Table 2 Multivariable regression models for in-hospital mortality, ICU admissions, LOS, and ICU LOS

Patients without rare diseases

Ref

Ref

Ref

Ref

Patients with one rare disease

1.80

(1.67,1.95)

1.64

(1.57,1.71)

1.28

(1.27,1.29)

1.14

(1.10,1.18)

Patients with more than one rare disease

2.78

(2.39,3.23)

2.23

(2.01,2.48)

1.49

(1.45,1.54)

1.40

(1.30,1.51)

Patients aged 18–34

Ref

Ref

Ref

Ref

Patients aged 35–49

2.05

(1.72,2.45)

1.49

(1.40,1.58)

1.07

(1.06,1.08)

1.03

(0.98,1.09)

Patients aged 50–64

3.76

(3.20,4.41)

2.18

(2.06,2.30)

1.10

(1.09,1.11)

0.97

(0.93,1.01)

Patients aged 65–79

4.46

(3.81,5.23)

2.03

(1.92,2.14)

1.04

(1.03,1.05)

0.85

(0.82,0.89)

Patients aged 80 and older

7.88

(6.72,9.25)

1.16

(1.09,1.25)

0.97

(0.95,0.98)

0.71

(0.67,0.75)

Female sex

Ref

Ref

Ref

Ref

Male sex

1.19

(1.11,1.26)

1.71

(1.66,1.77)

0.95

(0.94,0.95)

0.97

(0.94,0.99)

Number of diagnoses (excluding rare diseases),

per additional diagnosis

1.20

(1.19,1.20)

1.20

(1.20,1.21)

1.10

(1.10,1.10)

1.12

(1.12,1.12)

Year discharged,

per additional year

0.91

(0.90,0.92)

0.94

(0.93,0.94)

0.99

(0.99,0.99)

0.95

(0.94,0.95)