Toenail: Toenail Data

In prLogistic: Estimation of Prevalence Ratios using Logistic Models

Description

Data are from a multicenter study comparing two oral treatments for toe-nail infection, including information for 294 patients measured at 7 weeks, comprising a total of 1908 measurements. The outcome binary variable "onycholysis" indicates the degree of separation of the nail plate from the nail-bed (none or mild versus moderate or severe). Patients were evaluated at baseline (week 0) and at weeks 4, 8, 12, 24, 36, and 48 thereafter.

Usage

data(Toenail)

Format

A data frame with 1,908 observations on the following 5 variables:

ID

Subject's identification.

Response

Degree of onycholysis (0 if none or mild, 1 if moderate or severe).

Treatment

Oral treatment indicator (1=Treatment A, 0= Treatment B).

Month

Exact timing of measurements, in months.

Visit

Visit number (visit numbers 1-7 correspond to scheduled visits at 0, 4, 8, 12, 24, 36, and 48 weeks).

Source

The data come from
Data courtesy of Novoartis, Belgium (http://www.blackwellpublishing.com/rss/datasets/C4827r.txt)

References

De Backer, M., De Vroey, C., Lesaffre, E., Scheys, I., and De Keyser, P. (1998). Twelve weeks of continuous oral therapy for toenail onychomycosis caused by dermatophytes: A double-blind comparative trial of terbinafine 250 mg/day versus itraconazole 200 mg/day. Journal of the American Academy of Dermatology, 38, 57-63.

Lesaffre, E. and Spiessens, B. (2001). On the effect of the number of quadrature points in a logistic random-effects model: An example. Journal of the Royal Statistical Society, Series C, 50, 325-335.

Rabe-Hesketh S, Skrondal A (2008). Multilevel and Longitudinal Modeling Using Stata. Mahwah, NJ: Lawrence Erlbaum Associates. Second Edition.

Examples

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

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           Response        Treatment          Month       
 Min.   :  1.0   Min.   :0.0000   Min.   :0.0000   Min.   : 0.000  
 1st Qu.:101.8   1st Qu.:0.0000   1st Qu.:0.0000   1st Qu.: 1.000  
 Median :192.0   Median :0.0000   Median :1.0000   Median : 3.000  
 Mean   :189.8   Mean   :0.2138   Mean   :0.5089   Mean   : 4.691  
 3rd Qu.:276.2   3rd Qu.:0.0000   3rd Qu.:1.0000   3rd Qu.: 8.893  
 Max.   :383.0   Max.   :1.0000   Max.   :1.0000   Max.   :18.500  
     Visit      
 Min.   :1.000  
 1st Qu.:2.000  
 Median :4.000  
 Mean   :3.896  
 3rd Qu.:6.000  
 Max.   :7.000  

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