Confidence Intervals in Procedural Dermatology: An Intuitive Approach to Interpreting Data

BACKGROUND: Significant differences observed in therapeutic trials in procedural dermatology are typically denoted by p values of less than .05. Alternatively, significance can be conveyed by use of confidence intervals. OBJECTIVES: The purpose of this article is to clarify how confidence intervals convey the same information about outcomes as p values, albeit in a slightly different manner. METHODS: (1) Selective review of textbooks and other relevant literature and (2) presentation of a brief tutorial describing confidence interval determination for therapeutic clinical trials comparing differences between means of two groups. RESULTS: Routine use of confidence intervals is an intuitively satisfying means for conveying the statistical significance of results and can be used in combination with p values for understanding these results. Specifically, confidence intervals are a useful tool for indicating the size, spread, and direction of the observed differences. Unfortunately, dermatologic surgery trials tend to have low sample sizes, which frequently result in outcomes below the threshold of statistical significance (p > .05, or confidence intervals including 1.00). In the absence of statistical significance, neither p values nor confidence intervals yield definitive results. CONCLUSION: Confidence intervals can complement p values as a means for explaining statistical significant differences. When differences are not statistically significant but are clinically significant and approach statistical significance, neither p values nor confidence intervals can definitively establish whether the observed trends are indicative of an underlying difference. In these cases, common in procedural dermatology, larger, better designed, randomized prospective trials are needed.     

Challenges in Interpreting Germline Mutations in BARD1 and ATM in Breast and Ovarian Cancer Patients

Next‐generation sequencing promotes identification of mutations in non‐BRCA1/2 genes in hereditary cancer families. The contribution of mutations in moderate penetrance genes to hereditary cancer risk is not well established. Here, we report a family with early onset breast and fallopian tube cancer that was identified as carrying germline mutations in BARD1 and ATM genes. Loss of heterozygosity studies suggest a causative role of the BARD1 mutation in the development of primary peritoneal cancer, but fail to confirm an association between germline ATM mutations and breast cancer development in this family. Complexities in interpreting implications of mutations in moderate‐risk cancer susceptibility genes are discussed.     

Interpreting Post-Transplant Proteinuria in Patients with Proteinuria Pre-Transplant

Increasing numbers of patients receive kidney transplants before initiation of dialysis or shortly thereafter. Some of these patients have significant proteinuria pre-transplant making the interpretation of post-transplant proteinuria problematic. In this study, we evaluated post-transplant proteinuria in 115 patients who had urine protein measured within 3 months of transplant and assessed the association of proteinuria with allograft pathology. Proteinuria declined rapidly from 3650 +/- 3702 mg/day pre-transplant to 550 + 918 at 3 weeks (p < 0.0001) and continued to decline until 1 year post-transplant (472 +/- 1116, p < 0.0001 vs. 3 weeks). Proteinuria greater than 3000 mg/day was present in 48 patients (42%) pre-transplant, in 1 patient (1%) at 3 weeks and in 4 patients (4%) at 1 year. Surveillance graft biopsies were done at 1 year in 93% of patients. Proteinuria > or = 1500 mg/day and/or an absolute increase in proteinuria > 500 mg/day after 3 weeks post-transplant was associated with allograft glomerular pathology. In conclusion, pre-transplant proteinuria, even when high grade, declines rapidly after transplantation. Failure to decline or persistence of proteinuria greater than 1500 mg/day is indicative of allograft pathology.     

Interpreting drug levels

The interpretation of drug concentrations in plasma or serum depends on an understanding of drug behaviour. Summaries of the latter are provided for the use of doctors who do not have easy access to pharmacokinetic and pharmacodynamic information. This approach would be vital to a scheme for a nation-wide pharmacological analytical service.     

Interpreting positive studies

When examining the results of a positive research study, one needs to consider two issues of clinical relevance. First, is the outcome measure of direct interest to patients, or is it clearly linked to a measure of direct interest to patients? Second, is the difference large enough to lie outside the range of clinical indifference? Don't accept the findings of a positive research study without a careful consideration of clinical relevance.     

Challenges in the Treatment of Severe Traumatic Brain Injury Based on Data in the Japan Neurotrauma Data Bank

The Japan Neurotrauma Data Bank is a source of epidemiological data for patients with severe traumatic brain injury (TBI) and is sponsored by the Japan Society of Neurotraumatology. In this report, we examined the changes in the treatment of severe TBI in Japan based on data of the Japan Neurotrauma Data Bank. Controlling and decreasing intracranial pressure (ICP) are the primary objective of severe TBI treatment. Brain-oriented whole-body control or neurocritical care, including control of cerebral perfusion pressure, respiration, and infusion, are also increasingly considered important because cerebral tissues require oxygenation to improve the outcomes of patients with severe TBI. The introduction of neurocritical care in Japan was delayed compared with that in Western countries. However, the rate of ICP monitoring increased from 28.0% in 2009 to 36.7% in 2015 and is currently likely to be higher. Neurocritical care has also become more common, but the functional prognosis of patients has not significantly improved in Japan. Changes in the background of patients with severe TBI suggest the need for improvement of acute-phase treatment for elderly patients. Appropriate social rehabilitation from the subacute to chronic phases and introduction of cellular therapeutics are also needed for patients with TBI.     

Interpreting the chest radiograph

Presented is an approach to a chest radiograph, paying particular attention to features commonly seen in the intensive care unit (ICU) with regards to iatrogenic lines and tubes, together with common pathologies that may be encountered. This is accompanied by helpful images to use as an aide memoire when reviewing ICU chest X-rays. Pitfalls in interpreting these often complex X-rays are also discussed.