gistfile1.txt

    @cohort_patient_ids[:all] = PatientRegistrationDate.find(:all, 
#                                  :joins => 'LEFT JOIN patient_identifier ON  
#                                             patient_identifier.patient_id = patient_registration_dates.patient_id 
#                                             AND identifier_type = 18 AND voided = 0',
                                  :conditions => ["DATE(registration_date) >= ? AND DATE(registration_date) <= ?", 
                                                  @quarter_start, @quarter_end]
#                                  :order => 'CONVERT(RIGHT(identifier, LENGTH(identifier)-3), UNSIGNED)').map(&:patient_id)
  ).map(&:patient_id)

#    @cohort_patient_ids[:start_reasons] = start_reasons[1]