Response to Comment on Tone et al. Six-Week Versus Twelve-Week Antibiotic Therapy for Nonsurgically Treated Diabetic Foot Osteomyelitis: A Multicenter Open-Label Controlled Randomized Study. Diabetes Care 2015;38:302–307

We thank Nijenhuis-Rosien et al. for their comments (1) on our article (2). We thank them for their kind compliment and interesting questions and for giving us the opportunity to provide some additional information on our study.

First, we agree that off-loading of the foot ulcer is of paramount importance in patients with diabetic foot ulcer. The methods used for pressure off-loading in the five investigating centers that participated in the study were similar from one center to another as these centers work in a network and apply the same methods for pressure off-loading. A removable device was used in 29 patients (72.5%), including the so-called Ransart boot (3) in 19 patients. A nonremovable plaster cast boot was used in the 11 other patients (18.5%). The distribution of the method of pressure off-loading was similar in patients treated with 6 weeks (S6 group) or 12 weeks (S12 group) of antibiotic therapy and the patients' outcomes did not significantly differ according to the method used.

Second, a superiority design was used for our study. To assess the precision of our results and the risk of type 2 diabetes, we constructed the CIs of all the proportions. In order to compare the proportions of remission in the S6 and S12 groups (respectively, 60% [95% CI 36.05–80.88] and 70% [95% CI 45.72–88.11]), the ratio of these two values (i.e., 0.6/0.7) allowed us to calculate the prevalence ratio (PR 0.86 [95% CI 0.36–2.02]) of remission in the two groups. All of those CIs, whose large ranges reflect a default of power, suggest as outlined by Nijenhuis-Rosien et al. (1) a possible risk of type 2 diabetes or β error, which appears to be mainly in relation to the small size of the studied population of patients.

Third, we agree again with Nijenhuis-Rosien et al. (1) that it would have been better to register the study before it started. This was done in the French Agency for Safety of Health Products registry (15 March 2007) as mentioned in the article, but when the study started in June 2007, we were unaware of the necessity of being registered on the ClinicalTrials.gov site. This is why the study obtained its registration number on ClinicalTrials.gov after its completion.