PLEURODESIS CON IODOPOVIDONA

Efficacy of Iodopovidone Pleurodesis and Comparison of Small-Bore Catheter Versus Large-Bore Chest Tube
Annals of Surgical Oncology 15:2594-2599 (2008)

Background: To evaluate the efficacy of iodopovidone as an agent for pleurodesis in malignant pleural effusion (MPE) and to compare the efficacy of small-bore catheter (Pleuracan, Braun, Melsungen, Germany) and conventional large-bore chest tube in pleural fluid drainage and sclerotherapy.
Methods: Patients with MPE were prospectively consecutively randomized into two groups between August 2004 and February 2007: pleurodesis via conventional (32F) chest tube (group 1) and small-bore catheter (group 2), both using iodopovidone. After 3 months’ follow-up, response rates (complete or partial), complication rates, and duration of procedures within whole group, group 1, and group 2 were compared. Statistical analyses were performed by Mann-Whitney U, 2, and Fisher’s exact test.
Results: Forty-three pleurodeses were performed in 41 patients. The response was complete in 26 (60.5%) and partial in 12 (27.9%), and the overall success rate was 88.4%. The response rate was not associated with the type of inserted tube (P = .750), pleural fluid pH (P = .290), or pleural fluid lactate dehydrogenase (P = .727). In group 1 (n = 20), 12 demonstrated complete and 6 demonstrated partial response, with a 90% success rate; success was 86.9% in group 2, with complete response in 14 and partial response in 6 patients. Success rates were similar in the two groups (P = 1.000). Of 43 procedures, complications were observed in 14 (32.5%), and complication rates were 35% and 30.4% in groups 1 and 2, respectively (P = .750). The most frequent complication was pain (16.2%), followed by fever, subcutaneous emphysema, dyspnea, and hypotension.
Conclusion: Iodopovidone is an effective, inexpensive, safe, and easily available alternative in chemical pleurodesis in MPE. The success rates of pleurodesis were found to be similar regardless of the type of the tube inserted.

EL NUMERO NECESARIO A TRATAR

The "number needed to treat" turns 20 — and continues to be used and misused

CMAJ • September 9, 2008; 179 (6). doi:10.1503/cmaj.080484.© 2008 Canadian Medical Association or its licensors

In the 20 years since the initial description of the number needed to treat,1 this method of expressing the efficacy of an intervention has become widely used. Indeed, the Consolidated Standards of Reporting Trials statement recommends that the number needed to treat be reported in randomized trial publications,2 and journals of secondary publication (e.g., American College of Physicians Journal Club) routinely calculate and report the number needed to treat for studies of therapy. As well, there have been increasing calls for health care policy makers to use numbers needed to treat to inform their recommendations;3 and league tables comparing numbers needed to treat have appeared in the literature4–7 and on the internet (See www.cebm.utoronto.ca/glossary/nnts.htm#table and www.jr2.ox.ac.uk/bandolier/band50/b50-8.html for examples from different branches of medicine).
Having attended hundreds of journal clubs as well as departmental and divisional rounds over the past 2 decades, I am consistently impressed by the frequency with which audience members display skepticism about a therapy if its efficacy is presented only in relative terms such as odds ratios or relative risk reductions. Not infrequently, this skepticism is healthy — the dangers of misinterpreting the importance of a therapy when relying solely on relative effect estimates are well known.1 However, I have also been struck by the extent to which discussions of a therapy's number needed to treat, and even comparisons between therapies on this basis, are accepted at face value. A review of the literature and their experiences in journal club and critical appraisal settings led Chong and colleagues to also express concern that many clinicians appear to hold "the impression that NNT [number needed to treat] values in and of themselves are broadly comparable" and display "an implicit belief that an unadjusted NNT value adequately captures the overall worth of a treatment."8
In this article, I explore the factors (beyond the efficacy of a therapy) that influence the number needed to treat and that must be taken into account when comparing these values between therapies.
What is the number needed to treat?
The number needed to treat is an aggregate measure of clinical benefit that represents the number of patients who would need to be treated to prevent 1 additional adverse event. It is calculated by taking the reciprocal of the absolute risk reduction between 2 treatment options. This number is a useful way to summarize the potential impact of a therapy when discussing treatment options with patients. A detailed discussion of how to personalize this number to each patient's situation, including means to incorporate potential harms as well as patient values and preferences, has been published.9..................

http://www.cmaj.ca/cgi/content/full/179/6/549