| Age group; no. of morbidities | No. of participant-years (%) | Mortality, HR (95% CI) | Physician visits, RR (95% CI) | ED visits, RR (95% CI) | Hospital admissions, RR (95% CI) | Discharge to long-term care, HR (95% CI) |
|---|---|---|---|---|---|---|
| Age 65-74 yr | 2 093 043 | |||||
| None | 409 872 (19.6) | 6.38 (5.86-6.95) | 1.79 (1.73-1.85) | 2.40 (2.14-2.70) | 5.22 (4.38-6.22) | 179.85 (127.52-253.66) |
| 1 | 514 511 (24.6) | 5.02 (4.74-5.31) | 1.29 (1.27-1.32) | 2.07 (1.94-2.20) | 4.02 (3.70-4.38) | 63.74 (53.52-75.91) |
| 2 | 462 717 (22.1) | 4.43 (4.23-4.63) | 1.23 (1.21-1.25) | 1.93 (1.84-2.02) | 3.14 (2.95-3.33) | 28.52 (25.34-32.10) |
| 3 | 320 038 (15.3) | 3.41 (3.27-3.56) | 1.21 (1.19-1.23) | 1.65 (1.59-1.71) | 2.70 (2.57-2.83) | 11.54 (10.51-12.68) |
| 4 | 183 217 (8.8) | 2.55 (2.44-2.66) | 1.20 (1.18-1.22) | 1.46 (1.41-1.51) | 2.19 (2.09-2.28) | 5.41 (4.99-5.88) |
| 5 or more | 202 688 (9.7) | 1.80 (1.76-1.84) | 1.20 (1.19-1.21) | 1.35 (1.33-1.38) | 1.79 (1.75-1.83) | 2.16 (2.07-2.26) |
| Age 75-84 yr | 1 441 821 | |||||
| None | 146 923 (10.2) | 4.68 (4.46-4.91) | 1.87 (1.83-1.92) | 2.80(2.60-3.01) | 5.98 (5.36-6.67) | 65.57 (48.64-88.40) |
| 1 | 240 053 (16.7) | 3.66 (3.55-3.77) | 1.31 (1.29-1.32) | 1.95 (1.88-2.03) | 3.52 (3.33-3.72) | 18.20 (15.93-20.79) |
| 2 | 301 412 (20.9) | 3.19 (3.12-3.27) | 1.23 (1.22-1.24) | 1.75 (1.70-1.80) | 2.99 (2.88-3.10) | 6.41 (5.94-6.92) |
| 3 | 271 780 (18.9) | 2.74 (2.68-2.80) | 1.21 (1.20-1.22) | 1.54 (1.50-1.57) | 2.45 (2.38-2.53) | 3.73 (3.52-3.95) |
| 4 | 191 442 (13.3) | 2.31 (2.26-2.36) | 1.20 (1.19-1.21) | 1.42 (1.39-1.45) | 2.03 (1.98-2.08) | 2.12 (2.02-2.23) |
| 5 or more | 290 211 (20.1) | 1.74 (1.72-1.76) | 1.20 (1.20-1.21) | 1.27 (1.25-1.28) | 1.61 (1.59-1.63) | 1.30 (1.26-1.33) |
| Age ≥ 85 yr | 610 548 | |||||
| None | 70 565 (11.6) | 6.48 (6.18-6.79) | 4.48 (4.37-4.59) | 4.71 (4.33-5.12) | 10.48 (9.24-11.89) | 22.00 (17.15-28.24) |
| 1 | 60 779 (10.0) | 2.20 (2.13-2.26) | 1.50 (1.48-1.52) | 1.73 (1.65-1.80) | 3.12 (2.93-3.32) | 3.48 (3.13-3.88) |
| 2 | 97 128 (15.9) | 2.14 (2.10-2.19) | 1.35 (1.34-1.37) | 1.48 (1.44-1.52) | 2.53 (2.44-2.63) | 2.29 (2.14-2.45) |
| 3 | 107 891 (17.7) | 2.03 (1.99-2.07) | 1.30 (1.29-1.31) | 1.27 (1.25-1.30) | 2.01 (1.95-2.07) | 1.63 (1.56-1.72) |
| 4 | 93 241 (15.3) | 1.85 (1.81-1.88) | 1.26 (1.25-1.27) | 1.18 (1.16-1.20) | 1.60 (1.56-1.65) | 1.26 (1.21-1.31) |
| 5 or more | 180 944 (29.6) | 1.54 (1.52-1.55) | 1.23 (1.23-1.24) | 1.09 (1.07-1.10) | 1.32 (1.30-1.34) | 1.08 (1.06-1.11) |
Note: CI = confidence interval, ED = emergency department, HR = hazard ratio, RR = rate ratio. Ratios are adjusted for sex, Aboriginal status and rural/urban residence. These models include 3-way and 2-way interaction terms for dementia, age and number of morbidities. The table shows the likelihood of a 2-fold increase in the risk of the outcomes with repeat events (i.e., physician visits, ED visits, hospital admissions) that is associated with dementia, along with the risk of mortality and discharge to long-term care. For example, in participants age 65-74 years with no comorbidities, the presence of dementia is 1.79 times more likely to be associated with a 2-fold increase in the number of physician visits, compared with participants of similar age and with no comorbidities, but without dementia.