CoCASA Algorithm Reference

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This page describes the algorithms that CoCASA uses to produce reports.

Note: When running reports, the user can choose more or fewer than the number of doses that might be required by the algorithm for completeness. CoCASA will count the patient as complete for that particular antigen based on the lesser of the dose counts. For instance, if the algorithm requires 5 doses of an antigen, but the user chooses 2, then the patient will be counted as complete with 2 doses. Conversely, if the algorithm requires 2 doses but the user chooses 5, then the patient will still be counted as complete with 2 doses. Also note that when ACIP recommendations are applied, the intervals for compliance, missed opportunities, eligibility, and for coming due are calculated from the last valid or invalid dose.

Definitions

Note: Unless otherwise noted, the definitions listed below apply to all of the algorithms.

Complete and Up To Date:

The patient has received all of the selected vaccinations by either the compliance date or the compliance age as chosen by the user. If, when using compliance age, the patient’s date of birth causes his/her compliance age to fall after the assessment date, the patient is not included in the report, even if he/she falls within the age range chosen for the report. In other words, if you choose compliance by a specified age (e.g., 24 months), any patients that have not yet reached that age at the assessment date will be excluded from the report.

Complete But Late Up To Date:

The patient is not up to date at the compliance date or the compliance age requested for the report, but he/she becomes up to date according to the rules of the algorithm between the compliance date/age and the assessment date.

Bring Up To Date with One Visit:

The patient is not currently up to date by the assessment date, but is one dose shy of being complete for the particular antigen in question. If a report is run against a series of antigens and all of the remaining vaccinations could be given on the same day, then the patient could still be brought up to date with one visit.

Missed Opportunity On the Last Immunization Visit:

On the patient’s last visit for an immunization he/she received a dose of a different antigen than the antigen in question, or there was a reason a different antigen was not given, and at the time of that visit a valid dose of the antigen in question could have been administered in keeping with the patient’s age and the time interval from the previous valid or invalid dose.

Missed Opportunity On All Immunization Visits:

During any of the patient’s immunization visits he/she received a dose of a different antigen than the antigen in question, or there was a reason a different antigen was not given, and at the time of that visit a valid dose of the antigen in question could have been administered in keeping with the patient’s age and the time interval from the previous valid or invalid dose.

Missed Opportunity On All Previous Visits:

During any of the patient’s visits, not just immunization visits, he/she received a dose of a different antigen than the antigen in question, or there was a reason a different antigen was not given, or there was a non-immunization visit of some kind, and at the time of that visit a valid dose of the antigen in question could have been administered in keeping with the patient’s age and the time interval from the previous valid or invalid dose. Dates when only Influenza was given are not considered as a Missed Opportunity for other antigens.

Missed Opportunity On Only Non-Immunization Visits:

During any of the patient’s non-immunization visits, a valid dose of the antigen in question could have been administered in keeping with the patient’s age and the time interval from the previous valid or invalid dose.

NOTE: For the above missed opportunity calculations, influenza vaccinations are never considered to be a missed opportunity.  The reasoning behind this is that on many occasions influenza is administered as part of an immunization drive at locations like schools, clinics, or pharmacies where it would not be reasonable to expect other vaccinations to be given at the same time.

Eligible for Immunization:

Those patients who are not complete and up to date as of the assessment date and have no missed opportunities and, based on the rules of the antigen in question, could receive a valid dose of that antigen at the assessment date.

Last Visit < 12 Months Ago or Last Visit ≥= 12 Months Ago:

Only patients who are eligible for immunization are counted in these totals. Both immunization visits and non-immunization visits are counted.

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Rules for Each Antigen

The rules listed below are applied for each antigen.
DTaP | HepA | HepB | HIB | HPV | IIV or LAIV | IPV | MenACWY | MenB | MMR | PCV13 | RV | Tdap | VAR

DTaP—Diphtheria, tetanus, and acellular pertussis vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 6 weeks or later.
  • Dose 2 must be given at 10 weeks or later and at least 4 weeks after dose 1.
  • Dose 3 must be given at 14 weeks or later and at least 4 weeks after dose 2.
  • Dose 4 must be given at 12 months or later and at least 6 months after dose 3.
  • Dose 5 must be given at 4th birthday or later and at least 6 months after Dose 4.

Note: DTwP, DTP and DT are all valid substitutes for DTaP.
Note: If Dose 4 is given between 4 and 6 months after Dose 3 it will still be considered valid, but if Dose 4 has not been given yet, the patient will not be overdue until after a 6 month interval has passed.
  • 4 valid doses were given and Dose 4 was given on or after the 4th birthday, or
  • 5 valid doses were given and Dose 4 was given before the 4th birthday.

 List of Antigens

HepA—Hepatitis A vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 1 year or later.
  • Dose 2 must be given at 18 months or later and at least 6 months after dose 1.
  • There is a “reason not given” entry before the compliance date that specifies, “Lab evidence of positive serology”, or “MD diagnosis of previous disease”, or
  • 2 valid doses were given.

 List of Antigens

HepB—Hepatitis B vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 can be given at birth.
  • Dose 2 must be given at 4 weeks or later and at least 4 weeks after the previous dose.
  • Dose 3 must be given at 24 weeks or later and at least 8 weeks after the previous dose and at least 16 weeks after Dose 1. If this dose is invalid, the minimum interval to the next dose is set to zero.

Note: The use of combination vaccines may result in an extra (4th) dose of HepB. This algorithm accounts for a valid 4th dose but considers it Dose 3 if the 3rd dose does not meet the Dose 3 parameters above but the 4th dose does.
  • There is a “reason not given” entry before the compliance date that specifies, “Lab evidence of positive serology”, or “MD diagnosis of previous disease”, or
  • 3 valid doses were given.

 List of Antigens

Hib—Haemophilus influenza type b vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given between 6 weeks and 5 years.
  • Dose 2 must be given between 10 weeks and 5 years and at least 4 weeks after Dose 1.
  • Dose 3 must be given between 14 weeks and 5 years and at least 4 weeks after Dose 2.
  • Dose 4 must be given between 12 months and 5 years and at least 8 weeks after Dose 3.
  • The patient has 4 valid doses, or
  • any valid dose was given after 15 months of age, or
  • the third dose was given after 12 months of age and more than 8 weeks after Dose 2, or
  • the patient’s first two doses were given after 12 months of age and Dose 2 was given more than 8 weeks after Dose 1.

 List of Antigens

HPV—Human papillomavirus vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
2-dose schedule
  • Dose 1 must be given on or after the 9th birthday and before the 15th birthday.
  • Dose 2 must be given at least 5 months after Dose 1.
3-dose schedule
  • Dose 1 must be given on or after the 9th birthday.
  • Dose 2 must be given at least 4 weeks after Dose 1.
  • Dose 3 must be given at least 12 weeks after Dose 2 and at least 5 months after Dose 1.

Note: CoCASA determines which schedule to use by examining the interval between valid Dose 1 and valid Dose 2. If the interval is greater than or equal to 5 months, the 2-dose schedule is used, otherwise the 3-dose schedule is used.
  • 2 valid doses were given on the 2-dose schedule, or
  • 3 valid doses were given on the 3-dose schedule.

 List of Antigens

IIV—Influenza vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Doses must be given between July 1 and June 30 of the succeeding year to be valid.
  • Dose 1 must be given at 6 months or later.
  • Dose 2, if required, must be given at 6 months plus 4 weeks or later and at least 4 weeks after Dose 1.
  • 1 dose was given within the influenza season and either the patient was 9 years of age or more at the time of the dose or the patient was less than 9 years of age and this dose was greater than or equal to the third dose of the patient’s life, or
  • 2 doses were given in the season and Dose 1 was the 1st or 2nd dose of the patient’s life, and the patient was less than 9 years of age at the time of Dose 1.

 List of Antigens

IPV—Inactivated poliovirus vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 6 weeks or later.
  • Dose 2 must be given at 10 weeks or later and at least 4 weeks after Dose 1.
  • Dose 3 must be given at 14 weeks or later and at least 4 weeks after Dose 2.
  • 4 valid doses were given, or
  • 3 valid doses were given and Dose 3 was given on or after the 4th birthday and at least 6 months after Dose 2.

 List of Antigens

MMR—Measles, mumps, and rubella vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 12 months or later and either on the same day as or at least 28 days after receiving varicella, smallpox, LAIV (Flumist), yellow fever, or monovalent measles, mumps, or rubella.
  • Dose 2 must be given at 13 months or later and either on the same day as or at least 28 days after receiving herpes zoster (shingles), varicella, smallpox, LAIV (Flumist), yellow fever, or monovalent measles, mumps, or rubella.
  • There is a “reason not given” entry before the compliance date that specifies, “Lab evidence of positive serology”, or “MD diagnosis of previous disease”, or
  • 2 valid doses were given.

 List of Antigens

MenACWY—Meningococcal vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given greater than or equal to 10 years of age.
  • Dose 2, if needed, must be given at greater than or equal to 16 years of age and at least 8 weeks after Dose 1.
  • The patient was under 16 years of age at the compliance date, and 1 valid dose was given.
  • The patient was 16 years of age or greater at the time of compliance, and
    • 2 valid doses were given, or
    • 1 valid dose was given at 16 years or older.

Note: the patient will not have any missed opportunities until on or after the 11th birthday.

 List of Antigens

MenB—Meningococcal serogroup B vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
Note: CoCASA requires entry of brand name (Bexsero or Trumenba) for each MenB vaccine dose administered.
Bexsero
  • Dose 1 must be given greater than or equal to 10 years of age.
  • Dose 2 must be given at least 4 weeks after Dose 1.
Trumenba
  • Dose 1 must be given greater than or equal to 10 years of age.
  • Dose 2 must be given at least 6 months after Dose 1, or, if the interval is less than 6 months, the minimum interval to the next dose is set to 4 months.

Note: Administration of MenB vaccine for individuals aged 16–23 years is based on shared clinical decision making. Thus, MenB vaccine will not appear on any CoCASA missed opportunity reports.
  • 2 valid doses were given.

 List of Antigens

PCV13—Pneumococcal conjugate vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given between 6 weeks and 5 years.
  • Dose 2 must be given between 10 weeks and 5 years and at least 4 weeks after Dose 1.
  • Dose 3 must be given between 14 weeks and 5 years and at least 4 weeks after Dose 2.
  • Dose 4 must be given between 12 months and 5 years and at least 8 weeks after Dose 3.
  • 4 valid doses were given, or
  • the patient’s first, second, or third valid dose was given at 24 months or older, or
  • the patient’s first two doses were given after 12 months of age and Dose 2 was given 8 weeks or more after Dose 1, or
  • the patient’s third valid dose was given after 12 months and more than 8 weeks after Dose 2.

 List of Antigens

RV—Rotavirus vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given between 6 weeks and 15 weeks old.
  • Dose 2 must be given between 10 weeks and 8 months old and at least 4 weeks after Dose 1.
  • Dose 3 must be given between 14 weeks and 8 months old and at least 4 weeks after Dose 2.
  • 2 valid doses of Rotarix were given, or
  • 3 valid doses were given, and any dose in the series was RotaTeq or vaccine product is unknown for any vaccine in the series.

 List of Antigens

Tdap—Tetanus, diphtheria, and acellular pertussis vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 7 years of age or later.
  • 1 valid dose was given.

 List of Antigens

VAR—Varicella vaccination

ACIP-recommended rules used by CoCASA to define valid doses Rules used by CoCASA to assess complete or up-to-date (UTD) vaccination status
  • Dose 1 must be given at 12 months or later and either on the same day as or at least 28 days after receiving herpes zoster (shingles), MMR, smallpox, LAIV (Flumist), yellow fever, or monovalent measles, mumps, or rubella.
  • Dose 2 must be given at least 4 weeks after dose 1 and either on the same day as or at least 28 days after receiving herpes zoster (shingles), MMR, smallpox, LAIV (Flumist), yellow fever, or monovalent measles, mumps, or rubella.
  • There is a “reason not given” entry before the compliance date that specifies “History of varicella”, “Lab evidence of positive serology for varicella”, or “Parent/patient report of disease”, or
  • 2 valid doses were given.

 List of Antigens

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Page last reviewed: January 17, 2019
Content source: National Center for Immunization and Respiratory Diseases