TABLE 4.
IRR for 30-day Mortality After Hip fracture Surgery
| IRR (95% CI) | p | |
|---|---|---|
| BB therapy | ||
| No | Reference | |
| Yes | 0.35 (0.32–0.39) | <0.001 |
| RCRI | ||
| 0 | Reference | |
| 1 | 1.57 (1.49–1.66) | <0.001 |
| 2 | 2.28 (2.13–2.43) | <0.001 |
| 3 | 3.00 (2.72–3.31) | <0.001 |
| ≥4 | 3.95 (3.36–4.65) | <0.001 |
| BB therapy (BB+) × RCRI* | ||
| BB+ × RCRI 1 | 0.87 (0.76–1.00) | 0.046 |
| BB+ × RCRI 2 | 0.79 (0.68–0.92) | 0.002 |
| BB+ × RCRI 3 | 0.81 (0.67–0.98) | 0.027 |
| BB+ × RCRI ≥4 | 0.58 (0.42–0.79) | <0.001 |
| Age | 1.06 (1.06–1.07) | <0.001 |
| Sex | ||
| Female | Reference | |
| Male | 1.66 (1.59–1.73) | <0.001 |
| ASA classification | ||
| 1 | Reference | |
| 2 | 1.32 (1.09–1.61) | 0.005 |
| 3 | 2.26 (1.86–2.75) | <0.001 |
| 4 | 3.78 (3.09–4.61) | <0.001 |
| 5 | 6.60 (4.73–9.21) | <0.001 |
| Type of fracture | ||
| Nondisplaced cervical (garden 1–2) | Reference | |
| Displaced cervical (garden 3–4) | 1.29 (1.18–1.42) | <0.001 |
| Basicervical | 1.24 (1.05–1.46) | 0.013 |
| Peritrochanteric (two fragments) | 1.24 (1.06–1.45) | 0.006 |
| Peritrochanteric (multiple fragments) | 1.36 (1.16–1.59) | <0.001 |
| Subtrochanteric | 1.38 (1.17–1.63) | <0.001 |
| Type of surgery | ||
| Pins or screws | Reference | |
| Screws or pins with side plate | 0.97 (0.84–1.12) | 0.676 |
| Intramedullary nail | 0.93 (0.80–1.08) | 0.369 |
| Hemiarthroplasty | 1.02 (0.94–1.10) | 0.722 |
| Total hip replacement | 0.67 (0.57–0.79) | <0.001 |
| Peripheral vascular disease | ||
| No | Reference | |
| Yes | 1.09 (1.00–1.19) | 0.041 |
| Chronic obstructive pulmonary disease | ||
| No | Reference | |
| Yes | 1.23 (1.16–1.30) | <0.001 |
| Liver disease | ||
| No | Reference | |
| Yes | 1.70 (1.41–2.06) | <0.001 |
| Dementia | ||
| No | Reference | |
| Yes | 1.41 (1.35–1.47) | <0.001 |
| Connective tissue disease | ||
| No | Reference | |
| Yes | 1.01 (0.91–1.12) | 0.835 |
| Local tumor | ||
| No | Reference | |
| Yes | 1.09 (1.02–1.15) | 0.007 |
| Metastatic carcinoma | ||
| No | Reference | |
| Yes | 1.78 (1.61–1.98) | <0.001 |
| Year of surgery | ||
| 2008 | Reference | |
| 2009 | 0.87 (0.79–0.97) | 0.008 |
| 2010 | 0.94 (0.86–1.04) | 0.234 |
| 2011 | 0.88 (0.80–0.96) | 0.006 |
| 2012 | 0.95 (0.87–1.04) | 0.278 |
| 2013 | 0.85 (0.77–0.93) | <0.001 |
| 2014 | 0.77 (0.70–0.85) | <0.001 |
| 2015 | 0.78 (0.71–0.86) | <0.001 |
| 2016 | 0.78 (0.71–0.86) | <0.001 |
| 2017 | 0.77 (0.70–0.85) | <0.001 |
Poisson regression model with robust standard errors of variance. Multiple imputation with chained equations was used to manage missing values. Model is adjusted for age, sex, peripheral vascular disease, chronic obstructive tissue disease, liver disease, dementia, connective tissue disease, local tumor, metastatic carcinoma, ASA classification, type of fracture, type of surgery, and year of surgery.
*The interaction between BB therapy and RCRI.
BB−, no β-blocker therapy; BB+, ongoing β-blocker therapy.