LBW: Low Birth Weight Data

In prLogistic: Estimation of Prevalence Ratios using Logistic Models

Description

Data are from a hypothetical study to evaluate factors associated to low birth weight. This data set contains information on 488 births to 188 women seen in an obstetrics clinic, comprising 1 to 3 births for each woman and yielding an average of 2.6 births per women. The outcome binary variable "low" indicates low birth weight defined as birth weight less than 2500 grams. These data are copyrighted by John Wiley & Sons Inc. and are used here to illustrate the calculation of prevalence ratios and corresponding confidence intervals.

Usage

data(LBW)

Format

A data frame with 488 observations on the following 6 variables:

ID

Subject's identification.

birth

Birth order.

smoke

Smoking Status During Pregnancy (1=Yes, 0= No).

race

Race (1=White, 0= Others).

age

Age of Mother (1= age greater than 35 years, 0= age less or equal to 35 years).

low

Low Birth Weight (1 if birth weight less than 2500 grams, 0 if birth weight greater or equal to 2500 grams).

Source

The data come from
Data courtesy of University of Massachusetts Amherst (http://www.umass.edu/statdata/statdata/stat-logistic.html)

These data are copyrighted by John Wiley & Sons Inc. We acknowledged it and use the data to illustrate the methodology included in this library.

References

Hosmer and Lemeshow (2000) Applied Logistic Regression. New York: Wiley Inter-Science. Second Edition.

Examples

data("LBW", package = "prLogistic")
attach(LBW)
summary(LBW)

Example output

Loading required package: boot
Loading required package: stats4
Loading required package: lme4
Loading required package: Matrix
Loading required package: Hmisc
Loading required package: lattice

Attaching package: 'lattice'

The following object is masked from 'package:boot':

    melanoma

Loading required package: survival

Attaching package: 'survival'

The following object is masked from 'package:boot':

    aml

Loading required package: Formula
Loading required package: ggplot2

Attaching package: 'Hmisc'

The following objects are masked from 'package:base':

    format.pval, units

       ID             birth           smoke             race       
 Min.   :  1.00   Min.   :1.000   Min.   :0.0000   Min.   :0.0000  
 1st Qu.: 46.75   1st Qu.:1.000   1st Qu.:0.0000   1st Qu.:0.0000  
 Median : 93.00   Median :2.000   Median :0.0000   Median :0.0000  
 Mean   : 93.56   Mean   :1.873   Mean   :0.3996   Mean   :0.1475  
 3rd Qu.:139.25   3rd Qu.:2.000   3rd Qu.:1.0000   3rd Qu.:0.0000  
 Max.   :188.00   Max.   :4.000   Max.   :1.0000   Max.   :1.0000  
      age               low        
 Min.   :0.00000   Min.   :0.0000  
 1st Qu.:0.00000   1st Qu.:0.0000  
 Median :0.00000   Median :0.0000  
 Mean   :0.06762   Mean   :0.3094  
 3rd Qu.:0.00000   3rd Qu.:1.0000  
 Max.   :1.00000   Max.   :1.0000  

prLogistic documentation built on May 1, 2019, 10:28 p.m.