers in the study were willing to provide contact information (either their own or spouses) as reported in previous studies.12,14–16 Contact details are needed for reminders, and thus the fact that mothers were willing to provide the contact details would be of aid in utilizing reminders to improve vaccination coverage.

Most mothers (69.0%) responded positively and accepted immunization reminders, which is slightly higher than the value of 62.6% reported in Benin12 but lower than that reported from Lagos15 and Ibadan14 (77.0% and 95.1%, respectively). Mothers who were not willing to receive reminders believed that the appointment date provided on the vaccination card would serve as a sufficient reminder thus buttressing the importance of the vaccination card. The finding of a majority preference for text messages compared to phone calls in the current study differs from the findings reported in Benin, Lagos, and Ibadan where phone calls were preferred.12,14,15 The majority preference for text messages may be supported by the fact that majority of the mothers had at least a secondary school level education and would be able to read the text messages.

Postsecondary maternal education was an important maternal household characteristic that determined the mothers’ willingness to accept reminders. Studies have identified maternal educational level as an important determinant of reminders for immunization.12,14 This earlier finding supports the current study findings for maternal education but differs from the paternal education finding, which was not significant.

Typically, the mother takes the child for immunization (as demonstrated by 100% maternal presentation at immunization clinic); therefore, an educated mother is better able to understand the information provided on vaccination, which is needed to ensure complete immunization status. Indeed, the role of maternal education in completion of child immunization is important as reported previously.1,17–19

ANC attendance was a significant predictor of mothers who were willing to receive reminders. This finding may be attributable to the health education (including the benefits of immunization) provided by the healthcare worker (usually nurses) during ANC visits. The health talk, reinforced at all ANC visits, serves as a source of information, especially to first-time mothers, who may lack or have inadequate knowledge about childhood immunization. This current study finding can be supported by studies that have reported ANC as an accessible source of information on immunization,20,21 as well as a determinant of complete childhood immunization.3,22 Therefore, improvement in maternal access to health care services during pregnancy and delivery may be a step towards improving vaccination uptake.

Total number of children and previous immunization experience were important predictors of willingness to receive reminders as mothers who had no previous experience and fewer (< 4) children were more likely to be willing to receive reminders than mothers with previous immunization experience and had five or more children. Reasons for this finding could probably be attributed to lack of confidence and also fear of failure to remember an appointment on the part of the mother with no previous immunization experience and fewer children. Also, this is supported by the findings of the current study of a higher proportion of mothers who could not correctly identify the NPI schedule being willing to receive reminders. An earlier study had reported mothers with fewer children as being more willing to receive reminders.12

Mothers who were students or housewives were more likely to want reminders compared to those who worked as artisans, junior clerks, or primary school teachers. This finding is similar to the reports from Benin.12 The fact that the former group of mothers wanted reminders may be attributable to the fact that they may have limited experience with taking a child for immunization and are yet to develop confidence in childrearing. This could be adduced from the fact that majority of these unemployed mothers were also mothers with only one or two children. Thus, they would benefit from the reminders prompting them to take the children for vaccination. Indeed, an earlier Nigerian study had identified unemployed mothers as those likely to complete the immunization of their children.17

Conclusion

Mothers have ready access to mobile phones, and most are willing to receive reminders about immunization appointments. Determinants of maternal willingness to receive reminders include mothers with less than four children, postsecondary education, and ANC attendance. Program planners should consider utilizing reminders as a strategy to increase the immunization uptake as accessibility to contact details will make it feasible.

Disclosure

The authors declared no conflicts of interest. No funding was received for this study.

Acknowledgements

The authors are grateful to Dr. MJ Mohammed of Adewole Cottage Hospital, and the nurses in the immunization units of General Hospital, and Adewole Cottage Hospital, Ilorin for the support and cooperation rendered during the collection of data.

references

1. 1. Adegboye OA, Kotze D. Multi-year trend analysis of childhood immunization uptake and coverage in Nigeria. J Biosoc Sci 2014 Mar;46(2):225-239.
2. 2. Abdulraheem IS, Onajole AT, Jimoh AAG, Oladipo AR. Reasons for incomplete vaccination and factors for missed opportunities among rural Nigerian children. J Public Health Epidemiol 2011;3(4):194-203.
3. 3. Adedire EB, Ajayi I, Fawole OI, Ajumobi O, Kasasa S, Wasswa P, et al. Immunisation coverage and its determinants among children aged 12-23 months in Atakumosa-west district, Osun State Nigeria: A cross-sectional study. BMC Public Health 2016 Aug;16(1):905.
4. 4. Antai D. Inequitable childhood immunization uptake in Nigeria: A multilevel analysis of individual and contextual determinants. BMC Infect Dis 2009 Nov;9:181.
5. 5. Sadoh AE, Eregie CO. Timeliness and completion rate of immunization among Nigerian children attending a clinic-based immunization service. J Health Popul Nutr 2009 Jun;27(3):391-395.
6. 6. Ibraheem RM, Bello AO, Adeboye MA, Adeyeba DT, Mohammed MJ. Missed vaccination opportunities at a secondary health facility in Ilorin, Nigeria. JCMPHC 2016;28(1):31-37.
7. 7. Dini EF, Linkins RW, Sigafoos J. The impact of computer-generated messages on childhood immunization coverage. Am J Prev Med 2000 Feb;18(2):132-139.
8. 8. Szilagyi PG, Schaffer S, Shone L, Barth R, Humiston SG, Sandler M, et al. Reducing geographic, racial, and ethnic disparities in childhood immunization rates by using reminder/recall interventions in urban primary care practices. Pediatrics 2002 Nov;110(5):e58.
9. 9. Szilagyi P, Vann J, Bordley C, Chelminski A, Kraus R, Margolis P, et al. Interventions aimed at improving immunization rates. Cochrane Database Syst Rev 2002;(4):CD003941.
10. 10. Fiks AG, Grundmeier RW, Biggs LM, Localio AR, Alessandrini EA. Impact of clinical alerts within an electronic health record on routine childhood immunization in an urban pediatric population. Pediatrics 2007 Oct;120(4):707-714.
11. 11. Free C, Phillips G, Felix L, Galli L, Patel V, Edwards P. The effectiveness of M-health technologies for improving health and health services: a systematic review protocol. BMC Res Notes 2010 Oct;3:250.
12. 12. Sadoh A, Okungbowa E. Nigerian mothers opinion of reminder/recall for immunization. Niger J Paediatr 2014;41(1):38-42.
13. 13. Oyedeji GA. Socio-economic and cultural background of the hospitalized children in Ilesha Nig J Paediatr 1985;12:111-117.
14. 14. Brown VB, Oluwatosin A, Ogundeji MO. Experiences, perceptions and preferences of mothers towards childhood immunization reminder/recall in Ibadan, Nigeria: A cross-sectional study. Pan Afr Med J 2015;20:243.
15. 15. Balogun MR, Sekoni AO, Okafor JP, Odukoya OO, Ezeiru SS, Ogunnowo BF, et al. Access to information technology and willingness to receive text message reminders for childhood immunization among mothers attending a tertiary facility in Lagos, Nigeria. SAJCH 2012;6:76-80.
16. 16. Diallo O, Schlumberger M, Sanou C, Dicko H, Aplogan A, Drabo F. [Use of SMS to ask mothers to come to vaccination sessions in Bobo-Dioulasso]. Bull Soc Pathol Exot 2012 Oct;105(4):291-295.
17. 17. Fatiregun AA, Okoro AO. Maternal determinants of complete child immunization among children aged 12-23 months in a southern district of Nigeria. Vaccine 2012 Jan;30(4):730-736.
18. 18. Brown VB, Oluwatosin OA. Socio-demographic factors associated with childhood immunization uptake in Akinyele Local Government Area, Oyo State, Nigeria. Afr J Med Med Sci 2012 Jun;41(2):161-167.
19. 19. Devasenapathy N, Ghosh Jerath S, Sharma S, Allen E, Shankar AH, Zodpey S. Determinants of childhood immunisation coverage in urban poor settlements of Delhi, India: a cross-sectional study. BMJ Open 2016 Aug;6(8):e013015.
20. 20. Hagan D, Phethlu DR. Determinants of parents’ decisions on childhood immunisations at Kumasi Metropolis in Ghana. Curationis 2016 Jul;39(1):e1-e10.
21. 21. Hu Y, Chen Y, Wang Y, Song Q, Li Q. Prenatal vaccination education intervention improves both the mothers’ knowledge and children’s vaccination coverage: Evidence from randomized controlled trial from eastern China. Hum Vaccin Immunother 2017 Jun;13(6):1-8.
22. 22. Etana B, Deressa W. Factors associated with complete immunization coverage in children aged 12-23 months in Ambo Woreda, Central Ethiopia. BMC Public Health 2012 Jul;12(1):566.