Preface: Canadian Tuberculosis Standards 7th Edition: 2014

Preface

The last 10 years have witnessed remarkable progress in our understanding of the pathogenesis, immunology and epidemiology of tuberculosis as well as the development of new diagnostic and therapeutic tools. This 7^th edition of the Canadian Tuberculosis Standards (the Standards) has been extensively revised to incorporate much of this new information, building upon the six previous versions of the Standards, which were published in 1972 (with a pediatric supplement in 1974), 1981, 1988, 1996, 2000 and 2007.

As in the past, each chapter is written by authors from across Canada with expertise in the specific areas. Again, the Standards is jointly funded, edited and produced by the Canadian Thoracic Society (CTS) of the Canadian Lung Association (CLA) and the Public Health Agency of Canada (PHAC). However, it is important to note that the clinical recommendations in the Standards are those of the CTS.

This edition was also developed in close collaboration with the Association of Medical Microbiology and Infectious Disease Canada (AMMI Canada), whose expert representatives served as chapter authors and external reviewers.

In response to feedback from users of previous versions of the Standards, some sections have been expanded, while others have been reduced or eliminated. The document is intended to provide information to public health and clinical professionals and does not supersede any provincial/territorial legislative, regulatory, policy and practice requirements or professional guidelines that govern the practice of health professionals in their respective jurisdictions. The Standards does not replace consultations between clinical practitioners and public health authorities with respect to a particular patient or circumstance.

As with previous editions, the 7th edition of the Standards is based upon the best available scientific evidence. The authors of each chapter carefully reviewed all published evidence, particularly the most recent studies, and synthesized and rated this evidence as summarized below. Recommendations are considered strong or conditional on the basis of these ratings of evidence:

Quality of Evidence

1. Strong

• Evidence from multiple randomized controlled trials (RCTs – for therapeutic evidence), or cohort studies (etiologic evidence) with strong designs and consistent results.

2. Moderate

• Evidence from multiple randomized controlled trials (RCTs – for therapeutic evidence), or cohort studies (etiologic evidence) with strong designs and consistent results.

3. Weak

• Evidence from observational analytic studies that had weak designs, weak effect estimates or inconsistent results, or generalization from a randomized trial that involved one type of patients to a different group of patients.

4. Very Weak

• Evidence from published case series and/or opinion of the authors and other experts.

Strength of Recommendations

1. Strong

• The recommendation implies that the desirable effects clearly outweigh undesirable effects, was based on strong/moderate evidence and was considered unlikely to change with additional published evidence.

• The recommendation implies that the desirable effects are closely balanced with undesirable effects, and/or was based on moderate/weak/very weak evidence and was considered likely to change with additional published evidence.

Reference is made to specific tests, procedures and therapies throughout the Standards. For the most part generic terms are used rather than trade names or manufacturers' names. However, in a few instances when only a single manufacturer or product is available, a trade name may be mentioned. This is done only to enhance readers' understanding by providing a name with which they are more likely to be familiar. Use of trade names and commercial sources is for identification only and does not imply endorsement by PHAC, the CTS or CLA.