title: Risk adjustment for inter-hospital comparison of caesarean delivery rates in low-risk deliveries.
abstract: BACKGROUND
  Caesarean delivery (CD) rates have been frequently used as quality measures for maternity service comparisons. More recently, primary CD rates (CD in women without previous CD) or CD rates within selected categories such as nulliparous, term, cephalic singleton deliveries (NTCS) have been used. The objective of this study is to determine the extent to which risk adjustment for clinical and socio-demographic variables is needed for inter-hospital comparisons of CD rates in women without previous CD and in NTCS deliveries.
  
  
  METHODS
  Hospital discharge records of women who delivered in Emilia-Romagna Region (Italy) from January, 2007 to June 2009 and in Tuscany Region for year 2009 were linked with birth certificates. Adjusted RRs of CD in women without a previous Caesarean and NTCS were estimated using Poisson regression. Percentage differences in RR before and after adjustment were calculated and hospital rankings, based on crude and adjusted RRs, were examined.
  
  
  RESULTS
  Adjusted RR differed substantially from crude RR in women without a previous Caesarean and only marginally in NTCS group. Hospital ranking was markedly affected by adjustment in women without a previous CD, but less in NTCS.
  
  
  CONCLUSIONS
  Risk adjustment is warranted for inter-hospital comparisons of primary CD rates but not for NTCS CD rates. Crude NTCS CD rates are a reliable estimate of adjusted NTCS CD.
authors: Department of Medicine and Public Health-Alma Mater Studiorum University of Bologna, Bologna, Italy. elisa.stivanello2@unibo.it
authors: Elisa
authors: E
authors: Stivanello
authors: Paola
authors: P
authors: Rucci
authors: Elisa
authors: E
authors: Carretta
authors: Giulia
authors: G
authors: Pieri
authors: Chiara
authors: C
authors: Seghieri
authors: Sabina
authors: S
authors: Nuti
authors: Eugene
authors: E
authors: Declercq
authors: Martina
authors: M
authors: Taglioni
authors: Maria Pia
authors: MP
authors: Fantini
mesh_terms: D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D011247:Pregnancy; D020379:Risk Adjustment / Q000706:statistics & numerical data*; D012307:Risk Factors