class VaccinationCriteria

This class handles all the business logic related to determining whether a patient should be considered vaccinated for a particular programme type and academic year.

This reason this exists outside the StatusGenerator module is that it is used by each of the status generators but is not a status by itself.

Public Class Methods

new ( programme_type:, academic_year:, patient:, vaccination_records: )

Source

# File app/lib/vaccination_criteria.rb, line 21
def initialize(
  programme_type:,
  academic_year:,
  patient:,
  vaccination_records:
)
  @programme_type = programme_type
  @academic_year = academic_year
  @patient = patient

  @vaccination_records =
    vaccination_records.select do
      it.patient_id == patient.id && it.programme_type == programme_type &&
        if programme.seasonal?
          it.academic_year == academic_year
        else
          it.academic_year <= academic_year
        end
    end
end

Create a new instance of the class for the programme_type, academic_year, and patient.

The vaccination_records argument is required to allow for a preloaded array to be passed in, rather than fetching the records from the database. Any vaccination records can be passed in and will be filtered on the patient, programme type, and academic year. The filtered list is then available to read back as the vaccination_records method on the class instance.

Public Instance Methods

filter_doubles_vaccination_records (vaccination_records)

Source

# File app/lib/vaccination_criteria.rb, line 104
def filter_doubles_vaccination_records(vaccination_records)
  vaccination_records.select { patient.age_years(now: it.performed_at) >= 10 }
end

filter_hpv_vaccination_records (vaccination_records)

Source

# File app/lib/vaccination_criteria.rb, line 108
def filter_hpv_vaccination_records(vaccination_records)
  vaccination_records
end

filter_mmr_vaccination_records (vaccination_records)

Source

# File app/lib/vaccination_criteria.rb, line 112
def filter_mmr_vaccination_records(vaccination_records)
  # Any child who hasn't had two doses of MMR with the first dose above 1
  # year of age and the second above 15 months and the doses at least 4
  # weeks apart is eligible for catch up vaccinations by SAIS until they
  # have had two valid doses.
  #
  # Use `performed_at_date` (always a Date) rather than `performed_at` to
  # avoid type-mixing issues in sort order, comparison, and arithmetic.

  sorted_vaccination_records =
    vaccination_records.sort_by(&:performed_at_date)

  first_dose =
    sorted_vaccination_records.find do
      patient.age_months(now: it.performed_at_date) >= 12
    end

  return [] if first_dose.nil?

  # The second dose must be at least 28 days after the most recent dose
  second_dose =
    sorted_vaccination_records.find do |record|
      next if record.performed_at_date <= first_dose.performed_at_date

      previous_dose =
        sorted_vaccination_records
          .select { it.performed_at_date < record.performed_at_date }
          .last

      record.performed_at_date >= previous_dose.performed_at_date + 28.days &&
        patient.age_months(now: record.performed_at_date) >= 15
    end

  [second_dose, first_dose].compact
end

programme ()

Source

# File app/lib/vaccination_criteria.rb, line 148
def programme
  @programme ||= Programme.find(programme_type)
end

vaccinated? (= vaccinated_vaccination_record != nil)

Source

# File app/lib/vaccination_criteria.rb, line 44
  def vaccinated? = vaccinated_vaccination_record != nil

  ##
  # Returns the first vaccination record that confirms that the patient is
  # vaccinated.
  def vaccinated_vaccination_record
    @vaccinated_vaccination_record ||=
      begin
        if (already_had_record = valid_vaccination_records.find(&:already_had?))
          return already_had_record
        end

        if programme.mmr?
          if valid_vaccination_records.count >= programme.maximum_dose_sequence
            valid_vaccination_records.first
          end
        elsif programme.td_ipv?
          valid_vaccination_records.find do
            it.dose_sequence == 5 || it.sourced_from_service?
          end
        else
          valid_vaccination_records.first
        end
      end
  end

  ##
  # Returns the administered vaccination records that are considered valid
  # doses according to the specific criteria of the programme.
  def valid_vaccination_records
    @valid_vaccination_records ||=
      if programme.seasonal?
        vaccination_records.select { it.administered? || it.already_had? }
      else
        if (
             already_had_records = vaccination_records.select(&:already_had?)
           ).present?
          return already_had_records
        end

        administered_records = vaccination_records.select(&:administered?)

        if programme.doubles?
          filter_doubles_vaccination_records(administered_records)
        elsif programme.hpv?
          filter_hpv_vaccination_records(administered_records)
        elsif programme.mmr?
          filter_mmr_vaccination_records(administered_records)
        else
          raise UnsupportedProgrammeType, programme_type
        end
      end
  end

  attr_reader :vaccination_records

  private

  attr_reader :programme_type, :academic_year, :patient

  def filter_doubles_vaccination_records(vaccination_records)
    vaccination_records.select { patient.age_years(now: it.performed_at) >= 10 }
  end

  def filter_hpv_vaccination_records(vaccination_records)
    vaccination_records
  end

  def filter_mmr_vaccination_records(vaccination_records)
    # Any child who hasn't had two doses of MMR with the first dose above 1
    # year of age and the second above 15 months and the doses at least 4
    # weeks apart is eligible for catch up vaccinations by SAIS until they
    # have had two valid doses.
    #
    # Use `performed_at_date` (always a Date) rather than `performed_at` to
    # avoid type-mixing issues in sort order, comparison, and arithmetic.

    sorted_vaccination_records =
      vaccination_records.sort_by(&:performed_at_date)

    first_dose =
      sorted_vaccination_records.find do
        patient.age_months(now: it.performed_at_date) >= 12
      end

    return [] if first_dose.nil?

    # The second dose must be at least 28 days after the most recent dose
    second_dose =
      sorted_vaccination_records.find do |record|
        next if record.performed_at_date <= first_dose.performed_at_date

        previous_dose =
          sorted_vaccination_records
            .select { it.performed_at_date < record.performed_at_date }
            .last

        record.performed_at_date >= previous_dose.performed_at_date + 28.days &&
          patient.age_months(now: record.performed_at_date) >= 15
      end

    [second_dose, first_dose].compact
  end

  def programme
    @programme ||= Programme.find(programme_type)
  end
end

Returns true if the patient should be considered vaccinated.

vaccinated_vaccination_record ()

Source

# File app/lib/vaccination_criteria.rb, line 49
def vaccinated_vaccination_record
  @vaccinated_vaccination_record ||=
    begin
      if (already_had_record = valid_vaccination_records.find(&:already_had?))
        return already_had_record
      end

      if programme.mmr?
        if valid_vaccination_records.count >= programme.maximum_dose_sequence
          valid_vaccination_records.first
        end
      elsif programme.td_ipv?
        valid_vaccination_records.find do
          it.dose_sequence == 5 || it.sourced_from_service?
        end
      else
        valid_vaccination_records.first
      end
    end
end

Returns the first vaccination record that confirms that the patient is vaccinated.

valid_vaccination_records ()

Source

# File app/lib/vaccination_criteria.rb, line 73
def valid_vaccination_records
  @valid_vaccination_records ||=
    if programme.seasonal?
      vaccination_records.select { it.administered? || it.already_had? }
    else
      if (
           already_had_records = vaccination_records.select(&:already_had?)
         ).present?
        return already_had_records
      end

      administered_records = vaccination_records.select(&:administered?)

      if programme.doubles?
        filter_doubles_vaccination_records(administered_records)
      elsif programme.hpv?
        filter_hpv_vaccination_records(administered_records)
      elsif programme.mmr?
        filter_mmr_vaccination_records(administered_records)
      else
        raise UnsupportedProgrammeType, programme_type
      end
    end
end

Returns the administered vaccination records that are considered valid doses according to the specific criteria of the programme.