Table 2 Results of simple and multiple logistic regression for appendiceal perforation, appendicitis patients in Taiwan (aged 15 or above), 1997–2001

Mental disorder status

   No major mental disorder

1.00

1.00

   Schizophrenia

2.61 ***

2.05–3.34

2.83 ***

2.20–3.64

   Affective psychosis

1.14

0.77–1.69

1.15

0.77–1.73

   Other major mental disorders

2.29 **

1.33–3.94

1.58

0.89–2.81

Gender

   Female

1.00

1.00

   Male

1.44 ***

1.40–1.49

1.46 ***

1.42–1.51

Age (years)

   15–24

1.00

1.00

   25–34

1.02

0.98–1.07

1.00

0.96–1.05

   35–44

1.40 ***

1.34–1.46

1.37 ***

1.31–1.43

   45–54

1.90 ***

1.81–2.00

1.85 ***

1.76–1.95

   55–64

2.68 ***

2.53–2.84

2.54 ***

2.40–2.70

   65–74

3.57 ***

3.37–3.79

3.27 ***

3.08–3.49

   ≥ 75

4.91 ***

4.56–5.30

4.60 ***

4.25–4.98

Ethnicity

   Non-aboriginal

1.00

1.00

   Aboriginal

0.96

0.89–1.04

1.14 **

1.04–1.24

SES

   ≥ NT$40,000

1.00

1.00

   NT$20,000 ~ NT$39,999

0.90 ***

0.86–0.95

1.03

0.98–1.08

   <NT$20,000

0.91 ***

0.87–0.95

1.04

0.99–1.10

   Without a well-defined monthly wage

1.24 ***

1.19–1.30

1.09 ***

1.04–1.14

Hospital ownership

   Public

1.00

1.00

   Nonprofit

1.13 ***

1.09–1.18

1.19 ***

1.14–1.25

   Profit

1.14 ***

1.10–1.19

1.38 ***

1.30–1.46

Hospital accreditation level

   District Hospital-nonteaching

1.00

1.00

   District Hospital-teaching

0.67 ***

0.64–0.71

0.75 ***

0.70–0.79

   Regional Hospital

0.92 ***

0.89–0.96

1.11 **

1.03–1.19

   Medical Center

1.11 ***

1.06–1.16

1.38 ***

1.27–1.51

Hospital volume

   ≥ 360

1.00

1.00

   210–360

0.92 ***

0.88–0.96

1.00

0.96–1.05

   80–210

0.80 ***

0.76–0.83

1.04

0.98–1.10

   0–80

0.89 ***

0.85–0.93

1.11 **

1.03–1.20

Hospital's geographic location

   Taipei Branch

1.00

1.00

   Northern Branch

0.96

0.92–1.01

1.00

0.95–1.05

   Central Branch

1.39 ***

1.33–1.45

1.33 ***

1.27–1.39

   Southern Branch

1.26 ***

1.20–1.31

1.25 ***

1.19–1.32

   Kao-Ping Branch

1.20 ***

1.15–1.25

1.14 ***

1.09–1.20

   Eastern Branch

1.00

0.91–1.09

0.91

0.82–1.01

Year

   1997

1.00

1.00

   1998

0.95 *

0.90–0.99

0.96

0.92–1.01

   1999

0.92 **

0.88–0.97

0.93 **

0.88–0.97

   2000

0.84 ***

0.80–0.87

0.81 ***

0.77–0.85

   2001

0.79 ***

0.76–0.83

0.77 ***

0.74–0.81