Table 4.
Factors significantly associated with new vaccine delays at 2–4-6 and 12 months of age, 2006–2016 (N = 7183)a
| Factors associated with vaccine delaysb | DTaP1 at 2 months | DTaP2 at 4 monthsc | DTaP3 at 6 monthsd | Measles at 12 monthse | ||||
|---|---|---|---|---|---|---|---|---|
| Unadjusted RR (95% CI) | Adjusted RR (95% CI) | Unadjusted RR (95% CI) | Adjusted RR (95% CI) | Unadjusted RR (95% CI) | Adjusted RR (95% CI) | Unadjusted RR (95% CI) | Adjusted RR (95% CI) | |
| Year of survey: | ||||||||
| 2006 | 1.86 (1.26; 2.74) | 1.38 (0.91; 2.09) | 1.44 (1.08;1.93) | 1.56 (1.15; 2.12) | 1.55 (1.23; 1.96) | 1.71 (1.35; 2.17) | 2.17 (1.75; 2.69) | 1.84 (1.45; 2.32) |
| 2008 | 1.53 (1.06; 2.23) | 1.20 (0.82; 1.75) | 1.24 (0.94; 1.63) | 1.29 (0.97; 1.71) | 1.17 (0.93; 1.47) | 1.24 (0.98; 1.56) | 2.00 (1.64; 2.45) | 1.74 (1.41; 2.15) |
| 2010 | 1.82 (1.26; 2.61) | 1.55 (1.08; 2.22) | 1.48 (1.13; 1.93) | 1.53 (1.17; 2.02) | 1.33 (1.06; 1.66) | 1.40 (1.12; 1.76) | 1.60 (1.29; 1.98) | 1.53 (1.23; 1.90) |
| 2012 | 1.77 (1.24; 2.52) | 1.57 (1.11; 2.24) | 1.41 (1.09; 1.83) | 1.38 (1.06; 1.81) | 1.18 (0.94; 1.47) | 1.20 (0.96; 1.51) | 1.44 (1.16; 1.78) | 1.39 (1.12; 1.73) |
| 2014 | 1.22 (0.83;1.79) | 1.13 (0.78; 1.66) | 1.18 (0.90; 1.55) | 1.20 (0.91; 1.58) | 1.02 (0.81; 1.28) | 1.02 (0.81; 1.29) | 1.09 (0.87; 1.36) | 1.09 (0.87; 1.37) |
| 2016 (reference) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Maternal level of education for each increase of one level | 0.82 (0.74; 0.90) | 0.90 (0.81; 0.99) | 0.83 (0.77; 0.90) | 0.86 (0.79; 0.92) | ||||
| Child’s rank: | ||||||||
| ≥ 2 | 1.72 (1.39; 2.12) | 1.68 (1.36; 2.09) | 1.63 (1.39; 1.91) | 1.63 (1.39; 1.92) | 1.45 (1.27; 1.66) | 1.47 (1.28; 1.68) | 1.15 (1.03; 1.30) | 1.16 (1.03; 1.30) |
| First (reference) | 1 | 1 | 1 | 1 | 1 | |||
| Gestational age at birth | ||||||||
| < 37 weeks | 1.30 (1.58; 1.07) | 1.26 (1.04; 1.53) | ||||||
| ≥ 37 weeks (reference) | 1 | 1 | ||||||
| Daycare attendance: | ||||||||
| No | 1.81 (1.48; 2.22) | 1.48 (1.20; 1.84) | ||||||
| Yes (reference) | 1 | 1 | ||||||
| Living with a partner: | ||||||||
| No | 1.60 (1.17; 2.19) | 1.48 (1.07; 2.05) | ||||||
| Yes (reference) | 1 | 1 | ||||||
| Vaccine provider (2-months): | ||||||||
| Medical clinic or Hospital | 0.82 (0.69; 0.98) | 0.80 (0.67; 0.96) | 0.84 (0.73; 0.98) | 0.79 (0.68; 0.92) | ||||
| Public health clinics (reference) | 1 | 1 | 1 | 1 | ||||
| Main vaccine provider (all vaccines): | ||||||||
| Medical clinic/ Hospital or both settings | 1.47 (1.32; 1.65) | 1.22 (1.08; 1.39) | ||||||
| Public health clinics only (reference) | 1 | 1 | ||||||
| Missed opportunities at the 2-month visit: | ||||||||
| Yes | 4.49 (3.43; 5.89) | 4.28 (3.18; 5.77) | ||||||
| No (reference) | 1 | 1 | ||||||
| Missed opportunities at the 12-month visit: | ||||||||
| Yes | 1.90 (1.68; 2.16) | 1.47 (1.26; 1.71) | ||||||
| No (reference) | 1 | 1 | ||||||
RR relative risk, CI confidence interval
a Both cohorts were included in this analysis. Analysis limited to children born in Quebec. Multivariable analysis exclude children unvaccinated since birth (n = 43 for 1-year cohort and n = 42 for 2-year cohort)
bFactors selected with robust Poisson multivariable regression with backward selection. Mother’s language, mother’s country of origin and the birth attendant were excluded from this analysis as they were not collected in 2006 and 2008 (more than 10% of missing). For each visit, results are presented only for covariates significant in the models
cRestricted to children without vaccine delay at 2 month vaccines /d Restricted to children without vaccine delay at 2 and 4 month vaccines / eRestricted to children without vaccine delay at 2, 4 and 6 month vaccines