Results of the logistic regression model for unscheduled readmission to hospital within 30 days
| Variable* | OR† (95% CI) |
|---|---|
| AMA discharge from index admission‡ | |
| Between-person effect | 3.04 (2.79–3.30) |
| Within-person effect | 2.10 (1.99–2.21) |
| Any AMA discharges in previous 5 yr | 1.25 (1.16–1.34) |
| No. of admissions in previous 5 yr (per admission) | 1.12 (1.11–1.12) |
| Age (per yr) | 1.02 (1.02–1.02) |
| Male sex | 1.08 (1.06–1.10) |
| Household income quintile | |
| Urban 1 (lowest urban stratum) | 1.00 (ref) |
| Urban 3 | 0.93 (0.90–0.95) |
| Urban 5 (highest urban stratum) | 0.82 (0.79–0.84) |
| Rural 1 (lowest rural stratum) | 1.30 (1.26–1.33) |
| Rural 3 | 1.26 (1.22–1.29) |
| Rural 5 (highest rural stratum) | 1.08 (1.05–1.12) |
| Not calculated | 0.99 (0.95–1.03) |
| Comorbid conditions§ | |
| Metastatic cancer | 3.01 (2.91–3.10) |
| Lymphoma | 2.45 (2.31–2.60) |
| AIDS/HIV | 2.41 (1.98–2.94) |
| Renal failure | 1.66 (1.60–1.72) |
| Liver disease | 1.59 (1.51–1.68) |
| Solid tumor without metastasis | 1.45 (1.41–1.50) |
| Congestive heart failure | 1.44 (1.41–1.47) |
| Drug abuse | 1.25 (1.13–1.34) |
| Diabetes | 1.21 (1.19–1.24) |
| Chronic pulmonary disease | 1.17 (1.15–1.20) |
| Arrhythmia | 1.08 (1.06–1.11) |
| Hypertension, complicated | 1.08 (1.03–1.14) |
| Hypothyroidism | 1.05 (1.00–1.10) |
| Alcohol abuse | 1.00 (0.95–1.04) |
| Hypertension, uncomplicated | 0.98 (0.96–0.99) |
| Obesity | 0.95 (0.90–1.00) |
| Main diagnosis at index admission | |
| Cardiovascular disorder | 1.00 (ref) |
| Complication of pregnancy, childbirth or puerperium | 2.11 (2.05–2.18) |
| Disease of blood or blood-forming organs | 1.17 (1.04–1.31) |
| Neoplasm | 0.94 (0.91–0.97) |
| Infectious or parasitic disease | 0.93 (0.89–0.99) |
| Disease of the digestive system | 0.93 (0.91–0.95) |
| Mental disorder | 0.92 (0.89–0.96) |
| Disease of the respiratory system | 0.90 (0.88–0.92) |
| Disease of nervous system or sense organs | 0.75 (0.70–0.80) |
| Injury or poisoning | 0.74 (0.72–0.76) |
| Disease of the musculoskeletal system or connective tissue | 0.74 (0.71–0.76) |
| Length of the index admission (per d) | 0.997 (0.997–0.998) |
Note: AMA = against medical advice, CI = confidence interval, OR = odds ratio. Comorbid conditions and diagnoses at admission are listed in descending order of OR and, thus, influence on odds of readmission.
↵* Only selected variables are shown. Please see Appendix 3 for full results.
↵† Adjusted for between-person and within-person AMA discharge status, age, sex, year of index admission, comorbid conditions, household income, diagnosis of the index admission, length of index admission, number of admissions in the previous 5 yr and existence of any AMA discharges in the previous 5 yr.
↵‡ Within-person effects indicate the difference in readmission risk after an AMA discharge and a non-AMA discharge for the same patient. Between-person effects indicate the difference in readmission risk after an AMA discharge for one patient and a non-AMA discharge for another patient with otherwise identical characteristics.
↵§ Because a patient can have any number of comorbidities, they are represented in the regression model as individual binary indicator variables, thus no reference condition was chosen.