Extracting clinical relevance of published literature

Having found and appraised the best available evidence, the next step is to decide how the results of the search apply to your clinical ‘problem’ or question.

When assessing the clinical relevance of a study, the questions to ask are:

Is this form of care or treatment feasible in my clinical setting?

It is often very difficult to exactly replicate the ‘recipe’ of a study, and it may be necessary to investigate further before assuming that an alternative way of treating a patient will work in your setting.

Are the patients in my clinical setting very different from those in this study?

The most important question is whether your patients match the subjects in the study. You will also need to consider other factors such as age, co-morbidity, and likely compliance. In terms of changing the way ‘things are done’, such as providing water birth facilities, you will need to consider policies for practice, training, and work health and safety requirements. These factors will help you to decide whether your patient/s is likely to benefit more or less than those in the studies you have considered.

Will the potential benefits outweigh the potential harms of this form of care (or treatment) for my patients?

Work out the number needed to treat (NNT) and for adverse effects, the number needed for harm (NNH) in the study you are considering. The benefit of treatment will increase with the risk or severity of illness, but the harm will not usually change with the degree of risk or severity. Therefore, once a patient is sufficiently at risk or their condition is sufficiently severe, the benefit of treatment will outweigh the possible harms from treatment.

What alternatives are available?

If there are alternative treatments or options for care these need to be weighed up to decide which would be most suitable in each particular case, balancing up the benefits and harms. Cost factors may also be a consideration. Doing nothing may be an option. What are the patients’ preferences based on past experience, age, and social circumstances?

This section has enabled you to define terms related to critical appraisal and utilise a rapid critical appraisal framework to assess the quality of intervention studies.

The next section focuses on how to apply the evidence to practice.