TABLE 4.
Summary of Results of the Adjacent-Categories Logit Regression Model With MMSE Intervals as Outcome Variable
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Model 1 (only demographics)
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Model 2 (Model 1+ CERAD neuritic plaque score + Braak NFT stage)
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Model 3 (Model 2+Thal amyloid stage)
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Model 4 (Model 3+concurrent pathologies)
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|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | p Value | OR (95% CI) | p Value | OR (95% CI) | p Value | OR (95% CI) | p Value | |
| Sex (female as reference) | 1.01 (0.79, 1.28) | 0.957 | 1.20 (0.88, 1.63) | 0.256 | 1.21 (0.89, 1.66) | 0.223 | 1.42 (0.99, 2.04) | 0.055 |
| Age at death (in 5-years unit) | 0.87 (0.82, 0.93) | <0.001 | 0.92 (0.84 1.00) | 0.058 | 0.92 (0.84, 1.00) | 0.061 | 0.95 (0.86, 1.05) | 0.325 |
| Education (in 4-years unit) | 0.91 (0.79, 1.05) | 0.203 | 0.91 (0.75, 1.10) | 0.327 | 0.90 (0.74, 1.09) | 0.290 | 0.90 (0.72, 1.13) | 0.355 |
| CERAD neuritic plaque score (none/sparse as reference) | ||||||||
| Moderate | 1.59 (0.81, 3.12) | 0.181 | 1.30 (0.64, 2.67) | 0.466 | 1.24 (0.56, 2.76) | 0.597 | ||
| Frequent | 2.00 (0.97, 4.09) | 0.059 | 1.72 (0.80, 3.67) | 0.162 | 1.71 (0.73, 4.00) | 0.215 | ||
| Braak NFT stage (none/I/II as reference) | ||||||||
| Stage III/IV | 1.32 (0.65, 2.65) | 0.439 | 1.26 (0.62, 2.56) | 0.531 | 1.30 (0.59, 2.87) | 0.522 | ||
| Stage V/VI | 3.40 (1.62, 7.16) | 0.001 | 3.58 (1.64, 7.85) | 0.001 | 4.64 (1.78, 12.08) | 0.002 | ||
| Thal amyloid stage (0 as reference) | ||||||||
| Stage 1/2 | 2.25 (0.47, 10.79) | 0.310 | 1.71 (0.36, 8.06) | 0.500 | ||||
| Stage 3 | 3.39 (0.74, 15.44) | 0.115 | 1.94 (0.41, 9.23) | 0.403 | ||||
| Stage 4/5 | 2.51 (0.55, 11.48) | 0.234 | 1.47 (0.32, 6.84) | 0.624 | ||||
| Cerebral amyloid angiopathy (none as reference) | ||||||||
| Mild | 1.10 (0.73, 1.68) | 0.642 | ||||||
| Moderate | 1.36 (0.82, 2.26) | 0.231 | ||||||
| Severe | 1.19 (0.69, 2.06) | 0.525 | ||||||
| Lewy bodies (present vs absent) | 1.64 (1.13, 2.39) | 0.010 | ||||||
| Arteriosclerosis (none as reference) | ||||||||
| Mild | 0.82 (0.48, 1.42) | 0.487 | ||||||
| Moderate | 0.83 (0.50, 1.40) | 0.495 | ||||||
| Severe | 1.10 (0.59 2.06) | 0.763 | ||||||
| Hippocampal sclerosis present vs absent) | 2.24 (0.95, 5.29) | 0.067 | ||||||
Five ordinal levels of the response variable MMSE ([27, 30], [21, 26], [15, 20], [10, 14], [0, 9]) are represented by k = 0, 1, 2, 3, 4. Therefore, it follows that the higher the k, the worse the cognitive status. Following are some examples of interpretation based on model 4. Effect of education: holding other factors constant, the odds ratio of having MMSE at a certain category (k = 1, 2, 3, 4) versus the adjacent lower category (k-1) associated with every 4-year increase in education is 0.90, with a 95% CI (0.72, 1.13). Effect of CERAD neuritic plaque score: holding other factors constant, the odds of having MMSE at a certain category (k = 1, 2, 3, 4) versus the adjacent lower category (k-1) for subjects with moderate neuritic plaques are 1.24 times the odds for subjects with sparse or no neuritic plaques, with a 95% CI (0.56, 2.76). Similarly, holding other factors constant, the odds of having MMSE at a certain category (k = 1, 2, 3, 4) versus the adjacent lower category (k-1) for subjects with frequent neuritic plaques are 1.71 times the odds for subjects with sparse or no neuritic plaques, with a 95% CI (0.73, 4.00).
CERAD, Consortium to Establish a Registry for Alzheimer Disease; NFT, neurofibrillary tangle; MMSE, Mini-Mental State Examination; OR, odds ratio.