Table 5.
Differences in Healthcare Utilization between the Study Groups
| Unadjusted mean | Standard error | Incidence rate ratio | 95% confidence interval | P value | |
|---|---|---|---|---|---|
| Office visits, N | |||||
| TNF-alpha blocker nonusers with mild RA | 12.09 | 0.71 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 12.83 | 1.13 | 0.88 | 0.71–1.10 | .274 |
| TNF-alpha blocker nonusers with severe RA | 19.55 | 3.57 | 0.88 | 0.71–1.09 | .243 |
| TNF-alpha blocker users | 19.63 | 3.18 | 1.16 | 0.96–1.40 | .131 |
| Outpatient visits, N | |||||
| TNF-alpha blocker nonusers with mild RA | 1.26 | 0.14 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 2.54 | 1.35 | 0.77 | 0.45–1.33 | .353 |
| TNF-alpha blocker nonusers with severe RA | 2.28 | 0.46 | 0.68 | 0.44–1.04 | .077 |
| TNF-alpha blocker users | 1.62 | 0.47 | 0.98 | 0.52–1.86 | .962 |
| Emergency department visits, N | |||||
| TNF-alpha blocker nonusers with mild RA | 0.23 | 0.03 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 0.58 | 0.10 | 1.59 | 1.10–2.31 | .014 |
| TNF-alpha blocker nonusers with severe RA | 0.89 | 0.11 | 1.76 | 1.24–2.52 | .002 |
| TNF-alpha blocker users | 0.42 | 0.20 | 1.35 | 0.54–3.39 | .525 |
| Hospitalizations, N | |||||
| TNF-alpha blocker nonusers with mild RA | 0.76 | 0.14 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 2.40 | 0.54 | 1.40 | 0.85–2.29 | .188 |
| TNF-alpha blocker nonusers with severe RA | 4.15 | 0.99 | 2.24 | 1.24–4.04 | .008 |
| TNF-alpha blocker users | 1.48 | 0.73 | 1.64 | 0.71–3.79 | .248 |
| Average length of stay, days | |||||
| TNF-alpha blocker nonusers with mild RA | 0.16 | 0.03 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 0.44 | 0.09 | 1.56 | 0.99–2.45 | .053 |
| TNF-alpha blocker nonusers with severe RA | 0.59 | 0.08 | 1.65 | 1.07–2.53 | .022 |
| TNF-alpha blocker users | 0.40 | 0.15 | 1.91 | 0.86–4.23 | .112 |
| Prescription medications, refills included, N | |||||
| TNF-alpha blocker nonusers with mild RA | 28.98 | 1.35 | Reference group | ||
| TNF-alpha blocker nonusers with moderate RA | 53.36 | 5.00 | 1.22 | 1.04–1.43 | .012 |
| TNF-alpha blocker nonusers with severe RA | 69.77 | 4.90 | 1.25 | 1.07–1.46 | .006 |
| TNF-alpha blocker users | 52.24 | 5.35 | 1.49 | 1.22–1.82 | .000 |
Models were adjusted for number of chronic conditions, age, education, race, ethnicity, and type of insurance coverage.
RA indicates rheumatoid arthritis; TNF, tumor necrosis factor.