Diagnosis: How to select a diagnostic test or how to interpret the results of a particular test.

• In patients with suspected depression what is the accuracy of a two-question case-finding instrument for depression compared with six previously validated instruments?

Therapy: Which treatment is the most effective, or what is an effective treatment given a particular condition.

• In children with colds, are zinc lozenges safe and effective for relief of cold symptoms?
• In patients with acute bronchitis, do antibiotics reduce sputum production, cough or days off work?
• in children with cancer what are the current treatments that manage fever and infection?
• In patients with PMS, does traditional medical treatment or alternative (complementary) treatments improve patient symptoms better?

Harm or Etiology: Are there harmful effects of a particular treatment, or how can these harmful effects be avoided.

• What are the risks of treating asthma patients with beta-adrenergic agonists?
• Is there an increased risk of breast cancer for a healthy post-menopausal patient on HRT?
• In women taking oral contraceptives, is there an association between their use and cardiovascular disease?

Prognosis: What is the patient's likely course of disease, or how to screen for or reduce risk.

• In a healthy woman who has suffered a miscarriage, what is the normal grief process and are any factors associated with longer than normal grieving?
• What are the risk factors for developing diabetes mellitus type II in adolescent males?

Prevention: How can the patient's risk factors be adjusted to help reduce the risk of disease?

• For patients 65 years and older, does the use of influenza vaccine reduce the future risk of pneumonia compared with patients who have not received the vaccine?

Qualitative: Helps to understand clinical phenomona with emphasis on understanding the experiences and values of patients.

• How do women diagnosed with fibromyalgia perceive others' perceptions of their physical limitations?