title: Neonatal withdrawal syndrome, Michigan, 2000-2009.
abstract: BACKGROUND
  Neonatal withdrawal syndrome, which is associated most frequently with opioid use in pregnancy, is an emerging public health concern, with recent studies documenting an increase in the rate of U.S. infants diagnosed.
  
  
  OBJECTIVE
  This study examined neonatal withdrawal syndrome diagnosis among Michigan infants from 2000 to 2009 and hospital length of stay (LOS) between infants with and without the syndrome for a subset of years (2006-2009).
  
  
  METHODS
  Michigan live birth records from 2000 to 2009 were linked with hospital discharge data to identify infants with neonatal withdrawal syndrome. Linked data were restricted to infants born between 2006 and 2009 to examine the difference in hospital LOS between infants with and without the syndrome. Multivariable regression models were constructed to examine the adjusted impact of syndrome diagnosis on infant LOS and fit using negative binomial distribution. Data were analyzed from July 2011 to February 2012.
  
  
  RESULTS
  From 2000 to 2009, the overall birth rate of infants with neonatal withdrawal syndrome increased from 41.2 to 289.0 per 100,000 live births (p<0.0001). Among infants born from 2006 to 2009, the average hospital LOS for those with the syndrome was between 1.36 (95% CI=1.24, 1.49) and 5.75 (95% CI=5.41, 6.10) times longer than for infants without it.
  
  
  CONCLUSIONS
  Diagnosis of neonatal withdrawal syndrome increased significantly in Michigan with infants who had the syndrome requiring a significantly longer LOS compared to those without it.
authors.affiliation: Bureau of Disease Control, Prevention, and Epidemiology Michigan Department of Community Health, Lansing, Michigan. Electronic address: hekman.kim@gmail.com.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Hekman
authors.affiliation: Applied Sciences Branch, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, Georgia.
authors.forename: Violanda I
authors.initials: VI
authors.lastname: Grigorescu
authors.affiliation: Bureau of Disease Control, Prevention, and Epidemiology Michigan Department of Community Health, Lansing, Michigan.
authors.forename: Lorraine L
authors.initials: LL
authors.lastname: Cameron
authors.affiliation: Bureau of Disease Control, Prevention, and Epidemiology Michigan Department of Community Health, Lansing, Michigan.
authors.forename: Corinne E
authors.initials: CE
authors.lastname: Miller
authors.affiliation: Applied Sciences Branch, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, CDC, Atlanta, Georgia.
authors.forename: Ruben A
authors.initials: RA
authors.lastname: Smith
mesh_terms: D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007231:Infant, Newborn; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008824:Michigan / Q000453:epidemiology; D015999:Multivariate Analysis; D009357:Neonatal Abstinence Syndrome / Q000453:epidemiology*; D009293:Opioid-Related Disorders / Q000150:complications*; D011247:Pregnancy; D011248:Pregnancy Complications; D012044:Regression Analysis; D012189:Retrospective Studies