Introduction

In addition to the Five "A"s in evidence based healthcare, there are five steps to carrying out a search for evidence. Developing a search strategy will help you find what you're looking for. Defining the question is an important first step that feeds all other steps. When looking for research evidence you could think about the way research articles are constructed - this will help you construct your question:

• the Sample or Group
• the Setting
• the Problem
• what was done - Method or Intervention
• the results or Outcomes

Step one: Asking the Right Question

Sometimes called the PICOT formula (see below), it is a useful way to construct focused questions, makes searching more structured, and increases the chance of finding an answer.

PICOT formula

Think about

P: the patient's or populaton condition you're interested in

I: the intervention you're interested in (for example, test, drug, treatment)

C: a comparison if relevant (for example, placebo, standard care)

O: a patient-centred outcome.

T: Time

So the clinical question based on the first assumption would be:

In a patient with a suspected deep vein thrombosis (patient), can clinical examination (intervention) compared with a venogram (comparison) diagnose a deep vein thrombosis (outcome)?

Step two: What to Search

• HSE Library Online (requires HSE Athens login)
• Cochrane Library (FREE to all Ireland)
• All Ireland electronic Health Library (AIeHL) (FREE: grey literature)
• Search Association of Public Health Observatories (APHO)
• Google: Netting the Evidence: Search engine dedicated to the methodology of evidence based practice
• PrimeAnswers- is a collection of evidence summaries, practice guidelines, prediction rules and management algorithms from sources for primary care.
• Search for Critical Appraisals - BestBets
• Search PubMed
• Curbside: enter naturally phrased clinical questions to search evidence based material.
• Links to libraries and search resources
• Links to useful search tools and guidelines

Step three: Carrying out your Search

Develop your Search Terms

Your search terms should be based on each component of your research question (PICOT)

Refining your Search
The terms generated in step one are then used to build up a search strategy with the use of the Boolean operators (OR AND)
E.g. [(elderly OR aged OR geriatric OR older person) AND (residential care or nursing home)] AND [oral supplement OR food supplement] AND [nutritional status OR BMI OR nutritional assessment OR weight]

Fields
Different field are uses in the search engines such as keyword search advanced search and thesaurus or MeSH search; electronic search engines have tutorials which will bring you through the searching process. 

Limits
You can limit your search by language age bracket journal type, publication year etc, be careful that you do not exclude useful literature by the over use of limits

Step Four: Acquiring documents

• HSE Library Online (requires HSE Athens login)
• Cochrane Library (FREE to all Ireland)
• PubMed Central (Free)
• All Ireland electronic Health Library (AIeHL) (FREE: grey literature)
• Search Association of Public Health Observatories database (Free)
• Ask you local library service and Inter-library-loan Facilities. Click here to view a Directory of Library services in your area.

Step Five: Follow up, Appraisal

• Appraise the Evidence
• Hierarchy of Evidence