Mr W, 63 years old and otherwise fit and healthy, has been referred to you with symptoms of benign prostatic hyperplasia (BPH) (frequency, nocturia, and slow flow). Digital rectal examination reveals an enlarged prostate gland, about 45 g, with no nodules. His postvoid is approximately 100 cc and he reports three documented urinary tract infections over the course of the last year. His serum creatinine and prostate-specific antigen (PSA) levels are normal.

He has been advised by his family physician that he may require surgery to resolve his condition. He is apprehensive about this and asks if there are medical interventions for the BPH that could be tried first. He has searched the web and has found information that saw palmetto may be an effective herbal remedy to improve his voiding symptoms.

What do you want? Asking a focused clinical question

The first two steps of the protocol of evidence-based practice (Assess, Ask, Acquire, Appraise, Apply) [1] involve assessing the situation – pulling out the salient features of a patient’s presentation and history – and asking one or more questions that are both focused and answerable. Assessing the situation may require some background information about the condition itself – for example, “how does BPH promote voiding complaints?.” To find primary research evidence to apply to the patient at hand, however, a focused, answerable question must be crafted. Asking a focused clinical question is a mental discipline that will also pay off enormously in effective searching and in finding good evidence to apply to practice.

Assigning a domain – therapy/prevention, diagnosis, prognosis, etiology/harm – is the essential first step in framing the question, because questions are asked differently, depending on the domain (Box 1.2). Often questions regarding a single case will fall into multiple domains. In this instance, separate focused questions for each relevant domain will result in clearer answers.

Once the domain has been established, the elements of the focused clinical question must be identified.

• P = Population. The patient’s characteristics, including age, gender, and condition, plus other relevant clinical or medical history features.
  
• I = Intervention. What intervention are you considering using? In a diagnostic question, this becomes “what new test do I wish to try?.” In a prognostic question, this equates to “prognostic factor” and in the etiology domain, this becomes “exposure.”
  
• C = Comparison. In the therapy domain, this might be the standard of care or a placebo, where this is appropriate; in diagnosis, the comparison is always the “gold standard” diagnostic test; in the case of a causation/etiology question, this obviously might be “no exposure;” and in prognosis, this might be the lack of the relevant prognostic factor.
  
• O = Outcome. For therapy, what changes are you looking to accomplish in the patient’s condition? Are they clinical changes, such as the reduction of the number of urinary tract infection (UTI) recurrences? Or are they surrogate, such as reduction in the size of the prostate? In diagnosis, how likely is the new test, in comparison with the gold standard, to predict or rule out the presence of a condition? In a prognostic question – often the most important for the patient – what is the expected disease progression? And in the etiology domain, how closely is this risk factor associated with the condition?
  
• T = Type of study. What study design will generate the best level of evidence with which to answer this question? This will vary from domain to domain, and also depending upon the subject itself.