Toenail onychomycosis data from dermatophyte infections

Results of a clinical trial (De Backer et al. 1998) to compare two oral antifungal treatments: itraconazole and terbinafine to treat toenail onychomycosis causes by dermatophytes.

Usage

data("toenail")

Format

A data frame with 1908 observations on the following 8 variables.

patientID: a unique identifier for each patient in the trial.
outcome: a factor indicating the severity of the patient's onycholysis (separation of the nail plate from the nail bed), with levels none or mild and moderate or severe.
treatment: a factor indicating the treatment used with levels itraconazole and terbinafine.
time: exact timing of visit in months.
visit: An integer represent the sequential visit number for each subject.

Details

The data in lme4 was copied from the toenail data found in the HSAUR3 package. From the dataset documentation from the HSAUR3 package: There is a clinical trial (De Backer et al. 1998) to compare two competing oral antifungal treatments for toenail infection (dermatophyte onychomycosis). A total of 378 patients were randomly allocated into two treatment groups, one group receiving 250mg per day of terbinafine and the other group 200mg per day of itraconazole. Patients were evaluated at seven visits, intended to be at weeks 0, 4, 8, 12, 24, 36, and 48 for the degree of separation of the nail plate from the nail bed (onycholysis) dichotomized into moderate or severe and none or mild. But patients did not always arrive exactly at the scheduled time and the exact time in months that they did attend was recorded. The data is not balanced since not all patients attended for all seven planned visits.

Source

(De Backer et al. 1998)

References

De Backer M, De Vroey C, Lesaffre E, Scheys I, 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(5, Supplement 2), S57-S63. ISSN 0190-9622, doi:10.1016/S0190-9622(98)70486-4 .

Examples

toemod <- glmer(outcome ~ time*treatment + (1 | patientID), 
                data = toenail, family = binomial(link = "logit"))