Event to calculate items searched in the table

I need to calculate the table items and display them in a certain field on my page.

There is a search field with some filters, as it is searched the patients appear in the table, with the event I wanted to listen to the patients as they are searched and show the result (number of patients that were found) in another field. p>

The id="countPatients" is a < span> where the number of patients surveyed should appear.

.pacientes-table-plugin is my table

My event in .js looks like this:

Pacientes.prototype = {
     $('.pacientes-table-plugin').on('change', function(){
          self.count_pac();
     });
}

And my function like this:

count_pac : function(){
     const t = $('.pacientes-table-plugin tr').length;
     $('#countPacientes').text(t);
}

But my event is not working