Lab Literacy for Canadian Doctors: A Guide to Ordering the Right Tests for Better Patient Care

by Christopher Naugler

Overview

Lab Literacy for Canadian Doctors is an affordable and comprehensive pocket guide for choosing appropriate lab tests. It quickly and efficiently improves patient care through better test decisions for clinical situations. This unique resource reduces the risks of: ordering the wrong test, not clearly understanding test results and options, delaying treatments, and making misdiagnoses. Refer to this essential guide for: Diagnostic algorithms. Advice and information on lab errors, false positives and negatives, and blood and tissue collection. A quick index summarizing the clinical utility of common tests. Sections on dermatology, ENT and respiratory system, endocrine system, fatigue, GI and hepatic system, gynecology and pregnancy, routine screening, and more. Protocols for screening tests that follow Canadian guidelines. Values in both conventional and SI units.

Product Details

ISBN-13:	9781550594928
Publisher:	Brush Education
Publication date:	05/05/2014
Sold by:	De Marque
Format:	eBook
Pages:	328
File size:	5 MB

About the Author

Christopher Naugler, MD, FRCPC, is Assistant Professor in the Department of Pathology and Laboratory Medicine and the Department of Family Medicine at the University of Calgary, and the Zone Clinical Section Chief of General Pathology with Alberta Health Services.

Read an Excerpt

Introduction: Why this guide?

Five years ago, new evidence about vitamin D alerted doctors to the impacts of vitamin D deficits on patient health. This drove a meteoric increase in vitamin D testing in labs across North America. At some clinics, vitamin D testing became one of the single biggest expenses in the budget for lab services.

For all those tests and all that money, you would expect that doctors were at least getting useful information from the results. But they weren't.

Vitamin D levels are not good predictors of bone health—or other health outcomes for that matter. Patients have different underlying disease susceptibilities, and, depending on supplements, their serum vitamin D levels go up and down. So, knowing a patient's current vitamin D level has dubious value.

Ample evidence, however, shows the benefits of vitamin D supplements for almost everyone, regardless of their baseline vitamin D level. Therefore, a strategy of “treat don't test” makes eminent sense and saves valuable health-care resources for testing that actually has a clinical impact.

In the setting of finite health-care resources, tradeoffs such as this—between clinical utility and costs of testing—will become increasingly important.

As health practitioners, we share an ethical responsibility to provide good stewardship of limited health-care dollars and testing resources. Whether you are a primary-care physician or resident, a medical student, or a health professional in an allied field, you need to be lab literate: you need to know which tests have the highest yield for the clinical situations you typically encounter.

Many references help you interpret lab investigations, but they don't tell you what investigations to do in the first place.

This guide is about what lab investigations to do first. We outline the most efficient and cost-effective way for you to use laboratory investigations to support clinical diagnosis and management.

How to use this guide

The main guide

The guide is organized the way clinicians think: by clinical presentation and by organ system. So, if you have a patient with a skin problem, go to the section on dermatology. If a patient presents with fatigue, go to the section on fatigue.

In addition to information on lab investigations, we provide, where useful, differential diagnoses, etiologies, and summaries of signs and symptoms. We also share some “pearls”—particular knowledge about lab investigations we have gathered as experts and clinicians in our fields.

Lab basics

Lab investigations are only as good as the specimens delivered for analysis, and lab results are only as useful as human slip-ups and margins of error allow.

Find advice and information here on lab errors, false positives and negatives, and blood and tissue collection.

Lab investigations index

This index describes the diagnostic purpose of the lab investigations discussed in the guide, plus other common lab tests.

If you need a quick check on what an investigation is for, look it up here.

What's not in this guide

This guide focuses on laboratory investigations. It does not cover diagnostic imaging.

It covers typical disorders and clinical presentations. It does not cover every disorder and clinical presentation, and is not meant to replace sound clinical judgement.

A note about units

This guide gives laboratory values in both SI units (the International System of Units) and conventional units. We give the SI units first and the conventional units second.

We did this because Canadian laboratories generally, but not always, report test results in SI units. In addition, Canadian laboratories refer some esoteric tests to the United States, and laboratories in the United States generally, but again not always, report results in conventional units.

For these reasons, we felt it was important to provide laboratory values in both systems as a reference.

Table of Contents

1. Dermatology 2. Ears, nose, and throat, and respiratory system 3. Endocrine system 4. Fatigue 5. Gastrointestinal and hepatic system 6. Genitourinary system 7. Gynecology and pregnancy 8. Hematology 9. Intoxication and toxidromes 10. Musculoskeletal system 11. Neuropsychiatry 12. Routine screening 13. Therapeutic drug monitoring 14. Lab basics Lab investigations index

Reading Group Guide

Introduction: Why this guide?

Five years ago, new evidence about vitamin D alerted doctors to the impacts of vitamin D deficits on patient health. This drove a meteoric increase in vitamin D testing in labs across North America. At some clinics, vitamin D testing became one of the single biggest expenses in the budget for lab services.

For all those tests and all that money, you would expect that doctors were at least getting useful information from the results. But they weren't.

Vitamin D levels are not good predictors of bone health—or other health outcomes for that matter. Patients have different underlying disease susceptibilities, and, depending on supplements, their serum vitamin D levels go up and down. So, knowing a patient's current vitamin D level has dubious value.

Ample evidence, however, shows the benefits of vitamin D supplements for almost everyone, regardless of their baseline vitamin D level. Therefore, a strategy of “treat don't test” makes eminent sense and saves valuable health-care resources for testing that actually has a clinical impact.

In the setting of finite health-care resources, tradeoffs such as this—between clinical utility and costs of testing—will become increasingly important.

As health practitioners, we share an ethical responsibility to provide good stewardship of limited health-care dollars and testing resources. Whether you are a primary-care physician or resident, a medical student, or a health professional in an allied field, you need to be lab literate: you need to know which tests have the highest yield for the clinical situations you typically encounter.

Many references help you interpret lab investigations, but they don't tell you what investigations to do in the first place.

This guide is about what lab investigations to do first. We outline the most efficient and cost-effective way for you to use laboratory investigations to support clinical diagnosis and management.

How to use this guide

The main guide

The guide is organized the way clinicians think: by clinical presentation and by organ system. So, if you have a patient with a skin problem, go to the section on dermatology. If a patient presents with fatigue, go to the section on fatigue.

In addition to information on lab investigations, we provide, where useful, differential diagnoses, etiologies, and summaries of signs and symptoms. We also share some “pearls”—particular knowledge about lab investigations we have gathered as experts and clinicians in our fields.

Lab basics

Lab investigations are only as good as the specimens delivered for analysis, and lab results are only as useful as human slip-ups and margins of error allow.

Find advice and information here on lab errors, false positives and negatives, and blood and tissue collection.

Lab investigations index

This index describes the diagnostic purpose of the lab investigations discussed in the guide, plus other common lab tests.

If you need a quick check on what an investigation is for, look it up here.

What's not in this guide

This guide focuses on laboratory investigations. It does not cover diagnostic imaging.

It covers typical disorders and clinical presentations. It does not cover every disorder and clinical presentation, and is not meant to replace sound clinical judgement.

A note about units

This guide gives laboratory values in both SI units (the International System of Units) and conventional units. We give the SI units first and the conventional units second.

We did this because Canadian laboratories generally, but not always, report test results in SI units. In addition, Canadian laboratories refer some esoteric tests to the United States, and laboratories in the United States generally, but again not always, report results in conventional units.

For these reasons, we felt it was important to provide laboratory values in both systems as a reference.

Editorial Reviews

Finally, a highly readable, practical guide for physicians that focuses on the ordering of laboratory tests based on the underlying clinical context. A valuable resource that promises to advance health care quality through promoting patient-centred, appropriate care.

Appropriate utilization of clinical laboratory tests is an important part of practicing medicine in the 21st century. Dr. Naugler has done an excellent job by providing the most up-to-date information in a relatively complicated subject in an easy-to-follow format.

I would recommend this book to physicians as worthwhile reading material, particularly those who... are starting out in their careers. This text would also be an excellent choice for the laboratory scientist seeking a concise view of the clinical aspects of laboratory testing.

From the Publisher

Appropriate utilization of clinical laboratory tests is an important part of practicing medicine in the 21st century. Dr. Naugler has done an excellent job by providing the most up-to-date information in a relatively complicated subject in an easy-to-follow format.

Hossein Sadrzadeh

Finally, a highly readable, practical guide for physicians that focuses on the ordering of laboratory tests based on the underlying clinical context. A valuable resource that promises to advance health care quality through promoting patient-centred, appropriate care.

Richard G. Hegele

I would recommend this book to physicians as worthwhile reading material, particularly those who... are starting out in their careers. This text would also be an excellent choice for the laboratory scientist seeking a concise view of the clinical aspects of laboratory testing.

Canadian Journal of Pathology