# Clinical Trial Classification of SNS24 Calls with Neural Networks
## 3 Materials and Methods  
### Dataset  
SPMS (Servicos Partilhados do Ministerio da Saude) [[https://www.spms.min-saude.pt/](https://www.spms.min-saude.pt/)]([https://www.spms.min-saude.pt/](https://www.spms.min-saude.pt/)) (accessed on 2 April 2022) cooperates, shares knowledge, and develops activities in the domains of health information and communication systems, making sure that all information is available in the best way for all citizens. SPMS advocates the definition and usage of standards, methodologies, and requirements. This guarantees the interoperability and interconnection among the health information systems, and as well with cross-sectional information systems of the Public Administration. The SPMS provided the anonymized data, and the competent ethics committee approved the study protocol used in this paper.  
The original dataset used for our task was collected by the SNS24 phone-line from January to March 2018. It contains information of call records received, which has a total of 269,658 records with 18 fields. Table 1 lists all 18 fields both in the original Portuguese and in English. Each call record includes personal data, such as age, gender, and encrypted primary care unit. It also contains the calling information, such as the start/end time, initial intention, comments, contact reason, clinical pathway, and final disposition. The \"contact reason\" and \"comments\" fields are free text written in Portuguese by the technician or nurse who answered the respective call. The date related information is recorded in date format and the other remaining fields are nominal attributes.  
Within the original 3-month dataset, there are 52 clinical pathways from the total of 59 defined by the SPMS. The proportions for each clinical pathway varies significantly. For example, _Tosse (Cough)_ has the highest number of records and accounts for 14.006% of the calls, while _Pr. por calor (Heat problems)_ represents only 0.001% of the calls; six of the clinical pathways have over 10,000 calls, and three under 100. Table 1, in the Appendix A, lists the existing 52 clinical pathways, their record numbers, and the proportions to the whole dataset.  
While building the dataset to be used for this research, instances belonging to one clinical pathway with a number smaller than 50 were discarded. Thus, instances belonging to _Pr. por calor_ were removed (see Table 1). As a result, the final dataset used for our task is composed of 269,654 records belonging to the 51 clinical pathways. Following conclusions from previous experiments [17], the \"contact reason\" field was selected as the discriminant information for our experiments; other fields, such as age, gender, etc. were not used. The \"contact reason\" field is one of the 18 descriptive attributes. It is written with a medium-length free text, consisting of straightforward information about the patient'sproblem. Table A2 (in the Appendix A) presents examples of \"contact reason\" field texts from the five most frequent clinical pathways and their respective label. As a summary, the statistics of the original and experimental dataset are presented in Table 2.