This section deals with two issues: firstly, is the information that you have found valid? In other words, is it a truthful representation of reality? Secondly, is the information applicable in your setting? For example, if a set of clinical practice guidelines has been developed in an urban setting in the USA, are they relevant to a rural setting in Australia? Or, does a study looking at issues relating to diabetic care in Sweden apply to an Aboriginal population in the Northern Territory?

Validity

In the ideal world, the clinician or consumer should be able to look at a research or review article and be able to trust that, because it was published by a reputable organisation, the contents are valid. Of course, this isn't an ideal world!

Assessing validity is also known as critical appraisal, and it's easier to learn with a group of people face to face. Nevertheless, there are some useful resources on the web to get you started and keep you going. Oh, and to dispel a common myth... you don't need to understand statistics to develop workable appraisal skills!

When appraising articles, do two things - work out what type of article it is and then use a checklist to help you go through it.

Here are some resources to help you with critical appraisal.

Basic Critical Thinking Skills is an online course that is free to all health professionals in Australia. It consists of 12 one-hour modules.

"How to read a paper" is a series of articles that are available in the BMJ archives. The articles are:

• Getting your bearings (deciding what the paper is about);
• Papers that go beyond numbers (qualitative research);
• Papers that summarise other papers;
• Papers that tell you what things cost (economic analyses);
• Papers that report diagnostic or screening tests;
• Papers that report drug trials;
• Statistics for the non-statistician I: different types of data need different statistical tests;
• Statistics for the non-statistician II: "significant" relations and their pitfalls, and
• Assessing the methodological quality of published papers.

CASP is the Critical Appraisal Skills Program provided by the NHS and currently has tools for three types of study.

DISCERN is a joint initiative of Oxford University and the National Health Service and provides a step by step guide to judging the quality of material published on the web.It has been designed for consumers but is also useful to health professionals who may be involved in writing or sourcing patient information

The following templates are suggested to help you appraise:

• reviews;
• qualitative studies, and
• guidelines.

Applicability

Applicability is perhaps less scary to the average clinician, but unless you think it through in a structured way you may accidentally reject useful information and accept information that just doesn't fit.

Ask yourself the following questions:

• Is my patient so different from those in the study that its results cannot apply?

If you are considering an intervention, ask yourself

• Is the intervention actually feasible in my practice setting?
• What is the balance between benefit and harm with this intervention for my patient?
• What are my patient's values and expectations for both the outcome we are trying to prevent and the treatment we are offering?