TABLE 2.
Comorbidities, Health Care Resource Use, and Health Care Costs in the Observation Period
| Characteristicsa | High-Cost Patientsb (n = 1,859) | Lower-Cost Patientsb (n = 7,432) | P Valuec | ||
|---|---|---|---|---|---|
| N or Mean | % or SD | N or Mean | % or SD | ||
| Comorbidities | |||||
| Charlson Comorbidity Index | 1.60 | 2.29 | 0.42 | 1.05 | < 0.001 |
| Components of Charlson Comorbidity Index | |||||
| Chronic pulmonary disease | 447 | 24.0% | 784 | 10.5% | < 0.001 |
| Mild-to-moderate diabetes | 200 | 10.8% | 387 | 5.2% | < 0.001 |
| Rheumatologic disease | 154 | 8.3% | 176 | 2.4% | < 0.001 |
| Congestive heart failure | 226 | 12.2% | 161 | 2.2% | < 0.001 |
| Any malignancy including leukemia and lymphoma | 138 | 7.4% | 180 | 2.4% | < 0.001 |
| Cerebrovascular disease | 214 | 11.5% | 197 | 2.7% | < 0.001 |
| Diabetes with chronic complications | 120 | 6.5% | 126 | 1.7% | < 0.001 |
| Peripheral vascular disease | 123 | 6.6% | 105 | 1.4% | < 0.001 |
| Mild liver disease | 92 | 4.9% | 95 | 1.3% | < 0.001 |
| Renal disease | 144 | 7.7% | 70 | 0.9% | < 0.001 |
| Peptic ulcer disease | 65 | 3.5% | 52 | 0.7% | < 0.001 |
| Myocardial infarction | 73 | 3.9% | 43 | 0.6% | < 0.001 |
| Hemiplegia or paraplegia | 49 | 2.6% | 40 | 0.5% | < 0.001 |
| Metastatic solid tumor | 44 | 2.4% | 16 | 0.2% | < 0.001 |
| HIV/AIDS | 19 | 1.0% | 25 | 0.3% | < 0.001 |
| Moderate or severe liver disease | 32 | 1.7% | 16 | 0.2% | < 0.001 |
| Dementia | 13 | 0.7% | 14 | 0.2% | < 0.001 |
| Other selected comorbidities | |||||
| Nonopioid substance abuse diagnoses | 984 | 53.0% | 3,351 | 47.2% | < 0.001 |
| Psychotic disorders | 1,244 | 67.1% | 3,374 | 47.5% | < 0.001 |
| Other mental disorders | 1,302 | 70.2% | 4,081 | 57.5% | < 0.001 |
| Annual Health Care Resource Use | |||||
| Medical resource use | |||||
| Any visit | |||||
| Inpatient | 1,529 | 82.2% | 2,702 | 36.4% | < 0.001 |
| Emergency department | 1,640 | 88.2% | 4,528 | 60.9% | < 0.001 |
| Outpatient | 1,855 | 99.8% | 7,274 | 97.9% | < 0.001 |
| Drug/alcohol rehabilitation facility | 559 | 30.1% | 1,632 | 22.0% | < 0.001 |
| Other | 1,487 | 80.0% | 4,005 | 53.9% | < 0.001 |
| Number of visits/days | |||||
| Inpatient days | 16.1 | 23.9 | 2.9 | 7.2 | < 0.001 |
| Emergency department days | 8.9 | 13.6 | 1.9 | 3.2 | < 0.001 |
| Outpatient visits | 38.2 | 24.6 | 18.7 | 15.9 | < 0.001 |
| Drug/alcohol rehabilitation facility days | 9.5 | 22.3 | 5.6 | 18.0 | < 0.001 |
| Other visits | 8.2 | 13.7 | 2.6 | 5.3 | < 0.001 |
| Abuse-related medical resource use | |||||
| Inpatient days | 4.7 | 10.7 | 1.6 | 4.7 | < 0.001 |
| Emergency department days | 1.3 | 3.0 | 0.5 | 1.1 | < 0.001 |
| Outpatient visits | 2.5 | 7.5 | 3.4 | 7.0 | < 0.001 |
| Drug/alcohol rehabilitation facility days | 4.6 | 14.9 | 4.3 | 16.4 | < 0.001 |
| Other visits | 0.6 | 2.6 | 0.7 | 2.6 | < 0.001 |
| Abuse-related share of total medical resource use | |||||
| Inpatient days | 29% | - | 56% | - | - |
| Emergency department days | 15% | - | 25% | - | - |
| Outpatient visits | 7% | - | 18% | - | - |
| Drug/alcohol rehabilitation facility days | 49% | - | 76% | - | - |
| Other visits | 8% | - | 27% | - | - |
| Prescription drug use | |||||
| Any prescription drug fill | 1,802 | 96.9% | 6,871 | 92.5% | < 0.001 |
| Number of prescriptions filled | 71.4 | 50 | 32.6 | 32 | < 0.001 |
| Number of unique NDC numbers filled | 29.0 | 20 | 12.9 | 11 | < 0.001 |
| Annual Health Care Costs | $89,177 | $87,211 | $11,653 | $9,031 | < 0.001 |
| Medical costs | $79,386 | $86,986 | $8,986 | $8,075 | < 0.001 |
| Inpatient | $34,600 | $68,531 | $1,577 | $3,752 | < 0.001 |
| Emergency department | $16,597 | $35,913 | $1,630 | $3,102 | < 0.001 |
| Outpatient | $19,513 | $25,233 | $3,696 | $4,474 | < 0.001 |
| Drug/alcohol rehabilitation facility | $4,393 | $11,696 | $1,263 | $3,666 | < 0.001 |
| Other | $4,283 | $10,949 | $821 | $2,178 | < 0.001 |
| Abuse-related medical costs | $15,706 | $31,980 | $3,429 | $4,978 | < 0.001 |
| Inpatient | $8,089 | $29,449 | $909 | $2,774 | < 0.001 |
| Emergency department | $3,320 | $10,675 | $559 | $1,774 | < 0.001 |
| Outpatient | $1,231 | $5,336 | $617 | $1,473 | 0.029 |
| Drug/alcohol rehabilitation facility | $2,336 | $7,924 | $940 | $3,106 | < 0.001 |
| Other | $730 | $3,271 | $405 | $1,537 | < 0.001 |
| Abuse-related share of total medical costs | 20% | - | 38% | - | - |
| Inpatient | 23% | - | 58% | - | - |
| Emergency department | 20% | - | 34% | - | - |
| Outpatient | 6% | - | 17% | - | - |
| Drug/alcohol rehabilitation facility | 53% | - | 74% | - | - |
| Other | 17% | - | 49% | - | - |
| Prescription drug costs | $9,791 | $16,811 | $2,667 | $3,864 | < 0.001 |
aThe observation period was defined as the 12-month period centered on the index date.
bHigh-cost patients were defined as patients with health care costs in the top 20% of health care costs among all patients in the study cohort during the observation period.
cP values were calculated using chi-square tests for dichotomous variables and Wilcoxon rank-sum tests for continuous variables. Results were considered statistically significant at P < 0.05.
AIDS = acquired immune deficiency syndrome; HIV = human immunodeficiency virus; NDC = National Drug Code; SD = standard deviation.