title: Nonuse of contraception among women at risk of unintended pregnancy in the United States.
abstract: OBJECTIVE
  This paper seeks to determine factors associated with nonuse of contraception by women at risk of unintended pregnancy in the United States. This nonuse may be associated with about 900,000 unintended births in the US each year.
  
  
  METHODS
  The 2002 and 2006-2010 National Surveys of Family Growth were combined to yield a nationally representative sample of 9,445 women at risk of unintended pregnancy. Logistic regression analyses identified factors associated with nonuse of contraception.
  
  
  RESULTS
  This analysis reveals previously undocumented patterns of nonuse: controlling for confounding variables, cohabiting women [adjusted odds ratio (AOR)=2.3, 95% confidence interval (CI)=1.45-3.52] had higher odds of nonuse than married women; women who reported a difficulty getting pregnant (AOR=2.5, 95% CI=2.01-3.01) had higher odds of nonuse than those who did not. Nonuse was also more common among women with a master's degree or more (AOR=1.5, 95% CI=1.11-2.08) compared with those with some college or bachelor's degree, and it was more common among women in their first year after first intercourse than after the first year (AOR 1.6, 95% CI=1.12-2.22). Among women who had a recent unintended birth, the most common reason for not using contraception prior to conception was that she did not think she could get pregnant.
  
  
  CONCLUSIONS
  This study establishes national estimates of reasons for nonuse of contraception and identifies some new subgroups at risk of nonuse.
  
  
  CONCLUSIONS
  These results may help better understand factors affecting nonuse of contraception and develop strategies for preventing unintended pregnancy in the United States.
authors.affiliation: Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD. Electronic address: wmosher1@jhu.edu.
authors.forename: William
authors.initials: W
authors.lastname: Mosher
authors.affiliation: National Center for Health Statistics, 3311 Toledo Road, Hyattsville, MD 20782.
authors.forename: Jo
authors.initials: J
authors.lastname: Jones
authors.affiliation: National Center for Health Statistics, 3311 Toledo Road, Hyattsville, MD 20782.
authors.forename: Joyce
authors.initials: J
authors.lastname: Abma
mesh_terms: D000293:Adolescent; D000328:Adult; D003268:Contraception Behavior; D000069216:Contraceptive Prevalence Surveys; D059026:Diagnostic Self Evaluation; D004522:Educational Status; D005193:Family Planning Services; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000175:diagnosis / Q000453:epidemiology; D016015:Logistic Models; D011247:Pregnancy; D049168:Pregnancy, Unplanned; D012044:Regression Analysis; D012306:Risk; D012847:Single Person; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: National Survey of Family Growth; Reasons for nonuse of contraception; Unintended pregnancy; Women aged 15–44