Table 3.
Rates of Dementia by Number of Infections, and Results from Cox Regression Models
| Infection | Total Dementia Cases | Total Person Time | Rate per 1000 Person Years (95% CI) | HR (95% CI) | P-value ** | |||
|---|---|---|---|---|---|---|---|---|
| Crude | Sex and Age Adjusted | Fully Adjusted* | ||||||
| Early Dementia | ||||||||
| All | GP-recorded infections only | |||||||
| No Infection | 1145 | 35,284 | 32.45 (30.63–34.39) | 1 | 1 | 1 | 0.0002 | |
| 1 infection | 211 | 3851 | 54.79 (47.88–62.71) | 1.77 (1.52–2.05) | 1.44 (1.24–1.67) | 1.48 (1.23–1.78) | ||
| 2 or more infections | 50 | 884 | 56.57 (42.87–74.63) | 1.94 (1.46–2.58) | 1.43 (1.07–1.90) | 1.26 (0.88–1.82) | ||
| Restricted to patients with linked HES | GP recorded infections only | |||||||
| No Infection | 877 | 22,658 | 38.71 (36.23–41.36) | 1 | 1 | 1 | <0.001 | |
| 1 infection | 175 | 2453 | 71.35 (61.52–82.74) | 1.92 (1.63–2.26) | 1.58 (1.34–1.86) | 1.59 (1.31–1.92) | ||
| 2 or more infections | 39 | 559 | 69.83 (51.02–95.58) | 1.99 (1.44–2.75) | 1.50 (1.09–2.07) | 1.31 (0.89–1.94) | ||
| GP recorded and all hospital infections | ||||||||
| No Infection | 581 | 19,052 | 30.50 (28.11–33.08) | 1 | 1 | 1 | <0.001 | |
| 1 infection | 305 | 4673 | 65.28 (58.35–73.03) | 2.17 (1.89–2.49) | 1.69 (1.47–1.95) | 1.57 (1.32–1.87) | ||
| 2 or more infections | 205 | 1944 | 105.46 (91.97–120.93) | 3.65 (3.11–4.28) | 2.71 (2.31–3.19) | 2.53 (2.06–3.11) | ||
| GP recorded and primary hospital infections | ||||||||
| No Infection | 775 | 21,778 | 35.59 (33.17–39.18) | 1 | 1 | 1 | <0.001 | |
| 1 infection | 230 | 3051 | 75.38 (66.24–85.78) | 2.21 (1.90–2.56) | 1.78 (1.54–2.07) | 1.69 (1.41–2.02) | ||
| 2 or more infections | 86 | 840 | 102.43 (82.92–126.54) | 3.18 (2.54–3.99) | 2.38 (1.90–2.99) | 2.16 (1.64–2.84) | ||
| Late Dementia | ||||||||
| All | GP recorded infections only | |||||||
| No Infection | 2009 | 84,239 | 23.85 (22.83–24.92) | 1 | 1 | 1 | 0.023 | |
| 1 infection | 572 | 20,900 | 27.37 (25.22–29.71) | 1.16 (1.06–1.28) | 1.00 (0.91–1.10) | 1.01 (0.90–1.14) | ||
| 2 infections | 232 | 7729 | 30.02 (26.39–34.14) | 1.29 (1.12–1.48) | 1.03 (0.90–1.18) | 1.03 (0.87–1.21) | ||
| 3 infections | 126 | 3402 | 37.03 (31.10–44.10) | 1.60 (1.34–1.92) | 1.23 (1.03–1.47) | 1.16 (0.93–1.45) | ||
| 4 infections | 61 | 1668 | 36.58 (28.46–47.01) | 1.59 (1.23–2.06) | 1.20 (0.93–1.54) | 0.97 (0.69–1.35) | ||
| 5 or more infections | 106 | 2451 | 43.24 (35.74–52.31) | 1.91 (1.56–2.32) | 1.41 (1.16–1.72) | 1.40 (1.11–1.77) | ||
| Restricted to patients with linked HES | GP recorded infections only | |||||||
| No Infection | 1562 | 53,194 | 29.36 (27.94–30.86) | 1 | 1 | 1 | 0.002 | |
| 1 infection | 428 | 12,783 | 33.48 (30.46–36.81) | 1.15 (1.03–1.28) | 1.00 (0.90–1.12) | 1.05 (0.93–1.19) | ||
| 2 infections | 187 | 4762 | 39.27 (34.03–45.32) | 1.35 (1.16–1.58) | 1.09 (0.93–1.27) | 1.05 (0.88–1.26) | ||
| 3 infections | 100 | 2107 | 47.46 (39.01–57.74) | 1.65 (1.34–2.02) | 1.27 (1.03–1.55) | 1.25 (0.99–1.57) | ||
| 4 infections | 44 | 1009 | 43.61 (32.45–58.60) | 1.52 (1.12–2.05) | 1.14 (0.85–1.55) | 1.02 (0.72–1.45) | ||
| 5 or more infections | 88 | 1460 | 60.28 (48.91–74.28) | 2.11 (1.69–2.62) | 1.57 (1.26–1.95) | 1.55 (1.22–1.97) | ||
| GP recorded and all hospital infections | ||||||||
| No Infection | 955 | 43,680 | 21.86 (20.52–23.30) | 1 | 1 | 1 | <0.001 | |
| 1 infection | 606 | 16,527 | 36.67 (33.86–39.71) | 1.70 (1.53–1.88) | 1.40 (1.26–1.55) | 1.28 (1.13–1.45) | ||
| 2 infections | 366 | 7220 | 50.69 (45.75–56.16) | 2.37 (2.10–2.67) | 1.78 (1.58–2.01) | 1.70 (1.47–1.96) | ||
| 3 infections | 186 | 3480 | 53.45 (46.29–61.71) | 2.52 (2.15–2.95) | 1.86 (1.59–2.18) | 1.53 (1.26–1.86) | ||
| 4 infections | 110 | 1774 | 62.03 (51.45–74.77) | 2.94 (2.41–3.59) | 2.09 (1.71–2.55) | 1.88 (1.48–2.38) | ||
| 5 or more infections | 186 | 2634 | 70.61 (61.16–81.53) | 3.41 (2.90–4.00) | 2.44 (2.08–2.86) | 2.22 (1.84–2.70) | ||
| GP recorded and primary hospital infections | ||||||||
| No Infection | 1269 | 49,488 | 25.64 (24.27–27.09) | 1 | 1 | 1 | <0.001 | |
| 1 infection | 539 | 14,345 | 37.58 (34.53–40.80) | 1.49 (1.34–1.64) | 1.25 (1.13–1.38) | 1.27 (1.13–1.43) | ||
| 2 infections | 262 | 5664 | 46.26 (40.98–52.21) | 1.84 (1.61–2.11) | 1.44 (1.26–1.65) | 1.31 (1.11–1.54) | ||
| 3 infections | 145 | 2654 | 54.63 (46.42–64.29) | 2.20 (1.85–2.61) | 1.66 (1.39–1.97) | 1.50 (1.22–1.85) | ||
| 4 infections | 74 | 1271 | 58.23 (46.36–73.13) | 2.35 (1.86–2.98) | 1.71 (1.35–2.17) | 1.71 (1.31–2.23) | ||
| 5 or more infections | 120 | 1893 | 63.39 (53.01–75.81) | 2.60 (2.15–3.15) | 1.92 (1.58–2.32) | 1.86 (1.50–2.32) | ||
Notes: *Adjusted for age, sex, country, consultation frequency, ethnicity, deprivation, alcohol, smoking, BMI, pre-morbid conditions, pre-stroke use of medication, anti-coagulant prescribing post-stroke and depression (pre- and post-stroke). **Likelihood ratio test.