The first step in the process of EBM is to formulate an answerable clinical question. Do not start looking for infomation on a general topic like diabetes or cardiovascular disease. Rather have a question that is specific and that attempts to answer a particlular problem or condition, e.g.
Question: In populations with a high prevalence of HIV infection, how effective is male circumcision for reducing HIV acquisition in heterosexual men?
The type of question asked will determine the type of study that must be found to answer that question:
Therapy Systematic reviews, RCT, meta-analyses
Diagnosis cross-sectional, validation studies
Prognosis cohort, case control, case series
Aetiology/harm (causes, risk) case control, cross sectional, RCT, cohort studies
Prevention RCT, cohort studies
Quality improvement RCT
Qualitative client, carer, family or community experiences
Once an assessment of the patient has taken place and a problem or question has been identified, it can be useful to break that question up into its component parts using the PICO method.
P Population (patient, population, particular conditon under review)
I Intervention ( treatment, intervention or exposure)
C Comparison (alternative to compare with intervention)
O Outcome (affect, improvement or measurement)
P populations with a high incidence of HIV infection
I male circumcision
C no circumcision
O reduced rate of HIV infections amongst heterosexual men
Once you have identified your subject terms or keywords and their synonyms, your strategy should look something like this:
(HIV OR AIDS) AND (infection OR transmission OR prevention) AND
(heterosexual males OR heterosexual men) AND circumcision
These templates will enable you to record your literature searches by indicating your search strategy, keywords, filters, limits and results.