# Table 1

Variable definitions and descriptive statistics.

Mean

Variable

Definition

1976

Whole material

2005

caesar

= the proportion of Caesarean sections

0.047

0.108

0.146

(0.028)

(0.044)

(0.049)

rev_hosp

= hospital revenue per bed in NOK 1000, deflated to 1970 prices

101.32

205.42

364.43

(20.25)

(91.41)

(66.99)

age_le201

= the proportion of mothers less than 20 years

0.116

0.057

0.026

(0.033)

(0.033)

(0.013)

age_hi351

= the proportion of mothers older than 35 years

0.044

0.072

0.117

(0.015)

(0.031)

(0.030)

edu_univ2

= the proportion of mothers with university/college education

0.126

0.305

0.450

(0.037)

(0.101)

(0.107)

edu_uss2

= the proportion of mothers with upper secondary school education

0.557

0.453

0.362

(0.056)

(0.073)

(0.076)

weight_le25003

= the proportion of babies with a birthweight less than 2500 g

0.045

0.034

0.031

(0.016)

(0.020)

(0.021)

weight_hi45003

= the proportion of babies with a birthweight greater than 4500 g

0.031

0.039

0.042

(0.011)

(0.013)

(0.013)

ab_present

= the proportion of babies with abnormal presentation (including breech

0.043

0.059

0.088

presentation, transverse presentation, abnormal cephalic presentation and other)

(0.016)

(0.024)

(0.030)

preeclam

= the proportion of mothers with preeclampsia (including unspecified, mild and severe)

0.021

0.029

0.031

(0.111)

(0.015)

(0.016)

mult_birth

= the proportion of mothers with multiple births

0.025

0.024

0.025

(0.010)

(0.024)

(0.019)

no_births

= the number of births in total

838

1028

1176

(723)

(1034)

(1388)

weekend

= the proportion of births on a Saturday or a Sunday

0.248

0.248

0.274

(0.025)

(0.031)

(0.111)

year_2002

= 1 if year equals 2002 to 2005, 0 otherwise

Mean values and standard deviation in brackets.

1 Reference category: the proportion of mothers aged 20-35 years

2 Reference category: the proportion of mothers with compulsory school education

3 Reference category: the proportion of babies with a birthweight 2500-4500 g

Grytten et al. BMC Health Services Research 2011 11:267   doi:10.1186/1472-6963-11-267