Table 2. Risk of heart failure hospitalization in chronic kidney disease patients stratified by vaccination status during influenza and non-influenza season.
| Unvaccinated (n) | Vaccinated (n) | Unadjusted HR (95% CI) | Adjusted HR* (95% CI) | |
| Whole cohort | ||||
| Influenza season | 163 | 89 | 0.36 (0.28, 0.47)# | 0.35 (0.26, 0.45)# |
| Non-influenza season | 138 | 65 | 0.30 (0.23, 0.41)# | 0.28 (0.21, 0.38)# |
| All season | 301 | 154 | 0.33 (0.27, 0.41)# | 0.31 (0.26, 0.39)# |
| Age, 55-64 (years) | ||||
| Influenza season | 51 | 13 | 0.36 (0.20, 0.67)† | 0.43 (0.23, 0.79)† |
| Non-influenza season | 42 | 8 | 0.25 (0.12, 0.53)# | 0.25 (0.12, 0.55)# |
| All season | 93 | 21 | 0.31 (0.19, 0.50)# | 0.34 (0.21, 0.55)# |
| Age, 65-74 (years) | ||||
| Influenza season | 55 | 38 | 0.26 (0.17, 0.39)# | 0.28 (0.18, 0.43)# |
| Non-influenza season | 45 | 31 | 0.25 (0.16, 0.40)# | 0.29 (0.18, 0.47)# |
| All season | 100 | 69 | 0.25 (0.19, 0.35)# | 0.29 (0.21, 0.39)# |
| Age, ≥ 75 (years) | ||||
| Influenza season | 57 | 38 | 0.31 (0.21, 0.47)# | 0.33 (0.21, 0.50)# |
| Non-influenza season | 51 | 26 | 0.25 (0.15, 0.40)# | 0.26 (0.16, 0.43)# |
| All season | 108 | 64 | 0.28 (0.21, 0.38)# | 0.30 (0.22, 0.41)# |
| Female | ||||
| Influenza season | 93 | 34 | 0.28 (0.19, 0.41)# | 0.27 (0.18, 0.40)# |
| Non-influenza season | 68 | 26 | 0.28 (0.18, 0.44)# | 0.28 (0.18, 0.45)# |
| All season | 161 | 60 | 0.28 (0.21, 0.38)# | 0.27 (0.20, 0.37)# |
| Male | ||||
| Influenza season | 70 | 55 | 0.46 (0.32, 0.66)# | 0.42 (0.29, 0.61)# |
| Non-influenza season | 70 | 39 | 0.33 (0.22, 0.48)# | 0.28 (0.19, 0.43)# |
| All season | 140 | 94 | 0.39 (0.30, 0.51)# | 0.35 (0.27, 0.46)# |
| CKD without dialysis | ||||
| Influenza season | 134 | 67 | 0.32 (0.24, 0.43)# | 0.30 (0.22, 0.41)# |
| Non-influenza season | 114 | 49 | 0.27 (0.19, 0.38)# | 0.25 (0.17, 0.35)# |
| All season | 248 | 116 | 0.30 (0.24, 0.37)# | 0.27 (0.22, 0.35)# |
| CKD with dialysis | ||||
| Influenza season | 29 | 22 | 0.59 (0.34, 1.03) | 0.60 (0.33, 1.07) |
| Non-influenza season | 24 | 16 | 0.49 (0.26, 0.93)‡ | 0.43 (0.22, 0.84) ‡ |
| All season | 53 | 38 | 0.54 (0.36, 0.83)† | 0.52 (0.33, 0.81)† |
CI, confidence interval; CKD, chronic kidney disease; HR, hazard ratio.
* Adjusted HR was based on Cox proportional regression with adjustment for age, gender, comorbidity condition, hypertension, diabetes, dyslipidemia, dialysis, arrhythmia, anemia, pneumonia, monthly income, level of urbanization, and geographic region in propensity score. # p < 0.001. † p < 0.01. ‡ p < 0.05.