Table 2.
Risk factors associated with Non-vaccination Among Influenza-Negative Participants in the United States Influenza Vaccine Effectiveness Network 2013–2019 Influenza Seasons (n=36707)
| OR | 95% CI | AOR | 95% CI | |
|---|---|---|---|---|
| States | ||||
| Michigan | 1.23 | (1.16–1.32) | 1.06 | (0.99–1.14) |
| Pennsylvania | 1.47 | (1.37–1.54) | 1.22 | (1.14–1.31) |
| Texas | 1.82 | (1.72–1.92) | 1.52 | (1.42–1.63) |
| Washington | REF | REF | REF | REF |
| Wisconsin | 1.33 | (1.25–1.41) | 1.20 | (1.12–1.29) |
| Sex | ||||
| Female | REF | REF | REF | REF |
| Male | 1.15 | (1.11–1.20) | 1.24 | (1.18–1.30) |
| Race/Ethnicity a | ||||
| White, non-Hispanic | REF | REF | REF | REF |
| Black, non-Hispanic | 1.72 | (1.61–1.85) | 1.62 | (1.49–1.76) |
| Hispanic, any race | 1.41 | (1.33–1.52) | 1.06 | (0.98–1.15) |
| Other, non-Hispanic | 1.03 | (0.97–1.10) | 1.05 | (0.97–1.14) |
| Age Group | ||||
| 6 months-4 months | 2.94 | (2.70–3.23) | 1.63 | (1.46–1.82) |
| 5–12 years | 5.56 | (5.00–6.25) | 3.14 | (2.81–3.51) |
| 13–17 years | 7.69 | (6.67–8.33) | 4.40 | 3.86–6.00) |
| 18–49 years | 5.88 | (5.26–6.25) | 3.74 | (3.41–4.10) |
| 50–64 years | 2.70 | (2.50–2.94) | 3.74 | (3.41–4.10) |
| ≥65 years | REF | REF | REF | REF |
| Highest education level in household b | ||||
| College graduate or less | 1.76 | (1.68–1.84) | 1.61 | (1.58–1.74) |
| Advanced | REF | REF | REF | REF |
| Comorbidities c | ||||
| None | 3.70 | (3.45–4.00) | 2.66 | (2.44–2.90) |
| 1 High risk condition | 2.50 | (2.27–2.70) | 1.83 | (1.67–2.00) |
| 2 High risk conditions | 1.64 | (1.49–1.82) | 1.46 | (1.31–1.62) |
| ≥3 High risk conditions | REF | REF | REF | REF |
| Smoking status d | ||||
| Yes | 1.72 | (1.64–1.82) | 1.39 | (1.31–1.48) |
| No | REF | REF | REF | REF |
| Self-reported general health status | ||||
| Excellent | 1.44 | (1.32–1.57) | ||
| Very good | 1.34 | (1.23–1.46) | ||
| Good | 1.21 | (1.10–1.32) | ||
| Fair/poore | REF | REF | ||
| Body Mass Index (BMI) f | ||||
| Underweight (BMI <18.5) | 1.37 | (1.04–1.82) | 1.18 | (0.87–1.61) |
| Normal (18.5 ≤ BMI < 25) | REF | REF | REF | REF |
| Overweight (25 ≤ BMI < 30) | 1.20 | (1.12–1.20) | 1.08 | (1.00–1.18) |
| Obese (30 ≤ BMI < 40) | 1.02041 | (0.94–1.09) | 0.99 | (0.92–1.06) |
| Morbidly obese (BMI ≥40) | 1.16279 | (1.06–1.28) | 1.18 | (1.07–1.31) |
Enrollees were categorized into one of four mutually exclusive racial/ethnic populations: white, black, other race, and Hispanic. Persons identifying as Hispanic might have been of any race. Persons identifying as white, black, or other race were non-Hispanic. Race/ethnicity data were missing for 121 enrollees (<1%).
Data on education level were only collected from 2013–2014 through 2018–2019 influenza seasons, data missing/refused for 153 enrollees (<1%)
Comorbidities are defined as ≥1 medical record-documented high-risk code in prior year, as defined by Advisory Committee on Immunization Practices guidance for conditions that increase risk for complications from influenza. High-risk conditions were categorized into groups: asthma, cerebrovascular diseases, chronic obstructive pulmonary diseases (COPD) and other lung diseases, diabetes, cardiovascular diseases, hematologic conditions/blood disorders, liver diseases, neurologic conditions, renal diseases, and immunosuppressive conditions (including rheumatoid arthritis, immune system disorders or immunodeficiency, antineoplastic chemotherapy, HIV, organ transplants).
Includes current smoker and exposure to cigarette smoke in the household. Data on exposure to cigarette smoke in household were missing/refused for 170 enrollees.
“Fair” and “Poor” were grouped together for self-reported health status.
Body mass index was calculated as kg/m2 from height and weight recorded in the electronic medical record. Calculated for adults aged ≥18 years only.