title: Estimating family planning coverage from contraceptive prevalence using national household surveys.
abstract: BACKGROUND
  Contraception is one of the most important health interventions currently available and yet, many women and couples still do not have reliable access to modern contraceptives. The best indicator for monitoring family planning is the proportion of women using contraception among those who need it. This indicator is frequently called demand for family planning satisfied and we argue that it should be called family planning coverage (FPC). This indicator is complex to calculate and requires a considerable number of questions to be included in a household survey.
  
  
  OBJECTIVE
  We propose a model that can predict FPC from a much simpler indicator - contraceptive use prevalence - for situations where it cannot be derived directly.
  
  
  METHODS
  Using 197 Multiple Indicator Cluster Surveys and Demographic and Health Surveys from 82 countries, we explored least-squares regression models that could be used to predict FPC. Non-linearity was expected in this situation and we used a fractional polynomial approach to find the best fitting model. We also explored the effect of calendar time and of wealth on the models explored.
  
  
  RESULTS
  Given the high correlation between the variables involved in FPC, we managed to derive a relatively simple model that depends only on contraceptive use prevalence but explains 95% of the variability of the outcome, with high precision for the estimated regression line. We also show that the relationship between the two variables has not changed with time. A concordance analysis showed agreement between observed and fitted results within a range of ±9 percentage points.
  
  
  CONCLUSIONS
  We show that it is possible to obtain fairly good estimates of FPC using only contraceptive prevalence as a predictor, a strategy that is useful in situations where it is not possible to estimate FPC directly.
authors.affiliation: International Center for Equity in Health, Federal University of Pelotas, Pelotas, Brazil; abarros@equidade.org.
authors.forename: Aluisio J D
authors.initials: AJ
authors.lastname: Barros
authors.affiliation: World Health Organization, Geneva, Switzerland.
authors.forename: Ties
authors.initials: T
authors.lastname: Boerma
authors.affiliation: World Health Organization, Geneva, Switzerland.
authors.forename: Ahmad R
authors.initials: AR
authors.lastname: Hosseinpoor
authors.affiliation: International Center for Equity in Health, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: María C
authors.initials: MC
authors.lastname: Restrepo-Méndez
authors.affiliation: International Center for Equity in Health, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Kerry L M
authors.initials: KL
authors.lastname: Wong
authors.affiliation: International Center for Equity in Health, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Cesar G
authors.initials: CG
authors.lastname: Victora
mesh_terms: D000293:Adolescent; D000328:Adult; D003267:Contraception; D003268:Contraception Behavior / Q000706:statistics & numerical data*; D000069216:Contraceptive Prevalence Surveys; D003906:Developing Countries; D005191:Family Characteristics; D005193:Family Planning Services; D005260:Female; D005298:Fertility; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D011157:Population Dynamics; D055815:Young Adult
keywords: contraception; coverage; family planning; health indicators; prevalence