# Nigeria - Demographic and Health Survey, 2003, Fourth Round

Reference ID | NGA-NPC-DHS-2003-v1.0 |

Year | 2003 |

Country | Nigeria |

Producer(s) | National Population Commission (NPC) - Federal Government of Nigeria (FGN) |

Sponsor(s) | President’s Emergency Plan for AIDS Relief - PEPFAR - funding United Nations Population Fund - UNFPA - funding MEASURE DHS Project - MEASURE - funding |

Metadata | Documentation in PDF Download DDI Download RDF |

Created on | Oct 18, 2010 |

Last modified | Dec 02, 2013 |

Page views | 1263868 |

Downloads | 24206 |

Data Appraisal

Estimates of Sampling Error Sampling errors for the 2003 NDHS are calculated for selected variables considered to be of primary interest for woman's survey and for man's surveys, respectively. The results are presented in this appendix for the country as a whole, for urban and rural areas, and for each of the 6 regions. For each variable, the type of statistic (mean, proportion, or rate) and the base population are given in Table B.1. Tables B.2 to B.10 present the value of the statistic (R), its standard error (SE), the number of unweighted (N) and weighted (WN) cases, the design effect (DEFT), the relative standard error (SE/R), and the 95 percent confidence limits (R±2SE), for each variable. The DEFT is considered undefined when the standard error considering simple random sample is zero (when the estimate is close to 0 or 1). In the case of the total fertility rate, the number of unweighted cases is not relevant, as there is no known unweighted value for woman-years of exposure to childbearing. The confidence interval (e.g., as calculated for children ever born to women aged 40-49) can be interpreted as follows: the overall average from the national sample is 6.808 and its standard error is 0.134. Therefore, to obtain the 95 percent confidence limits, one adds and subtracts twice the standard error to the sample estimate, i.e., 6.808±2×0.134. There is a high probability (95 percent) that the true average number of children ever born to all women aged 40 to 49 is between 6.540 and 7.077. Sampling errors are analyzed for the national woman sample and for two separate groups of estimates: (1) means and proportions, and (2) complex demographic rates. The relative standard errors (SE/R) for the means and proportions range between 1.1 percent and 32.7 percent with an average of 6.36 percent; the highest relative standard errors are for estimates of very low values (e.g., currently using female sterilization). If estimates of very low values (less than 10 percent) were removed, then the average drops to 4.2 percent. So in general, the relative standard error for most estimates for the country as a whole is small, except for estimates of very small proportions. The relative standard error for the total fertility rate is small, 2.5 percent. However, for the mortality rates, the average relative standard error is much higher, 6.04 percent. There are differentials in the relative standard error for the estimates of sub-populations. For example, for the variable want no more children, the relative standard errors as a percent of the estimated mean for the whole country, and for the urban areas are 4.9 percent and 6.1 percent, respectively. For the total sample, the value of the design effect (DEFT), averaged over all variables, is 1.78 which means that, due to multi-stage clustering of the sample, the average standard error is increased by a factor of 1.78 over that in an equivalent simple random sample. Note: Further table on this can be seen in Appendix Bs page 239 to 248 in the report attached to external resources. | |

Other forms of Data Appraisal Data quality tables in Appendix D in the report attached to external resources. |