Appointment systems try to achieve a balance between the time the doctor waits for patients to arrive and the time patients spend waiting to be seen. Mathematical analysis reveals that the time a patient can expect to wait increases exponentially as the appointment interval is reduced. An appointment interval that is less than the median consultation length can result in long waits for patients...

There are many alternatives to treat vitiligo, including surgical procedures, which are recommended for patients resistant to other therapies. The melanocyte/keratinocyte transplantation consists in the separation of epidermal cells obtained from a donor site and spreading these cells on the depigmented and dermabraded recipient area. Two patients were submitted to transplantation, showing more...

We describe necessary and sufficient conditions for a knot in an L-space to have an L-space homology sphere surgery. We use these conditions to reformulate a conjecture of Berge about which knots in S admit lens space surgeries.

Bias is an inclination to present or hold a partial perspective at the expense of possibly equal or more valid alternatives. In this paper, we present a series of conditional arguments to prove that intervention bias exists in the practice of medicine. We then explore its potential causes, consequences, and criticisms. We use the term to describe the bias on the part of physicians and the medic...

The concentrations of nitrous oxide were determined at various positions in four dental surgeries in which nitrous oxide sedation was used without scavenging. Contamination was present in all the surgeries, the greatest concentration being recorded at the dentist's nose and the least in the peripheral air. The reception area adjoining the surgeries was found also to be contaminated by nitrous o...

SUMMARY Immediate breast reconstruction usually is a multistep surgical treatment. We introduce a new technique with positive results that reduces the reconstruction to 1 single step. This new technique promises to reduce patient consequences from multistaged procedures while reducing the costs. A retrospective review of 7 patients is presented.

BACKGROUND Randomised controlled trials are being increasingly used to evaluate new surgical interventions. There are a number of problematic methodological issues specific to surgical trials, the most important being identifying whether patients are eligible for recruitment into the trial. This is in part due to the diversity in practice patterns across institutions and the enormous range of a...

The complexity of surgical procedures oft en poses challenges for conducting a rigorous and comprehensive evaluation. This paper considers the fi nal two IDEAL stages of surgical innovation. Surgical randomised controlled trials are oft en challenging to undertake and require careful consideration of the intervention defi nition, who should deliver it, and the impact of surgeon and patient pref...