private ModelAndView remove(String returnPage, HttpServletRequest request) {
    String externalID = request.getParameter("externalId");

    Patient patient = patientDataService.findByExternalId(externalID);
    if (patient != null) {
      patientDataService.delete(patient);
    }

    List<Patient> patientList = patientDataService.retrieveAll();

    Map<String, Object> modelMap = new TreeMap<>();
    modelMap.put("patients", patientList); // List of patients is for display purposes only

    return new ModelAndView(returnPage, modelMap);
  }
  private ModelAndView add(String returnPage, HttpServletRequest request) {
    String phoneNum = request.getParameter("phoneNum");
    String externalID = request.getParameter("externalId");

    patientScheduler.saveMotechPatient(externalID, phoneNum);

    List<Patient> patientList = patientDataService.retrieveAll();

    Map<String, Object> modelMap = new TreeMap<String, Object>();
    modelMap.put("patients", patientList); // List of patients is for display purposes only

    return new ModelAndView(returnPage, modelMap);
  }