Uncertainty and information management

From Oncology for Medical Students
Ideal oncology curriculum > Uncertainty and information management

Objective 3.3

At graduation, the student should be able to:

a) describe the importance of evidence based medical practice
b) demonstrate an understanding of the need to be able to critically appraise evidence
c) appraise information from patients and other subjective sources critically, and record in a way that allows the information to be retrieved and communicated effectively for optimal management
d) critically appraise the available information guiding the management of common cancers and be able to distinguish different levels of evidence
e) locate published high quality evidence and guidelines for practitioners and patients using electronic literature searches, both locally and from overseas
f) adapt and apply information to the management of individual cases and to the formulation of management options in the absence of definitive information (tolerating uncertainty)
g) demonstrate an understanding of clinical trials and their importance; explain their value to patients and encourage patients to participate in trials
h) describe basic elements of clinical trials, cohort studies and case control studies
i) appraise studies of treatment, prevention, diagnosis, prognosis, causation and harm, systematic reviews, clinical practice guidelines and cost-effectiveness studies
j) demonstrate an understanding of the limits of evidence, its broad application and its advancement over time
k) discuss unproven or alternative/complementary cancer therapies in a way that encourages patients to appraise their claimed benefits and their costs in a critical manner.

Prerequisite knowledge

  • Basic understanding of clinical epidemiology.
  • Ability to describe and utilise clinical epidemiological terms such as sensitivity and specificity
  • Understanding of processes of critical appraisal
  • Ability to locate available evidence based medicine and guideline information by manual and electronic literature searches, including the internet and Cochrane collaboration databases
  • Ability to describe basic elements of research methods: randomised control trials; cohort and case control studies
  • Understanding the relative value of evidence provided by such different research methods and how they are quantified
  • Understanding the role of qualitative research findings in guiding clinical decision making
  • Understanding the principles of evidence based medicine and levels of evidence
  • Understanding the strengths and weaknesses of different study designs

Representative questions that suggest the required depth of knowledge

1. Mr Cathari, a 58 year old man with metastatic colon cancer, visits you in your general practice. He has some mild lethargy but is otherwise well. He wants advice about alternative/complementary treatments for his cancer. What do you tell him?

Essential in answer:

  • Concept of unproven as opposed to alternative therapy
  • Critical appraisal of cost benefits
  • Knowledge of guidelines

2. A patient who has breast cancer comes to you with some information on breast cancer from the internet. She is very worried and has a lot of difficulty knowing what to believe. What do you tell her about retrieving useful information from the internet?

Essential in answer:

  • Critical appraisal
  • Knowledge of useful websites
  • Encouragement of use of well written evidence based literature in addition to web-based information
  • Awareness of other sources of information such as breast cancer support services and the Australasian Lymphology Association

3. “Clinical practice guidelines are a waste of time” – discuss.

Essential in answer:

  • Levels of evidence
  • Variation in practice
  • Limits to knowledge
  • Accountability
  • Individualising care

4. A randomised phase III was performed between drug X and Docetaxel as second line therapy for metastatic non-small cell lung cancer. Fifty patients were randomised to each arm and when comparing objective response rates no significant difference was found between the two arms p>0.05. Discuss the possible meanings of this result.

Essential in answer: The numbers may not provide sufficient power to detect a clinically meaningful difference so it is not necessarily a negative study, but an indeterminate result. Is objective response rate the best endpoint in this situation?