Table 3.

Incident rate ratios for postoperative mortality after hip fracture surgery

Mortality cause*	30 days mortality IRR (95% CI)	p value	90 days mortality IRR (95% CI)	p value
All-cause
Non-frail	Reference		Reference
Pre-frail	1.90 (1.67–2.16)	< 0.001	2.05 (1.87–2.24)	< 0.001
Frail	3.80 (3.36–4.30)	< 0.001	3.88 (3.56–4.23)	< 0.001
Cardiovascular
Non-frail	Reference		Reference
Pre-frail	1.61 (1.29–2.00)	< 0.001	1.62 (1.38–1.89)	< 0.001
Frail	3.24 (2.64–3.99)	< 0.001	3.08 (2.65–3.57)	< 0.001
Respiratory
Non-frail	Reference		Reference
Pre-frail	1.69 (1.27–2.26)	< 0.001	1.68 (1.35–2.10)	< 0.001
Frail	2.60 (1.96–3.45)	< 0.001	2.54 (2.04–3.16)	< 0.001
Cerebrovascular
Non-frail	Reference		Reference
Pre-frail	2.64 (1.05–6.62)	0.038	3.72 (2.03–6.82)	< 0.001
Frail	4.75 (1.88–11.98)	0.001	6.38 (3.46–11.77)	< 0.001
Sepsis
Non-frail	Reference		Reference
Pre-frail	2.22 (0.79–6.23)	0.129	3.30 (1.73–6.32)	< 0.001
Frail	3.79 (1.38–10.42)	0.010	4.14 (2.15–7.95)	< 0.001
Multiorgan failure
Non-frail	Reference		Reference
Pre-frail	2.36 (1.85–3.01)	< 0.001	2.54 (2.17–2.99)	< 0.001
Frail	4.99 (3.95–6.32)	< 0.001	4.86 (4.16–5.68)	< 0.001
Unknown
Non-frail	Reference		Reference
Pre-frail	2.50 (1.15- 5.42)	0.020	2.16 (1.36–3.43)	0.001
Frail	6.50 (3.09–13.67)	< 0.001	5.46 (3.50–8.51)	< 0.001

IRRs are calculated using Poisson regression models with robust standard errors. Missing values were managed using multiple imputation by chained equations. All analyses were adjusted for age, sex, American Society of Anesthesiologists classification, type of fracture, type of surgery, myocardial infarction, cerebrovascular disease, peripheral vascular disease, diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, connective tissue disease, and liver disease

IRR incident rate ratio, CI Confidence Interval

*Non-frail, pre-frail, and frail are defined as OFS 0, OFS 1, and OFS ≥ 2