biostudies-literatureUnknown8(2)Wehberg SOBJECTIVES:The aim of this study was to estimate the effects of risk factors on elective and emergency caesarean section (CS) and to estimate the between-hospital variation of risk-adjusted CS proportions. DESIGN:Historical registry-based cohort study. SETTINGS AND PARTICIPANTS:The study was based on all singleton deliveries in hospital units in Denmark from January 2009 to December 2012. A total of 226 612 births by 198 590 mothers in 29 maternity units were included. PRIMARY AND SECONDARY OUTCOME MEASURES:We estimated (1) OR of elective and emergency CS adjusted for several risk factors, for example, body mass index, parity, age and size of maternity unit and (2) risk-adjusted proportions of elective and emergency CS to evaluate between-hospital variation. RESULTS:The CS proportion was sBMJ opene019120https://www.ebi.ac.uk/biostudies/studies/S-EPMC5829888biostudies-literatureRisk factors and between-hospital variation of caesarean section in Denmark: a cohort study.PMC5829888Norgard BMGuldberg RAndersson CBWehberg SMunk LJolving LRGradel KONielsen JKesmodel USfalseRisk factors and between-hospital variation of caesarean section in Denmark: a cohort study.OBJECTIVES:The aim of this study was to estimate the effects of risk factors on elective and emergency caesarean section (CS) and to estimate the between-hospital variation of risk-adjusted CS proportions. DESIGN:Historical registry-based cohort study. SETTINGS AND PARTICIPANTS:The study was based on all singleton deliveries in hospital units in Denmark from January 2009 to December 2012. A total of 226 612 births by 198 590 mothers in 29 maternity units were included. PRIMARY AND SECONDARY OUTCOME MEASURES:We estimated (1) OR of elective and emergency CS adjusted for several risk factors, for example, body mass index, parity, age and size of maternity unit and (2) risk-adjusted proportions of elective and emergency CS to evaluate between-hospital variation. RESULTS:The CS proportion was s2018-01-01T00:00:00Z2018 Feb2025-04-19T00:08:51.112Z2019-03-26T22:46:50ZS-EPMC58298882944015810.1136/bmjopen-2017-019120