Acceptance and use of the Information System of the National Immunization Program*

Objective: to analyze the acceptance and use of the Information System of the National Immunization Program in primary health care vaccination rooms. Method: a unique case study of a qualitative approach in the light of the Unified Theory of Acceptance and Use of Technology. Data collection included an interview with 18 professionals responsible for the implementation of the information system, observation of vaccination rooms in 12 municipalities of the West Macro-region of Minas Gerais, selected from a preliminary study. Data was systematized and analyzed through Content Analysis. Results: the interviewees are satisfied with the usefulness and ease of the system usage, but do not have the same satisfaction with the organizational infrastructure due to the lack of computers and low Internet connectivity in the health units, as well as with the incipient training for the use of the information system and the lack of skills with the technology among the human resources. Conclusion: nursing professionals perceive advantages in the acceptance and use of the Information System of the National Immunization Program. It was clear that the vaccinated individual’s history control and the decrease of records in paper are evidenced as facilitators of this acceptance. The system was considered reliable and secure.

some factors -such as lack of knowledge and of resources and infrastructure -have influenced the acceptance and use of the system (10) . Based on these considerations, the guiding question for this study is the following: What factors have influenced the acceptance and use of the SIPNI in primary health care vaccination rooms?
For these reasons, the objective of the study is to analyze the acceptance and use of the Information System of the National Immunization Program in primary health care vaccination rooms.

Method
This is a unique case study (11) , using the Unified Theory of Acceptance and Use of Technology (UTAUT) model with a qualitative approach. As the unit of analysis, we define the acceptance and use of the SIPNI and, as a context, the municipalities of the West Macroregion of Minas Gerais.
The UTAUT model aims to explain an individual's intention to use a technology device and considers four key attributes in determining acceptance and use (performance expectation, effort expectation, enabling conditions and social influence) influenced by age, gender, experience, and voluntariness, as shown in Figure 1 (9) .

Performance expectation
The individual believes that using the system will help them to make gains in work performance.

Effort expectation
It concerns the ease of use of the information system.

Social influence
It consists of an individual's perception of how important it is, for close and relevant people, that they use the system.

Enabling conditions
The individual believes that the existing organizational and technical infrastructure in the company is sufficient to support the use of the information system.  the interviewees were coded with the letter E followed by the chronological sequence of the interviews.
The data were analyzed using the Content Analysis technique, Thematic-Categorical Mode (14) . For the application of the content analysis, the stages of preanalysis, material exploration, or codification and treatment of the results obtained by interpretation were used. In the pre-analysis, or floating reading of the interviews, the key points were identified, that is, the main points addressed by the interviewees in each question from the script. The material was then exploited and coded. The registration units, meaning units, context units, and thematic categories were extracted. The categories can be created a priori or a posteriori. When defined a priori, validity or relevance can be built from a theoretical base (14) . So, the categories were defined a priori, according to the four UTAUT model attributes: performance expectation, effort expectation, enabling conditions and social influence. In the last phase, the results were treated in such a way as to be significant

Results
We interviewed thirteen nurses, one community health worker, two nursing technicians, one biomedical, and one public manager. Age ranged from 27 to 57 years old, with a mean of 38 years. There was predominance of females (94.4%). Also, six interviewees had specialization of the lato sensu type and two were masters. The length In the UTAUT theory, acceptance of a new system is related to users' perception that the value gained from adopting it can be greater than the challenges and The implementation of an information system is a complex and multidimensional process influenced by technical, individual, human, and organizational factors which must be approached innovatively, according to the specific needs of each system and each group of users (15) .
In the context of primary care, the precariousness of material inputs required for the use of information systems, such as technological devices and the Internet, negatively affects the process of acceptance and use of information systems (16)(17) .
One of the limiting factors, identified in most municipalities with a web system, was the slow Internet connectivity, leading to the slowness of the information system and, consequently, to the maintenance of the paper record and to the non-input of data in realtime. This result corroborates the findings of a study conducted in Kenya to evaluate an electronic health information system with an immunization component, which identified barriers such as power outage, slow Internet connectivity, the time required for data entry, paper, and system data entry (18) .
If the SII is not properly fed with real-time data entry, it may generate under-registration, compromising the integration of nominal vaccination data and, consequently, the range of vaccine coverage (7) . The time between vaccination and the data entered into the SII must be minimized so that the information comes to be in real-time (19) .
According to the UTAUT theory model, the acceptance of technology is related to the individual's belief in the contribution of the technological resource use to the improvement of the quality of their work (9) .
During the technical visit in one municipality we making (20)(21) .
In this sense, the incipient use before the simultaneous use of other forms of paper registration, to the detriment of the SIPNI, may hinder the perception of the potential of this system for the performance of the service. A similar phenomenon was observed in the context of the e-SUS Basic Care (e-SUS AB) strategy, in which paper-based registration and the information system emerged as an important incompatibility between the use of technology and traditional means of registration (16) . In the interviews, the participants highlighted influences of this whole process of not typing in real-time on the reach of vaccination coverage.
Vaccine coverage is considered a monitoring pillar of the SII (1) . The still immature use of the SIPNI reveals the fragility of the data produced from the system. For the interviewees, the information in the system does not reflect the actual scenario of vaccination coverage, which consequently may lead to unsafe use of the information by professionals, in addition to allowing data underreporting.
The discrepancy of the SIPNI data was pointed out in a study when it describes the risk classification of vaccine-preventable diseases in Brazilian municipalities.
According to the authors, most municipalities presented a high risk of disease; their findings pointed to possible Oliveira VC, Guimarães EAA, Amaral GG, Silva TIM, Fabriz LA, Pinto IC.
inconsistencies in the SIPNI data capable of distorting vaccination coverage and abandonment proportions, interfering with the risk indicator (22) .
In implementing changes that affect the structure, culture, work processes, behavior, and communication channels of a health care organization, some resistance is expected (23) . One solution is to conduct progressive training and educational activities (17) . In a systematic review it was identified in the studies that, where there was adequate technical support and training, the acceptance of the information system was easier. In contrast, in studies in which inadequate or non-existent IT support or training was reported, the tendency was to conclude that these factors were barriers to system implementation (15) . However, as well as the implementation of e-SUS AB in the scenario studied, the SIPNI has also been implemented in a sudden and vertical way (16) , without an offer (or with an insufficient offer) of training, which may compromise its acceptance.
In implementing an information system in a big teaching hospital in the UK, it was identified that the way people reacted to the adoption and implementation of the system was influenced by age and attitude towards

Information and Communication Technologies (ICTs).
Younger employees, who were familiar with computers, easily accepted the technology, unlike older physicians and nurses, who were reluctant to do so (23) .
The findings of this study indicate that older nursing professionals and/or those with little familiarity with technology tend to be more resistant to the SIPNI innovation. According to the UTAUT theory, the ease of the information system usage is influenced by age, in such a way that the effect will be stronger for older workers, with increasing experience (9) . The acceptance and use of electronic recording by nurses was the subject of a literature review, in which the nurses' low acceptance of the technology was related to the lack of perception on advantages of its use due to incipient use (24) . Another aspect listed by the authors was the effects of the characteristics of the technology itself, but mainly the personal specificities of the nurses affecting greatly the acceptance of technological artifacts. In this sense, organizational psychologists have realized that older workers, due to the increase in cognitive and physical limitations associated with age, assign greater importance to receiving help in the context of using information technologies (9) . However, even in the face of resistance to the use of information systems, technology has become an indispensable tool in the health scope. Studies show that preparation/training in the use of systems was related to ease of use as it improves people's skills with technology, favoring the perception of its usefulness and ease of handling it (15,17) . Social pressure in the use of innovation tends to attenuate over time, as experience increases, and in the UTAUT theory it is suggested that women tend to be more sensitive to the opinions of others and, therefore, social influence becomes more relevant in the intention to use the new technology (9) .
In Brazil, the predominantly female nursing team (25) is responsible for immunization activities.
Considering this data, the acceptance of the SIPNI, identified in this study, may be influenced by this female predominance in the vaccination room. In this sense, it is important in health courses to prepare students for the use of technological resources, aiming at training in the use of information technology as an ally of care (17) , considering the context of growing dependence on information technology.
Innovation alone is not enough to impact on the quality of the services provided. It is essential that service planners and managers understand the human and organizational processes involved in motivating change and adopting innovation (23) .
This study, of a qualitative nature, has the limitation of not statistically demonstrating the relationships and power of each of the attributes in the acceptance and use of the SIPNI, besides the lack of data generalization, because it is a case study in a macro-region. However, the unveiling of the difficulties faced in the process of acceptance and use of the SIPNI in the macro-region is presented as a strength.
The results of the research bring contributions to the implementation of an information system that really enables complete and correct vaccination records, with electronic access in real-time. Also, it is important to highlight the unprecedented nature of the study, as this is a recent innovation in the vaccination room, and the scarcity of studies with the theoretical approach used.

Conclusion
Nursing professionals perceive advantages in the acceptance and use of the SIPNI. It was revealed that the control of the vaccination history and the reduction in paper records were evidenced as facilitators of this acceptance. Furthermore, the SIPNI was considered reliable and safe.
It is important that new research is triggered to quantitatively analyze the influence of each attribute of the UTAUT theory on the SIPNI acceptance and use.