Concept: Adult Immunizations

Introduction

This concept describes the adult immunization program in Manitoba and the methods used to investigate this program as published in the MCHP deliverable Manitoba Immunization Study by Hildeman et al. (2011). The concept includes information about the Manitoba Immunization Monitoring System (MIMS), the Manitoba adult immunization schedule and two specific programs that are available. It also lists the groups of adults that are considered high risk or target groups for these programs and how these groups are identified in the data. The tariff codes for each type of vaccine that are available in the data are also identified. Hypertext links to the results / findings of MCHP research related to adult immunizations are also provided.

Adult Immunizations in Manitoba

The following sections describe the adult immunization program in Manitoba. This includes the role of the Manitoba Immunization Monitoring System (MIMS), the immunization schedule for adults, and the two adult immunization programs available in Manitoba.

1. Manitoba Immunization Monitoring System (MIMS)

The Manitoba Immunization Monitoring System (MIMS) records all immunizations of provincial registrants (as of Jan 1, 1980) and provides monitoring and reminders to families. The MIMS began recording adult immunization data in 2000 (Manitoba Health, 2009).

The Regional Health Authorities (RHAs) of Manitoba, the provincial and federal governments, and two types of providers (physicians and public health nurses) are involved in the delivery of immunizations in Manitoba. Immunizations are provided through a longstanding provincial program. Vaccines are entered into the MIMS by one of two methods:


1. Publicly-funded immunizations administered by physicians are entered via the physician billing system (approximately 80% of immunizations).
2. All other publicly-funded immunizations (e.g., those done by public health nurses) are recorded by data entry staff.

The MIMS database is housed in the Manitoba Population Research Data Repository at MCHP and contains:


• registry information
  
• a code that identifies the vaccine administered and its sequence in the immunization schedule
  
• service date
  
• provider identifiers-to distinguish physician administered immunizations from those given by public health nurses

2. Manitoba Immunization Schedule for Adults

Adult immunization recommendations vary depending on several factors including age, living with a chronic disease, and birth year. If an adult (18 years or older) has been previously immunized according to Manitoba Health guidelines, it is recommended that he/she receive the following vaccinations, assuming he/she falls within the specified target group (Manitoba Health, 2008):


• Influenza (Inf) - One influenza vaccine is recommended annually for all adults above 65 years of age and all adults having a chronic disease, regardless of age. Adults involved with high-risk groups (adults above 65 years old and infants) are also advised to receive this vaccine once a year.
  
  
• Tetanus & Diphtheria (Td) - It is recommended that all adults receive both vaccines as a booster dose every ten years.
  
  
• Pneumonia - It is recommended that all adults above 65 years old and/or those with a chronic disease receive a pneumonia shot once a lifetime.
  
  
• Measles, Mumps & Rubella (MMR) - For adults born in or after 1970, it is recommended that they receive one or two MMR immunizations depending on certain individual factors, such as occupation. Individuals born prior to 1970 are "assumed to have acquired natural immunity to measles and mumps" but may require a MMR vaccine if they are health care workers or military personnel (Manitoba Health, 2009, p.2).

If an adult has not been immunized or is only partially immunized according to Manitoba Health guidelines, it is recommended that he/she receive additional doses of select vaccines (Td and MMR). For more information on the immunization schedule for adults, please see the Communicable Disease Control - Routine Immunization Schedule - Immunization Schedule for Adults on the Manitoba Health web site.

3. Manitoba Adult Immunization Programs

The following adult immunization programs are available in Manitoba:


1. Influenza Immunization Program
   
   The influenza vaccine has been publicly funded since 1999 for health care workers and individuals above 65 years old and/or those with a weakened immune function or chronic disease (Manitoba Government, 1999). Since then, the individuals eligible to receive a free influenza vaccine has expanded to include:
   
   
   • Pregnant women with chronic health conditions, such as cardiac or pulmonary diseases, metabolic disease (diabetes mellitus), cancer, renal disease, respiratory diseases and immunodeficiency;
     
   • Healthy pregnant women;
     
   • Residents of nursing homes or chronic care facilities; and
     
   • Others
   
   A complete description of individuals who are publicly funded for the influenza vaccine can be found in Chapter 3: Influenza Immunization Program of the Manitoba Immunization Study.
   
   
2. Pneumococcal Polysaccharide (PPV-23) Immunization Program
   
   PPV-23 is recommended for individuals over 65 years of age and/or with immunodeficiency or a chronic disease. More information can be found in Chapter 4: Pneumococcal Polysaccharide (PPV-23) Immunization Program of the Manitoba Immunization Study.

Methods

Adult vaccination is a new area of study included in immunization research completed at MCHP. MIMS began collecting adult immunization information in 2000, therefore only eight years of data was used for analysis by Hilderman et al. (2011) in the Manitoba Immunization Study. The following describes the methods used in this study to identify individuals of various target groups in order to evaluate the rate of Influenza and PPV-23 immunization in adults, and the vaccine tariff codes that were used to determine the vaccines administered.

Target Groups

The following target groups were identified using the methods described:


• Adults aged 65 years and older - Adults were categorized into the following age groups, based on administrative data from the registry database: 65-74 years old, 75-84 years old, and 85 years and older.
  
  
• Resident of Personal Care Homes (PCH) - If an adult was 75 years or older AND living in a PCH during the specified fiscal year, as identified by the Long Term Care Database, the adult was considered a resident of a PCH.
  
  
• Adults with a chronic disease - these illnesses included:
  
  
  • Total respiratory morbidity (TRM) - Administrative claims data was used to evaluate TRM in adults. For adults 45 years and older, they were considered to have TRM if they had "one or more hospitalizations with a diagnosis of asthma, chronic or acute bronchitis, emphysema, or chronic airway obstruction (ICD-9-CM codes 466, 490, 491, 492, 493, or 496; ICD-10-CA codes J20, J21, J40-J45) OR one or more physician visits with a diagnosis of asthma, chronic or acute bronchitis, emphysema, or chronic airway obstruction (ICD-9-CM codes as above)" (Hilderman et al., 2011).
    
    For adults younger than 45 years, only asthma was used to evaluate respiratory morbidity. Asthma was defined by having a least one of the following: "one or more hospitalizations with primary diagnosis of 493 (ICD-9-CM) or J45 (ICD10-CA) in a fiscal year OR two or more physician visits with diagnosis of 493 in a fiscal year OR two or more prescriptions for medications used to treat asthma in a fiscal year" (Hilderman et al., 2011).
    
    
  • Cancer - Adults were considered to have cancer if they had a diagnosis of cancer from CancerCare Manitoba (regardless of type of cancer or severity).
    
    
  • Congestive heart failure (CHF) - Using hospital discharge abstracts and medical services/physician claims data, an adult was identified as having CHF if he/she had "one or more hospitalizations with diagnosis code 428 (ICD-9 CM) or I50.0, I50.1, I50.9, I13.0, I13.2 (ICD-10-CA) in any diagnosis field over three years of data OR one or more physician claims with diagnosis code 428 over three years of data" (Hilderman et al., 2011).
    
    
  • Diabetes - If an adult had "one or more hospitalizations with diagnosis codes 250 (ICD-9 CM) or E10-E14 (ICD-10-CA) in any diagnosis field over three years of data OR two or more physician claims with diagnosis code 250 over three years of data OR one or more prescriptions for diabetic drugs over three years of data", he/she was considered to have diabetes (Hilderman et al., 2011).
    
    
  • Chronic renal failure - Medical claims that denoted dialysis for chronic renal failure within the last five years (MB tariff codes: 9801, 9802, 9806, 9819, 9821, 9610, or 9820) were used to define chronic renal failure.
    
    
  • Splenic disorder - The following diagnostic codes were used to identify adults with splenic disorder: ICD-10 (D73.0, Q89.0); Canadian Classification of Health Indicators (CCI) (1.OB.83, 1.OB.89, 1.OB.87); ICD-9-CM diagnoses (289.59, 759.0); and ICD-9-CM procedures (41.5 or 41.43).
  
  
• Adults who are pregnant - Hospital discharge abstracts were used to identify all women who gave birth within specified fiscal years (with the exception of homebirths as this information was not available). A woman was considered to be immunized while pregnant if the immunization was received 270 days before delivery.

Vaccine Tariff Codes

The following immunization tariff codes were used by Hilderman et al. (2011) to determine whether an individual received a vaccine:


• Influenza vaccine: 8791, 8792, or 8799 - from the Immunization Data / Manitoba Immunization Monitoring System (MIMS) data
  
• Pneumococcal Polysaccharide (PPV-23): 8683 or 8961 - from the Medical Services data

In Katz et al. (2014), they used the same tariff codes for influenza vaccinations, but expanded the list of tariff codes for pneumococcal immunizations to include: 8681, 8682, 8683, 8684 and 8691.

Adult Immunization Rates in MCHP Research

Adult immunization rates have been reported in two MCHP deliverables:


• In the Manitoba Immunization Study by Hildeman et al. (2011), they report:
  
  
  • influenza immunization rates for those aged 65+ by RHA, RHA District, Winnipeg Community Areas, and Income Quintiles. Other results include influenza immunization rates by individual chronic diseases and other factors. To access these immunization rates, start with Figure 3.1: Manitoba Influenza Immunization Rates, aged 65+
    
  • Pneumococcal Polysaccharide (PPV-23) immunization rates for those aged 65+ by RHA, RHA District, Winnipeg Community Areas, and Income Quintiles. Other results include Pneumococcal Polysaccharide (PPV-23) immunization rates by individual chronic diseases and other factors. To access these immunization rates, start with Figure 4.1: Manitoba Pneumococcal Polysaccharide (PPV-23) Immunization Rates, aged 65+
  
  
• In the Physician Integrated Network: A Second Look deliverable by Katz et al. (2014), they report on:
  
  
  • influenza immunization rates for adults aged 65+ related to the implementation of Physician Integrated Network (PIN) clinics; see Table 3.4: Annual Influenza Immunization, Adults Aged 65+ for more information.
    
  • pneumococcal immunizations rates for adults aged 65+ related to the implementation of Physician Integrated Network (PIN) clinics; see Table 3.6: Pneumococcal Immunizations, Adults Aged 65+ for more information.

Limitations/Cautions

• The validity of the MIMS data may be compromised by possible systematic or personnel errors. Inaccurate immunization records may occur due to errors in physician coding or data entry at multiple levels (Hilderman et al., 2011). In the Canadian Immunization Guide (7th edition), the PHAC (2006) stated that many people may be over- or under-immunized due to inadequate immunization records and "the absence of a standardized approach to their management" (p.105).
  
  
• Not all vaccinations, such as those given in private settings (work places), are entered into MIMS. This can lead to underreporting of vaccines. Hilderman et al. (2011) indicate that the rates of the influenza immunization are most commonly affected by this limitation. As well, tariff codes are not assigned if an individual receives an immunization when he/she does not fall under Manitoba's eligibility criteria for publicly funded vaccines, thus this vaccine would not be entered into MIMS.