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Posts tagged ‘EBM’

Chapter #4 Part 8: Evidence-Based Practice

Assalamu`alaikum and greetings to all…

“Bridging the gap between health care research and practice”. I realized that most of my posts for this year are about research. It was a good exposure but deep down in my heart I am not happy with what am I doing right now. I tried to look at the positive side of it but the negativity always engulfed my mind and my surroundings. I was forced to work once per week in CRC and I have to replace the day if it clashed with my ward duty. I am not dealing with patient as much as other nurses. I am kind of lost with what happen in real practice. Back to the real topic, here I am going to share with you about the first step of doing a study that is how to find an evidence?

EBP Step 1: Formulate an answerable question

The ‘PICO’ principle

  • Population/problem
    • Population and clinical problem – this shows who the relevant people are in relation to the clinical problem that you have in mind.
  • Intervention
    • This shows the management strategy, exposure or test that you want to find out about in relation to the clinical problem. This might be:
      • a procedure, such as drug treatment, surgery or diet (intervention)
      • exposure to an environment chemical or other hazard, a physical feature (such as being overweight), or a factor that might affect a health outcome (indicator)
      • a diagnostic test, such as blood test or brain scan (index test)
  • Comparator
    • This shows an alternative or control strategy, exposure or test for comparison with the one you are interested in.
  • Outcome
    • This shows:
      • what are you most concerned about happening (or stop happening) AND/OR
      • what the patient is most concerned about.

EBP Step 2: Track down the best evidence of outcomes available

Hierarchy of study designs for intervention:

  • Randomised controlled trials → Least biased → Analytical → Experimental
  • Cohort studies → Analytical → Observational
  • Case-control studies → Analytical → Observational
  • Cross-sectional studies → Descriptive → Observational
  • Clinical observation (case reports, case-series) → Most biased → Descriptive → Observational

Where to search?

EBP Step 3: Critically appraise the evidence (find out how good it is and what if means)

If the study that you have identified has eliminated bias, then there is a good chance that the study’s results (which answer the PICO ) will be reliable… But how can you tell? Steps in critical appraisal of primary research ‘RAMMbo’:

  • Recruitment
    • were the subjects representative of the target population?
  • Allocation or adjustment
    • was the treatment allocation concealed before randomization and were the groups comparable at the start of the trial?
  • Maintenance
    • was the comparable status of the study groups maintained through equal management and adequate follow-up?
  • Measurement
    • were the outcomes measured with:
      • blinded subjects and assessors, and/or
      • objective outcomes?

Results can be presented either as binary outcomes (which are also called dichotomous outcomes), that is, ‘yes’ or ‘no’ outcomes that either happen or don’t happen; or continuous outcomes, such as weight, height or the amount of cholesterol in blood.

  • Relative risk (RR) = risk of outcome in the treatment group/risk of event in the control group
    • RR tells us how many times more likely it is that an event will occur in the treatment group relative to the control group
    • RR = 1 means that there is no difference between the 2 groups
    • RR < 1 means that the treatment reduces the risk of the event
    • RR > 1 means that the treatment increases the risk of the event
  • Absolute risk reduction (ARR) = risk of event in the control group − risk of event in the treatment group (a.k.a the absolute risk difference)
    • ARR tell us the absolute difference in the rates of events between the two groups and gives an indication of the baseline risk and treatment effect
    • ARR = 0 means that there is no difference between the 2 groups (thus, the treatment had no effect)
    • ARR positive means that the treatment is beneficial
    • ARR negative means that the treatment is harmful
  • Relative risk reduction (RRR) = ARR/risk of event in control group or RRR = 1−RR
    • RRR tells us the reduction in rate of the event in the treatment group relative to the rate in the control group
    • RRR is probably the most commonly reported measure of treatment effects
  • Number needed to treat (NNT) = 1/ARR
    • NNT tells us the number of patients we need to treat in order to prevent 1 bad event

EBP Step 4: Apply the evidence (integrate the results with clinical expertise and patient values)

A simple communication process to explain natural history and integrate it with decision about treatment can be guided by the following three steps:

  • What would happen if we did nothing?
  • Explain what the options are
  • Check the patient’s expectation and ideas
Not For Sale

Not For Sale

Reference: Glasziou, P., Del Mar, C., & Salisbury, J. (2007). Evidence-based practice workbook (2nd Ed.). Blackwell Publishing.

Sesungguhnya di sisi Allah ilmu tentang hari kiamat; dan Dia yang menurunkan hujan dan yang mengetahui apa yang ada di dalam rahim. Dan tiada seorang pun yang dapat mengetahui (dengan pasti) apa yang akan dikerjakan esok. Dan tidak ada seorang pun yang dapat mengetahui bumi mana dia akan mati. Sesungguhnya, Allah Maha Mengetahui, lagi amat meliputi pengetahuan-Nya.

(Surah Luqman 31: 34)

Until we meet again.

May peace be upon you.

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