Clinical trials in dermatology, part 3: measuring responses to treatment

End points in dermatologic clinical trials: A review for clinicians

Clinical trials are critical for the development of new therapies in dermatology, and their results help determine US Food and Drug Administration (FDA) approval and guide care. Of special relevance is the clinical trial efficacy end point, the metric from which statistically significant outcome is derived. Clinicians' understanding of a clinical trial's end point is necessary for critical analysis of the trial results and for applying those results to daily practice. This review provides practical knowledge and critical evaluation of end points used in treatment approvals by the FDA. The end points for actinic keratosis, acne vulgaris, atopic dermatitis, onychomycosis, and cutaneous ulcer serve as examples.

The hand eczema severity index (HECSI): a scoring system for clinical assessment of hand eczema. A study of inter- and intraobserver reliability

BACKGROUND

There is a need for a standardized clinical grading system for a more objective and accurate assessment of the severity of hand eczema (HE).

OBJECTIVES

To develop and validate a scoring system called the hand eczema severity index (HECSI) designed for clinical assessment of HE.

METHODS

Twelve dermatologists (observers) assessed 15 HE patients twice, with an interval of 30 min. The study was performed blinded for the observers, and only the hands and wrists of the patients were visible to the observers. Agreement between the observers was determined by using the intraclass correlation coefficient (ICC), which is the correlation between (single) ratings of the same patient.

RESULTS

ICC for total HECSI score was 0.79 at the first assessment and 0.84 at the second assessment. ICC for intraobserver agreement was 0.90.

CONCLUSIONS

Overall excellent agreement existed for both inter- and intraobserver reliability and the scoring system is suggested for use in future clinical studies on HE. Because HECSI is an entirely objective assessment of clinical signs, in addition, inclusion of patient-rated symptoms should be considered.

The assessment of acne: An evaluation of grading and lesion counting in the measurement of acne

The basic morphology of acne--comedones, papules, pustules, and nodules--and the extent of involvement do not permit simple evaluation due to the number of variables involved. Because these acne lesions may vary in number during the natural course of the disease, various measurements have been developed, based on clinical examination and photographic documentation. These range from global assessments to lesion counting, with the latter providing more objective data.

Understanding and evaluating clinical trials

In this review, we attempt to provide the basic knowledge necessary to understand and evaluate clinical trials because properly conducted, randomized clinical trials are the best sources for determining the best available treatment. Other commonly used sources rarely provide sufficient detail necessary to determine the efficacy and safety of any treatment, and they often contain biases or pitfalls that make them unacceptable or unreliable. Our method for reviewing clinical trials allows a busy clinician to use his or her time most efficiently by deciding not to read the majority of poorly conceived, designed, executed, or reported trials and those trials with insignificant results. It provides a means to determine the quality of the trials that one does decide to read and to retain and retrieve the information when it is needed. The method involves recognizing and evaluating the features that strengthen clinical trials and help validate their conclusions. These features include proper selection and allocation of patients, inclusion of an appropriate control group, randomization, prior selection of clinically and biologically important outcome variables, blinding of assessment, consideration of patient compliance and drop out, and proper presentation and statistical analysis of results.

Development of anthralin short-contact therapy in psoriasis: survey of published clinical trials

In a survey of clinical trials concerning the efficacy of short-contact therapy with anthralin in psoriasis vulgaris, focusing principally on methodologic issues, twenty-four papers published between January 1982 and December 1989, in English, French, and Italian, were selected. Nine of 24 papers reported on more than one trial, giving a total of 37 clinical trials to be evaluated. A great heterogeneity was evident in many aspects of the design and conduct of these trials, making pooling of results impossible. Most trials suffered from flaws in general methodologic aspects such as randomization and blinding. Limitations in general applicability of results were discussed with reference to the popular use of self-control design and selection of composite indexes (e.g., PASI) as an outcome variable. Published trials are not a reliable guide to clinical decisions concerning short-contact therapy, and some methodologic observations we made could be of general interest in designing clinical trials of psoriasis.

Group psychotherapy as an aid in the medical treatment of eczema

The ongoing management of severe adult eczema is often difficult and problematic for both patient and doctor. A group of ten adult eczema patients were given group psychotherapy as a supplement to their regular medical regimen. Five target symptoms were rated on a biweekly basis first to establish individual baselines of disease course and later to measure treatment effect. The psychologic treatment combined behavioral and cognitive interventions with relaxation training. Patients used multiple self-rating sheets to provide feedback with the goal of increasing their skills in the management of scratching behaviors. At the end of treatment all ten patients showed significant reduction in targeted symptoms.

The assessment of acne vulgaris--the Leeds technique

We describe two simple, reproducible scoring systems for assessing acne severity, and we emphasize the technical problems which could invalidate either technique. Constant baseline data is desirable for any clinical trial, and our data clearly show that acne patients should ideally be off all treatment for at least 2 months before the start of a therapeutic trial.

Treatment of rosacea with i% metronidazole cream. A double-blind study

Eighty-one patients with rosacea were treated with either I% metronidazole cream or the cream base as a placebo for two months. The trial was performed double-blind, and the patients were assessed once each month. The variates studied were: (I) overall clinical assessment, (2) lesion counts, (3) degree of erythema, (4) independent photographic evaluation, and (5) patient's opinion. Four patients dropped out of the trial (one treated with metronidazole, three with placebo). In all the variates, I% metronidazole cream proved to be significantly more effective than placebo.