Table 3.
Distribution of variable values and readmissions (population size is 69,984).
| Variable |
Number of encounters |
% of the population |
Readmitted | |
|---|---|---|---|---|
| Number of encounters | % in group | |||
| HbA1c | ||||
| No test was performed | 57,080 | 81.6% | 5,342 | 9.4% |
| Result was high and the diabetic medication was changed | 4,071 | 5.8% | 361 | 8.9% |
| Result was high but the diabetic medication was not changed | 2,196 | 3.1% | 166 | 7.6% |
| Normal result of the test | 6,637 | 9.5% | 590 | 8.9% |
| Gender | ||||
| Female | 37,234 | 53.2% | 3,462 | 9.3% |
| Male | 32,750 | 46.8% | 2,997 | 9.2% |
| Discharge disposition | ||||
| Discharged to home | 44,339 | 63.4% | 3,184 | 7.2% |
| Otherwise | 25,645 | 36.6% | 3,275 | 12.8% |
| Admission source | ||||
| Admitted from emergency room | 37,277 | 53.3% | 3,563 | 9.6% |
| Admitted because of physician/clinic referral | 22,800 | 32.6% | 2,032 | 8.9% |
| Otherwise | 9,907 | 14.2% | 846 | 8.5% |
| Specialty of the admitting physician | ||||
| Internal Medicine | 10,642 | 15.2% | 1,044 | 9.8% |
| Cardiology | 4,213 | 6.0% | 309 | 7.3% |
| Surgery | 3,541 | 5.1% | 284 | 8.0% |
| Family/general practice | 4,984 | 7.1% | 492 | 9.9% |
| Missing or unknown | 33,641 | 48.1% | 3,237 | 9.6% |
| Other | 12,963 | 18.5% | 1,093 | 8.4% |
| Primary diagnosis | ||||
| A disease of the circulatory system (icd9: 390–459, 785) | 21,411 | 30.6% | 2,129 | 9.9% |
| Diabetes (icd9: 250.xx) | 5,747 | 8.2% | 529 | 9.2% |
| A disease of the respiratory system (icd9: 460–519, 786) | 9,490 | 13.6% | 710 | 7.5% |
| Diseases of the digestive system (icd9: 520–579, 787) | 6,485 | 9.3% | 532 | 8.2% |
| Injury and poisoning (icd9: 800–999) | 4,697 | 6.7% | 524 | 11.2% |
| Diseases of the musculoskeletal system and connective tissue (icd9: 710–739) | 4,076 | 5.8% | 354 | 8.7% |
| Diseases of the genitourinary system (icd9: 580–629, 788) | 3,435 | 4.9% | 313 | 9.1% |
| Neoplasms (icd9: 140–239) | 2,536 | 3.6% | 239 | 9.4% |
| Other | 12,107 | 17.3% | 1,129 | 9.3% |
| Race | ||||
| African American | 12,626 | 18.0% | 1,116 | 8.8% |
| Caucasian | 52,300 | 74.7% | 4,943 | 9.5% |
| Other | 3,138 | 4.5% | 256 | 8.2% |
| Missing | 1,920 | 2.7% | 144 | 7.5% |
| Agea | ||||
| 30 years old or younger | 1,808 | 2.6% | 112 | 6.2% |
| 30–60 years old | 21,871 | 31.3% | 1,614 | 7.4% |
| Older than 60 | 46,305 | 66.2% | 4,733 | 10.2% |
|
| ||||
| Age (numeric) | mean | median | 1st Qu. | 3rd Qu. |
|
| ||||
| Age in years | 64.9 | 67 | 55 | 77 |
| Time in hospital | ||||
| Days between admission and discharge (1–14) | 4.3 | 3 | 2 | 6 |
aAfter the preliminary analysis of the relationship between age and the logistic transformation of the readmission rate. See Figure 2.