Clinical characteristics of patients with MPA during the pre- and post-period. All costs are US$.
| Characteristics | 6 Months Pre-diagnosis, n = 612 | 6 Months Post-diagnosis, n = 612 | p* |
|---|---|---|---|
| Diagnoses of major relapse-associated conditions based on BVAS*, n (%) | |||
| Acute/chronic renal failure | 329 (53.8) | 435 (71.1) | |
| Gangrene | 10 (1.6) | 23 (3.8) | |
| Scleritis | 2 (0.3) | 3 (0.5) | |
| Retinal exudates/hemorrhage | 0 (0.0) | 2 (0.3) | |
| Sensorineural deafness | 14 (2.3) | 18 (2.9) | |
| Mesenteric ischemia | 7 (1.1) | 10 (1.6) | |
| Lung-related condition | 61 (10.0) | 99 (16.2) | |
| Hemoptysis** | 24 (3.9) | 44 (7.2) | |
| Respiratory failure | 43 (7.0) | 68 (11.1) | |
| Meningitis | 3 (0.5) | 2 (0.3) | |
| Cord lesion | 0 (0.0) | 1 (0.2) | |
| Stroke | 30 (4.9) | 49 (8.0) | |
| Cranial nerve palsy | 1 (0.2) | 1 (0.2) | |
| Sensory peripheral neuropathy | 30 (4.9) | 39 (6.4) | |
| Motor mononeuritis multiplex | 0 (0.0) | 3 (0.5) | |
| Any relapse-associated diagnosis | 370 (60.5) | 476 (77.8) | |
| All-cause healthcare use and costs | |||
| Inpatient admissions | |||
| At least 1 inpatient admission, n (%) | 238 (38.9) | 297 (48.5) | 0.0003 |
| Mean (SD) inpatient costs | $15,344 ($43,332) | $34,776 ($95,590) | < 0.0001 |
| ER visits | |||
| At least 1 ER visit, n (%) | 256 (41.8) | 290 (47.4) | 0.0295 |
| Mean (SD) ER costs | $893 ($2610) | $1019 ($2483) | 0.0144 |
| Outpatient office visits | |||
| At least 1 outpatient office visit, n (%) | 563 (92.0) | 573 (93.6) | 0.1138 |
| Mean (SD) outpatient office visit costs | $832 ($1496) | $1213 ($1796) | < 0.0001 |
| Other outpatient services | |||
| At least 1 other outpatient service, n (%) | 601 (98.2) | 612 (100.0) | N/A |
| Mean (SD) other outpatient service costs | $10,498 ($25,452) | $16,725 ($32,036) | < 0.0001 |
| Outpatient pharmacy | |||
| At least 1 prescription drug claim, n (%) | 579 (94.6) | 583 (95.3) | 0.3938 |
| Mean (SD) prescription drug costs | $2599 ($3758) | $2909 ($3946) | < 0.0001 |
| Total | |||
| Mean (SD) total costs | $30,166 ($58,253) | $56,642 ($108,227) | < 0.0001 |
↵* Statistical comparisons were done only for use and costs measures.
↵** Patients with hemoptysis (ICD-9-CM 786.30, 786.39) were identified because no diagnosis codes were available for alveolar hemorrhage. BVAS: Birmingham Vasculitis Activity Score; ER: emergency room; MPA: microscopic polyangiitis; ICD-9-CM: International Classification of Diseases-9-Clinical Modification.