Principle 5: Base treatment on the best available research evidence

Key messages

  1. Healthcare professionals need to use the best available research evidence to inform their decision making.
  2. Systematic reviews provide the most comprehensive and unbiased source of research evidence.
  3. A high quality, randomised, controlled trial is the strongest research design for evaluating treatment efficacy.
  4. Treatments with good evidence for efficacy are preferred over other treatments.
  5. Where there is good evidence that treatment lacks efficacy, it should not be used.

Treatment needs to be informed by the best available and highest level research evidence. Using the best available research evidence to develop a treatment plan optimises an injured person’s health outcomes. It also:

  • ensures treatment is offered that has the best chance of success
  • avoids treatment that is likely to be ineffective or harmful
  • increases the likelihood that treatment complements and assists other evidence-based medical and allied healthcare treatments that the injured person is likely to access

Levels of evidence

Systematic reviews of research evidence are now available on the efficacy of many treatments and decision making must be directed by this evidence. Evidence-based clinical practice guidelines can be useful to refer to for specific conditions and other evidence summaries may also be available. Where evidence summaries are not available, or are out of date, high quality individual studies can provide some guidance for treatment decision making. A high quality, randomised, controlled trial is the strongest research design for evaluating treatment efficacy.

The National Health and Medical Research Council (NHMRC), evidence hierarchy ranks study designs in order of the confidence with which they are able to answer questions about treatment efficacy1:

Level I

A systematic review of Level II studies

Level II

A randomised, controlled trial

Level III

i. A pseudo-randomised, controlled trial

ii. A comparative study with concurrent controls

iii. A comparative study without concurrent controls

Level IV

Case series with either post-test or pre-test/post-test outcomes

How to use research evidence

Healthcare professionals will have a preference for treatment that is based on their training, clinical experience and the specific needs of the injured person. Preferences for treatment need to be continually reviewed so that they are in line with the best available evidence.

Research evidence can only be generalised to people like those who were included in the clinical trials. For example, interventions generally have different effects when tested on people with acute and chronic back pain. Treatments:

  • with good evidence for effectiveness are preferred over those without evidence
  • with good evidence of no effectiveness should not be used
  • without sufficient evidence of effectiveness may be used when there is no other treatment of proven effectiveness.

Research evidence quantifies the average effect of an intervention on a group of people compared to an alternative treatment, placebo, or no treatment. Individuals will have a response to treatment that may be larger or smaller than the average response. For this reason, and because sometimes there is not sufficient evidence available on a particular treatment, healthcare professionals must use appropriate outcome measures to monitor each person’s response to treatment.

Where to find the best available research evidence

  • The Cochrane Library of systematic reviews is freely available online.
  • PubMed is the largest free online abstracting database with millions of citations.
  • Online evidence databases are also available for individual disciplines:
    • Physiotherapy (PEDro)
    • Occupational Therapy (OT seeker)
    • Speech Pathology (speech BITE)
    • Chiropractic (Chiroindex)
    • Psychological Database for Brain Impairment Treatment Efficacy (PsycBITE)
  • Many clinical practice guidelines are available online, for example, from the NHMRC Clinical Practice Guidelines Portal.

1. NHMRC 2009, NHMRC additional levels of evidence and grades for recommendations for developers of guidelines. Stage 2 Consultation. Retrieved from