|  | Unadjusted analysis | Adjusted analysis | |||
---|---|---|---|---|---|---|
 | Insomnia (n = 407,969) | No Insomnia (n = 603,677) | Differencea | 95% CI | IRRb | 95% CI |
Healthcare use, mean ± SD |  |  |  |  |  |  |
Outpatient visits | 4.81 ± 8.64 | 3.78 ± 6.22 | 1.03** | 1.00–1.06 | 1.17** | 1.16–1.18 |
Hospitalizations | 1.57 ± 1.15 | 1.46 ± 0.99 | 0.11** | 0.10–0.12 | 1.02* | 1.02–1.03 |
Hospitalization LOS (Days)c | 90.70 ± 114.60 | 65.51 ± 93.40 | 25.19** | 22.67–27.71 | 1.26** | 1.22–1.31 |
Prescription fills for steroids and/or antibiotics | 4.80 ± 6.08 | 3.64 ± 4.90 | 1.16** | 1.05–1.26 | 1.15** | 1.13–1.18 |
Healthcare costs, median ± IQR |  |  |  |  | Difference at Median d | 95% CI |
Outpatient visit-related costs ($) | 885.13 ± 1,276.18 | 806.54 ± 1,015.48 | 78.59** | 75.74–81.44 | 3.46 | -1.43–8.34 |
Hospitalization-related costs ($) | 79,428.00 ± 209,460.00 | 69,068.00 ± 159,719.00 | 10,360.00** | 6,936.54–13,783.00 | 10,344.51** | 6,715.18–13,973.84 |