Table 1.
Number of delirium episodes and rates of delirium cases detected using International Classification of Diseases (ICD) codes or a natural language processing (NLP) algorithm
| ICD codes | NLP algorithm | ||||||
|---|---|---|---|---|---|---|---|
| Hospitalizations N | Delirium episodes N | Rate per 100 hospitalizations (95% CI+) | P value | Delirium episodes* N | Rate per 100 hospitalizations (95% CI+) | P value | |
| Overall | 37,554 | 1,135 | 3.02 (2.85,3.20) | 2,763 | 7.36 (7.09,7.64) | ||
| Age group | <0.0001 | <0.0001 | |||||
| 65-69 | 6,759 | 116 | 1.72 (1.42,2.06) | 248 | 3.67 (3.23,4.16) | ||
| 70-74 | 6,850 | 155 | 2.26 (1.92,2.65) | 294 | 4.29 (3.82,4.81) | ||
| 75-79 | 6,973 | 170 | 2.44 (2.09,2.83) | 412 | 5.91 (5.35,6.51) | ||
| 80-84 | 6,707 | 247 | 3.68 (3.24,4.17) | 556 | 8.29 (7.62,9.01) | ||
| ≥85 | 10,265 | 447 | 4.35 (3.96,4.78) | 1,253 | 12.21 (11.54,12.90) | ||
| Sex | 0.03 | 0.89 | |||||
| Men | 17,945 | 578 | 3.22 (2.96,3.49) | 1,324 | 7.38 (6.99,7.79) | ||
| Women | 19,609 | 557 | 2.84 (2.61,3.09) | 1,439 | 7.34 (6.96,7.73) | ||
| Race | 0.19 | 0.001 | |||||
| White | 34,111 | 1,040 | 2.66 (1.52,4.32) | 2,569 | 7.53 (7.24,7.83) | ||
| Black | 602 | 16 | 2.36 (1.72,3.16) | 30 | 4.98 (3.36,7.11) | ||
| Asian | 1,905 | 45 | 3.74 (2.59,5.23) | 107 | 5.62 (4.60,6.79) | ||
| Other/mixed | 909 | 34 | 3.05 (2.87,3.24) | 57 | 6.27 (4.75,8.12) | ||
| Hispanic ethnicity | 0.82 | 0.20 | |||||
| No | 36,790 | 1,113 | 3.03 (2.85,3.21) | 2,716 | 7.38 (7.11,7.67) | ||
| Yes | 764 | 22 | 2.88 (1.80,4.36) | 47 | 6.15 (4.52,8.18) | ||
| Year | <0.0001 | <0.0001 | |||||
| 2011 | 4,941 | 105 | 2.13 (1.74,2.57) | 295 | 5.97 (5.31,6.69) | ||
| 2012 | 5,365 | 121 | 2.26 (1.87,2.69) | 378 | 7.05 (6.35,7.79) | ||
| 2013 | 5,104 | 143 | 2.80 (2.36,3.30) | 366 | 7.17 (6.45,7.94) | ||
| 2014 | 5,110 | 121 | 2.37 (1.96,2.83) | 390 | 7.63 (6.89,8.43) | ||
| 2015 | 5,342 | 129 | 2.41 (2.02,2.87) | 357 | 6.68 (6.01,7.41) | ||
| 2016 | 5,796 | 208 | 3.59 (3.12,4.11) | 484 | 8.35 (7.34, 9.58)** | ||
| 2017 | 5,896 | 308 | 5.22 (4.66,5.84) | 493 | 8.36 (7.64,9.13) | ||
+
CI = confidence interval.
*
Numbers reflect cloned cases for 2016.
**
CI based on using only cases from 7/1/2016-12/31/2016.