Evidence and common sense – not the same but both are useful

By Jan Tunér

If you are interested in Evidence Based Medicine and have a sense of humour, I recommend the following paper.

Smith GC, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ. 2003; 20; 327 (7429): 1459-1461.

OBJECTIVES: To determine whether parachutes are effective in preventing major trauma related to gravitational challenge. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists. STUDY SELECTION: Studies showing the effects of using a parachute during free fall. MAIN OUTCOME MEASURE: Death or major trauma, defined as an injury severity score > 15. RESULTS: We were unable to identify any randomised controlled trials of parachute intervention. CONCLUSIONS: As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

This is a fine example of British humour but has a serious undertone. Evidence Based Medicine is the golden rule, but should we only practice EBM (and we do not) there would be rather few options for doctors and dentists. Remember that there is no EBM ground for performing endodontics. But we still do.

It must be underlined, again, that many “common sense” therapies have caused many casualties and been proven ineffective or even dangerous when randomised controlled studies have been performed in the end. However, common sense must also be used. If a therapy like Laser Phototherapy has been proven not to cause any serious side effects, why not use it? The following is a case where non-EBM founded therapy has been used on a patient who had been exposed to EBM therapies for four months. The wound had been subjected the frequent sessions of cleaning and dressings, but had only been increasing week by week. At the dental office (!…) it was decided to remove the dressings and one session of LPT was performed. The patient then treated herself with a home care laser device (Treatlite Active, Sweden, 808 nm, 100 mW) for ten days. She showed the results to the nurses and they said they were “shocked”.

In a previous article on LaserAnnals we have discussed the lack of EBM for wound healing. But again, are the EBM methods working well and are they cost effective? And are there any risks associated with adding LPT? The answer to both questions is NO. Common sense would suggest introducing LPT.

If you want to study the EBM for the use of parachutes, you can visit this link:


And if you doubt the seriousness of that article, here is how the authors themselves present their work:

Contributors: GCSS had the original idea. JPP tried to talk him out of it. JPP did the first literature search but GCSS lost it. GCSS drafted the manuscript but JPP deleted all the best jokes. GCSS is the guarantor, and JPP says it serves him right.