Evidence-Based Dentistry Flashcards
Peer-reviewed journals are the ideal reference source.
Oxford Centre for Evidence-Based Medicine (OCEBM)
Hierarchy of Levels of Evidence (6)
Systematic Review Randomized controlled trial Cohort Case control Case series Expert opinion (OCEBM)
Quality of a systematic review relies on
The quality of the studies included. OCEBM
Systematic reviews vs Meta-analysis
SR = comprehensive search and review of all the existing literature on a topic. MA = delves deeper through statistical analyses to make direct comparisons between studies. OCEBM
Highest level of evidence for clinical research
Randomized controlled trials. OCEBM
Difficulties of randomized controlled trials.
Resource- and time-intensive, ethical concerns (children and the disabled).
Cohort studies
Prospective. Longitudinal, measure incidence of new cases of a disease and assess risk factors. Not practical for rare outcomes.
Case-control studies
Retrospective. Compare past risk factors and exposures in a disease group vs a control group. More useful for rare outcomes.
Case series
Present an outcome without provision of a control.
Expert opinion
Lowest level of evidence, often the starting point for further higher-level research.
How to increase the odds of obtaining statistically significant results. (How to increase power)
Sample population is large and diverse
Most common measure of statistical significance.
P value
Likelihood of an outcome having occurred by chance
P value
P value that indicates statistical significance
less than or equal to 0.05. The probability of the results being obtained by chance is less than 5%
Separated NiTi instrument success rates
Spili et al
91.8% with separated NiTi
94.5% with control
P value of 0.49 = 49% chance that results were by chance, no statistical significance.
Probability of a positive test in a diseased individual.
Sensitivity
Probability of a negative test in a healthy individual.
Specificity
Likelihood of a positive result correctly identifying a diseased individual.
Positive predictive value
Likelihood of a negative result correctly identifying a healthy individual.
Negative predictive value
Cold testing sensitivity
Jespersen et al
sensitivity of 0.92
92% of necrotic teeth were correctly identified
Cold testing specificity
Jespersen et al
specificity of 0.90
90% of vital teeth were correctly identified
Cold Testing predictive values
Jespersen et al
0.86 positive predictive value
0.94 negative predictive value
86% of positive results correctly identified pulpal necrosis while 94% of negative results correctly identified vital pulp.
Prevalence
Number of cases at one point in time
Better for chronic conditions (apical periodontitis)
Incidence
Number of new cases during a range of time
Better for acute conditions (toothache)
Prevalence of apical periodontitis
Eriksen et al
26% to 70%
Incidence of toothache in US
Lipton et al
12% over 6 months
Success
The absence of symptoms and radiographic periapical pathology.
Survival
Absolute presence or absence of a tooth in the mouth.
Impact of CBCT on success vs survival
Wu et al
CBCT will inevitably detect more lesions, so the lines between success and survival may become more blurred.
